Vauxhall/Opel Omega Service and Repair Manual - Motor-Talk

Vauxhall/Opel Omega Service and Repair Manual - Motor-Talk
Vauxhall/Opel Omega
Service and Repair Manual
Mark Coombs and Spencer Drayton
Models covered
(3510 - 352)
Vauxhall Omega Saloon and Estate models with petrol engines, including special/limited editions
1998 cc, 2498 cc & 2969 cc petrol engines
Does not cover diesel engine or bi-fuel (LPG) models
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© Haynes Publishing 1999
A book in the Haynes Service and Repair Manual Series
All rights reserved. No part of this book may be reproduced or transmitted
in any form or by any means, electronic or mechanical, including
photocopying, recording or by any information storage or retrieval system,
without permission in writing from the copyright holder.
Printed by J H Haynes & Co. Ltd, Sparkford, Nr Yeovil, Somerset BA22 7JJ
Haynes Publishing
Sparkford, Nr Yeovil, Somerset BA22 7JJ, England
Haynes North America, Inc
861 Lawrence Drive, Newbury Park, California 91320, USA
ISBN 1 850960 510 9
Editions Haynes S.A.
Tour Aurore - La Défense 2, 18 Place des Reflets,
92975 PARIS LA DEFENSE Cedex France
British Library Cataloguing in Publication Data
A catalogue record for this book is available from the British Library.
Haynes Publishing Nordiska AB
Box 1504, 751 45 UPPSALA, Sverige
3510 Vauxhall/Opel Omega
Contents
LIVING WITH YOUR VAUXHALL OMEGA
Introduction
Page
0•4
Safety First!
Page
0•5
Introduction
Page
0•6
If your car won’t start
Page
0•6
Jump starting
Page
0•7
Wheel changing
Page
0•8
Identifying leaks
Page
0•9
Towing
Page
0•9
Roadside Repairs
Weekly Checks
Introduction
Page 0•10
Underbonnet check points
Page 0•10
Engine oil level
Page 0•11
Coolant level
Page 0•11
Brake (and clutch) fluid level
Page 0•12
Power steering fluid level
Page 0•12
Battery
Page 0•13
Electrical systems
Page 0•13
Tyre condition and pressure
Page 0•14
Tyre tread wear patterns
Page 0•14
Washer fluid level
Page 0•15
Wiper blades
Page 0•15
Lubricants and fluids
Page 0•16
Tyre pressures
Page 0•17
MAINTENANCE
Routine Maintenance and Servicing
Servicing specifications
Page
1•2
Maintenance schedule
Page
1•3
Maintenance procedures
Page
1•6
3510 Vauxhall/Opel Omega
Contents
REPAIRS & OVERHAUL
Engine and Associated Systems
2.0 litre SOHC engine in-car repair procedures
Page 2A•1
2.0 litre DOHC engine in-car repair procedures
Page 2B•1
2.5 and 3.0 litre engine in-car repair procedures
Page 2C•1
General engine overhaul procedures
Page 2D•1
Cooling, heating and ventilation systems
Page
Fuel and exhaust systems
Page 4A•1
Emission control systems
Page 4B•1
Starting and charging systems
Page 5A•1
Ignition system
Page 5B•1
3•1
Transmission
Clutch
Page
Manual transmission
Page 7A•1
6•1
Automatic transmission
Page 7B•1
Final drive, driveshafts and propeller shaft
Page
8•1
Braking system
Page
9•1
Suspension and steering
Page 10•1
Brakes and Suspension
Body equipment
Bodywork and fittings
Page 11•1
Body electrical system
Page 12•1
Wiring Diagrams
Page 12•23
REFERENCE
Dimensions and weights
Page REF•1
Conversion Factors
Page REF•2
Buying Spare Parts and Vehicle Identification
Page REF•3
General Repair Procedures
Page REF•4
Jacking and vehicle support
Page REF•5
Radio/cassette unit anti-theft system precaution
Page REF•5
Tools and working facilities
Page REF•6
MOT Test Checks
Page REF•8
Fault Finding
Page REF•12
Glossary of Technical Terms
Page REF•20
Index
Page REF•24
3510 Vauxhall/Opel Omega
0•4
Introduction
The Vauxhall Omega was introduced into the UK in April of 1994 as a
replacement for the Vauxhall Carlton and Senator. At its launch, the
Omega was available in both Saloon and Estate body styles with a
choice of either 2.0 litre (1998 cc) or a 2.5 litre (2498 cc) petrol engine
both available with either a 5-speed manual transmission unit or a 4speed automatic transmission unit. Shortly afterwards a 3.0 (2968 cc)
litre petrol engine was also introduced. A 2.5 litre Diesel engine (not
covered in this manual) was also available. The petrol engines are all
well-proven units which are used in many other Vauxhall vehicles; the
engine is mounted at the front of vehicle with the transmission
mounted on its rear.
Two versions of the four-cylinder 2.0 litre engine were used; low
specification vehicles were fitted with a single overhead camshaft
(SOHC) 8-valve engine were as all other vehicles were fitted with the
double overhead camshaft (DOHC) 16-valve engine often referred to as
the ECOTEC engine. The 2.5 and 3.0 litre engines are both V6, double
overhead camshaft (DOHC) units which are also often referred as
ECOTEC engines.
All models have fully-independent front and rear suspension and are
equipped with front and rear disc brakes.
A wide range of standard and optional equipment is available within
the range to suit most tastes, including central locking, electric
windows and an electric sunroof. An air conditioning system was
available as an option on certain models.
Provided that regular servicing is carried out in accordance with the
manufacturer’s recommendations, the vehicle should prove reliable
and very economical. The engine compartment is well-designed, and
most of the items requiring frequent attention are easily accessible.
Vauxhall Omega 2.0 16V Select
Vauxhall Omega Estate CD
The Vauxhall Omega Team
Haynes manuals are produced by dedicated and
enthusiastic people working in close co-operation. The
team responsible for the creation of this book included:
Authors
Sub-editor
Editor & Page Make-up
Workshop manager
Photo Scans
Cover illustration & Line Art
Wiring diagrams
Marc Coombs
Spencer Drayton
Ian Barnes
Steve Churchill
Paul Buckland
Steve Tanswell
John Martin
Roger Healing
Matthew Marke
We hope the book will help you to get the maximum
enjoyment from your car. By carrying out routine
maintenance as described you will ensure your car’s
reliability and preserve its resale value.
Your Vauxhall Omega manual
The aim of this manual is to help you get the best value from your
vehicle. It can do so in several ways. It can help you decide what work
must be done (even should you choose to get it done by a garage). It
will also provide information on routine maintenance and servicing, and
give a logical course of action and diagnosis when random faults
occur. However, it is hoped that you will use the manual by tackling the
work yourself. On simpler jobs it may even be quicker than booking the
car into a garage and going there twice, to leave and collect it. Perhaps
most important, a lot of money can be saved by avoiding the costs a
garage must charge to cover its labour and overheads.
The manual has drawings and descriptions to show the function of
the various components so that their layout can be understood. Tasks
are described and photographed in a clear step-by-step sequence.
References to the ‘left’ and ‘right’ are in the sense of a person in the
driver’s seat, facing forwards.
Acknowledgements
Thanks are due to Champion Spark Plug, who supplied the
illustrations showing spark plug conditions. Certain illustrations are the
copyright of Vauxhall Motors Limited, and are used with their
permission. Thanks are also due to Draper Tools Limited, who
provided some of the workshop tools, and to all those people at
Sparkford who helped in the production of this manual.
We take great pride in the accuracy of information given in this
manual, but vehicle manufacturers make alterations and design
changes during the production run of a particular vehicle of which
they do not inform us. No liability can be accepted by the authors
or publishers for loss, damage or injury caused by any errors in, or
omissions from, the information given.
3510 Vauxhall/Opel Omega
Safety first!
Working on your car can be dangerous.
This page shows just some of the potential
risks and hazards, with the aim of creating a
safety-conscious attitude.
General hazards
Scalding
• Don’t remove the radiator or expansion
tank cap while the engine is hot.
• Engine oil, automatic transmission fluid or
power steering fluid may also be dangerously
hot if the engine has recently been running.
Burning
• Beware of burns from the exhaust system
and from any part of the engine. Brake discs
and drums can also be extremely hot
immediately after use.
Crushing
• When working under or near
a raised vehicle,
always
supplement the
jack with axle
stands, or use
drive-on
ramps.
Never
venture
under a car which
is only supported by a jack.
• Take care if loosening or tightening hightorque nuts when the vehicle is on stands.
Initial loosening and final tightening should be
done with the wheels on the ground.
• Mains voltage is also dangerous. Make
sure that any mains-operated equipment is
correctly earthed. Mains power points should
be protected by a residual current device
(RCD) circuit breaker.
Fume or gas intoxication
• Exhaust fumes are
poisonous; they often
contain carbon
monoxide, which is
rapidly fatal if inhaled.
Never run the
engine in a
confined space
such as a garage
with the doors shut.
• Fuel vapour is also
poisonous, as are the vapours from some
cleaning solvents and paint thinners.
Poisonous or irritant substances
• Avoid skin contact with battery acid and
with any fuel, fluid or lubricant, especially
antifreeze, brake hydraulic fluid and Diesel
fuel. Don’t syphon them by mouth. If such a
substance is swallowed or gets into the eyes,
seek medical advice.
• Prolonged contact with used engine oil can
cause skin cancer. Wear gloves or use a
barrier cream if necessary. Change out of oilsoaked clothes and do not keep oily rags in
your pocket.
• Air conditioning refrigerant forms a
poisonous gas if exposed to a naked flame
(including a cigarette). It can also cause skin
burns on contact.
Fire
Asbestos
• Fuel is highly flammable; fuel vapour is
explosive.
• Don’t let fuel spill onto a hot engine.
• Do not smoke or allow naked lights
(including pilot lights) anywhere near a
vehicle being worked on. Also beware of
creating sparks
(electrically or by use of tools).
• Fuel vapour is heavier than air, so don’t
work on the fuel system with the vehicle over
an inspection pit.
• Another cause of fire is an electrical
overload or short-circuit. Take care when
repairing or modifying the vehicle wiring.
• Keep a fire extinguisher handy, of a type
suitable for use on fuel and electrical fires.
• Asbestos dust can cause cancer if inhaled
or swallowed. Asbestos may be found in
gaskets and in brake and clutch linings.
When dealing with such components it is
safest to assume that they contain asbestos.
Electric shock
• Ignition HT
voltage can be
dangerous,
especially to
people with heart
problems or a
pacemaker. Don’t
work on or near the
ignition system with
the engine running or
the ignition switched on.
0•5
Special hazards
Hydrofluoric acid
• This extremely corrosive acid is formed
when certain types of synthetic rubber, found
in some O-rings, oil seals, fuel hoses etc, are
exposed to temperatures above 4000C. The
rubber changes into a charred or sticky
substance containing the acid. Once formed,
the acid remains dangerous for years. If it
gets onto the skin, it may be necessary to
amputate the limb concerned.
• When dealing with a vehicle which has
suffered a fire, or with components salvaged
from such a vehicle, wear protective gloves
and discard them after use.
The battery
• Batteries contain sulphuric acid, which
attacks clothing, eyes and skin. Take care
when topping-up or carrying the battery.
• The hydrogen gas given off by the battery
is highly explosive. Never cause a spark or
allow a naked light nearby. Be careful when
connecting and disconnecting battery
chargers or jump leads.
Air bags
• Air bags can cause injury if they go off
accidentally. Take care when removing the
steering wheel and/or facia. Special storage
instructions may apply.
Diesel injection equipment
• Diesel injection pumps supply fuel at very
high pressure. Take care when working on
the fuel injectors and fuel pipes.
Warning: Never expose the hands,
face or any other part of the body
to injector spray; the fuel can
penetrate the skin with potentially fatal
results.
Remember...
DO
DON’T
• Do use eye protection when using power
tools, and when working under the vehicle.
• Don’t attempt to lift a heavy component
which may be beyond your capability – get
assistance.
• Do wear gloves or use barrier cream to
protect your hands when necessary.
• Do get someone to check periodically
that all is well when working alone on the
vehicle.
• Do keep loose clothing and long hair well
out of the way of moving mechanical parts.
• Do remove rings, wristwatch etc, before
working on the vehicle – especially the
electrical system.
• Do ensure that any lifting or jacking
equipment has a safe working load rating
adequate for the job.
3510 Vauxhall/Opel Omega
• Don’t rush to finish a job, or take
unverified short cuts.
• Don’t use ill-fitting tools which may slip
and cause injury.
• Don’t leave tools or parts lying around
where someone can trip over them. Mop
up oil and fuel spills at once.
• Don’t allow children or pets to play in or
near a vehicle being worked on.
0•6
Roadside repairs
The following pages are intended to help in dealing with
common roadside emergencies and breakdowns. You will find
more detailed fault finding information at the back of the
manual, and repair information in the main chapters.
If your car won’t start
and the starter motor
doesn’t turn
If your car won’t start
even though the starter
motor turns as normal
M If it’s a model with automatic transmission, make sure the
selector is in ‘P’ or ‘N’.
M Open the bonnet and make sure that the battery terminals
are clean and tight.
M Switch on the headlights and try to start the engine. If the
headlights go very dim when you’re trying to start, the
battery is probably flat. Get out of trouble by jump starting
(see next page) using a friend’s car.
M Is there fuel in the tank?
M Is there moisture on electrical components under the
bonnet? Switch off the ignition, then wipe off any obvious
dampness with a dry cloth. Spray a water-repellent aerosol
product (WD-40 or equivalent) on ignition and fuel system
electrical connectors like those shown in the photos.
Pay special attention to the ignition coil wiring connector
and HT leads.
A
Check the condition and security of the
battery connections
B
Check that the spark plug HT leads are
securely connected by pushing them
onto the plugs (where accessible)
Check that electrical connections are secure (with the ignition switched off) and spray them
with a water dispersant spray like WD40 if you suspect a problem due to damp
3510 Vauxhall/Opel Omega
C
Check that the spark plug HT leads are
securely connected by pushing them
onto the DIS module (where accessible)
D
Check that the engine management
system wiring connectors are securely
connected
Roadside repairs
Jump starting will get you out
of trouble, but you must correct
whatever made the battery go
flat in the first place. There are
three possibilities:
The battery has been drained by
repeated attempts to start, or by
leaving the lights on.
1
The charging system is not working
properly (alternator drivebelt slack
or broken, alternator wiring fault or
alternator itself faulty).
2
3
1
The battery itself is at fault
(electrolyte low, or battery worn out).
Connect one end of the red jump lead to
the positive (+) terminal of the flat
battery
0•7
Jump starting
When jump-starting a car using a
booster battery, observe the following
precautions:
4 Before connecting the booster
battery, make sure that the ignition is
switched off.
4 Make sure that the booster battery is
the same voltage as the discharged
one in the vehicle.
4 If the battery is being jump-started
from the battery in another vehicle,
the two vehicles MUST NOT TOUCH
each other.
4 Ensure that all electrical equipment
(lights, heater, wipers, etc) is
switched off.
4 Take note of any special precautions
4 Make sure that the transmission is in
neutral (or PARK, in the case of
automatic transmission).
printed on the battery case.
2
Connect the other end of the red lead to
the positive (+) terminal of the booster
battery.
3510 Vauxhall/Opel Omega
3
Connect one end of the black jump lead
to the negative (-) terminal of the booster
battery
4
Connect the other end of the black jump
lead to a bolt or bracket on the engine
block, well away from the battery, on the
vehicle to be started.
5
Make sure that the jump leads will not
come into contact with the fan, drivebelts or other moving parts of the
engine.
6
Start the engine using the booster
battery and run it at idle speed. Switch
on the lights, rear window demister and
heater blower motor, then disconnect
the jump leads in the reverse order of
connection. Turn off the lights etc.
0•8
Roadside repairs
Wheel changing
Some of the details shown here will vary
according to model.
Warning: Do not change a wheel in a situation where you risk being hit by
another vehicle. On busy roads, try to stop in a lay-by or a gateway. Be wary of
passing traffic while changing the wheel - it is easy to become distracted by
the job in hand.
Preparation
M When a puncture occurs, stop as soon as
it is safe to do so.
M Park on firm level ground, if possible,
and well out of the way of other traffic.
M Use hazard warning lights if necessary.
M If you have one, use a warning triangle to
alert other drivers of your presence.
M Apply the handbrake and engage first or
reverse gear (or Park on models with
automatic transmission.
M Chock the wheel diagonally opposite the
one being removed – a couple of large
stones will do for this.
M If the ground is soft, use a flat piece of
wood to spread the load under the jack.
Changing the wheel
1
On Saloon models unclip the luggage
compartment left-hand trim panel then
release the retaining strap and remove
the spare wheel . . .
2
. . . The tools and jack are stored in the
smaller compartment on the right-hand
side of the luggage compartment. Remove
the cover (where fitted) then unscrew the bolt
and remove the jack and wheelbrace.
3
4
5
6
. . . then unscrew the retaining bolt and
remove the jack from behind the wheel.
On models with steel wheels, use the
removal tool supplied to pull off the wheel
trim and on models with alloy wheels, use
the tool supplied to unscrew the anti-theft bolt
and remove the hub cap. Slacken each wheel
bolt by half a turn.
On Estate models lift up the luggage
compartment floor panel and remove the
tools from the centre of the spare wheel.
Undo the retaining nut and remove the spare
wheel . . .
Unclip the access cover from the sill trim
panel then make sure the jack is located
on firm ground and engage the jack head
correctly with the lifting point on the sill. Make
sure that the lug on the jack head is correctly
located in the sill seam cutout and the base of
the jack is directly underneath the sill seam.
Finally...
M Remove the wheel chocks.
M Stow the punctured wheel, jack and tools
in the correct locations in the car.
7
Raise the jack until the wheel is raised
clear of the ground. Unscrew the wheel
bolts and remove the wheel. Fit the spare
wheel and screw on the bolts. Lightly tighten
the bolts with the wheelbrace then lower the
vehicle to the ground.
8
Securely tighten the wheel bolts in a
diagonal sequence then refit the hub
cap/wheel trim (as applicable). Note that
the wheel bolts should be slackened and
retightened to the specified torque at the
earliest possible opportunity.
3510 Vauxhall/Opel Omega
M Check the tyre pressure on the wheel just
fitted. If it is low, or if you don’t have a
pressure gauge with you, drive slowly to
the nearest garage and inflate the tyre to
the right pressure.
M Have the damaged tyre or wheel repaired
as soon as possible.
Roadside repairs
0•9
Identifying leaks
Puddles on the garage floor or drive, or
obvious wetness under the bonnet or
underneath the car, suggest a leak that needs
investigating. It can sometimes be difficult to
decide where the leak is coming from,
especially if the engine bay is very dirty
already. Leaking oil or fluid can also be blown
rearwards by the passage of air under the car,
giving a false impression of where the
problem lies.
Warning: Most automotive oils
and fluids are poisonous. Wash
them off skin, and change out
of contaminated clothing,
without delay.
The smell of a fluid leaking
from the car may provide a
clue to what’s leaking. Some
fluids are distictively coloured.
It may help to clean the car carefully
and to park it over some clean paper
overnight as an aid to locating the
source of the leak.
Remember that some leaks may only
occur while the engine is running.
Sump oil
Oil from filter
Gearbox oil
Engine oil may leak from the drain plug...
...or from the base of the oil filter.
Gearbox oil can leak from the seals at the
inboard ends of the driveshafts.
Antifreeze
Brake fluid
Power steering fluid
Leaking antifreeze often leaves a crystalline
deposit like this.
A leak occurring at a wheel is almost
certainly brake fluid.
Power steering fluid may leak from the pipe
connectors on the steering rack.
Towing
When all else fails, you may find yourself
having to get a tow home – or of course you
may be helping somebody else. Long-distance
recovery should only be done by a garage or
breakdown service. For shorter distances, DIY
towing using another car is easy enough, but
observe the following points:
M Use a proper tow-rope – they are not
expensive. The vehicle being towed must
display an ‘ON TOW’ sign in its rear window.
M Always turn the ignition key to the ‘on’
position when the vehicle is being towed, so
that the steering lock is released, and that the
direction indicator and brake lights will work.
M Both front and rear towing eyes are
provided. They are located behind the access
covers on the front and rear bumper.
M Before being towed, release the handbrake
and select neutral on the transmission.
M Note that greater-than-usual pedal
pressure will be required to operate the
brakes, since the vacuum servo unit is only
operational with the engine running.
M On models with power steering, greater-
3510 Vauxhall/Opel Omega
than-usual steering effort will also be required.
M The driver of the car being towed must
keep the tow-rope taut at all times to avoid
snatching.
M Make sure that both drivers know the route
before setting off.
M Only drive at moderate speeds and keep
the distance towed to a minimum. Drive
smoothly and allow plenty of time for slowing
down at junctions.
M On models with automatic transmission,
special precautions apply. If in doubt, do not
tow, or transmission damage may result.
0•10
Weekly checks
Introduction
There are some very simple checks which
need only take a few minutes to carry out, but
which could save you a lot of inconvenience
and expense.
M Keeping an eye on tyre condition and
pressures, will not only help to stop them
wearing out prematurely, but could also save
your life.
These "Weekly checks" require no great skill
or special tools, and the small amount of time
they take to perform could prove to be very
well spent, for example;
M Many breakdowns are caused by electrical
problems. Battery-related faults are particularly
common, and a quick check on a regular basis
will often prevent the majority of these.
M If your car develops a brake fluid leak, the
first time you might know about it is when
your brakes don't work properly. Checking
the level regularly will give advance warning of
this kind of problem.
M If the oil or coolant levels run low, the cost
of repairing any engine damage will be far
greater than fixing the leak, for example.
Underbonnet check points
§ 2.0 litre DOHC
engine
A
B
C
D
Engine oil level dipstick
E
F
Battery
Engine oil filler cap
Coolant expansion tank
Brake (and clutch) fluid
reservoir
Power steering fluid reservoir
§ 2.5 and
3.0 litre engine
3510 Vauxhall/Opel Omega
A
B
C
D
Engine oil level dipstick
E
F
G
Battery
Engine oil filler cap
Coolant expansion tank
Brake (and clutch) fluid
reservoir
Power steering fluid reservoir
Screen washer fluid reservoir
Weekly checks
0•11
Engine oil level
Before you start
4 Make sure that your car is on level ground.
4 Check the oil level before the car is driven,
or at least 5 minutes after the engine has been
switched off.
If the oil is checked
immediately after driving the
vehicle, some of the oil will
remain in the upper engine
components, resulting in an inaccurate
reading on the dipstick!
The correct oil
1
The dipstick is located on the left-hand
side of the engine (see Underbonnet
check points on page 0•10 for exact
location). Withdraw the dipstick.
2
Using a clean rag or paper towel remove
all oil from the dipstick. Insert the clean
dipstick into the tube as far as it will go,
then withdraw it again.
3
4
Modern engines place great demands on their
oil. It is very important that the correct oil for
your car is used (See “Lubricants and fluids”
on page 0•16).
Car Care
l If you have to add oil frequently, you should
check whether you have any oil leaks. Place
some clean paper under the car overnight,
and check for stains in the morning. If there
are no leaks, the engine may be burning oil
(see “Fault Finding”).
l Always maintain the level between the
upper and lower dipstick marks (see photo 3).
If the level is too low severe engine damage
may occur. Oil seal failure may result if the
engine is overfilled by adding too much oil.
Note the oil level on the end of the
dipstick, which should be between the
upper (MAX) mark and lower (MIN) mark.
Approximately 1.0 litre of oil will raise the level
from the lower mark to the upper mark.
Oil is added through the filler cap. Rotate
the cap through a quarter-turn anticlockwise and withdraw it. Top-up the
level. A funnel may help to reduce spillage.
Add the oil slowly, checking the level on the
dipstick often. Do not overfill.
Coolant level
Warning: DO NOT attempt to
remove the expansion tank
pressure cap when the engine
is hot, as there is a very great
risk of scalding. Do not leave
open containers of coolant
about, as it is poisonous.
1
The coolant level varies with the
temperature of the engine. When the
engine is cold, the coolant level should
be slightly above the KALT/COLD mark on the
side of the tank. When the engine is hot, the
level will rise.
Car Care
l With a sealed-type cooling system, adding
coolant should not be necessary on a regular
basis. If frequent topping-up is required, it is
likely there is a leak. Check the radiator, all
hoses and joint faces for signs of staining or
wetness, and rectify as necessary.
2
If topping up is necessary, wait until the
engine is cold. Slowly unscrew the
expansion tank cap, to release any
pressure present in the cooling system, and
remove it.
3510 Vauxhall/Opel Omega
l It is important that antifreeze is used in the
cooling system all year round, not just during
the winter months. Don’t top-up with water
alone, as the antifreeze will become too
diluted.
3
Add a mixture of water and antifreeze to
the expansion tank until the coolant level
is slightly above the KALT/COLD mark
then securely refit the expansion tank cap.
0•12
Weekly checks
Brake and clutch* fluid level
*On manual transmission models the brake fluid reservoir also supplies fluid to the clutch master cylinder.
Warning:
l Brake fluid can harm your
eyes and damage painted
surfaces, so use extreme
caution when handling and
pouring it.
l
Do not use fluid that has
been standing open for some
time, as it absorbs moisture
from the air, which can cause a
dangerous loss of braking
effectiveness.
1
The upper (MAX) and lower (MIN) fluid
level markings are on the side of the
reservoir, which is located in the righthand rear corner of the engine compartment.
The fluid level must always be kept in
between these two marks.
• Make sure that your car is
on level ground.
• The fluid level in the
reservoir will drop slightly as
the brake pads wear down, but the fluid
level must never be allowed to drop
below the “MIN” mark.
Safety First!
l If the reservoir requires repeated toppingup this is an indication of a fluid leak
somewhere in the system, which should be
investigated immediately.
l If a leak is suspected, the car should not be
driven until the braking system has been
checked. Never take any risks where brakes
are concerned.
2
If topping-up is necessary, first wipe
clean the area around the filler cap to
prevent dirt entering the hydraulic
system.
3
Carefully add fluid, taking care not to spill
it onto the surrounding components. Use
only the specified fluid; mixing different
types can cause damage to the system. After
topping-up to the correct level, securely refit
the cap and wipe off any spilt fluid.
Power steering fluid level
Before you start:
For the check to be
accurate, the steering must
not be turned once the
engine has been stopped.
4 Park the vehicle on level ground.
4 Set the steering wheel straight-ahead.
4 The engine should be turned off.
1
The power steering fluid reservoir is
located on the left-hand side of the
engine compartment. Wipe clean the
reservoir before unscrewing and removing the
cap.
2
Wipe clean the filler cap dipstick then
refit the filler cap and remove it again.
Note the fluid level on the dipstick.
3510 Vauxhall/Opel Omega
Safety First!
l The need for frequent topping-up indicates
a leak, which should be investigated
immediately.
3
When the engine is cold the fluid level
should be up to the lower mark up the
dipstick and when the engine is at
operating temperature it should be at the
upper mark. Top up the fluid level using the
specified type of fluid (do not overfill) then
securely refit the filler cap.
Weekly checks
0•13
Battery
Caution: Before carrying out any work on the
vehicle battery, read the precautions given in
"Safety first" at the start of this manual.
4 Make sure that the battery tray is in good
condition, and that the clamp is tight.
Corrosion on the tray, retaining clamp and the
battery itself can be removed with a solution
of water and baking soda. Thoroughly rinse all
cleaned areas with water. Any metal parts
damaged by corrosion should be covered
with a zinc-based primer, then painted.
4 Periodically (approximately every three
months), check the charge condition of the
battery as described in Chapter 5A.
4 If the battery is flat, and you need to jump
start your vehicle, see Roadside Repairs.
Battery corrosion can be kept to a
minimum by applying a layer of
petroleum jelly to the clamps and
terminals after they are reconnected.
1
The battery is located at the front lefthand corner of the engine compartment.
If necessary, unclip the fusible link
housing (where fitted) from side of the relay
box then open up the insulating cover to gain
access to the battery.
2
3
4
If corrosion (white, fluffy deposits) is
evident, remove the cables from the
battery terminals, clean them with a small
wire brush, then refit them. Automotive stores
sell a tool for cleaning the battery post . . .
Electrical systems
4 Check all external lights and the horn. Refer
to the appropriate Sections of Chapter 12 for
details if any of the circuits are found to be
inoperative.
4 Visually check all accessible wiring
connectors, harnesses and retaining clips for
security, and for signs of chafing or damage.
1
2
If a single indicator light, stop-light or
headlight has failed, it is likely that a bulb
has blown and will need to be replaced.
Refer to Chapter 12 for details. If both stop
lights have failed, it is possible that the switch
has failed (see Chapter 12, Section 4).
If more than one indicator light or tail light
has failed it is likely that either a fuse has
blown or that there is a fault in the circuit
(see Chapter 12). Most fuses are located behind
in the fusebox, behind the cover on the driver’s
side of the facia; depress the locking button and
remove the cover to gain access. Additional
fuses can be found in the engine compartment
relay box and fusible link housing.
3510 Vauxhall/Opel Omega
The exterior of the battery should be
inspected periodically for damage such
as a cracked case or cover. Check the
battery lead clamps for tightness to ensure
good electrical connections and check the
leads for signs of damage.
. . . as well as the battery cable clamps
If you need to check your
brake lights and indicators
unaided, back up to a wall or
garage door and operate the
lights. The reflected light should show if
they are working properly.
3
To replace a blown fuse, remove it, where
applicable, using the plastic tool
provided. Fit a new fuse of the same
rating, available from car accessory shops. It
is important that you find the reason that the
fuse blew (see Electrical fault finding in
Chapter 12).
0•14
Weekly checks
Tyre condition and pressure
It is very important that tyres are in good
condition, and at the correct pressure - having
a tyre failure at any speed is highly dangerous.
Tyre wear is influenced by driving style - harsh
braking and acceleration, or fast cornering,
will all produce more rapid tyre wear. As a
general rule, the front tyres wear out faster
than the rears. Interchanging the tyres from
front to rear ("rotating" the tyres) may result in
more even wear. However, if this is
completely effective, you may have the
expense of replacing all four tyres at once!
Remove any nails or stones embedded in the
tread before they penetrate the tyre to cause
deflation. If removal of a nail does reveal that
the tyre has been punctured, refit the nail so
that its point of penetration is marked. Then
immediately change the wheel, and have the
tyre repaired by a tyre dealer.
Regularly check the tyres for damage in the
form of cuts or bulges, especially in the
sidewalls. Periodically remove the wheels,
and clean any dirt or mud from the inside and
outside surfaces. Examine the wheel rims for
signs of rusting, corrosion or other damage.
Light alloy wheels are easily damaged by
"kerbing" whilst parking; steel wheels may
also become dented or buckled. A new wheel
is very often the only way to overcome severe
damage.
1 Tread Depth - visual check
2 Tread Depth - manual check 3 Tyre Pressure Check
The original tyres have tread wear safety
bands (B), which will appear when the tread
depth reaches approximately 1.6 mm. The
band positions are indicated by a triangular
mark on the tyre sidewall (A).
Alternatively, tread wear can be
monitored with a simple, inexpensive device
known as a tread depth indicator gauge.
New tyres should be balanced when they are
fitted, but it may become necessary to rebalance them as they wear, or if the balance
weights fitted to the wheel rim should fall off.
Unbalanced tyres will wear more quickly, as
will the steering and suspension components.
Wheel imbalance is normally signified by
vibration, particularly at a certain speed
(typically around 50 mph). If this vibration is
felt only through the steering, then it is likely
that just the front wheels need balancing. If,
however, the vibration is felt through the
whole car, the rear wheels could be out of
balance. Wheel balancing should be carried
out by a tyre dealer or garage.
Check the tyre pressures regularly with
the tyres cold. Do not adjust the tyre
pressures immediately after the vehicle has
been used, or an inaccurate setting will result.
Tyre pressures are shown on page 0•17.
Tyre tread wear patterns
Shoulder Wear
Centre Wear
Uneven Wear
Underinflation (wear on both sides)
Under-inflation will cause overheating of the
tyre, because the tyre will flex too much, and
the tread will not sit correctly on the road
surface. This will cause a loss of grip and
excessive wear, not to mention the danger of
sudden tyre failure due to heat build-up.
Check and adjust pressures
Incorrect wheel camber (wear on one side)
Repair or renew suspension parts
Hard cornering
Reduce speed!
Overinflation
Over-inflation will cause rapid wear of the
centre part of the tyre tread, coupled with
reduced grip, harsher ride, and the danger of
shock damage occurring in the tyre casing.
Check and adjust pressures
Front tyres may wear unevenly as a result of
wheel misalignment. Most tyre dealers and
garages can check and adjust the wheel
alignment (or "tracking") for a modest charge.
Incorrect camber or castor
Repair or renew suspension parts
Malfunctioning suspension
Repair or renew suspension parts
Unbalanced wheel
Balance tyres
Incorrect toe setting
Adjust front wheel alignment
Note: The feathered edge of the tread which
typifies toe wear is best checked by feel.
If you sometimes have to inflate your car’s
tyres to the higher pressures specified for
maximum load or sustained high speed, don’t
forget to reduce the pressures to normal
afterwards.
3510 Vauxhall/Opel Omega
Weekly checks
0•15
Washer fluid level
Screenwash additives not only keep the
winscreen clean during foul weather, they also
prevent the washer system freezing in cold
weather - which is when you are likely to need it
most. Don’t top up using plain water as the
screenwash will become too diluted, and will
1
The reservoir for the windscreen/
tailgate/headlamps (as applicable) is
located at the front of vehicle. The fluid
level in the reservoir can be checked using the
dipstick attached to the filler cap.
freeze during cold weather. On no account use
coolant antifreeze in the washer system this could discolour or damage paintwork.
2
When topping-up the reservoir, a
screenwash additive should be added in
the quantities recommended on the
bottle.
Wiper blades
1
Check the condition of the wiper blades;
if they are cracked or show any signs of
deterioration, or if the glass swept area is
smeared, renew them. Wiper blades should
be renewed annually.
2
To remove a windscreen wiper blade, pull
the arm fully away from the screen until it
locks. Swivel the blade through 90°,
press the locking tab with your fingers and
slide the blade out of the arm’s hooked end.
3510 Vauxhall/Opel Omega
0•16
Lubricants and fluids
Lubricants and fluids
Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cooling system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Manual transmission:
Early (pre 1999) vehicles:
Up to number JP3097A01361659* . . . . . . . . . . . . . . . . . . .
From number JP3097A01361659* . . . . . . . . . . . . . . . . . . .
Later (1999 onwards) vehicles . . . . . . . . . . . . . . . . . . . . . . . .
Multigrade engine oil, viscosity SAE 10W/40 to 15W/50 to API
SG/CD or SH/CD
(Duckhams QXR Premium Petrol Engine Oil or
Duckhams Hypergrade Petrol Engine Oil)
Ethylene glycol based antifreeze
(Duckhams Antifreeze and Summer Coolant)
Vauxhall transmission oil 19 40 704
Vauxhall transmission oil 19 40 764
Vauxhall transmission oil 19 40 768
Automatic transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Vauxhall transmission fluid 19 40 763
(Duckhams ATF Autotrans III)
Final drive unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
See Chapter 8 specifications
Braking and clutch system . . . . . . . . . . . . . . . . . . . . . . . . . . .
Hydraulic fluid DOT 4
(Duckhams Universal Brake and Clutch Fluid)
Power steering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Vauxhall transmission fluid 19 40 700
(Duckhams ATF Autotrans III)
*The identification number is stamped on the transmission housing. Note: There have been three different types of oil used in the
transmission by Vauxhall. The different types of oil should never be mixed, and it is essential that the transmission is refilled either
with the same type of oil as that drained, or the latest oil used in production from 1999 model year. If it is not known what type of
oil has been drained, the transmission unit should be flushed before filling with the latest specification oil. To do this, refer to
Chapter 7A, Section 2.
Choosing your engine oil
Engines need oil, not only to lubricate moving
parts and minimise wear, but also to maximise
power output and to improve fuel economy.
By introducing a simplified and improved
range of engine oils, Duckhams has taken
away the confusion and made it easier for you
to choose the right oil for your engine.
HOW ENGINE OIL WORKS
• Beating friction
Without oil, the moving surfaces inside your
engine will rub together, heat up and melt,
quickly causing the engine to seize. Engine oil
creates a film which separates these moving
parts, preventing wear and heat build-up.
• Cooling hot-spots
Temperatures inside the engine can exceed
1000º C. The engine oil circulates and acts as
a coolant, transferring heat from the hot-spots
to the sump.
• Cleaning the engine internally
DUCKHAMS ENGINE OILS
Good quality engine oils clean the inside of
your engine, collecting and dispersing
combustion deposits and controlling them
until they are trapped by the oil filter or flushed
out at oil change.
For the driver who demands a premium
quality oil for complete reassurance, we
recommend synthetic formula Duckhams
QXR Premium Engine Oils.
For the driver who requires a straightforward quality engine oil, we recommend
Duckhams Hypergrade Engine Oils.
OIL CARE - FOLLOW THE CODE
To handle and dispose of used engine oil
safely, always:
• Avoid skin contact
with used engine oil.
Repeated or prolonged
contact can be harmful.
• Dispose of used oil
and empty packs in a
responsible manner in an
authorised disposal site.
Call 0800 663366 to find
the one nearest to you.
Never tip oil down drains
or onto the ground.
3510 Vauxhall/Opel Omega
For further information and advice, call the
Duckhams UK Helpline on 0800 212988.
Tyre pressures
0•17
Tyre pressures
Note: Pressures apply to original-equipment tyres only and may vary if any other make or type of tyre is fitted; check with the tyre manufacturer or
supplier for correct pressures if necessary.
Note: Tyre pressures must always be checked with the tyres cold to ensure accuracy.
Saloon models
2.0 litre engine
Up to 3 passengers (including driver) . . . . . . . . . . . . . . . . . . . .
Fully loaded . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Front
28.5 psi (2.0 bar)
36 psi (2.5 bar)
Rear
28.5 psi (2.0 bar)
42 psi (2.9 bar)
2.5 and 3.0 litre engine
Up to 3 passengers (including driver) . . . . . . . . . . . . . . . . . . . .
Fully loaded . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31.5 psi (2.2 bar)
36 psi (2.5 bar)
31.5 psi (2.2 bar)
42 psi (2.9 bar)
28.5 psi (2.0 bar)
33.0 psi (2.3 bar)
38.0 psi (2.6 bar)
31.5 psi (2.2 bar)
45.0 psi (3.1 bar)
45.0 psi (3.1 bar)
31.5 psi (2.2 bar)
34.0 psi (2.3 bar)
39.0 psi (2.7 bar)
34.0 psi (2.3 bar)
46.0 psi (3.2 bar)
46.0 psi (3.2 bar)
28.5 psi (2.0 bar)
33.0 psi (2.3 bar)
38.0 psi (2.6 bar)
31.5 psi (2.2 bar)
45.0 psi (3.1 bar)
45.0 psi (3.1 bar)
Estate models
2.0 litre engine
Up to 3 passengers (including driver) . . . . . . . . . . . . . . . . . . . .
4 or 5 passengers (including driver) and 60 kg of luggage . . . .
Fully loaded . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.5 and 3.0 litre engine
195/65 R 15 tyres:
Up to 3 passengers (including driver) . . . . . . . . . . . . . . . . . . .
4 or 5 passengers (including driver) and 60 kg of luggage . . .
Fully loaded . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
205/65 R 15 and 225/55 R 15 tyres:
Up to 3 passengers (including driver) . . . . . . . . . . . . . . . . . . .
4 or 5 passengers (including driver) and 60 kg of luggage . . .
Fully loaded . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3510 Vauxhall/Opel Omega
1•1
Chapter 1
Routine maintenance and servicing
Contents
Air filter element - renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Automatic transmission fluid - renewal . . . . . . . . . . . . . . . . . . . . . . . 25
Automatic transmission fluid level - check . . . . . . . . . . . . . . . . . . . . 19
Auxiliary drivebelt - check and renewal . . . . . . . . . . . . . . . . . . . . . . . 6
Bodywork/underbody corrosion protection - check . . . . . . . . . . . . . 8
Brake fluid - renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Coolant - renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Driveshaft gaiter condition - check . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Engine oil and filter - renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Exhaust system - check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Front and rear disc brakes - pad wear check . . . . . . . . . . . . . . . . . . 5
Fuel filter - renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
General information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Handbrake - shoe condition check . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Handbrake operation - check and adjustment . . . . . . . . . . . . . . . . . 9
Headlight and auxiliary driving light beam alignment - check . . . . . . 12
Lock and hinge lubrication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Monitoring, lighting and signalling equipment - check . . . . . . . . . . . 4
Pollen filter - renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Regular maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Remote control keyfob battery - renewal . . . . . . . . . . . . . . . . . . . . . 27
Road test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Spark plugs - renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Suspension and steering condition and operation - check . . . . . . . . 10
Timing belt - renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Underbonnet/underbody hose and fluid leak - check . . . . . . . . . . . . 7
Wheel alignment - check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Wheel bolt torque - check and adjustment . . . . . . . . . . . . . . . . . . . . 11
1
Degrees of difficulty
Easy, suitable for
novice with little
experience
1
Fairly easy, suitable
for beginner with
some experience
2
Fairly difficult,
suitable for competent
DIY mechanic
3
3510 Vauxhall/Opel Omega
Difficult, suitable for
experienced DIY
mechanic
4
Very difficult,
suitable for expert DIY
or professional
5
1•2
Servicing specifications
Lubricants and fluids
..................................
Refer to end of Weekly checks on page 0•16
Capacities
Engine oil
2.0 litre engine:
SOHC engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DOHC engine:
Engines with a one-piece sump . . . . . . . . . . . . . . . . . . . . . . . . .
Engines with a two-piece sump . . . . . . . . . . . . . . . . . . . . . . . . .
2.5 and 3.0 litre engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Difference between MIN and MAX on dipstick (all engines) . . . . . . . . . .
Cooling system
2.0 litre engine:
SOHC engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DOHC engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.5 and 3.0 litre engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.5 litres
4.5 litres
5.0 litres
5.75 litres
1.0 litre
Manual transmission
Automatic transmission
9.0 litres
8.8 litres
9.7 litres
8.8 litres
8.6 litres
9.5 litres
Transmission
Manual transmission (approximate) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.2 litres
Automatic transmission (approximate):
From dry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.4 litres
After removing main sump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.4 litres
Final drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.0 litre*
*On models with limited-slip differential, observe the notes in Chapter 8 regarding the correct mixture of oil and additive to be used when refilling
the final drive unit.
Washer fluid reservoir
Without headlight washers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
With headlight washers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.0 litres
6.4 litres
Fuel tank
All models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
75 litres
Engine
Oil filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Champion G102
Cooling system
Antifreeze mixture:
50% antifreeze . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
55% antifreeze . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Note: Refer to antifreeze manufacturer for latest recommendations.
Protection down to -37ºC
Protection down to -45ºC
Fuel system
Air filter element:
2.0 litre engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.5 and 3.0 litre engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Champion U595
Champion U601
Champion L225
Ignition system
Spark plugs (gap not adjustable - see text) . . . . . . . . . . . . . . . . . . . . . .
Champion RC10DMC
Brakes
Friction material minimum thickness:
Front brake pads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rear brake pads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Handbrake shoes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Torque wrench settings
Automatic transmission fluid level plug . . . . . . . . . . . . . . . . . . . . . . . . .
Oil filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Roadwheel bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Spark plugs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Sump drain plug:
2.0 litre SOHC engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.0 litre DOHC engine:
Hex-head bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Torx-head bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.5 and 3.0 litre engine:
Hex-head bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Torx-head bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8.0 mm including backing plate
6.0 mm including backing plate
1.0 mm excluding backing plate
Nm
33
15
110
25
lbf ft
24
11
81
18
55
41
45
10
33
7
55
10
41
7
3510 Vauxhall/Opel Omega
Maintenance schedule
The maintenance intervals in this manual
are provided with the assumption that you,
not the dealer, will be carrying out the work.
These are the minimum maintenance intervals
recommended by us for vehicles driven daily.
If you wish to keep your vehicle in peak
condition at all times, you may wish to
perform some of these procedures more
often. We encourage frequent maintenance,
because it enhances the efficiency,
performance and resale value of your vehicle.
If the vehicle is driven in dusty areas, used
to tow a trailer, or driven frequently at slow
speeds (idling in traffic) or on short journeys,
1•3
more frequent maintenance intervals are
recommended.
When the vehicle is new, and/or still within
its warranty period, it should be serviced by a
factory-authorised dealer service department,
in order to preserve the factory warranty.
Every 5000 miles (7500 km) or
6 months, whichever comes first
Every 40 000 miles (60 000 km) or
4 years, whichever comes first
m Engine oil and filter - renewal (Section 3)
Carry out all the operations listed for the 15,000 km/12 month and the
30,000 km/2 year intervals, plus the following additional operations:
Note: Vauxhall recommend that the engine oil and filter are changed
every 10 000 miles or 12 months. However, oil and filter changes are
good for the engine and we recommend that the oil and filter are
renewed more frequently, especially if the vehicle is used on a lot of
short journeys.
Every 10 000 miles (15 000 km) or
12 months, whichever comes first
m Monitoring, lighting and signalling equipment check (Section 4)
m Front and rear brakes - pad and disc wear check
(Section 5)
m Auxiliary drivebelt condition and tension - check
and adjust (Section 6)*
m Underbonnet/underbody hose and fluid leak check (Section 7)*
m Bodywork/underbody corrosion protection - check
(Section 8)*
m Handbrake operation - check and adjustment
(Section 9)*
m Suspension and steering condition and operation check (Section 10)*
m Wheel bolt torque - check and adjustment
(Section 11)
m Headlight and auxiliary driving light beam
alignment - check (Section 12)*
m Road test (Section 13)
m Wheel alignment - check (Section 14)
m Exhaust system - check (Section 15)*
* Note: On vehicles covering a high mileage (more than 20 000
m Spark plugs - renewal (Section 22)*
m Fuel filter - renewal (Section 23)
m Timing belt - renewal (Section 24)**
* Note: On pre-1999 model year vehicles, renew the spark plugs
every 40 000 miles (60 000 km) regardless of the time elapsed.
**Note: Since the introduction of the Omega in 1994, Vauxhall have
gradually increased the specified interval for timing belt renewal as
follows:
1994 model year vehicle,
36 000 miles or 4 years, whichever comes first.
1995 and 1996 model year vehicles,
40 000 miles or 4 years, whichever comes first.
1997 model year vehicles onwards,
80 000 miles or 8 years, whichever comes first.
However, if the vehicle is used mainly for short journeys or a lot of
stop-start driving, or if the vehicle’s history is unknown, it is
recommended that the earlier (1994 model year) recommendation is
adhered to. The actual belt renewal interval is very much up to the
individual owner but, bearing in mind that severe engine damage will
result if the belt breaks in use, we recommend you err on the side of
caution.
Every 70 000 miles (105 000 km) or
7 years whichever comes first
m Automatic transmission fluid - renewal (Section 25)*
Note: This operation applies only to vehicles covering a high mileage
(more than 20 000 miles/30 000 km annually)
miles/30 000 km annually) carry out the items marked with an asterisk
at the 12 month interval; carry out the items not marked with an
asterisk every 10 000 miles/15 000 km, regardless of elapsed time.
Every 2 years, regardless of mileage
Every 20 000 miles (30 000 km) or
2 years, whichever comes first
m Brake fluid - renewal (Section 26)
m Remote control keyfob battery - renewal
(Section 27)
m Coolant - renewal (Section 28)
Carry out all the operations listed for the 15,000 km/12 month
interval, plus the following additional operations:
m
m
m
m
m
m
Air filter element - renewal (Section 16)
Pollen filter - renewal (Section 17)
Lock and hinge lubrication (Section 18)
Automatic transmission fluid level check (Section 19)
Handbrake - shoe condition check (Section 20)
Driveshaft gaiter condition - check (Section 21)
3510 Vauxhall/Opel Omega
1
1•4
Maintenance - component location
Underbonnet view of a 2.0 litre DOHC engine model
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Engine oil filler cap
Air cleaner
Front suspension strut
upper mounting
Brake (and clutch) fluid
reservoir
Relay box
Cooling system expansion
tank
Battery
Fusible link housing
Power steering pump
Engine oil level dipstick
Oil filter
Alternator
Airflow meter
Throttle housing
Power steering fluid
reservoir
Underbonnet view of a 2.5 litre engine model (3.0 litre engine similar)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
3510 Vauxhall/Opel Omega
Engine oil filler cap
Power steering fluid
reservoir
Front suspension strut
upper mounting
Relay box
Fusible link housing
Engine oil level dipstick
Battery
Multi-ram air intake system
pre-volume chamber
Airflow meter
Air cleaner
Cooling system expansion
tank
Brake (and clutch) fluid
reservoir
Exhaust gas recirculation
(EGR) valve
Inlet manifold
Idle speed adjuster valve
Maintenance - component location
1•5
Front underbody view (2.0 litre DOHC engine shown - others similar)
1
2
3
4
5
6
7
8
9
10
11
12
13
Exhaust front downpipe
Oil filter
Engine oil drain plug
Air conditioning system
compressor
Front suspension lower
arm
Steering outer tie rod
Steering drop arm
Steering centre tie rod
Steering idler
Steering outer tie rod
Manual transmission
Oxygen sensor
Transmission unit rear
mounting crossmember
1
Rear underbody view (2.0 litre DOHC engine shown - others similar)
1
2
3
4
5
6
7
8
Exhaust tailpipe
Fuel tank
Final drive unit
Fuel filter
Rear shock absorber
Driveshaft
Rear suspension tie rod
Rear suspension lower
arm
9 Propeller shaft
10 Handbrake cable
3510 Vauxhall/Opel Omega
1•6
Maintenance procedures
1 General information
1 This Chapter is designed to help the home
mechanic maintain his/her vehicle for safety,
economy, long life and peak performance.
2 The
Chapter
contains
a
master
maintenance schedule, followed by Sections
dealing specifically with each task in the
schedule. Visual checks, adjustments,
component renewal and other helpful items
are included. Refer to the accompanying
illustrations of the engine compartment and
the underside of the vehicle for the locations
of the various components.
3 Servicing your vehicle in accordance with the
mileage/time maintenance schedule and the
following Sections will provide a planned
maintenance programme, which should result
in a long and reliable service life. This is a
comprehensive plan, so maintaining some
items but not others at the specified service
intervals, will not produce the same results.
4 As you service your vehicle, you will
discover that many of the procedures can and should - be grouped together, because of
the particular procedure being performed, or
because of the proximity of two otherwiseunrelated components to one another. For
example, if the vehicle is raised for any reason,
the exhaust can be inspected at the same time
as the suspension and steering components.
5 The first step in this maintenance pro-
gramme is to prepare yourself before the actual
work begins. Read through all the Sections
relevant to the work to be carried out, then
make a list and gather all the parts and tools
required. If a problem is encountered, seek
advice from a parts specialist, or a dealer
service department.
2 Regular maintenance
compression test indicates serious internal
engine wear, conventional maintenance as
described in this Chapter will not greatly
improve the performance of the engine, and
may prove a waste of time and money, unless
extensive overhaul work is carried out first.
4 The following series of operations are those
most often required to improve the performance of a generally poor-running engine:
Primary operations
1 If, from the time the vehicle is new, the
routine maintenance schedule is followed
closely, and frequent checks are made of fluid
levels and high-wear items, as suggested
throughout this manual, the engine will be
kept in relatively good running condition, and
the need for additional work will be minimised.
2 It is possible that there will be times when
the engine is running poorly due to the lack of
regular maintenance. This is even more likely
if a used vehicle, which has not received
regular and frequent maintenance checks, is
purchased. In such cases, additional work
may need to be carried out, outside of the
regular maintenance intervals.
3 If engine wear is suspected, a compression
test (refer to Chapter 2A, 2B or 2C, as
applicable) will provide valuable information
regarding the overall performance of the main
internal components. Such a test can be used
as a basis to decide on the extent of the work
to be carried out. If, for example, a
a) Clean, inspect and test the battery (refer
to Weekly checks).
b) Check all the engine-related fluids (refer
to Weekly checks).
c) Check the condition and tension of the
auxiliary drivebelt (Section 6).
d) Renew the spark plugs (Section 22).
e) Check the condition of the air filter, and
renew if necessary (Section 16).
f) Renew the fuel filter (Section 23).
g) Check the condition of all hoses, and
check for fluid leak.
5 If the above operations do not prove fully
effective, carry out the following secondary
operations:
Secondary operations
All items listed under Primary operations, plus
the following:
a) Check the charging system (refer to
Chapter 5A).
b) Check the ignition system (refer to
Chapter 5B).
c) Check the fuel system (refer to Chapter 4A).
Every 5000 miles or 6 months
3 Engine oil and filter renewal
2
1 Frequent oil and filter changes are the most
important
preventative
maintenance
procedures which can be undertaken by the
DIY owner. As engine oil ages, it becomes
diluted and contaminated, which leads to
premature engine wear.
2 Before starting this procedure, gather
together all the necessary tools and materials.
3.5 Removing the sump drain plug
Also make sure that you have plenty of clean
rags and newspapers handy, to mop up any
spills. Ideally, the engine oil should be warm,
as it will drain more easily, and more built-up
sludge will be removed with it. Take care not
to touch the exhaust or any other hot parts of
the engine when working under the vehicle.
To avoid any possibility of scalding, and to
protect yourself from possible skin irritants
and other harmful contaminants in used
engine oils, it is advisable to wear gloves
when carrying out this work.
3 Firmly apply the handbrake then jack up the
front of the vehicle and support it on axle
stands (see Jacking and Vehicle Support).
Undo the retaining screws and remove the
undercover from beneath the engine unit.
4 Remove the oil filler cap.
5 Using a spanner, or preferably a suitable
socket and bar, slacken the drain plug about
half a turn (see illustration). Position the
draining container under the drain plug, then
remove the plug completely (see Haynes
Hint).
6 Allow some time for the oil to drain, noting
that it may be necessary to reposition the
container as the oil flow slows to a trickle.
7 After all the oil has drained, wipe the drain
plug and the sealing washer with a clean rag.
3510 Vauxhall/Opel Omega
Examine the condition of the sealing washer,
and renew it if it shows signs of scoring or
other damage which may prevent an oil-tight
seal. Clean the area around the drain plug
opening, and refit the plug complete with the
washer and tighten it to the specified torque.
8 Move the container into position under the
oil filter. On 2.0 litre engines the filter is
located on the front end of the engine, where
As the drain plug releases from the
threads, move it quickly away so that
the stream of oil running out of the
sump goes into the container and not
over your arm
Every 5000 miles
1•7
3.8 Oil filter location - 2.0 litre engine
3.11a Lubricate the sealing ring of the new
filter with a smear of engine oil . . .
3.11b . . . then screw the filter on by hand
only (2.5 litre engine shown)
it is screwed onto the oil pump housing, and
on 2.5 and 3.0 litre engines it is screwed onto
the left-hand side of the cylinder block (see
illustration).
9 Use an oil filter removal tool to slacken the
filter initially, then unscrew it by hand the rest
of the way. Empty the oil from the old filter
into the container.
10 Use a clean rag to remove all oil, dirt and
sludge from the filter sealing area on the
engine.
11 Apply a light coating of clean engine oil
to the sealing ring on the new filter, then
screw the filter into position on the engine.
Tighten the filter firmly by hand only - do not
use any tools (see illustrations). If a genuine
filter is being fitted and the special oil filter
tool (Tool no. KM-726A - a socket which fits
over the end of the filter) is available, tighten
the filter to the specified torque.
12 Refit the undercover, tightening its
retaining screws securely, then remove the
old oil and all tools from under the vehicle
before lowering the vehicle to the ground.
13 Fill the engine through the filler hole, using
the correct grade and type of oil (refer to
Weekly Checks for details of topping-up).
Pour in half the specified quantity of oil first,
then wait a few minutes for the oil to drain into
the sump. Continue to add oil, a small
quantity at a time, until the level is up to the
lower mark on the dipstick. Adding
approximately a further 1.0 litre will bring the
level up to the upper mark on the dipstick.
14 Start the engine and run it for a few
minutes, while checking for leaks around the
oil filter seal and the sump drain plug. Note
that there may be a delay of a few seconds
before the low oil pressure warning light goes
out when the engine is first started, as the oil
circulates through the new oil filter and the
engine oil galleries before the pressure builds
up.
15 Stop the engine, and wait a few minutes
for the oil to settle in the sump once more.
With the new oil circulated and the filter now
completely full, recheck the level on the
dipstick, and add more oil as necessary.
16 Dispose of the used engine oil safely with
reference to General repair procedures.
1
Every 10 000 miles or 12 months
4 Monitoring, lighting and
signalling equipment check
1
1 Turn the ignition switch to the second
position and check that the instrument panel
CHECK lamp lights up and then extinguishes
after 4 approximately seconds. If the lamp
fails to extinguish, observe the fault
description message(s) displayed and rectify
the cause.
2 Start the engine and check that all tell-tale
system operation/fault lamps extinguish. Note
that some lamps (such as the automatic
transmission sport programme, or traction
control system lamps) may remain lit,
depending on the driving mode selected;
consult your drivers handbook for the exact
meaning of each lamp.
3 Release handbrake, depress the brake
pedal and check that the brake lights fault
display extinguishes.
4 Switch on all interior and exterior lights in
turn and check their operation. Pay particular
attention to the tail lamps, fog lamps, brake
lamps, main and dipped beam headlamps,
position lamps and front and rear direction
indicators. Renew any blown bulbs with
reference to Chapter 12.
5 Finally, check the operation of the horn.
5 Front and rear brakes pad and disc wear check
2
Front brakes
1 Firmly apply the handbrake, select first gear
or P, then jack up the front of the vehicle and
support it securely on axle stands (see
Jacking and Vehicle Support). Remove the
front roadwheels.
2 For a quick check, the pad thickness can
be carried out via the inspection hole on the
front surface of each caliper (see illustration).
Using a steel rule, measure the thickness of
each pad lining, including the backing plate.
This must not be less than that indicated in
the Specifications.
3 The view through the caliper inspection
hole gives only a rough indication of the
state of the brake pads. For a comprehensive
check, the brake pads should be removed
and cleaned. The operation of the caliper can
then also be checked, and the condition of the
brake disc itself can be fully examined on both
sides. Chapter 9 contains a detailed
description of how the brake discs should be
checked for wear and/or damage.
4 If any pad’s friction material is worn to the
specified thickness or less, all four pads must
be renewed as an axle set; for example - if the
pads in the left hand caliper are found to be
worn, those in the right hand caliper must also
be renewed, regardless of their condition.
Refer to Chapter 9 for details.
5 On completion, refit the roadwheels and
lower the vehicle to the ground.
Rear brakes
5.2 The brake pad wear can be assessed
by observing the thickness of the friction
material, visible through the inspection
aperture at the front of the brake caliper
3510 Vauxhall/Opel Omega
6 Chock the front wheels, then jack up the
rear of the vehicle and support it securely on
axle stands (see Jacking and Vehicle
Support). Remove the rear roadwheels.
1•8
Every 10 000 miles
6.3a On 2.0 litre engines check that the drivebelt tensioner arm
indicator (2) is correctly positioned between the stops (1 and 3) on
the backplate
7 Proceed as described in paragraphs 2 to 4
inclusive, noting that the inspection aperture
is at the rear of the caliper.
8 On completion, refit the rear roadwheels
and lower the vehicle to the ground.
6 Auxiliary drivebelt check and renewal
3
Check
1 Although the drivebelt tension is
automatically adjusted by the spring-loaded
tensioner, the belt itself should still be
regularly checked for damage or deterioration.
2 With the engine stopped, inspect the full
length of the drivebelt for cracks and
separation of the belt plies. It will be
necessary to turn the engine (using a spanner
or socket and bar on the crankshaft pulley
bolt) in order to move the belt from the pulleys
so that the belt can be inspected thoroughly.
Twist the belt between the pulleys so that
both sides can be viewed. Also check for
fraying, and glazing which gives the belt a
6.12 Lever the tensioner away from the
belt then slip the belt off from its pulleys
(2.5 litre engine shown)
6.3b On 2.5 and 3.0 litre engines ensure the stop (1) on the
drivebelt tensioner mounting plate is in between the lugs (2) on
the arm
shiny appearance. Check the pulleys for
nicks, cracks, distortion and corrosion.
3 Check the position of the drivebelt
tensioner assembly arm in relation to the
backplate. On 2.0 litre engines the arm
indicator should be in between the stops on
the backplate and should be free to move. On
2.5 and 3.0 litre engines the stop on the
tensioner mounting plate should be
positioned between the lugs on the arm and
the arm should be free to move (see
illustrations).
4 If the belt shows signs of wear or damage,
or the tensioner arm is against the stop, the
belt must be renewed.
Renewal
2.0 litre engine
5 Prior to removal make a note of the correct
routing of the belt around the various pulleys.
If the belt is to be reused, also mark the
direction of rotation on the belt to ensure the
belt is refitted the same way around.
6 Using a suitable spanner or socket fitted to
the tensioner pulley centre bolt, lever the
tensioner away from the belt until there is
sufficient slack to enable the belt to be
slipped off from the pulleys. Carefully release
the tensioner pulley until it is against its stop
then remove the belt from the vehicle. If
necessary, the tensioner can be locked in the
released position by aligning the arm hole with
the hole in the backplate and inserting a
suitable tool/pin.
7 Manoeuvre the belt into position, routing it
correctly around the pulleys; if the original belt
is being fitted use the marks made prior to
removal to ensure it is fitted the correct way
around.
8 Lever the tensioner roller back against is
spring, and seat the belt on the pulleys.
Ensure the belt is centrally located on all
pulleys then slowly release the tensioner
3510 Vauxhall/Opel Omega
pulley until the belt is correctly tensioned. Do
not allow the tensioner to spring back and
stress the belt.
9 Check the tensioner arm is correctly
positioned in relation to the backplate (see
paragraph 3).
2.5 and 3.0 litre engine
10 Remove the multi-ram air intake system
pre-volume chamber and the secondary air
injection system front connecting pipe as
described in the relevant Parts of Chapter 4.
11 Prior to removal make a note of the
correct routing of the belt around the various
pulleys. If the belt is to be reused, also mark
the direction of rotation on the belt to ensure
the belt is refitted the same way around.
12 Using a suitable spanner or socket fitted
to the tensioner pulley centre bolt, lever the
tensioner away from the belt until there is
sufficient slack to enable the belt to be
slipped off from the pulleys (see illustration).
Carefully release the tensioner pulley until it is
against its stop then remove the belt from the
vehicle.
13 Manoeuvre the belt into position, routing it
correctly around the pulleys; if the original belt
is being fitted use the marks made prior to
removal to ensure it is fitted the correct way
around.
14 Lever the tensioner roller back against is
spring, and seat the belt on the pulleys.
Ensure the belt is centrally located on all
pulleys then slowly release the tensioner
pulley until the belt is correctly tensioned. Do
not allow the tensioner to spring back and
stress the belt.
15 Check the tensioner arm is correctly
positioned in relation to the backplate (see
paragraph 3) then refit the secondary air
injection system connecting pipe and the
multi-ram air intake system pre-volume
chamber as described in the relevant part of
Chapter 4.
Every 10 000 miles
7 Underbonnet/underbody
hose and fluid leak check
2
Cooling system
Warning: Refer to the safety
information given in Safety First
and Chapter 3 before disturbing
any of the cooling system components.
1 Carefully check the radiator and heater
coolant hoses along their entire length. Renew
any hose which is cracked, swollen or which
shows signs of deterioration. Cracks will show
up better if the hose is squeezed. Pay close
attention to the clips that secure the hoses to
the cooling system components. Hose clips
that have been over-tightened can pinch and
puncture hoses, resulting in cooling system
leaks (see illustration).
2 Inspect all the cooling system components
(hoses, joint faces, etc) for leaks. Where any
problems of this nature are found on system
components, renew the component or gasket
with reference to Chapter 3.
A leak in the cooling system
will usually manifest itself as
white or rust-coloured,
crusty deposits on the area
adjacent to the leak
Inspect the petrol tank and filler neck for
punctures, cracks and other damage. The
connection between the filler neck and tank is
especially critical. Sometimes a rubber filler
neck or connecting hose will leak due to loose
retaining clamps or deteriorated rubber.
6 Carefully check all rubber hoses and metal
fuel lines leading away from the petrol tank.
Check for loose connections, deteriorated
hoses, kinked lines, and other damage. Pay
particular attention to the vent pipes and
hoses, which often loop up around the filler
neck and can become blocked or kinked,
making tank filling difficult. Follow the fuel
supply and return lines to the front of the
vehicle, carefully inspecting them all the way
for signs of damage or corrosion. Renew
damaged sections as necessary.
Engine oil
7 Inspect the area around the camshaft
cover, cylinder head, oil filter and sump joint
faces. Bear in mind that, over a period of time,
some very slight seepage from these areas is
to be expected - what you are really looking
for is any indication of a serious leak caused
by gasket failure. Engine oil seeping from the
base of the timing belt cover or the
transmission bellhousing may be an indication
of crankshaft or transmission input shaft oil
seal failure. Should a leak be found, renew the
failed gasket or oil seal by referring to the
appropriate Chapters in this manual.
1•9
Automatic transmission fluid
8 Check the hoses leading to the
transmission fluid cooler for leakage. Look for
deterioration caused by corrosion and
damage from grounding, or debris thrown up
from the road surface. Automatic transmission
fluid is a thin oil and is usually red in colour.
Check the area around the propeller shaft seal
at the rear of the transmission for signs of fluid
leakage. Should a leak be found, check the
fluid level as described in Section 19 then
rectify the cause of leakage as soon as
possible.
Power assisted steering (PAS)
fluid
9 Examine the hose running between the fluid
reservoir and the power steering pump, and
the return hose running from the steering rack
to the fluid reservoir. Also examine the high
pressure supply hose between the pump and
the steering rack.
10 Check the condition of each hose
carefully. Look for deterioration caused by
corrosion and damage from grounding, or
debris thrown up from the road surface.
11 Pay particular attention to crimped
unions, and the area surrounding the hoses
that are secured with adjustable worm drive
clips. Like automatic transmission fluid, PAS
fluid is a thin oil, and is usually red or light
brown in colour.
1
Fuel system
Warning: Refer to the safety
information given in Safety First
and Chapter 4A before disturbing
any of the fuel system components.
3 Petrol leaks can be difficult to pinpoint,
unless the leakage is significant and hence
easily visible. Fuel tends to evaporate quickly
once it comes into contact with air, especially
in a hot engine bay. Small drips can disappear
before you get a chance to identify the point
of leakage. If you suspect that there is a fuel
leak from the area of the engine bay, leave the
vehicle overnight then start the engine from
cold, with the bonnet open. Metal
components tend to shrink when they are
cold, and rubber seals and hoses tend to
harden, so any leaks will be more apparent
whilst the engine is warming up from a cold
start.
4 Check all fuel lines at their connections to
the fuel rail, fuel pressure regulator and fuel
filter (petrol models), Examine each rubber
fuel hose along its length for splits or cracks.
Check for leakage from the crimped joints
between rubber and metal fuel lines. Examine
the unions between the metal fuel lines and
the fuel filter housing. Also check the area
around the fuel injectors for signs of O-ring
leakage.
5 To identify fuel leaks between the fuel tank
and the engine bay, the vehicle should raised
and securely supported on axle stands.
7.1 Possible causes of coolant hose failure
3510 Vauxhall/Opel Omega
1•10
Every 10 000 miles
Air conditioning refrigerant
Warning: Refer to the safety
information given in Safety First
and Chapter 3, regarding the
dangers of disturbing any of the air
conditioning system components.
12 The air conditioning system is filled with a
liquid refrigerant, which is retained under high
pressure. If the air conditioning system is
opened and depressurised without the aid of
specialised equipment, the refrigerant will
immediately turn into gas and escape into the
atmosphere. If the liquid comes into contact
with your skin, it can cause severe frostbite. In
addition, the refrigerant contains substances
which are environmentally damaging; for this
reason, it should not be allowed to escape
into the atmosphere in an uncontrolled
fashion.
13 Any suspected air conditioning system
leaks should be immediately referred to a
Vauxhall dealer or air conditioning specialist.
Leakage will be shown up as a steady drop in
the level of refrigerant in the system.
14 Note that water may drip from the
condenser drain pipe, underneath the car,
immediately after the air conditioning system
has been in use. This is normal, and should
not be cause for concern.
Brake fluid
Warning: Refer to the safety
information given in Safety First
and Chapter 9, regarding the
dangers of handling brake fluid.
15 Examine the area surrounding the brake
pipe unions at the master cylinder for signs of
leakage. Check the area around the base of
fluid reservoir, for signs of leakage caused by
seal failure. Also examine the brake pipe
unions at the ABS hydraulic unit.
16 If fluid loss is evident, but the leak cannot
be pinpointed in the engine bay, the brake
calipers and underbody brake lines should be
carefully checked with the vehicle raised and
supported on axle stands (see illustration).
Leakage of fluid from the braking system is a
serious fault that must be rectified
immediately.
17 Brake/clutch hydraulic fluid is a toxic
substance with a watery consistency. New
fluid is almost colourless, but it becomes
darker with age and use.
7.16 Inspecting the flexible hose
connection to a front brake caliper
leakage. Should a leak be found, check the
differential fluid level as described in Chapter 8
then rectify the cause of leakage as soon as
possible.
Unidentified fluid leaks
20 If there are signs that a fluid of some
description is leaking from the vehicle, but
you cannot identify the type of fluid or its
exact origin, park the vehicle overnight and
slide a large piece of card underneath it.
Providing that the card is positioned in
roughly the right location, even the smallest
leak will show up on the card. Not only will
this help you to pinpoint the exact location of
the leak, it should be easier to identify the fluid
from its colour. Bear in mind, though, that the
leak may only be occurring when the engine is
running!
Vacuum hoses
21 Although the braking system is
hydraulically-operated, the brake servo unit
amplifies the effort applied at the brake pedal,
by making use of the vacuum in the inlet
manifold, generated by the engine. Vacuum is
ported to the servo by means of a large-bore
hose. Any leaks that develop in this hose will
reduce the effectiveness of the braking
system, and may affect the running of the
engine.
22 In addition, a number of the underbonnet
components, particularly the emission control
components, are driven by vacuum supplied
from the inlet manifold via narrow-bore rubber
Manual transmission fluid
18 Check the area around the propeller shaft
seal at the rear of the transmission for signs of
fluid leakage. Should a leak be found, check
the transmission fluid level as described in
Chapter 7A then rectify the cause of leakage
as soon as possible.
Final drive unit differential fluid
19 Check the area around the driveshaft and
propeller shaft seals, and the flange seal on
the rear of the final drive unit for signs of fluid
9.5 Handbrake cable adjustment nut
(arrowed)
3510 Vauxhall/Opel Omega
and plastic hoses. A leak in a vacuum hose
means that air is being drawn into the hose
(rather than escaping from it) and this makes
leakage very difficult to detect. One method is
to use an old length of vacuum hose as a kind
of stethoscope - hold one end close to (but
not in!) your ear and use the other end to
probe the area around the suspected leak.
When the end of the hose is directly over a
vacuum leak, a hissing sound will be heard
clearly through the hose. Care must be taken
to avoid contacting hot or moving
components, as the engine must be running,
when testing in this manner. Renew any
vacuum hoses that are found to be defective.
8 Bodywork/underbody
corrosion protection check
5
1 This work should be carried out by a
Vauxhall/Opel dealer in order to validate the
vehicle warranty. The work includes a
thorough inspection of the vehicle paintwork
and underbody for damage and corrosion
9 Handbrake operation check and adjustment
2
1 Chock the front wheels, then jack up the
rear of the vehicle and support it securely on
axle stands (see Jacking and Vehicle
Support). Remove the rear roadwheels.
2 Fully release the handbrake lever, then
apply it to the third notch. Check that both
rear wheels can still rotate by attempting to
turn them by hand (ensure that the
transmission is in neutral). Release the
handbrake lever.
3 Fully apply the handbrake lever, so that the
rear wheels are locked, counting how many
notches the lever passes through. If the
handbrake lever passes through more than
seven notches before the rear wheels lock,
adjustment is required.
4 If adjustment is necessary, first fully release
the handbrake, then pull it up to the third
notch.
5 Working underneath the vehicle, unbolt the
exhaust system heat shields from the
floorpan. Locate the handbrake cable
adjustment nut, at the cable compensation
bar, above the propeller shaft. Fully slacken
the adjustment nut so that there is a small
amount of clearance between it and the
compensation bar (see illustration).
6 Working on one brake disc at a time,
position the hole in the disc over the serrated
adjustment nut on the adjuster at the top of
the backplate. Using a screwdriver inserted
through the hole, turn the nut until the brake
disc locks, then turn the nut in opposite
direction until the disc is just free (see
illustration). Repeat the adjustment on the
remaining rear brake.
Every 10 000 miles
7 Check that the handbrake lever is still
positioned on the third notch, then working
underneath the vehicle, tighten the handbrake
cable
adjustment
nut
against
the
compensation bar, until the handbrake shoes
just start to take effect - test for this by turning
the brake discs by hand.
8 Refit the rear wheels, then carry out a final
check of the handbrake adjustment; the rear
wheels should turn freely with the lever
applied to the third notch and should be fully
locked before passing through the seventh
notch. Tighten the wheel bolts to the specified
torque then lower the car the ground. Check
the operation of the handbrake before using
the vehicle on the road.
9 After fitting new handbrake shoes, the
shoes should be bedded-in by driving a short
distance (approximately 300 metres) at low
speed with the handbrake lever lightly
applied. Check, and if necessary adjust the
handbrake again after completing the
bedding-in.
10 Suspension and steering
condition and operation check
2
Front suspension and steering
check
1 Raise the front of the vehicle, and securely
support it on axle stands (see Jacking and
Vehicle Support).
2 Visually inspect the balljoint dust covers
and the steering rack-and-pinion gaiters for
splits, chafing or deterioration. Any wear of
these components will cause loss of lubricant,
together with dirt and water entry, resulting in
rapid deterioration of the balljoints or steering
gear.
3 Check the power steering fluid hoses for
chafing or deterioration, and the pipe and
hose unions for fluid leaks. Also check for
signs of fluid leakage under pressure from the
steering gear rubber gaiters, which would
indicate failed fluid seals within the steering
gear.
4 Grasp the roadwheel at the 12 o’clock and
6 o’clock positions, and try to rock it (see
illustration). Very slight free play may be felt,
but if the movement is appreciable, further
investigation is necessary to determine the
source. Continue rocking the wheel while an
assistant depresses the footbrake. If the
movement is now eliminated or significantly
reduced, it is likely that the hub bearings are
at fault. If the free play is still evident with the
footbrake depressed, then there is wear in the
suspension joints or mountings.
5 Now grasp the wheel at the 9 o’clock and 3
o’clock positions, and try to rock it as before.
Any movement felt now may again be caused
by wear in the hub bearings or the steering
track-rod balljoints. If the outer balljoint is
worn, the visual movement will be obvious. If
the inner joint is suspect, it can be felt by
1•11
Shock absorber check
9.6 Adjusting the handbrake screws using
a screwdriver through the hole in the
disc/hub flange
placing a hand over the rack-and-pinion
rubber gaiter and gripping the track-rod. If the
wheel is now rocked, movement will be felt at
the inner joint if wear has taken place.
6 Using a large screwdriver or flat bar, check
for wear in the suspension mounting bushes
by levering between the relevant suspension
component and its attachment point. Some
movement is to be expected, as the
mountings are made of rubber, but excessive
wear should be obvious. Also check the
condition of any visible rubber bushes,
looking for splits, cracks or contamination of
the rubber.
7 With the car standing on its wheels, have an
assistant turn the steering wheel back-andforth, about an eighth of a turn each way.
There should be very little, if any, lost
movement between the steering wheel and
roadwheels. If this is not the case, closely
observe the joints and mountings previously
described. In addition, check the steering
column universal joints for wear, and also
check the rack-and-pinion steering gear itself.
Rear suspension check
8 Chock the front wheels, then jack up the
rear of the vehicle and support securely on
axle stands (see Jacking and Vehicle
Support).
9 Working as described previously for the
front suspension, check the rear hub
bearings, the suspension bushes and the strut
or shock absorber mountings (as applicable)
for wear.
10.4 To check for play in the wheel bearing,
grasp the roadwheel at the 12 o’clock and
6 o’clock positions, and try to rock it
3510 Vauxhall/Opel Omega
10 Check for any signs of fluid leakage
around the shock absorber body, or from the
rubber gaiter around the piston rod. Should
any fluid be noticed, the shock absorber is
defective internally, and should be renewed.
Note: Shock absorbers should always be
renewed in pairs on the same axle.
11 The efficiency of the shock absorber may
be checked by bouncing the vehicle at each
corner. Generally speaking, the body will
return to its normal position and stop after
being depressed. If it rises and returns on a
rebound, the shock absorber is probably
suspect. Also examine the shock absorber
upper and lower mountings for any signs of
wear.
11 Wheel bolt torque check and adjustment
2
Note: As well as being potentially damaging
to the vehicle’s roadwheels, over-tightened
wheel bolts may cause problems if you
have to change a wheel by the side of the
road. By ensuring that the wheel bolts are
tightened to the correct torque, you could
save yourself a lot of time and trouble in an
emergency situation.
1 Slacken the front wheel securing bolts
slightly, then apply the handbrake firmly, raise
the front of the vehicle, and securely support
it on axle stands (see Jacking and Vehicle
Support).
2 Fully slacken the each of the wheel bolts in
turn and clear any dirt of debris from the
threads. Re-insert the wheel bolts and tighten
them to the specified torque setting using a
good quality torque wrench.
3 Repeat the operation at the opposite wheel,
then lower the car the ground.
4 Chock the front wheels, then jack up the
rear of the vehicle and support securely on
axle stands (see Jacking and Vehicle
Support). Repeat the operations described in
paragraphs 2 and 3.
12 Headlight and auxiliary
driving light beam alignment
- check
5
1 Badly adjusted headlights and/or foglights
cause poor visibility and can dazzle other road
users. Accurate adjustment of the headlight
and auxiliary driving light beams is only
possible
using
optical
beam-setting
equipment, and this work should therefore be
carried out by a Vauxhall/Opel dealer or
suitably-equipped workshop.
2 For reference, the headlights can be
adjusted using the adjuster assemblies fitted
to the front upper outer mounting and to the
rear inner mounting. The inner screw is for
horizontal adjustment and the outer one for
1
1•12
Every 10 000 miles
vertical adjustment. When adjusting the
headlight aim, ensure that the facia -mounted
range adjustment switch is set to position 0
(see paragraph 3).
3 All models have an electric headlight beam
adjustment range system, controlled via a
rotary switch in the facia*. The recommended
settings are as follows.
0
1
2
3
Front seat(s) occupied
All seats occupied
All seats occupied, and load in luggage
compartment
Driver’s seat occupied and load in the
luggage compartment
*On models built from 1998 onwards with
Xenon headlights, an automatic headlamp
range adjustment system is fitted, to which
no manual adjustment can be made; see
Chapter 12 for details.
13 Road test
1
Instruments and
electrical equipment
1 Check the operation of all instruments and
electrical equipment.
2 Make sure that all instruments read correctly,
and switch on all electrical equipment in turn, to
check that it functions properly.
Steering and suspension
3 Check for any abnormalities in the steering,
suspension, handling or road feel.
4 Drive the vehicle, and check that there are
no unusual vibrations or noises.
5 Check that the steering feels positive, with
no excessive sloppiness, or roughness, and
check for any suspension noises when
cornering and driving over bumps.
Drivetrain
6 Check the performance of the engine,
clutch, transmission and driveshafts.
7 Listen for any unusual noises from the
engine, clutch and transmission.
8 Make sure that the engine runs smoothly
when idling, and that there is no hesitation
when accelerating.
9 Check that, where applicable, the clutch
action is smooth and progressive, that the
drive is taken up smoothly, and that the pedal
travel is not excessive. Also listen for any
noises when the clutch pedal is depressed.
10 Check that all gears can be engaged
smoothly without noise, and that the gear
lever action is not abnormally vague or
notchy.
11 On automatic transmission models, make
sure that all gearchanges occur smoothly,
without snatching, and without an increase in
engine speed between changes. Check that
all of the gear positions can be selected with
the vehicle at rest. If any problems are found,
they should be referred to a Vauxhall/Opel
dealer.
Check the operation and
performance of the braking
system
12 Make sure that the vehicle does not pull to
one side when braking, and that the wheels
do not lock prematurely when braking hard.
13 Check that there is no vibration through
the steering when braking.
14 Check that the handbrake operates
correctly, without excessive movement of the
lever, and that it holds the vehicle stationary
on a slope.
15 Test the operation of the brake servo unit
as follows. Depress the footbrake four or five
times to exhaust the vacuum, then start the
engine. As the engine starts, there should be a
noticeable give in the brake pedal as vacuum
builds up. Allow the engine to run for at least
two minutes, and then switch it off. If the
brake pedal is now depressed again, it should
be possible to detect a hiss from the servo as
the pedal is depressed. After about four or five
applications, no further hissing should be
heard, and the pedal should feel considerably
harder.
14 Wheel alignment check
5
1 Accurate wheel alignment is essential for
positive, accurate steering, stable road
holding and to prevent abnormal tyre wear.
Wheel alignment checking is carried out with
the car loaded to its kerbside weight, and with
the tyre pressures correctly adjusted.
2 The front toe setting, front camber angle,
rear toe setting and rear camber angle are all
adjustable, but can only be checked using
specialised equipment; work of this nature
should therefore be entrusted to a garage or
suitably-equipped tyre specialist.
15 Exhaust system check
2
1 Park the vehicle on a level surface and
switch off the engine. Chock the front wheels,
then raise the rear of the vehicle and support
it securely on axle stands - refer to Jacking
and vehicle support in Reference.
2 With the engine cold (wait at least an hour
after switching off the engine), check the
complete exhaust system from the engine to
the end of the tailpipe.
3 Check the exhaust pipes and connections
for evidence of leaks, severe corrosion and
damage. Make sure that all brackets and
mountings are in good condition, and that all
relevant nuts and bolts are tight. Leakage at
any of the joints or in other parts of the system
will usually show up as a black, sooty stain in
the vicinity of the leak.
4 Rattles and vibrations can often be traced
to the exhaust system. Tap the silencer units
with a soft mallet and listen for noises caused
by corroded or displaced baffle material. Do
not strike the catalytic converter, as this may
damage the ceramic block inside.
5 Carefully rock the pipes and silencers from
side to side on their mountings. If the
components are able to come into contact
with the body or suspension parts, look for
broken or worn rubber mountings.
Every 20 000 miles or 2 years
16 Air filter element renewal
1
1 The air cleaner is located in the front righthand corner of the engine compartment.
2 Release the retaining clip and disconnect
the intake duct from the air cleaner housing.
3 Release the retaining clips then lift the air
cleaner cover and filter element out of position.
4 Wipe out the casing and the cover.
5 Fit the new filter, noting that the rubber
locating flange should be uppermost, and
secure the cover with the clips.
6 Reconnect the intake duct to the air cleaner
housing and secure it in position with the
retaining clip.
17 Pollen filter renewal
2
1 Open the bonnet and support it in the
upright position.
2 Carefully peel the rubber beading away
from the bulkhead seam, at the rear of the
engine compartment, on the drivers side of
the car (see illustration).
3510 Vauxhall/Opel Omega
17.2 Carefully peel the rubber beading
away from the bulkhead seam
Every 20 000 miles
1•13
17.3 Hinge the grille panel upwards
17.4a Release the clips . . .
17.4b . . . then withdraw the pollen filter
element
3 Hinge the grille panel upwards to expose
the pollen filter housing (see illustration).
4 Release the clips at either side of the
housing, then withdraw the pollen filter
element (see illustrations).
5 Slide the new filter element into the housing
and secure it in position with the clips.
6 Hinge the grille panel down over the
housing and press the rubber beading into
position on the bulkhead seam.
2 Lightly lubricate the bonnet release
mechanism and exposed section of inner
cable with a smear of grease.
3 Check the security and operation of all
hinges, latches and locks, adjusting them
where required. Check the operation of the
central locking system.
4 Check the condition and operation of the
tailgate/boot lid struts, renewing them both if
either is leaking or no longer able to support
the tailgate/boot lid securely when raised.
Unscrew the plug and clean it.
4 The oil level should reach the lower edge of
the level plug hole. If topping up is necessary,
add the specified type of oil through the level
plug hole until oil begins to trickle out.
5 Allow the excess oil to drain out then fit a
new sealing washer to the level plug and refit
it to the sump, tightening it to the specified
torque.
18 Lock and hinge lubrication
1
1 Work around the vehicle and lubricate the
hinges of the bonnet, doors and tailgate/boot
lid with a light machine oil.
19.3 Removing the automatic
transmission unit fluid level plug
19 Automatic transmission
fluid level check
3
1 The transmission fluid level must be
checked with the engine warm. For the check
to be accurate, Vauxhall state that the
transmission fluid temperature should ideally
be 60ºC but can be anywhere in the range of
45 to 85ºC (113 to 185ºF).
2 Take the vehicle on a short run to warm the
engine and transmission unit up to operating
temperature. On your return position the
vehicle over an inspection pit, on vehicle
ramps, or jack it up, but make sure that it is
level.
3 Start the engine and allow it to idle. Wipe
clean the area around the level plug which is
fitted to the right-hand side of the
transmission main sump (see illustration).
20 Handbrake shoe condition check
1 Refer to the information given in Chapter 9
for details.
21 Driveshaft gaiter condition check
2
1 Chock the front wheels, then jack up the rear
of the vehicle and support it on axle stands.
2 With the handbrake released turn each
wheel separately and check the driveshaft
rubber gaiters for splits and damage. Check
that the securing clips are in good condition
and shows no signs of damage or corrosion.
Driveshaft grease sprayed in a line along the
underside of the car, above the joint is a sign
that the gaiter has failed and requires renewal.
Every 40 000 miles or 4 years
22 Spark plugs renewal
3
1 The correct functioning of the spark plugs is
vital for the correct running and efficiency of
the engine. It is essential that the plugs fitted
are appropriate for the engine; suitable types
are specified at the beginning of this Chapter,
or in the vehicle’s Owner’s Handbook. If the
correct type is used and the engine is in good
condition, the spark plugs should not need
attention between scheduled replacement
intervals. Spark plug cleaning is rarely
necessary, and should not be attempted unless
specialised equipment is available, as damage
can easily be caused to the firing ends.
2 On 2.0 litre DOHC engines, undo the
retaining screws and lift off the spark plug
cover from the top of the camshaft cover (see
illustration).
3 On 2.5 and 3.0 litre engines, carry out the
following operations referring to Chapter 4A
for further information.
a) Remove the idle speed control valve.
b) On models with air conditioning, undo the
retaining bolt and remove the air
conditioning pipe retaining clip from the
left-hand cylinder head.
3510 Vauxhall/Opel Omega
22.2 On 2.0 litre DOHC engine remove the
spark plug cover to gain access to the plugs
1
1•14
Every 40 000 miles
22.4a Unclip the tool (arrowed) . . .
22.4b . . . and use it to pull the HT leads off
from the plugs (2.5 litre engine shown)
22.10 The multi-electrode plugs fitted as
standard should not be adjusted
c) Undo the bolts securing the wiring
harness cover to the inlet manifold and
position the harness clear of the left-hand
cylinder head spark plugs.
d) Unscrew the union nut and disconnect
the braking system servo unit vacuum
hose from the manifold.
e) To improve access to the plugs on the
right-hand cylinder head, unclip the
accelerator cable from its mounting
bracket then unbolt and remove the
mounting bracket from the inlet manifold.
4 On all engines, if the marks on the originalequipment spark plug (HT) leads cannot be
seen, mark the leads to correspond to the
cylinder the lead serves. Pull the leads from
the plugs by gripping the end fitting, not the
lead, otherwise the lead connection may be
fractured. On 2.0 litre DOHC engines and all
2.5 and 3.0 litre engines use the tool clipped
to one of the plug leads to pull the HT leads
from the plugs (see illustrations).
5 It is advisable to remove the dirt from the
spark plug recesses using a clean brush,
vacuum cleaner or compressed air before
removing the plugs, to prevent dirt dropping
into the cylinders.
6 Unscrew the plugs from the cylinder head
using a spark plug spanner, suitable box
spanner or a deep socket and extension bar.
Keep the socket aligned with the spark plug if it is forcibly moved to one side, the ceramic
insulator may be broken off. As each plug is
removed, examine it as follows.
7 Examination of the spark plugs will give a
good indication of the condition of the engine.
If the insulator nose of the spark plug is clean
and white, with no deposits, this is indicative
of a weak mixture or too hot a plug (a hot plug
transfers heat away from the electrode slowly,
a cold plug transfers heat away quickly).
8 If the tip and insulator nose are covered
with hard black-looking deposits, then this is
indicative that the mixture is too rich. Should
the plug be black and oily, then it is likely that
the engine is fairly worn, as well as the mixture
being too rich.
9 If the insulator nose is covered with light tan
to greyish-brown deposits, then the mixture is
correct and it is likely that the engine is in
good condition.
10 All engines are fitted with multi-electrode
plugs as standard by Vauxhall (see
illustration). On these plugs, the electrode
gaps are all preset and no attempt should be
made to bend the electrodes.
11 If non-standard single electrode plugs are
to be installed (this is not recommended), the
spark plug electrode gap is of considerable
importance. If the gap is too large or too
small, the size of the spark and its efficiency
will be seriously impaired and it will not
perform correctly under all engine speed and
load conditions. The gap should be set to the
value specified by the manufacturer.
12 To set the gap on a single electrode plug,
measure it with a feeler blade or spark plug
gap gauge and then carefully bend the outer
plug electrode until the correct gap is
achieved. The centre electrode should never
be bent, as this may crack the insulator and
cause plug failure, if nothing worse. If using
feeler blades, the gap is correct when the
appropriate-size blade is a firm sliding fit (see
illustrations).
13 Special spark plug electrode gap
adjusting tools are available from most motor
accessory shops, or from some spark plug
manufacturers (see illustration).
14 Before fitting the spark plugs, check that
the threaded connector sleeves are tight, and
that the plug exterior surfaces and threads are
clean.
22.12a If single electrode plugs are being
fitted, check the electrode gap using a
feeler gauge . . .
22.12b . . . or a wire gauge . . .
22.13 . . . and if necessary adjust the gap
by bending the electrode
3510 Vauxhall/Opel Omega
It is very often difficult to insert spark
plugs into their holes without crossthreading them. To avoid this possibility,
fit a short length of 5⁄16 inch internal
diameter rubber hose over the end of
the spark plug. The flexible hose acts as
a universal joint to help align the plug
with the plug hole. Should the plug
begin to cross-thread, the hose will slip
on the spark plug, preventing thread
damage to the aluminium cylinder head
Every 40 000 miles
1•15
necessary) the air conditioning pipe
bracket.
d) Refit the idle speed control valve.
23 Fuel filter renewal
22.17 On 2.0 litre DOHC engines refit the
spark plug cover and securely tighten its
retaining screws
15 Remove the rubber hose (if used), and
tighten the plug to the specified torque using
the spark plug socket and a torque wrench.
Refit the remaining spark plugs in the same
manner.
16 Securely reconnect the HT leads in their
correct order.
17 On 2.0 litre DOHC engines refit the spark
plug cover and securely tighten its retaining
screws (see illustration).
18 On 2.5 and 3.0 litre engines carry out the
following operations, referring to Chapter 4A
for further information.
a) Refit the accelerator cable bracket to the
manifold and adjust the accelerator cable.
b) Reconnect the servo unit vacuum hose to
the manifold and tighten to the specified
torque.
c) Refit the wiring cover bolts and (where
3
1 The fuel filter is located under the rear of the
vehicle, just in front of the fuel tank.
2 Depressurise the fuel system as described
in Chapter 4A.
3 Chock the front wheels, then jack up the
rear of the vehicle and support on axle stands
(see Jacking and Vehicle Support).
4 Release the retaining clip holding the filter
to the underbody. Before removing the filter,
note the orientation of the fuel flow direction
arrow (see illustration).
5 Position a suitable container below the fuel
filter, to catch spilt fuel.
6 Release the connectors and disconnect the
fuel hoses from the fuel filter, noting their
locations to ensure correct refitting (see
illustration). A Vauxhall/Opel special tool is
available to disconnect the hose connectors,
but provided care it taken, the connections
can be released using a pair of pliers or a
screwdriver. Be prepared for fuel spillage, and
take adequate fire precautions.
7 Withdraw the filter from under the vehicle.
8 Fit the quick-release fitting clips to the new
filter offer up the filter making sure the flow
23.6 Depress the quick-release fitting tabs and detach the hoses
from the fuel filter
direction arrow on the filter body pointing in
the direction of fuel flow (see illustration).
9 Securely clip both hoses onto the filter then
secure the filter in position with the retaining
clip.
10 Start the engine and check the filter hose
unions for signs of leaks. If leakage is evident,
stop the engine immediately and rectify the
problem without delay.
11 If all is well, stop the engine and lower the
vehicle to the ground.
24 Timing belt renewal
1 Refer to the information given in Chapter 2A, 2B or 2C (as applicable).
23.8 On refitting ensure the arrow (1) on the filter is pointing in
the direction of fuel flow and the quick-release fitting clips (2) are
correctly fitted
Every 70 000 miles or 7 years
25 Automatic transmission fluid
- renewal
23.4 Release the retaining clip and free
the fuel filter from the body
1 Renew the transmission fluid and filter
assembly as described in Section 2 of
Chapter 7B.
3510 Vauxhall/Opel Omega
1
1•16
Every 2 years
Every 2 years, regardless of mileage
26 Brake fluid renewal
3
Warning: Brake hydraulic fluid
can harm your eyes and damage
painted surfaces, so use extreme
caution when handling and pouring it. Do
not use fluid that has been standing open
for some time, as it absorbs moisture from
the air. Excess moisture can cause a
dangerous loss of braking effectiveness.
1 The procedure is similar to that for the
bleeding of the hydraulic system as described
in Chapter 9.
2 Working as described in Chapter 9, open
the first bleed screw in the sequence, and
pump the brake pedal gently until nearly all
the old fluid has been emptied from the
master cylinder reservoir. Top-up to the MAX
level with new fluid, and continue pumping
until only the new fluid remains in the
reservoir, and new fluid can be seen
emerging from the bleed screw. Tighten the
screw, and top the reservoir level up to the
MAX level line.
Old hydraulic fluid is
invariably much darker in
colour than the new, making
it easy to distinguish the
two.
3 Work through all the remaining bleed screws
in the sequence until new fluid can be seen at
all of them. Be careful to keep the master
cylinder reservoir topped-up to above the MIN
level at all times, or air may enter the system
and greatly increase the length of the task.
4 When the operation is complete, check that
all bleed screws are securely tightened, and
that their dust caps are refitted. Wash off all
traces of spilt fluid, and recheck the master
cylinder reservoir fluid level.
5 Check the operation of the brakes before
taking the car on the road.
27 Remote control keyfob
battery renewal
1
Caution: The following procedure must be
completed within 3 minutes, otherwise the
remote control unit will have to be reprogrammed.
1 Using a small flat-bladed screwdriver, prise
the battery cover from the remote control unit.
2 Note how the battery is fitted, then carefully
remove it from the contacts.
3 Fit the new battery and refit the cover
making sure that it clips fully onto the base.
5 If the coolant has been drained for a reason
other than renewal, then provided it is clean
and less than two years old, it can be re-used,
though this is not recommended.
Cooling system flushing
6 If coolant renewal has been neglected, or if
the antifreeze mixture has become diluted, then
in time, the cooling system may gradually lose
efficiency, as the coolant passages become
restricted due to rust, scale deposits, and other
sediment. The cooling system efficiency can be
restored by flushing the system clean.
7 The
radiator
should
be
flushed
independently of the engine, to avoid
unnecessary contamination.
Radiator flushing
28 Coolant renewal
3
Cooling system draining
Warning: Wait until the engine is
cold
before
starting
this
procedure. Do not allow antifreeze
to come in contact with your skin,
or with the painted surfaces of the vehicle.
Rinse off spills immediately with plenty of
water. Never leave antifreeze lying around
in an open container, or in a puddle in the
driveway or on the garage floor. Children
and pets are attracted by its sweet smell,
but antifreeze can be fatal if ingested.
1 With the engine completely cold, remove
the expansion tank filler cap. Turn the cap
anti-clockwise, wait until any pressure
remaining in the system is released, then
unscrew it and lift it off.
2 Where applicable, remove the engine
undershield, then position a suitable container
beneath the left hand side of the radiator.
3 Open the drain plug at the base of the
radiator, and allow the coolant to drain into
the container (see illustration).
4 When the flow of coolant stops, close the
drain plug securely.
8 Disconnect the top and bottom hoses and
any other relevant hoses from the radiator,
with reference to Chapter 3.
9 Insert a garden hose into the radiator top
inlet. Direct a flow of clean water through the
radiator, and continue flushing until clean
water emerges from the radiator bottom outlet.
10 If after a reasonable period, the water still
does not run clear, the radiator can be flushed
with a good proprietary cleaning agent. It is
important that the manufacturer’s instructions
are followed carefully. If the contamination is
particularly bad, remove the radiator, insert
the hose in the radiator bottom outlet, and
reverse-flush the radiator.
Engine flushing
11 Remove the thermostat as described in
Chapter 3 then, if the radiator top hose has
been disconnected from the engine, temporarily
reconnect the hose.
12 With the top and bottom hoses
disconnected from the radiator, insert a
garden hose into the radiator top hose. Direct
a clean flow of water through the engine, and
continue flushing until clean water emerges
from the radiator bottom hose.
13 On completion of flushing, refit the
thermostat and reconnect the hoses with
reference to Chapter 3.
Cooling system filling
14 Before attempting to fill the cooling
system, make sure that all hoses and clips are
in good condition, and that the clips are tight.
Note that an antifreeze mixture must be used
all year round, to prevent corrosion of the
engine components.
15 Remove the expansion tank filler cap, and
top the level up to the KALT/COLD mark.
6-cylinder engine models
28.3 Open the drain plug at the base of the
radiator (arrowed)
28.18 Slowly fill the system via the
expansion tank filler neck, until the coolant
level again reaches the KALT/COLD mark
on the side of the expansion tank
3510 Vauxhall/Opel Omega
16 Disconnect the heater supply (upper) hose
from the bulkhead connection (see Chapter 3).
17 Pour coolant into the disconnected heater
hose with the aid of a funnel, until no more
coolant will flow in, then reconnect the heater
hose to the bulkhead connection and tighten
the clip securely.
Every 2 years
18 Slowly fill the system via the expansion
tank filler neck, until the coolant level again
reaches the KALT/COLD mark on the side of
the expansion tank (see illustration).
All models
19 Refit and tighten the expansion tank filler
cap.
20 Start the engine, and allow it to run until it
reaches normal operating temperature (until
the cooling fan cuts in and out). The cooling
system will bleed automatically as the engine
warms up.
21 Stop the engine, and allow it to cool, then
re-check the coolant level with reference to
Weekly checks. Top-up the level if necessary
and refit the expansion tank filler cap. Where
applicable, refit the engine undershield.
Antifreeze mixture
22 The antifreeze should always be renewed
at the specified intervals. This is necessary
not only to maintain the antifreeze properties,
but also to prevent corrosion which would
otherwise occur as the corrosion inhibitors
become progressively less effective.
23 Always use an ethylene-glycol based
antifreeze which is suitable for use in mixedmetal cooling systems. The quantity of
antifreeze and levels of protection are given in
the Specifications.
1•17
24 Before adding antifreeze, the cooling
system should be completely drained,
preferably flushed, and all hoses checked for
condition and security.
25 After filling with antifreeze, a label should
be attached to the expansion tank, stating the
type and concentration of antifreeze used,
and the date installed. Any subsequent
topping-up should be made with the same
type and concentration of antifreeze.
26 Do not use engine antifreeze in the windscreen/tailgate washer system, as it will cause
damage to the vehicle paintwork. A screenwash additive should be added to the washer
system in the quantities stated on the bottle.
1
3510 Vauxhall/Opel Omega
2A•1
Chapter 2 Part A:
2.0 litre SOHC engine in-car repair procedures
Contents
Camshaft cover - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . 4
Camshaft followers and hydraulic tappets - removal, inspection and
refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Camshaft housing and camshaft - removal, inspection and refitting 10
Camshaft oil seal - renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Compression test - description and interpretation . . . . . . . . . . . . . . 2
Crankshaft oil seals - renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Crankshaft pulley - removal and refitting . . . . . . . . . . . . . . . . . . . . . . 5
Cylinder head - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . 12
Engine oil and filter - renewal . . . . . . . . . . . . . . . . . . . . .See Chapter 1
Engine oil level check . . . . . . . . . . . . . . . . . . . . . . .See Weekly checks
Engine/transmission mountings - inspection and renewal . . . . . . . . 17
Flywheel/driveplate - removal, inspection and refitting . . . . . . . . . . . 15
General information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Oil pump - removal, overhaul and refitting . . . . . . . . . . . . . . . . . . . . 14
Sump - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Timing belt - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Timing belt covers - removal and refitting . . . . . . . . . . . . . . . . . . . . . 6
Timing belt tensioner and sprockets - removal and refitting . . . . . . . 8
Top dead centre (TDC) for No 1 piston - locating . . . . . . . . . . . . . . . 3
Degrees of difficulty
Easy, suitable for
novice with little
experience
1
Fairly easy, suitable
for beginner with
some experience
2
Fairly difficult,
suitable for competent
DIY mechanic
3
Difficult, suitable for
experienced DIY
mechanic
4
Very difficult,
suitable for expert DIY
or professional
5
Specifications
2A
General
Engine type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Manufacturer’s engine code:
Models with a catalytic converter . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Models not fitted with a catalytic converter* . . . . . . . . . . . . . . . . . . .
Bore . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stroke . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Firing order . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Direction of crankshaft rotation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Compression ratio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Maximum power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Maximum torque . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
*This model was never available in the UK
Four-cylinder, in-line, water-cooled. Single overhead camshaft, beltdriven, acting on hydraulic tappets
X20SE
20SE
86 mm
86 mm
1998 cc
1-3-4-2 (No 1 cylinder at timing belt end)
Clockwise (viewed from timing belt end of engine)
10:1
85 kW at 5400 rpm
178 Nm at 2800 rpm
Compression pressures
Standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Maximum difference between any two cylinders . . . . . . . . . . . . . . . . . .
12 to 15 bar (174 to 218 psi)
1 bar (15 psi)
Camshaft
Endfloat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Maximum permissible radial run-out . . . . . . . . . . . . . . . . . . . . . . . . . . .
0.09 to 0.21 mm
0.04 mm
Lubrication system
Oil pump type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Minimum permissible oil pressure at idle speed, with engine
at operating temperature (oil temperature of at least 80°C) . . . . . . . .
Oil pump clearances:
Gear teeth clearance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Gear endfloat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Gear type, driven directly from crankshaft
1.5 bar (22 psi)
0.08 to 0.15 mm
0.03 to 0.10 mm
3510 Vauxhall/Opel Omega
2A•2 2.0 litre SOHC engine in-car repair procedures
Torque wrench settings
Camshaft cover bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Camshaft sprocket bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Camshaft thrustplate bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Camshaft housing end cover bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Connecting rod big-end bearing cap bolt:
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Coolant pump bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Crankcase breather tube bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Crankshaft pulley bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Crankshaft sensor rotor bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Crankshaft sprocket bolt:
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cylinder head bolts:
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Driveplate bolts:
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine/transmission mountings:
Left- and right-hand mountings:
Mounting-to-subframe nut . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Mounting-to-mounting bracket nut . . . . . . . . . . . . . . . . . . . . . . . . .
Mounting bracket-to-cylinder block bolts . . . . . . . . . . . . . . . . . . . .
Rear mounting:
Mounting-to-transmission bolts . . . . . . . . . . . . . . . . . . . . . . . . . . .
Mounting-to-crossmember nuts . . . . . . . . . . . . . . . . . . . . . . . . . . .
Crossmember-to-body bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine to transmission support bracket bolts:
Bracket-to-engine bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Bracket-to-transmission bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine-to-transmission unit bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Flywheel bolts:
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Main bearing cap bolts:
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oil filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oil pump:
Retaining bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pump cover screws . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oil pressure relief valve bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oil pump pick-up/strainer bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Spark plug heatshields . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Sump bolts:
Retaining bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Drain plug . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Timing belt cover bolts:
Outer cover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rear cover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Timing belt tensioner bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Nm
8
45
8
8
lbf ft
6
33
6
6
35
Angle-tighten a further 45°
Angle-tighten a further 15°
25
25
20
13
26
18
18
15
10
130
Angle-tighten a further 40 to 50°
96
25
Angle-tighten a further 90°
Angle-tighten a further 90°
Angle-tighten a further 90°
18
55
Angle-tighten a further 30°
Angle-tighten a further 15°
41
55
40
60
41
30
44
40
20
45
30
15
33
40
22
60
30
16
44
65
Angle-tighten a further 30°
Angle-tighten a further 15°
48
50
Angle-tighten a further 45°
Angle-tighten a further 15°
15
37
11
8
6
50
8
25
6
4
37
6
18
8
55
6
41
4
6
20
3
4
15
3510 Vauxhall/Opel Omega
2.0 litre SOHC engine in-car repair procedures 2A•3
1 General information
Repair operations possible with
the engine in the car
9 The following operations can be carried out
without having to remove the engine from the
vehicle:
How to use this Chapter
1 This Part of Chapter 2 is devoted to in-car
repair procedures for the engine. All
procedures concerning engine removal and
refitting, and engine block/cylinder head
overhaul can be found in Chapter 2D.
2 Most of the operations included in this Part
are based on the assumption that the engine
is still installed in the car. Therefore, if this
information is being used during a complete
engine overhaul, with the engine already
removed, many of the steps included here will
not apply.
Engine description
3 The engine is a single overhead camshaft,
four-cylinder, in-line unit, mounted at the front
of the car with the clutch/transmission (as
applicable) on its rear.
4 The cylinder block is of the dry-liner type.
The crankshaft is supported within the
cylinder block on five shell-type main
bearings. Thrustwashers are fitted to number
3 main bearing, to control crankshaft endfloat.
5 The connecting rods are attached to the
crankshaft by horizontally split shell-type bigend bearings, and to the pistons by
interference-fit gudgeon pins. The aluminium
alloy pistons are of the slipper type, and are
fitted with three piston rings, comprising two
compression rings and a scraper-type oil
control ring.
6 The camshaft runs directly in the camshaft
housing, which is mounted on top of the
cylinder head, and driven by the crankshaft
via a toothed rubber timing belt (which also
drives the coolant pump). The camshaft
operates each valve via a follower. Each
follower pivots on a hydraulic self-adjusting
valve lifter (tappet) which automatically
adjusts the valve clearance.
7 Lubrication is by pressure-feed from a
gear-type oil pump, which is mounted on the
front end of the crankshaft. It draws oil
through a strainer located in the sump, and
then forces it through an externally mounted
full-flow cartridge-type filter. The oil flows into
galleries in the main bearing cap bridge
arrangement and cylinder block/crankcase,
from where it is distributed to the crankshaft
(main bearings) and camshaft. The big-end
bearings are supplied with oil via internal
drillings in the crankshaft, while the camshaft
bearings also receive a pressurised supply.
The camshaft lobes and valves are lubricated
by splash, as are all other engine
components.
8 A semi-closed crankcase ventilation system
is employed; crankcase fumes are drawn from
cylinder head cover, and passed via a hose to
the inlet manifold.
a) Removal and refitting of the cylinder
head.
b) Removal and refitting of the timing belt
and sprockets.
c) Renewal of the camshaft oil seal.
d) Removal and refitting of the camshaft
housing and camshaft.
e) Removal and refitting of the sump.
f) Removal and refitting of the connecting
rods and pistons*.
g) Removal and refitting of the oil pump.
h) Renewal of the crankshaft oil seals.
i) Renewal of the engine mountings.
j) Removal and refitting of the
flywheel/driveplate.
* Although the operation marked with an
asterisk can be carried out with the engine in
the car after removal of the sump, it is better
for the engine to be removed, in the interests
of cleanliness and improved access. For this
reason, the procedure is described in
Chapter 2D.
2 Compression test description and interpretation
3
1 When engine performance is down, or if
misfiring occurs which cannot be attributed to
the ignition or fuel systems, a compression
test can provide diagnostic clues as to the
engine’s condition. If the test is performed
regularly, it can give warning of trouble before
any other symptoms become apparent.
2 The engine must be fully warmed-up to
normal operating temperature, the battery
must be fully charged, and the spark plugs
must be removed (see Chapter 1). The aid of
an assistant will also be required.
3 Ensure the ignition is switched off then
disable the ignition system by disconnecting
the wiring connector from the DIS module
(see Chapter 5B) and the fuel system by
removing the fuel pump relay from the engine
compartment relay box (see Chapter 4A,
Section 13).
4 Fit a compression tester to the number 1
cylinder spark plug hole the type of tester
which screws into the plug thread is to be
preferred.
5 Have the assistant hold the throttle wide
open and crank the engine on the starter
motor; after one or two revolutions, the
compression pressure should build up to a
maximum figure, and then stabilise. Record
the highest reading obtained.
6 Repeat the test on the remaining cylinders,
recording the pressure in each.
7 All cylinders should produce very similar
pressures; any difference greater than that
3510 Vauxhall/Opel Omega
specified indicates the existence of a fault.
Note that the compression should build up
quickly in a healthy engine; low compression
on the first stroke, followed by graduallyincreasing pressure on successive strokes,
indicates worn piston rings. A low
compression reading on the first stroke, which
does not build up during successive strokes,
indicates leaking valves or a blown head
gasket (a cracked head could also be the
cause). Deposits on the undersides of the
valve heads can also cause low compression.
8 If the pressure in any cylinder is reduced to
the specified minimum or less, carry out the
following test to isolate the cause. Introduce a
teaspoonful of clean oil into that cylinder
through its spark plug hole, and repeat the
test.
9 If the addition of oil temporarily improves
the compression pressure, this indicates that
bore or piston wear is responsible for the
pressure loss. No improvement suggests that
leaking or burnt valves, or a blown head
gasket, may be to blame.
10 A low reading from two adjacent cylinders
is almost certainly due to the head gasket
having blown between them; the presence of
coolant in the engine oil will confirm this.
11 If one cylinder is about 20 per cent lower
than the others, and the engine has a slightly
rough idle, a worn camshaft lobe could be the
cause.
12 If the compression reading is unusually
high, the combustion chambers are probably
coated with carbon deposits. If this is the
case, the cylinder head should be removed
and decarbonised.
13 On completion of the test, refit the spark
plugs (see Chapter 1), refit the fuel pump relay
and reconnect the wiring connector to the DIS
module.
3 Top dead centre
(TDC) for No 1 piston locating
3
1 In its travel up and down its cylinder bore,
Top Dead Centre (TDC) is the highest point
that each piston reaches as the crankshaft
rotates. While each piston reaches TDC both
at the top of the compression stroke and
again at the top of the exhaust stroke, for the
purpose of timing the engine, TDC refers to
the piston position (usually number 1) at the
top of its compression stroke.
2 Number 1 piston (and cylinder) is at the
front (timing belt) end of the engine, and its
TDC position is located as follows. Note that
the crankshaft rotates clockwise when viewed
from the front of the vehicle.
3 Disconnect the battery negative terminal. If
necessary, remove all the spark plugs as
described in Chapter 1 to enable the engine to
be easily turned over.
4 To gain access to the camshaft sprocket
timing mark, remove the timing belt outer
cover as described in Section 6.
2A
2A•4 2.0 litre SOHC engine in-car repair procedures
5 Using a socket and extension bar on the
crankshaft sprocket bolt, turn the crankshaft
whilst keeping an eye on the camshaft
sprocket. Rotate the crankshaft until the
timing mark on the camshaft sprocket is
correctly aligned with the cutout on the top of
the timing belt rear cover and the mark on the
crankshaft sprocket rim is correctly aligned
with the cutout on the oil pump housing (see
illustration).
6 With the crankshaft pulley and camshaft
sprocket timing marks positioned as
described, the engine is positioned with No1
piston at TDC on its compression stroke.
4 Camshaft cover removal and refitting
2
not lever between the cover and camshaft
housing mating surfaces - if necessary, gently
tap the cover sideways to free it. Recover the
gasket; if it shows signs of damage or
deterioration it must be renewed.
Removal
Refitting
1 Release the retaining clip and disconnect
the breather hose from the camshaft cover.
2 Slacken and remove the retaining bolts,
noting the correct fitted location of any clips
or brackets retained by the bolts (as
applicable) then lift the camshaft cover from
the camshaft housing. If the cover is stuck, do
3 Prior to refitting, examine the inside of the
cover for a build-up of oil sludge or any other
contamination, and if necessary clean the
cover with paraffin, or a water-soluble solvent.
Examine the condition of the crankcase
ventilation filter inside the camshaft cover,
and clean as described for the inside of the
cover if clogging is evident (if desired, the filter
can be removed from the cover, after
removing the securing bolts). Dry the cover
thoroughly before refitting.
4 Ensure the cover is clean and dry and seat
the gasket in the cover recess then refit the
cover to the camshaft housing, ensuring the
gasket remains correctly seated.
5 Refit the retaining bolts, ensuring all relevant
clips/brackets are correctly positioned, and
tighten them to the specified torque working in
a diagonal sequence.
6 Reconnect the breather hose securely to
the cover.
5 Crankshaft pulley removal and refitting
2
Removal
1 Remove the auxiliary drivebelt as described
in Chapter 1. Prior to removal, mark the
direction of rotation on the belt to ensure the
belt is refitted the same way around.
2 Slacken and remove the small retaining
bolts securing the pulley to the crankshaft
sprocket and remove the pulley from the
engine. If necessary, prevent crankshaft
rotation by holding the sprocket retaining bolt
with a suitable socket.
Refitting
3 Seat the crankshaft pulley on the sprocket
and tighten its retaining bolts to the specified
torque.
4 Refit the auxiliary drivebelt as described in
Chapter 1 using the mark made prior to removal
to ensure the belt is fitted the correct way
around.
6 Timing belt covers removal and refitting
3
Outer cover
Removal
3.5 Align the camshaft sprocket timing mark with the cutout on the timing belt cover (1)
and align the crankshaft sprocket mark with the cutout on the oil pump housing (2) to
position No1 piston at TDC on its compression stroke
3510 Vauxhall/Opel Omega
1 Remove the crankshaft pulley as described
in Section 5.
2 Undo the retaining bolt and free the wiring
harness guide from the top of the timing belt
cover.
2.0 litre SOHC engine in-car repair procedures 2A•5
7.3 Slacken the timing belt tensioner bolt (1) and rotate the
tensioner clockwise using an Allen key in the arm cutout (2)
3 Undo the remaining retaining bolts then
unclip the timing belt outer cover and remove
it from the engine.
Refitting
4 Refitting is the reverse of removal, ensuring
the auxiliary drivebelt is fitted the same way
around as it was prior removal.
Rear cover
Removal
5 Remove the camshaft and crankshaft
timing belt sprockets and the timing belt
tensioner as described in Section 8.
6 Free the crankshaft sensor wiring from the
base of the timing belt rear cover, noting its
correct routing.
7 Slacken and remove the bolts securing the
rear cover to the camshaft housing and oil
pump housing and remove the cover from the
engine.
Refitting
8 Refitting is the reverse of removal,
tightening the cover retaining bolts to the
specified torque. Ensure the crankshaft
sensor wiring is correctly routed before
refitting the timing belt components.
7.8 Tension the belt by rotating the tensioner arm fully anticlockwise until the pointer is positioned as shown
2 Position No 1 cylinder at TDC on its
compression stroke as described in Section 3.
3 Slacken the timing belt tensioner bolt.
Using an Allen key, rotate the tensioner arm
clockwise to its stop, to relieve the tension in
the timing belt, and hold it in position by
securely tighten the retaining bolt (see
illustration).
4 Slide the timing belt off from its sprockets
and remove it from the engine. If the belt is to
be re-used, use white paint or similar to mark
the direction of rotation on the belt. Do not
rotate the crankshaft or camshaft until the
timing belt has been refitted.
5 Check the timing belt carefully for any signs
of uneven wear, splitting or oil contamination,
and renew it if there is the slightest doubt
about its condition. If the engine is undergoing
an overhaul and has covered 40 000 miles or
it was more than 4 years since the original belt
was fitted, renew the belt as a matter of
course, regardless of its apparent condition
(from 1997 onwards the belt renewal interval
was increased to 80 000 miles or 8 years). If
signs of oil contamination are found, trace the
source of the oil leak and rectify it, then wash
down the engine timing belt area and all
related components to remove all traces of oil.
Refitting
7 Timing belt removal and refitting
3
Note: The timing belt must be removed and
refitted with the engine cold.
Removal
1 Disconnect the battery negative terminal
then remove the timing belt outer cover as
described in Section 6. Note: On models with
a Vauxhall anti-theft warning system (ATWS),
the battery negative terminal must be
disconnected within 15 seconds of the
ignition being switched off to prevent the
alarm system being triggered.
6 On reassembly, thoroughly clean the timing
belt sprockets then check that the camshaft
sprocket timing mark is still correctly aligned
with the rear cover cutout and the crankshaft
sprocket mark is still aligned with the mark on
the oil pump housing.
7 Fit the timing belt over the crankshaft and
camshaft sprockets, ensuring that the belt
left-hand run is taut (ie, all slack is on the
tensioner pulley side of the belt), then fit the
belt over the coolant pump sprocket and
tensioner pulley. Do not twist the belt sharply
while refitting it. Ensure that the belt teeth are
correctly seated centrally in the sprockets,
and that the timing marks remain in alignment.
If a used belt is being refitted, ensure that the
3510 Vauxhall/Opel Omega
arrow mark made on removal points in the
normal direction of rotation, as before.
8 Slacken the timing belt tensioner bolt to
release the tensioner spring. Rotate the
tensioner arm anti-clockwise until the
tensioner pointer is fully over against its stop,
without exerting any excess strain on the belt
(see illustration). Hold the tensioner in
position and securely tighten its retaining bolt.
9 Check the sprocket timing marks are still
correctly aligned. If adjustment is necessary,
release the tensioner again then disengage
the belt from the sprockets and make any
necessary adjustments.
10 Using a socket on the crankshaft sprocket
bolt, rotate the crankshaft smoothly through
two complete turns (720º) in the normal
direction of rotation to settle the timing belt in
position.
11 Check that both the camshaft and
crankshaft sprocket timing marks are
correctly realigned then slacken the tensioner
bolt again.
12 If a new timing belt is being fitted, adjust
the tensioner so that the pointer is aligned
with either the cutout or NEW marking
(depending on type of tensioner fitted) on the
backplate (see illustration). Hold the
tensioner in the correct position and tighten
its retaining bolt to the specified torque.
Rotate the crankshaft smoothly through
another two complete turns in the normal
direction of rotation, to bring the sprocket
timing marks back into alignment. Check that
the tensioner pointer is still aligned with the
backplate cutout/marking (as applicable).
13 If the original belt is being refitted, adjust
the tensioner so that the pointer is either
positioned 4 mm to the left of the cutout or is
aligned with the USED marking (depending on
the type of tensioner fitted) on the backplate
(see illustration 7.12). Hold the tensioner in
the correct position and tighten its retaining
bolt to the specified torque. Rotate the
crankshaft smoothly through another two
complete turns in the normal direction of
2A
2A•6 2.0 litre SOHC engine in-car repair procedures
this can be achieved in one of two ways as
follows.
a) Make up a sprocket-holding tool using
two lengths of steel strip (one long, the
other short), and three nuts and bolts; one
nut and bolt forms the pivot of a forked
tool, with the remaining two nuts and
bolts at the tips of the ‘forks’ to engage
with the sprocket spokes as shown (see
illustration).
b) Remove the camshaft cover as described
in Section 4 and hold the camshaft with
an open-ended spanner on the flats
provided.
3 Unscrew the retaining bolt and washer and
remove the sprocket from the end of the
camshaft.
Refitting
4 Prior to refitting check the oil seal for signs
of damage or leakage, if necessary, renewing
it as described in Section 9.
5 Refit the sprocket to the end of the
camshaft, aligning its cutout with the
camshaft locating pin, then refit the retaining
bolt and washer (see illustration).
6 Tighten the sprocket retaining bolt to the
specified torque whilst prevent rotation using
the method employed on removal.
7 Refit the timing belt as described in Section
7 then (where necessary) refit the camshaft
cover as described in Section 4.
7.12 Ensure the timing belt tensioner arm (1) is correctly positioned in relation to the
backplate cutout/marking (2) as described in text
A Correct position for new belt - engines
with an unmarked tensioner
B Correct position for new belt - engines
with a marked tensioner
rotation, to bring the sprocket timing marks
back into alignment. Check that the tensioner
pointer is still correctly positioned in relation to
the backplate cutout/marking (as applicable).
14 If the tensioner pointer is not correctly
positioned in relation to the backplate, repeat
the procedure in paragraph 12 (new belt) or 13
(original belt) (as applicable).
15 Once the tensioner arm and backplate
remain correctly aligned, refit the timing belt
cover and crankshaft pulley as described in
Sections 5 and 6.
C Correct position for used belt - engines
with an unmarked tensioner
D Correct position for used belt - engines
with a marked tensioner
8 Timing belt tensioner
and sprockets removal and refitting
3
Camshaft sprocket
Removal
1 Remove the timing belt as described in
Section 7.
2 The camshaft must be prevented from
turning as the sprocket bolt is unscrewed, and
Crankshaft sprocket
Note: A new crankshaft sprocket retaining
bolt will be required on refitting.
Removal
8 Remove the timing belt as described in
Section 7.
9 The crankshaft must be prevented from
turning as the sprocket bolt is unscrewed (the
bolt is very tight), and this can be achieved in
anyone of the following ways.
a) Use the holding tool described in
paragraph 2 securing the tool to the
sprocket with two bolts screwed into
opposite pulley retaining bolt holes.
b) On manual transmission models have an
assistant select top gear and apply the
brakes firmly.
c) If the engine is removed from the vehicle
or the transmission unit has been
removed the flywheel/driveplate can be
locked as described in Section 15.
10 Unscrew the retaining bolt and washer
and remove the crankshaft sprocket from the
end of the crankshaft. Discard the bolt; a new
one must be used on refitting. If necessary,
remove the sprocket Woodruff key from the
crankshaft end and slide off the spacer.
Refitting
8.2 Using a home-made sprocket holding
tool to retain the camshaft sprocket whilst
the bolt is slackened
8.5 Refit the camshaft sprocket making
sure the locating pin (1) engages with the
sprocket hole (2)
3510 Vauxhall/Opel Omega
11 Slide the spacer (where removed) onto the
crankshaft then refit the Woodruff key to the
crankshaft slot.
12 Align the sprocket with the key and slide it
into position, ensuring the sprocket flange is
facing outwards. Fit the washer and new
retaining bolt.
2.0 litre SOHC engine in-car repair procedures 2A•7
13 Lock the crankshaft by the method used
on removal, and tighten the sprocket retaining
bolt to the specified stage 1 torque setting
then angle-tighten the bolt through the
specified stage 2 angle, using a socket and
extension bar. It is recommended that an
angle-measuring gauge is used during the
final stages of the tightening, to ensure
accuracy. If a gauge is not available, use white
paint to make alignment marks between the
bolt head and sprocket prior to tightening; the
marks can then be used to check that the bolt
has been rotated through the correct angle.
14 Refit the timing belt as described in
Section 7.
Tensioner assembly
Removal
15 Remove the timing belt as described in
Section 7.
16 Slacken and remove the retaining bolt and
remove the tensioner assembly from the
engine.
9.2 Removing the camshaft oil seal
9.4 Fitting a new camshaft oil seal
engine oil, and press it into position using a
suitable tubular drift (such as a socket) which
bears only on the hard outer edge of the seal
(see illustration). Take care not to damage
the seal lips during fitting; note that the seal
lips should face inwards.
5 Refit the camshaft sprocket as described in
Section 8.
whether this is a chance worth taking.
2 With the camshaft housing removed, undo
the retaining bolts and remove the end cover
and gasket from the rear of the housing.
Discard the gasket, a new one should be used
on refitting.
3 Measure the camshaft endfloat by inserting
feeler gauges between the thrustplate and the
camshaft; if the endfloat is not within the limits
given in the Specifications then the thrustplate
will need to be renewed. Unscrew the two
retaining bolts then slide out the camshaft
thrustplate, noting which way round it is fitted
(see illustrations).
4 Carefully withdraw the camshaft from the
rear of the housing, taking care not to damage
the bearing journals (see illustration).
Refitting
17 Fit the tensioner to the engine, making
sure that the lug on the backplate is correctly
located in the oil pump housing hole. Ensure
the tensioner is correctly seated then refit the
retaining bolt. Using an Allen key, rotate the
tensioner arm clockwise to its stop then
securely tighten the retaining bolt.
18 Refit the timing belt as described in
Section 7.
9 Camshaft oil seal renewal
3
1 Remove the camshaft sprocket as
described in Section 8.
2 Carefully punch or drill two small holes
opposite each other in the oil seal. Screw a
self-tapping screw into each, and pull on the
screws with pliers to extract the seal (see
illustration).
3 Clean the seal housing, and polish off any
burrs or raised edges which may have caused
the seal to fail in the first place.
4 Lubricate the lips of the new seal with clean
10.3a Undo the retaining bolts
(arrowed) . . .
10 Camshaft housing and
camshaft - removal,
inspection and refitting
4
Removal
1 The camshaft can only be removed once
the camshaft housing has been removed from
the engine. Since the camshaft housing is
secured in position by the cylinder head bolts,
it is not possible to remove the camshaft
without removing the cylinder head (see
Section 12). Note: In theory it is possible to
remove the camshaft housing once the
cylinder head bolts have been removed, and
leave the head in position. However, this
procedure carries a high risk of disturbing the
head gasket, resulting in the head gasket
blowing once the camshaft and housing are
refitted. If you wish to attempt this, proceed as
described in Section 12, noting that it will not
be necessary to remove the manifolds, etc. Be
warned though that after refitting, you may
find the head gasket will need renewing,
meaning that the cylinder head will have to be
removed after all. The decision is yours as to
10.3b . . . then remove the thrustplate . . .
3510 Vauxhall/Opel Omega
Inspection
5 With the camshaft removed, examine the
bearings in the camshaft housing for signs of
obvious wear or pitting. If evident, a new
camshaft housing will probably be required.
Also check that the oil supply holes in the
camshaft housing are free from obstructions.
6 The camshaft itself should show no marks
or scoring on the journal or cam lobe
surfaces. If evident, renew the camshaft. If the
camshaft lobes show signs of wear also
examine the followers (see Section 11). Check
the camshaft thrustplate for signs of wear or
grooves, and renew if necessary.
Refitting
7 Carefully prise the old seal out of from the
camshaft housing, using a suitable
10.4 . . . and slide the camshaft out from
the housing
2A
2A•8 2.0 litre SOHC engine in-car repair procedures
11.8a Remove each follower . . .
11.8b . . . thrust pad . . .
11.8c . . . and hydraulic tappet from the
cylinder head
screwdriver. Ensure the housing is clean then
press the in new seal, ensuring its sealing lip
is facing inwards, until it is flush with the
housing.
8 Liberally lubricate the camshaft and
housing bearings and the oil seal lip with fresh
engine oil.
9 Carefully insert the camshaft into the
housing, taking care not to mark the bearing
surfaces or damage the oil seal lip.
10 Slide the thrustplate into position, engaging it with the camshaft slot, and tighten its
retaining bolts to the specified torque. Check
the camshaft endfloat (see paragraph 3).
11 Ensure the mating surfaces are clean and
dry and fit a new gasket to the rear of the
housing. Refit the cover and tighten its
retaining bolts to the specified torque.
12 Refit the camshaft housing as described
in Section 12.
5 Lubricate the tappet and follower with fresh
engine oil then slide the tappet into its bore in
the cylinder head. Manoeuvre the follower into
position, ensuring it is correctly engaged with
the tappet and valve stem, then carefully
remove the service tool.
6 Repeat the operation on the remaining
followers and tappets then refit the spark
plug(s) (see Chapter 1).
follower bearing surface is badly scored, also
examine the corresponding lobe on the
camshaft for wear, as it is likely that both will
be worn. Also check the thrust pad for signs
of wear or damage. Renew worn components
as necessary.
10 If the hydraulic tappets are thought to be
faulty they should be renewed; testing of the
tappets is not possible.
Without special tool
Refitting
Removal
11 Lubricate the hydraulic tappets and their
cylinder head bores with clean engine oil.
Refit the tappets to the cylinder head, making
sure they are fitted in their original locations.
12 Fit each thrust pad to the top of its
respective valve.
13 Lubricate the followers with clean engine
oil. Fit each follower, making sure it is
correctly located with both the tappet and
thrust pad, then refit the camshaft housing
(see Section 10).
11 Camshaft followers and
hydraulic tappets - removal,
inspection and refitting
4
7 Without the use of the special tool, it will be
necessary to remove the camshaft housing to
allow the followers and tappets to be removed
(see Section 10, paragraph 1).
8 With the housing removed, obtain eight
small, clean plastic containers, and number
them 1 to 8; alternatively, divide a larger
container into eight compartments. Lift out
each follower, thrust pad and hydraulic tappet
in turn, and place them in their respective
container (see illustrations). Do not
interchange the cam followers, or the rate of
wear will be much-increased.
12 Cylinder head removal and refitting
Inspection
Using Vauxhall service tool
(tool no. KM-565)
1 If access to the special tool (KM-565) or a
suitable equivalent can be gained, the cam
followers and tappets can be removed as
follows, without disturbing the camshaft.
2 Remove the camshaft cover as described in
Section 4.
3 Using a socket and extension bar, rotate the
crankshaft in the normal direction of rotation
until the camshaft lobe of the first follower/
tappet to be removed is pointing straight
upwards. Remove the spark plug from the
corresponding cylinder (see Chapter 1).
4 Fit the service tool to the top of the
camshaft housing, making sure the tool end is
correctly engaged with the top of the valve.
Screw the tool stud into one of the housing
bolt holes until the valve is sufficiently
depressed to allow the follower to be slid out
from underneath the camshaft. The hydraulic
tappet can then also be removed as can the
thrust pad from the top of the valve. Inspect
the components (see paragraphs 10 and 11)
and renew if worn or damaged.
9 Examine the cam follower bearing surfaces
which contact the camshaft lobes for wear
ridges and scoring. Renew any follower on
which these conditions are apparent. If a
12.3 Prior to removing the timing belt,
rotate the crankshaft 60º backwards to
ensure the camshaft and pistons are safely
positioned
3510 Vauxhall/Opel Omega
4
Removal
Note: The engine must be cold when
removing the cylinder head. New cylinder
head bolts must be used on refitting.
1 Disconnect the battery negative lead. Note:
On models with a Vauxhall anti-theft warning
system (ATWS), the battery negative terminal
must be disconnected within 15 seconds of
the ignition being switched off to prevent the
alarm system being triggered.
2 Drain the cooling system and remove the
spark plugs and auxiliary drivebelt as
described in Chapter 1.
3 Remove the timing belt as described in
Section 7. Prior to releasing the timing belt
tension and removing the belt, rotate the
crankshaft backwards by approximately 60º
(4 teeth of movement); this will position the
camshaft so that the valve spring pressure is
evenly exerted along its the complete length,
preventing the shaft turning and reducing the
risk of the valves contacting the pistons (see
illustration).
2.0 litre SOHC engine in-car repair procedures 2A•9
4 Remove the inlet and exhaust manifolds as
described in Chapter 4A. If no work is to be
carried out on the cylinder head, the head can
be removed complete with manifolds once the
following operations have been carried out
(see Chapters 4A and 4B).
a) Remove the duct linking the air cleaner to
the throttle housing.
b) Disconnect the wiring connectors from
the throttle potentiometer, idle speed
adjuster, injectors, EGR valve, purge valve
and oxygen sensor. Unbolt the earth
connection from the fuel rail and release
all wiring from the inlet manifold.
c) Depressurise the fuel system then
disconnect the fuel hoses from the fuel
rail.
d) Disconnect the various vacuum and
coolant hoses from the inlet
manifold/throttle housing.
e) Unbolt the inlet manifold support bracket
and the alternator upper bracket.
f) Disconnect the accelerator cable.
g) Unbolt the exhaust front pipe from the
manifold and its mounting bracket.
5 Remove the camshaft cover as described in
Section 4.
6 Remove the camshaft sprocket as
described in Section 8.
7 Undo the retaining bolts securing the timing
belt rear cover to the camshaft housing.
8 Disconnect the wiring connectors from the
DIS module, the coolant temperature sensor,
the knock sensor and the crankshaft sensor.
Undo the bolt(s) securing the earth lead(s) to
the front of the cylinder head then position the
wiring cover assembly clear of the cylinder
head.
9 Slacken the retaining clips and disconnect
the coolant hoses from the thermostat
housing on the front end of the cylinder head.
Also disconnect the wiring connector from the
coolant temperature gauge sender unit on the
left-hand side of the thermostat housing.
10 Make a final check to ensure that all
relevant hoses, pipes and wires, etc, have
been disconnected.
11 Working in the reverse of the tightening
sequence
(see
illustration
12.29),
progressively slacken the cylinder head bolts
by a quarter of a turn at a time until all bolts
can be unscrewed by hand. Remove each
bolt in turn, along with its washer.
12 Lift the camshaft housing from the
cylinder head. If necessary, tap the housing
gently with a soft-faced mallet to free it from
the cylinder head, but do not lever at the
mating faces. Note the fitted positions of the
two locating dowels, and remove them for
safe keeping if they are loose.
13 Lift the cylinder head from the cylinder
block, taking care not to dislodge the cam
followers or thrust pads. If necessary, tap the
cylinder head gently with a soft-faced mallet
to free it from the block, but do not lever at
the mating faces. Note the fitted positions of
the two locating dowels, and remove them for
safe keeping if they are loose.
12.21 Fit the new gasket to the cylinder
block, engaging it with the locating dowels
(arrowed) . . .
12.22 . . . making sure its OBEN/TOP
marking is uppermost
14 Recover the cylinder head gasket, and
discard it.
block, making sure it is fitted with the correct
way up with its OBEN or TOP mark
uppermost and at the front end of the engine
(see illustration).
23 Carefully refit the cylinder head, locating it
on the dowels.
24 Ensure the mating surfaces of the cylinder
head and camshaft housing are clean and dry
and that all the camshaft followers are
correctly located with the tappets and thrust
pad.
25 Apply a bead of suitable sealant (Vauxhall
recommend the use of sealant 15 03 170 available from your Vauxhall dealer) to the
cylinder head mating surface (see
illustration).
26 Ensure the two locating dowels are in
position then lubricate the camshaft followers
with clean engine oil.
27 Carefully lower the camshaft housing
assembly into position, locating it on the
dowels.
28 Fit the washers to the new cylinder head
bolts then carefully insert them into position
(do not drop), tightening them finger-tight
only at this stage.
29 Working progressively and in the
sequence shown, first tighten all the cylinder
head bolts to the stage 1 torque setting (see
illustration).
30 Once all bolts have been tightened to the
stage 1 torque, again working in the sequence
shown, tighten each bolt through its specified
stage 2 angle, using a socket and extension bar.
Preparation for refitting
15 The mating faces of the cylinder head and
block must be perfectly clean before refitting
the head. Use a scraper to remove all traces
of gasket and carbon, and also clean the tops
of the pistons. Take particular care with the
aluminium surfaces, as the soft metal is
damaged easily. Also, make sure that debris
is not allowed to enter the oil and water
channels - this is particularly important for the
oil circuit, as carbon could block the oil supply
to the camshaft or crankshaft bearings. Using
adhesive tape and paper, seal the water, oil
and bolt holes in the cylinder block. To
prevent carbon entering the gap between the
pistons and bores, smear a little grease in the
gap. After cleaning the piston, rotate the
crankshaft so that the piston moves down the
bore, then wipe out the grease and carbon
with a cloth rag. Clean the piston crowns in
the same way.
16 Check the block and head for nicks, deep
scratches and other damage. If slight, they
may be removed carefully with a file. More
serious damage may be repaired by
machining, but this is a specialist job.
17 If warpage of the cylinder head is
suspected, use a straight-edge to check it for
distortion. Refer to Chapter 2D if necessary.
18 Ensure that the cylinder head bolt holes in
the crankcase are clean and free of oil.
Syringe or soak up any oil left in the bolt
holes. This is most important in order that the
correct bolt tightening torque can be applied
and to prevent the possibility of the block
being cracked by hydraulic pressure when the
bolts are tightened.
19 Renew the cylinder head bolts regardless
of their apparent condition.
Refitting
20 Ensure the crankshaft is till positioned
approximately 60º BTDC and wipe clean the
mating faces of the head and block.
21 Ensure that the two locating dowels are in
position at each end of the cylinder
block/crankcase surface (see illustration).
22 Fit the new cylinder head gasket to the
3510 Vauxhall/Opel Omega
12.25 Apply sealant to the cylinder head
upper mating surface then refit the
camshaft housing
2A
2A•10 2.0 litre SOHC engine in-car repair procedures
12.29 Cylinder head bolt tightening sequence
It is recommended that an angle-measuring
gauge is used during this stage of the tightening,
to ensure accuracy (see illustration).
31 Working in the specified sequence, go
around again and tighten all bolts through the
specified stage 3 angle.
32 Finally go around in the specified
sequence again and tighten all bolts through
the specified stage 4 angle.
33 Refit the bolts securing the timing belt
rear cover to the camshaft housing and
tighten them to the specified torque.
34 Refit the camshaft sprocket as described
in Section 8.
35 Align all the sprocket timing marks to
bring the camshaft and crankshaft back to
TDC (see Section 3) then refit the timing belt
as described in Section 7.
36 Reconnect the wiring connectors to the
cylinder head components, ensuring all wiring
is correctly routed, and secure it in position
with the necessary clips.
37 Reconnect the coolant hoses to the
thermostat housings and securely tighten the
retaining clips.
38 Refit/reconnect the manifolds as
described in Chapter 4A.
39 Refit the undercover then lower the
vehicle to the floor.
40 Ensure all pipes and hoses are securely
reconnected then refill the cooling system and
refit the spark plugs as described in Chapter 1.
41 Reconnect the battery then start the
engine and check for signs of leaks.
13 Sump removal and refitting
3
Removal
Note: A new baffle plate will be required on
refitting (the sump gasket is an integral part of
the plate).
12.30 Working in the specified sequence, tighten the cylinder
head bolts to the specified stage 1 torque setting and then
through the various specified angles (see text)
1 Disconnect the battery negative terminal.
Note: On models with a Vauxhall anti-theft
warning system (ATWS), the battery negative
terminal must be disconnected within 15
seconds of the ignition being switched off to
prevent the alarm system being triggered.
2 Firmly apply the handbrake then jack up the
front of the car and support it on axle stands.
Undo the retaining screws and remove the
undercover from beneath the engine.
3 Drain the engine oil as described in Chapter
1, then fit a new sealing washer and refit the
drain plug, tightening it to the specified
torque.
4 Where necessary, disconnect the wiring
connector from the oil level sender unit on the
sump.
5 Slacken and remove the bolts securing the
support brackets to the transmission housing
and sides of the cylinder block. Remove both
brackets from the engine then remove the
flywheel lower cover plate from the base of
the transmission housing.
6 Slacken and remove the nuts securing the
left- and right-hand engine mounting brackets
to the top of the rubber mountings. Unbolt the
right-hand mounting bracket and remove it
from the cylinder block.
7 Attach an engine hoist to the cylinder head
lifting brackets then raise the hoist until it is
supporting the weight of the engine.
8 Progressively slacken and remove the bolts
securing the sump to the base of the cylinder
block/oil pump. Break the sump joint by
striking the sump with the palm of the hand,
then lower the sump away from the engine
and withdraw it. Raise the engine unit slightly
to gain the necessary clearance required for
sump removal, taking care not to place any
excess strain on the engine wiring/hoses or
exhaust system.
9 Undo the retaining bolts and remove the oil
pump pick-up/strainer from the base of the oil
pump housing, noting the sealing ring, then
remove the baffle plate assembly.
3510 Vauxhall/Opel Omega
10 Check the oil pump pick-up/strainer for
signs of clogging or splitting and renew/clean
as necessary. Note: If the sump is to be
removed for any length of time, refit the
mounting bracket to the cylinder block and
lower the engine back down onto its mounting
rubbers.
Refitting
11 Remove all traces of dirt and oil from the
mating surfaces of the sump, cylinder block
and oil pump housing. Also remove all traces
of locking compound from the threads of the
oil pump pick-up/strainer bolts and the sump
retaining bolts.
12 Apply a smear of suitable sealant
(Vauxhall recommend the use of sealant 15 03
295 - available from your Vauxhall dealer) to
the areas of the cylinder block mating surface
around the areas of the oil pump housing and
rear main bearing cap joints.
13 Fit a new sealing ring to the oil pump pickup/strainer and apply a few drops of locking
compound (Vauxhall recommend the use of
locking compound 15 10 181 - available from
your Vauxhall dealer) to the threads of the
strainer retaining bolts.
14 Offer up the new baffle plate, making sure
it is correctly located, then refit the oil pump
strainer tightening its retaining bolts to the
specified torque.
15 Apply a drop of locking compound to
each of the sump retaining bolts then offer up
the sump to the cylinder block. Refit the
retaining bolts and progressively tighten them
to the specified torque, working out from the
centre in a diagonal sequence.
16 Refit the mounting bracket to the cylinder
block and tighten its retaining bolts to the
specified torque. Lower the engine back down
onto its mountings making sure the brackets
and mounting rubbers are correctly aligned.
Remove the hoist from the engine then refit
the mounting nuts, tightening them to the
specified torque setting.
2.0 litre SOHC engine in-car repair procedures 2A•11
14.8 Undo the retaining screws and
remove the oil pump cover
14.10 Lift the inner and outer gears
(arrowed) out from the pump housing
17 Refit the flywheel lower cover plate to the
transmission housing then refit the support
brackets. Screw in the bolts securing the
brackets to the cylinder block and
transmission housing and tighten them to
their specified torque settings.
18 Reconnect the oil level sender wiring
connector (where fitted).
19 Refit the undercover then lower the
vehicle to the ground then fill the engine with
fresh oil, with reference to Chapter 1.
of the end of the crankshaft, taking great care
not to lose the locating dowels. Remove the
housing gasket and discard it.
Overhaul
1 Drain the engine oil as described in Chapter 1, then fit a new sealing washer and refit
the drain plug, tightening it to the specified
torque. Remove the oil filter and discard it.
2 Remove the timing belt as described in
Section 7.
3 Remove the camshaft and crankshaft
timing belt sprockets and the tensioner as
described in Section 8.
4 Unbolt the timing belt rear cover from the
camshaft housing and oil pump and remove it
from the engine.
5 Remove the sump and oil pump pickup/strainer as described in Section 13.
6 Disconnect the wiring connector from the
oil pressure switch.
7 Slacken and remove the retaining bolts
then slide the oil pump housing assembly off
8 Undo the retaining screws and lift off the
pump cover from the rear of the housing (see
illustration).
9 Using a suitable marker pen, mark the
surface of both the pump inner and outer
gears; the marks can then be used to ensure
the rotors are refitted the correct way around.
10 Lift out the inner and outer gears from the
pump housing (see illustration).
11 Unscrew the oil pressure relief valve bolt
from the side of the housing and withdraw the
spring and plunger from the housing, noting
which way around the plunger is fitted (see
illustration). Remove the sealing washer from
the valve bolt. Note: The pressure relief valve
can be removed with pump in position on the
engine unit.
12 Clean the components, and carefully
examine the gears, pump body and relief
valve plunger for any signs of scoring or wear.
Renew any component which shows signs of
wear or damage; if the gears or pump housing
are marked then the complete pump
assembly should be renewed.
13 If the components appear serviceable,
measure the clearance between the inner gear
to outer gear clearance using feeler blades.
Also measure the gear endfloat, and check
the flatness of the end cover (see
illustrations). If the clearances exceed the
specified tolerances, the pump must be
renewed.
14.13a Using a feeler blade to check gear
clearance
14.13b Using a straight edge and feeler
blade to measure gear endfloat
14 Oil pump removal, overhaul and refitting
4
Removal
3510 Vauxhall/Opel Omega
14.11 Oil pressure relief valve components
1 Plunger
2 Spring
3 Sealing washer
4 Valve bolt
14 If the pump is satisfactory, reassemble the
components in the reverse order of removal,
noting the following.
a) Ensure both gears are fitted the correct
way around.
b) Fit a new sealing washer to the pressure
relief valve bolt and tighten the bolt to the
specified torque.
c) Remove all traces of locking compound
from the cover screws. Apply a drop of
fresh locking compound to each screw
and tighten the screws to the specified
torque.
d) On completion prime the oil pump by
filling it with clean engine oil whilst
rotating the inner gear.
Refitting
15 Prior to refitting, carefully lever out the
crankshaft oil seal using a flat-bladed
screwdriver. Fit the new oil seal, ensuring its
sealing lip is facing inwards, and press it
squarely into the housing using a tubular drift
which bears only on the hard outer edge of
the seal (see illustration). Press the seal into
position so that it is flush with the housing and
lubricate the oil seal lip with clean engine oil.
16 Ensure the mating surfaces of the oil
pump and cylinder block are clean and dry
and the locating dowels are in position.
17 Fit a new gasket to the cylinder block.
18 Carefully manoeuvre the oil pump into
position and engage the inner gear with the
crankshaft end. Locate the pump on the
dowels, taking great care not to damage the
oil seal lip.
14.15 Fitting a new crankshaft oil seal to
the oil pump housing
2A
2A•12 2.0 litre SOHC engine in-car repair procedures
15.2 Lock the flywheel/driveplate ring gear
with a tool similar to that shown
19 Refit the pump housing retaining bolts in
their original locations and tighten them to the
specified torque.
20 Reconnect the oil pressure sensor wiring
connector.
21 Refit the oil pump pick-up/strainer and
sump as described in Section 13.
22 Refit the rear timing belt cover to the
engine, tightening its retaining bolts to the
specified torque.
23 Refit the timing belt sprockets and
tensioner then refit the belt as described in
Sections 7 and 8.
24 On completion fit a new oil filter and fill the
engine with clean oil as described in Chapter 1.
15 Flywheel/driveplate removal, inspection
and refitting
4
Note: New flywheel/driveplate retaining bolts
will be required on refitting.
Removal
Manual transmission models
1 Remove the transmission as described in
Chapter 7A then remove the clutch assembly
as described in Chapter 6.
2 Prevent the flywheel from turning by locking
the ring gear teeth with a similar arrangement
to that shown (see illustration). Alternatively,
bolt a strap between the flywheel and the
cylinder block/crankcase. Make alignment
marks between the flywheel and crankshaft
using paint or a suitable marker pen.
3 Slacken and remove the retaining bolts and
remove the flywheel. Do not drop it, as it is
very heavy.
Automatic transmission models
4 Remove the transmission as described in
Chapter 7B.
5 Lock the driveplate as described in
paragraph 2 then slacken the driveplate
retaining bolts.
6 Unscrew the retaining bolts and remove the
retaining plate, centering ring and driveplate
from the end of the crankshaft, noting each
components correct fitted location.
15.12a On manual transmission models,
tighten the flywheel bolts to the specified
stage 1 torque setting . . .
15.12b . . . then tighten them through the
specified stage 2 and 3 angles
Inspection
Automatic transmission models
7 On manual transmission models, examine
the flywheel for scoring of the clutch face. If
the clutch face is scored, the flywheel may be
surface-ground, but renewal is preferable.
Check for wear or chipping of the ring gear
teeth. Renewal of the ring gear is possible on
models with a normal flywheel but is not a
task for the home mechanic; renewal requires
the new ring gear to be heated (up to 180º to
230ºC) to allow it to be fitted. On dual-mass
flywheels ring gear renewal is not possible.
8 On automatic transmission models closely
examine the driveplate for ring gear teeth for
signs of wear or damage and check the
driveplate surface for any signs of cracks.
9 If there is any doubt about the condition of
the flywheel/driveplate, seek the advice of a
Vauxhall dealer or engine reconditioning
specialist. They will be able to advise if it is
possible to recondition it or whether renewal
is necessary.
14 Clean the mating surfaces of the driveplate
and crankshaft and remove all traces of
locking compound from the driveplate
retaining bolt threads in the crankshaft.
15 Offer up the driveplate complete with the
centering ring and retaining plate, making
sure all components are fitted the correct way
around, then screw in the new retaining bolts.
16 Tighten the retaining bolts through the
specified torque and angles as described in
paragraph 12 then remove the locking tool
and refit the transmission as described in
Chapter 7B.
Refitting
Manual transmission models
10 Clean the mating surfaces of the flywheel
and crankshaft and remove all traces of
locking compound from the flywheel retaining
bolt threads in the crankshaft.
11 Offer up the flywheel and fit the new
retaining bolts. If the original is being refitted
align the marks made prior to removal.
12 Lock the flywheel by the method used on
removal, and tighten the retaining bolts to the
specified stage 1 torque setting then angletighten the bolts through the specified stage 2
angle, using a socket and extension bar, and
finally through the specified stage 3 angle. It is
recommended that an angle-measuring
gauge is used during the final stages of the
tightening, to ensure accuracy (see
illustrations). If a gauge is not available, use
white paint to make alignment marks between
the bolt head and flywheel prior to tightening;
the marks can then be used to check that the
bolt has been rotated through the correct
angle.
13 Refit the clutch as described in Chapter 6
then remove the locking tool, and refit the
transmission as described in Chapter 7A.
3510 Vauxhall/Opel Omega
16 Crankshaft oil seals renewal
4
Front (timing belt end) oil seal
1 Remove the crankshaft sprocket as
described in Section 8.
2 Carefully punch or drill two small holes
opposite each other in the oil seal. Screw a
self-tapping screw into each and pull on the
screws with pliers to extract the seal (see
illustration). Alternatively carefully lever the
seal out of position.
Caution: Great care must be taken to avoid
damage to the oil pump
3 Clean the seal housing and polish off any
burrs or raised edges which may have caused
the seal to fail in the first place.
16.2 Removing the crankshaft front oil
seal
2.0 litre SOHC engine in-car repair procedures 2A•13
16.4 Fitting a new crankshaft front oil seal
4 Lubricate the lips of the new seal with clean
engine oil and ease it into position on the end
of the shaft. Press the seal squarely into
position until it is flush with the housing. If
necessary, a suitable tubular drift, such as a
socket, which bears only on the hard outer
edge of the seal can be used to tap the seal
into position (see illustration). Take great
care not to damage the seal lips during fitting
and ensure that the seal lips face inwards.
5 Wash off any traces of oil, then refit the
crankshaft sprocket as described in Section 8.
Rear (flywheel/driveplate end)
oil seal
6 Remove the flywheel/driveplate as
described in Section 15.
7 Renew the seal as described in paragraphs 2
to 4.
8 Refit the flywheel/driveplate as described in
Section 15.
17 Engine/transmission
mountings inspection and renewal
3
Inspection
1 If improved access is required, raise the
front of the car and support it securely on axle
stands. Undo the retaining bolts and remove
the undercover from beneath the engine unit.
2 Check the mounting rubber to see if it is
cracked, hardened or separated from the
metal at any point; renew the mounting if any
such damage or deterioration is evident.
3 Check that all the mounting’s fasteners are
securely tightened; use a torque wrench to
check if possible.
4 Using a large screwdriver or a pry bar,
check for wear in the mounting by carefully
levering against it to check for free play;
where this is not possible, enlist the aid of an
assistant to move the engine/transmission
unit back and forth, or from side to side, while
you watch the mounting. While some free play
is to be expected even from new
components, excessive wear should be
obvious. If excessive free play is found, check
first that the fasteners are correctly secured,
then renew any worn components as
described below.
Renewal
Left- and right-hand engine mountings
Note: It is recommended that the engine
mountings are replaced as a matched pair.
5 Firmly apply the handbrake then jack up the
front of the vehicle and support it on axle
stands. Undo the retaining screws and remove
the undercover from beneath the engine.
6 Support the weight of the engine/
transmission using a trolley jack with a block
of wood placed on its head. Alternatively
attach an engine hoist to the lifting brackets
on the cylinder head and use the hoist to
support the engine.
7 Unscrew the upper and lower nuts securing
the relevant engine mounting to the cylinder
block bracket and subframe then raise the
engine unit slightly and manoeuvre the
mounting out of position. If necessary the
mounting bracket can be unbolted and
removed from the cylinder block. Note: Take
great care not to place any excess stress on
any engine wiring/hoses or the exhaust
system or when raising the engine.
8 Check all components for signs of wear or
damage, and renew as necessary.
9 On refitting, refit the mounting to the
3510 Vauxhall/Opel Omega
subframe aligning its locating lug with the
subframe slot then refit the lower nut and
tighten to the specified torque.
10 Refit the mounting bracket (where
removed) to the cylinder block and tighten its
retaining bolts to the specified torque.
11 Lower the engine unit back down onto the
mounting, making sure it is correctly located,
then remove the jack/hoist (as applicable). Fit
the upper retaining nut to the mounting and
tighten it to the specified torque.
12 Refit the undercover then lower the
vehicle to the ground.
Transmission unit rear mounting
13 Firmly apply the handbrake then jack up
the front of the vehicle and support it on axle
stands.
14 Place a jack with a block of wood beneath
the transmission, and raise the jack to take
the weight of the transmission.
15 With the transmission securely supported,
slacken and remove the bolts securing the
transmission unit rear mounting crossmember
to the vehicle body. Unscrew the nuts
securing the crossmember to the mounting
and remove it from the vehicle.
16 Slacken and remove the bolts and remove
the mounting from the base of the
transmission unit.
17 Check all components for signs of wear or
damage, and renew as necessary. Remove all
traces of locking compound from the
crossmember to body bolt threads.
18 Fit the mounting to the transmission unit
and tighten its retaining bolts to the specified
torque.
19 Refit the crossmember to the mounting
and lightly tighten its retaining nuts.
20 Apply a few drops of thread locking
compound (Vauxhall recommend the use of
locking compound 15 10 181 - available from
your Vauxhall dealer) to the threads of each
crossmember to body bolt then refit both
bolts and tighten them to the specified torque.
21 Remove the jack from underneath the
transmission unit then tighten the mounting to
crossmember nuts to the specified torque
before lowering the vehicle to the ground.
2A
2B•1
Chapter 2 Part B:
2.0 litre DOHC engine in-car repair procedures
Contents
Camshafts and followers - removal, inspection and refitting . . . . . . 10
Camshaft cover - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . 4
Camshaft oil seals - renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Compression test - description and interpretation . . . . . . . . . . . . . . 2
Crankshaft balancer unit (1998 model year onwards) - removal,
refitting and adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Crankshaft oil seals - renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Crankshaft pulley - removal and refitting . . . . . . . . . . . . . . . . . . . . . . 5
Cylinder head - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . 11
Engine oil and filter - renewal . . . . . . . . . . . . . . . . . . . . .See Chapter 1
Engine oil level check . . . . . . . . . . . . . . . . . . . . . . .See Weekly checks
Engine/transmission mountings - inspection and renewal . . . . . . . . 17
Flywheel/driveplate - removal, inspection and refitting . . . . . . . . . . . 15
General information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Oil pump - removal, overhaul and refitting . . . . . . . . . . . . . . . . . . . . 13
Sump - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Timing belt - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Timing belt covers - removal and refitting . . . . . . . . . . . . . . . . . . . . . 6
Timing belt sprockets, tensioner and idler pulleys - removal and
refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Top dead centre (TDC) for No 1 piston - locating . . . . . . . . . . . . . . . 3
Degrees of difficulty
Easy, suitable for
novice with little
experience
1
Fairly easy, suitable
for beginner with
some experience
2
Fairly difficult,
suitable for competent
DIY mechanic
3
Difficult, suitable for
experienced DIY
mechanic
4
Very difficult,
suitable for expert DIY
or professional
5
Specifications
General
Engine type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Manufacturer’s engine code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Bore . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stroke . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Firing order . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Direction of crankshaft rotation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Compression ratio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Maximum power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Maximum torque . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Four-cylinder, in-line, water-cooled. Double overhead camshaft, beltdriven
X20XEV
86.0 mm
86.0 mm
1998 cc
1-3-4-2 (No 1 cylinder at timing belt end)
Clockwise (viewed from timing belt end of engine)
10.8:1
100 kW at 5600 rpm
185 Nm at 4000 rpm
Compression pressures
Standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Maximum difference between any two cylinders . . . . . . . . . . . . . . . . . .
12 to 15 bar (174 to 218 psi)
1 bar (15 psi)
Camshaft
Cam lift . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9.2 mm
Lubrication system
Oil pump type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Minimum permissible oil pressure at idle speed, with engine
at operating temperature (oil temperature of at least 80°C) . . . . . . . .
Oil pump clearances:
Gear teeth clearance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Gear endfloat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Gear-type, driven directly from crankshaft
1.5 bar (22 psi)
0.08 to 0.15 mm
0.03 to 0.10 mm
3510 Vauxhall/Opel Omega
2B
2B•2 2.0 litre DOHC engine in-car repair procedures
Torque wrench settings
Nm
Camshaft bearing cap bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Camshaft cover bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Camshaft sprocket bolt:
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Angle-tighten a further 60°
Stage 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Angle-tighten a further 15°
Coolant pump bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Connecting rod big-end bearing cap bolt:
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Angle-tighten a further 45°
Stage 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Angle-tighten a further 15°
Crankcase breather tube bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Crankshaft balancer unit bolts - 1998-on engines:
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Angle-tighten a further 45°
Crankshaft pulley bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Crankshaft sensor rotor bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Crankshaft sprocket bolt:
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Angle-tighten a further 40 to 50°
Cylinder head bolts:
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Angle-tighten a further 90°
Stage 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Angle-tighten a further 90°
Stage 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Angle-tighten a further 90°
Stage 5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Angle-tighten a further 15°
Driveplate bolts:
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Angle-tighten a further 30°
Stage 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Angle-tighten a further 15°
Engine/transmission mounting bolts:
Left- and right-hand mountings:
Mounting-to-subframe nut . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Mounting-to-mounting bracket nut . . . . . . . . . . . . . . . . . . . . . . . . . 40
Mounting bracket-to-cylinder block bolts . . . . . . . . . . . . . . . . . . . . 60
Rear mounting:
Mounting-to-transmission bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Mounting-to-crossmember nuts . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Crossmember-to-body bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Engine-to-transmission unit bolts:
Transmission-to-cylinder block bolts . . . . . . . . . . . . . . . . . . . . . . . . . 60
Transmission-to-sump flange bolts
(engines with a two-piece sump) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Engine-to-transmission support bracket bolts - engines with one-piece sump:
Bracket-to-engine bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Bracket-to-transmission bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Flywheel bolts:
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Angle-tighten a further 30°
Stage 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Angle-tighten a further 15°
Main bearing cap bolts:
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Angle-tighten a further 45°
Stage 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Angle-tighten a further 15°
Main bearing cap bridge casting/baffle plate bolts - engines with
two piece sump:
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Angle-tighten a further 45°
Oil filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Oil pump:
Retaining bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Pump cover screws . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Oil pressure relief valve bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Oil pump pick-up/strainer bolts:
Engines with one-piece sump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3510 Vauxhall/Opel Omega
lbf ft
6
6
37
18
26
18
15
15
10
96
18
41
41
30
44
30
15
33
44
30
30
16
48
37
15
11
6
4
37
6
2.0 litre DOHC engine in-car repair procedures 2B•3
Torque wrench settings (continued)
Oil pump pick-up/strainer bolts (continued):
Engines with two piece sump:
Pick-up-to-oil pump housing bolts . . . . . . . . . . . . . . . . . . . . . . . . .
Pick-up-to-casting/balancer unit bolts:
M6 bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
M8 bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Sump bolts:
One-piece sump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Two-piece sump:
Sump pan bolts:
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Main casting bolts:
Casting-to-cylinder block/oil pump bolts . . . . . . . . . . . . . . . . . .
Casting flange-to-transmission bolts . . . . . . . . . . . . . . . . . . . . .
Sump drain plug:
Hex-head bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Torx-head bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Timing belt cover bolts:
Outer cover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rear cover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Timing belt idler pulley:
Pulley bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Mounting bracket bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Timing belt tensioner bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1 General information
How to use this Chapter
1 This Part of Chapter 2 is devoted to in-car
repair procedures for the engine. All
procedures concerning engine removal and
refitting, and engine block/cylinder head
overhaul can be found in Chapter 2D.
2 Most of the operations included in this Part
are based on the assumption that the engine
is still installed in the car. Therefore, if this
information is being used during a complete
engine overhaul, with the engine already
removed, many of the steps included here will
not apply.
Engine description
3 The engine is a double overhead camshaft,
four-cylinder, in-line unit, mounted at the front
of the car with the transmission on its rear.
This engine is often referred to as the 2.0 litre
ECOTEC engine (Emission Consumption
Optimized TEChnology).
4 The cylinder block is of the dry-liner type.
The crankshaft is supported within the
cylinder block on five shell-type main
bearings. Thrustwashers are fitted to number
3 main bearing, to control crankshaft endfloat.
5 The connecting rods are attached to the
crankshaft by horizontally split shell-type bigend bearings, and to the pistons by
interference-fit gudgeon pins. The aluminium
alloy pistons are of the slipper type, and are
fitted with three piston rings, comprising two
Nm
lbf ft
8
6
10
20
7
15
15
11
8
Angle-tighten a further 30°
6
20
40
15
30
45
10
33
7
6
8
4
6
25
25
20
18
18
15
compression rings and a scraper-type oil
control ring.
6 The camshafts run directly in the cylinder
head, and are driven by the crankshaft via a
toothed rubber timing belt (which also drives
the coolant pump). The camshafts operate
each valve via a follower. Each follower
incorporates a hydraulic self-adjusting valve
which automatically adjust the valve
clearances.
7 Lubrication is by pressure-feed from a
gear-type oil pump, which is mounted on the
front end of the crankshaft. It draws oil
through a strainer located in the sump, and
then forces it through an externally mounted
full-flow cartridge-type filter. The oil flows into
galleries in the main bearing cap bridge
arrangement and cylinder block/crankcase,
from where it is distributed to the crankshaft
(main bearings) and camshafts. The big-end
bearings are supplied with oil via internal
drillings in the crankshaft, while the camshaft
bearings also receive a pressurised supply.
The camshaft lobes and valves are lubricated
by splash, as are all other engine
components.
8 On later (1998 model year onwards)
engines, a crankshaft balancer unit is fitted to
the engine to smooth out the forces which
occur during normal crankshaft/piston
movement. The balancer unit houses two
balance shafts and is bolted onto the base of
the cylinder block, directly beneath number 2
cylinder. The balancer shaft gears are meshed
together and the gear of the first shaft is
driven by the crankshaft via a gear which
forms the third web of the crankshaft. The
crankshaft gear has twice as many teeth as
3510 Vauxhall/Opel Omega
the balance shaft gears and so drives the
balance shaft at twice the speed of the
crankshaft, the first balance shaft rotates in
the opposite direction to the crankshaft and
the second in the same direction.
9 A semi-closed crankcase ventilation system
is employed; crankcase fumes are drawn from
cylinder head cover, and passed via a hose to
the inlet manifold.
Repair operations possible with
the engine in the car
10 The following operations can be carried
out without having to remove the engine from
the vehicle.
a) Removal and refitting of the cylinder
head.
b) Removal and refitting of the timing belt
and sprockets.
c) Renewal of the camshaft oil seals.
d) Removal and refitting of the camshafts
and followers.
e) Removal and refitting of the sump.
f) Removal and refitting of the connecting
rods and pistons*.
g) Removal and refitting of the oil pump.
h) Renewal of the crankshaft balancer unit 1998 on engines.
i) Renewal of the crankshaft oil seals.
j) Renewal of the engine mountings.
k) Removal and refitting of the
flywheel/driveplate.
* Although the operation marked with an asterisk
can be carried out with the engine in the car after
removal of the sump, it is better for the engine to
be removed, in the interests of cleanliness and
improved access. For this reason, the procedure
is described in Chapter 2D.
2B
2B•4 2.0 litre DOHC engine in-car repair procedures
3.5 Align the camshaft sprocket timing
marks with the cutout on the camshaft
cover (1) and align the crankshaft pulley
notch with the pointer (2) to position No 1
piston at TDC on its compression stroke
2 Compression test description and interpretation
4 Camshaft cover removal and refitting
2
Removal
Refer to Chapter 2A, Section 2.
3 Top dead centre
(TDC) for No 1 piston locating
4 To gain access to the camshaft sprocket
timing marks, remove the timing belt outer
cover as described in Section 6.
5 Using a socket and extension bar on the
crankshaft sprocket bolt, rotate the crankshaft
until the timing marks on the camshaft
sprockets are both at the top and are
correctly aligned with the marks on the
camshaft cover. With the camshaft sprocket
marks correctly positioned, align the notch on
the crankshaft pulley rim with the pointer (see
illustration). The engine is now positioned
with No1 piston at TDC on its compression
stroke. Note: If the crankshaft pulley has been
removed, use the mark on the crankshaft
sprocket rim. The mark should be aligned with
the cutout on the oil pump housing (see
Section 7).
2
1 In its travel up and down its cylinder bore,
Top Dead Centre (TDC) is the highest point
that each piston reaches as the crankshaft
rotates. While each piston reaches TDC both
at the top of the compression stroke and
again at the top of the exhaust stroke, for the
purpose of timing the engine, TDC refers to
the piston position (usually number 1) at the
top of its compression stroke.
2 Number 1 piston (and cylinder) is at the
front (timing belt) end of the engine, and its
TDC position is located as follows. Note that
the crankshaft rotates clockwise when viewed
from the front of the vehicle.
3 Disconnect the battery negative terminal. If
necessary, remove all the spark plugs as
described in Chapter 1 to enable the engine to
be easily turned over.
4.1 Release the retaining clips and
disconnect the breather hoses from the
camshaft cover
1 Slacken the retaining clips and disconnect
the breather hoses from the camshaft cover
(see illustration).
2 Undo the retaining screws and remove the
spark plug cover. Disconnect the plug caps
from the plugs then unclip the HT leads and
position them clear of the cover (see
illustrations).
3 Slacken the nut securing the engine wiring
harness tray to the timing belt cover upper
fixing then free the tray from the front of the
cover and position it clear
4 Disconnect the camshaft sensor wiring
connector and unclip the wiring from the
camshaft cover.
5 Evenly and progressively slacken and
remove the camshaft cover retaining bolts.
6 Lift the camshaft cover away from the
cylinder head and recover the cover seal and
the sealing rings which are fitted to each of
the retaining bolt holes. Examine the seal and
sealing rings for signs of wear or damage and
renew if necessary.
Refitting
7 Ensure the cover and cylinder head
4.2a Remove the spark plug cover . . .
3510 Vauxhall/Opel Omega
surfaces are clean and dry then fit the
camshaft seals securely to the cover grooves.
Fit the sealing rings to the recesses around
each retaining bolt hole, holding them in
position with a smear of grease.
8 Apply a smear of suitable sealant (Vauxhall
recommend the use of sealant 15 03 295 available from your Vauxhall dealer) to the
areas of the cylinder head surface around the
front inlet and exhaust camshaft bearing caps
and also to the semi-circular cutouts on the
rear of the head.
9 Carefully manoeuvre the camshaft cover
into position, taking great care to ensure all
the sealing rings remain correctly seated. Refit
the cover retaining bolts and tighten the
retaining bolts to the specified torque,
working in a spiral pattern from the centre
outwards.
10 Reconnect the breather hoses, securing
them in position with the retaining clips, and
securely reconnect the plug caps to the spark
plugs.
11 Reconnect the camshaft sensor wiring
connector then refit the spark plug cover and
securely tighten its retaining screws. Clip the
wiring tray back into position and securely
tighten its retaining nut.
5 Crankshaft pulley removal and refitting
2
Removal
1 Remove the auxiliary drivebelt as described
in Chapter 1. Prior to removal, mark the
direction of rotation on the belt to ensure the
belt is refitted the same way around.
2 Using a socket and extension bar on the
crankshaft sprocket bolt, turn the crankshaft
until the notch on the pulley rim is correctly
aligned with the pointer on the cover (see
illustration).
3 Slacken and remove the small retaining
bolts securing the pulley to the crankshaft
sprocket and remove the pulley from the
engine. If necessary, prevent crankshaft
rotation by holding the sprocket retaining bolt
with a suitable socket.
4.2b . . . and disconnect the plug caps
from the spark plugs
2.0 litre DOHC engine in-car repair procedures 2B•5
into position. Align the notch on the pulley rim
with the pointer then seat the pulley on the
sprocket and tighten its retaining bolts to the
specified torque.
5 Refit the auxiliary drivebelt as described in
Chapter 1 using the mark made prior to
removal to ensure the belt is fitted the correct
way around.
6 Timing belt covers removal and refitting
3
5.2 Align the crankshaft pulley notch with
the pointer on the cover (arrowed - shown
with timing belt outer cover removed)
Outer cover
Refitting
Removal
4 Check that the crankshaft sprocket mark is
still aligned with the mark on the oil pump
housing then manoeuvre the crankshaft pulley
1 Remove the auxiliary drivebelt as described
in Chapter 1. Prior to removal, mark the
direction of rotation on the belt to ensure the
belt is refitted the same way around.
2 Slacken and remove the nut securing the
engine wiring harness tray to the outer cover
upper mounting and free the tray assembly
from the timing belt cover. Unclip the cover
from the tray then free the wiring harness and
coolant hose and remove the tray from the
engine compartment (see illustrations).
3 Slacken and remove the retaining bolts,
along with their washers and outer rubber
spacers, then remove the outer cover from the
engine unit along with its seal. Once the cover
has been removed, recover inner rubber
spacers
from
the
mountings
(see
illustrations).
6.2a Undo the retaining nut and free the
wiring tray from the outer cover . . .
Refitting
4 Ensure the inner rubber spacers are
correctly fitted to each of the mountings then
manoeuvre the cover into position (see
illustration).
5 Fit the washers and outer rubber spacers to
the mounting bolts then refit the bolts in their
original locations and tighten them to the
specified torque (see illustration).
6 Seat the wiring harness correctly in the tray
then refit the tray cover. Clip the tray securely
onto the timing belt cover and securely tighten
its retaining nut.
7 Refit the auxiliary drivebelt as described in
Chapter 1 using the mark made prior to
removal to ensure the belt is fitted the correct
way around.
Rear cover
Removal
8 Remove the timing belt as described in
Section 7.
9 Remove
the
camshaft
sprockets,
crankshaft sprocket, the timing belt tensioner
and the idler pulley assembly as described in
Section 8.
10 Unbolt the camshaft sensor from the
cylinder head.
11 Undo the retaining bolts, noting their
correct fitted locations, and remove the rear
cover from the engine unit.
Refitting
12 Refitting is the reverse of removal,
tightening all bolts to the specified torque.
2B
6.2b . . . then unclip the cover . . .
6.2c . . . and free the wiring and coolant
hose and remove the tray from the engine
compartment
6.3a Slacken and remove the cover
retaining bolts (upper bolt shown) and
recover the outer rubber spacers . . .
6.3b . . . then remove the outer cover from
the engine
6.4 Ensure the inner rubber spacers are
correctly fitted to the mountings before
installing the outer cover . . .
6.5 . . . and ensure the outer spacers are
correctly positioned before refitting the
retaining bolts
3510 Vauxhall/Opel Omega
2B•6 2.0 litre DOHC engine in-car repair procedures
7 Timing belt removal and refitting
3
Note: The timing belt must be removed and
refitted with the engine cold.
Removal
1 Disconnect the battery negative terminal
then position No1 cylinder at TDC on its
compression stroke as described in Section 3.
Note: On models with a Vauxhall anti-theft
warning system (ATWS), the battery negative
terminal must be disconnected within 15
seconds of the ignition being switched off to
prevent the alarm system being triggered.
2 Remove the crankshaft pulley as described
in Section 5.
3 Check the camshaft sprocket timing marks
are correctly aligned with the camshaft cover
marks and the crankshaft sprocket timing
mark is aligned with the cutout on the oil
pump housing.
4 Slacken the timing belt tensioner bolt (see
illustration). Using an Allen key, rotate the
tensioner arm clockwise to its stop, to relieve
the tension in the timing belt, and hold it in
position by and securely tighten the retaining
bolt.
5 Slide the timing belt off from its sprockets
and remove it from the engine. If the belt is to
be re-used, use white paint or similar to mark
the direction of rotation on the belt. Do not
rotate the crankshaft or camshafts until the
timing belt has been refitted.
6 Check the timing belt carefully for any signs
of uneven wear, splitting or oil contamination,
and renew it if there is the slightest doubt
about its condition. If the engine is undergoing
an overhaul and has covered 40 000 miles or
it was more than 4 years since the original belt
was fitted, renew the belt as a matter of
course, regardless of its apparent condition
(from 1997 onwards the belt renewal interval
was increased to 80 000 miles or 8 years). If
signs of oil contamination are found, trace the
source of the oil leak and rectify it, then wash
down the engine timing belt area and all
related components to remove all traces of oil.
7.8 Align the camshaft sprocket marks (1) with the marks on the bearing caps (2) or
cover and ensure the crankshaft sprocket timing mark is correctly aligned with the oil
pump cutout (3)
3510 Vauxhall/Opel Omega
7.4 Slacken the timing belt tensioner bolt
(1) and rotate the tensioner clockwise
using an Allen key in the arm cutout (2)
Refitting
7 On reassembly, thoroughly clean the timing
belt sprockets and tensioner/idler pulleys.
8 Check that the crankshaft sprocket timing
mark is still aligned with the cutout on the oil
pump housing and the camshaft sprocket
marks are aligned with the marks on the
camshaft cover. If the camshaft cover has
been removed, align the sprocket marks with
the lugs on the top of the camshaft front
bearing caps (see illustration).
9 Fit the timing belt over the crankshaft and
camshaft sprockets and around the idler
pulleys, ensuring that the belt left-hand run is
taut (ie, all slack is on the tensioner side of the
belt), then fit the belt over the coolant pump
sprocket and tensioner pulley. Do not twist
the belt sharply while refitting it. Ensure that
the belt teeth are correctly seated centrally in
the sprockets, and that the timing marks
remain in alignment. If a used belt is being
refitted, ensure that the arrow mark made on
removal points in the normal direction of
rotation, as before.
10 Slacken the timing belt tensioner bolt to
release the tensioner spring. Rotate the
tensioner arm anti-clockwise until the
tensioner pointer is fully over against its stop,
without exerting any excess strain on the belt
(see illustration). Hold the tensioner in
position and securely tighten its retaining bolt.
7.10 Tension the belt by rotating the
tensioner arm fully anti-clockwise until the
pointer is positioned as shown
2.0 litre DOHC engine in-car repair procedures 2B•7
11 Check the sprocket timing marks are still
correctly aligned. If adjustment is necessary,
release the tensioner again then disengage
the belt from the sprockets and make any
necessary adjustments.
12 Using a socket on the crankshaft sprocket
bolt, rotate the crankshaft smoothly through
two complete turns (720°) in the normal
direction of rotation to settle the timing belt in
position.
13 Check that both the camshaft and
crankshaft sprocket timing marks are
correctly realigned then slacken the tensioner
bolt again.
14 If a new timing belt is being fitted, adjust
the tensioner so that the pointer is aligned
with either the cutout or NEW marking
(depending on type of tensioner fitted) on the
backplate (see illustration). Hold the
tensioner in the correct position and tighten
its retaining bolt to the specified torque.
Rotate the crankshaft smoothly through
another two complete turns in the normal
direction of rotation, to bring the sprocket
timing marks back into alignment. Check that
the tensioner pointer is still aligned with the
backplate cutout/marking (as applicable).
15 If the original belt is being refitted, adjust
the tensioner so that the pointer is either
positioned 4 mm to the left of the cutout or is
aligned with the USED marking (depending on
the type of tensioner fitted) on the backplate
(see illustration 7.14). Hold the tensioner in the
correct position and tighten its retaining bolt
to the specified torque. Rotate the crankshaft
smoothly through another two complete turns
in the normal direction of rotation, to bring the
sprocket timing marks back into alignment.
Check that the tensioner pointer is still
correctly positioned in relation to the
backplate cutout/marking (as applicable).
16 If the tensioner pointer is not correctly
positioned in relation to the backplate, repeat
the procedure in paragraph 14 (new belt) or 15
(original belt) (as applicable).
17 Once the tensioner pointer and backplate
remain correctly aligned, refit the timing belt
cover and crankshaft pulley as described in
Sections 5 and 6.
8 Timing belt sprockets,
tensioner and idler pulleys removal and refitting
3
7.14 Ensure the timing belt tensioner arm (1) is correctly position in relation to the
backplate cutout/marking (2) as described in text
A Correct position for new belt - engines
with an unmarked tensioner
B Correct position for new belt - engines
with a marked tensioner
short), and three nuts and bolts; one nut and
bolt forms the pivot of a forked tool, with the
remaining two nuts and bolts at the tips of
the ‘forks’ to engage with the sprocket
spokes (see illustration 8.2 in Chapter 2A).
b) Remove the camshaft cover as described
in Section 4 and hold the camshaft with
an open-ended spanner on the flats
provided (see illustration).
3 Unscrew the retaining bolt and washer and
remove the sprocket from the end of the
camshaft. If the sprocket locating pin is a
loose fit in the camshaft end, remove it and
store it with the sprocket for safe-keeping.
4 If necessary, remove the remaining
sprocket using the same method.
C Correct position for used belt - engines
with an unmarked tensioner
D Correct position for used belt - engines
with a marked tensioner
Refitting
5 Prior to refitting check the oil seal(s) for
signs of damage or leakage. If necessary,
renew as described in Section 9.
6 Ensure the locating pin is in position in the
camshaft end.
7 Note that both inlet and exhaust camshaft
sprockets are the same but each one is
equipped with two locating pin cutouts. If the
sprocket is being fitted to the inlet camshaft
engage the locating pin in the IN cutout, and if
the sprocket is being fitted to the exhaust
camshaft engage the locating pin in the EX
(see illustration).
8 Ensure the camshaft locating pin is
Camshaft sprockets
Note: New sprocket retaining bolt(s) will be
required on refitting.
Removal
1 Remove the timing belt as described in
Section 7.
2 The camshaft must be prevented from
turning as the sprocket bolt is unscrewed, and
this can be achieved in one of two ways.
a) Make up a sprocket-holding tool using two
lengths of steel strip (one long, the other
8.2 Using an open-ended spanner to
retain the camshaft sprocket whilst the
sprocket bolt is slackened
3510 Vauxhall/Opel Omega
8.7 Ensure the locating pin is engaged in
the correct sprocket hole on refitting
(see text)
2B
2B•8 2.0 litre DOHC engine in-car repair procedures
engaged in the correct sprocket cutout then
fit the washer and new retaining bolt.
9 Retain the sprocket by the method used on
removal, and tighten the sprocket retaining
bolt to the specified stage 1 torque setting
then angle-tighten the bolt through the
specified stage 2 angle, using a socket and
extension bar, and finally through the
specified stage 3 angle. It is recommended
that an angle-measuring gauge is used during
the final stages of the tightening, to ensure
accuracy. If a gauge is not available, use white
paint to make alignment marks between the
bolt head and sprocket prior to tightening; the
marks can then be used to check that the bolt
has been rotated through the correct angle.
10 Refit the timing belt as described in
Section 7 then (where necessary) refit the
camshaft cover as described in Section 4.
Crankshaft sprocket
Note: A new crankshaft sprocket retaining
bolt will be required on refitting.
Removal
11 Remove the timing belt as described in
Section 7.
12 The crankshaft must be prevented from
turning as the sprocket bolt is unscrewed (the
bolt is very tight), and this can be achieved in
anyone of the following ways.
a) Use the holding tool described in
paragraph 2 securing the tool to the
sprocket with two bolts screwed into
opposite pulley retaining bolt holes.
b) On manual transmission models have an
assistant select top gear and apply the
brakes firmly.
c) If the engine is removed from the vehicle
or the transmission unit has been
removed the flywheel/driveplate can be
locked (see Chapter 2A, Section 15).
13 Unscrew the retaining bolt and washer
and remove the crankshaft sprocket from the
end of the crankshaft. Discard the bolt; a new
one must be used on refitting. If necessary,
remove the sprocket Woodruff key from the
crankshaft end and slide off the spacer.
Refitting
14 Slide the spacer (where removed) onto the
crankshaft then refit the Woodruff key to the
crankshaft slot.
15 Align the sprocket with the key and slide it
into position, ensuring the sprocket flange is
facing outwards. Fit the washer and new
retaining bolt.
16 Lock the crankshaft by the method used
on removal, and tighten the sprocket retaining
bolt to the specified stage 1 torque setting
then angle-tighten the bolt through the
specified stage 2 angle, using a socket and
extension bar. It is recommended that an
angle-measuring gauge is used during the
final stages of the tightening, to ensure
accuracy. If a gauge is not available, use white
paint to make alignment marks between the
bolt head and sprocket prior to tightening; the
marks can then be used to check that the bolt
Refitting
24 Refit the pulley mounting bracket (where
removed) to the cylinder block and tighten its
retaining bolts to the specified torque.
25 Refit the idler pulley(s) and tighten the
retaining bolt(s) to the specified torque.
26 Refit the timing belt as described in
Section 7.
9 Camshaft oil seals renewal
10.1 Prior to removing the timing belt,
rotate the crankshaft 60º backwards to
ensure the camshaft and pistons are safely
positioned
has been rotated through the correct angle.
17 Refit the timing belt as described in
Section 7.
Tensioner assembly
Removal
18 Remove the timing belt as described in
Section 7.
19 Slacken and remove the retaining bolt and
remove the tensioner assembly from the
engine.
Refitting
20 Fit the tensioner to the engine, making
sure that the lug on the backplate is correctly
located in the oil pump housing hole. Ensure
the tensioner is correctly seated then refit the
retaining bolt. Using an Allen key, rotate the
tensioner arm clockwise to its stop then
securely tighten the retaining bolt.
21 Refit the timing belt as described in
Section 7.
Idler pulleys
Removal
22 Remove the timing belt as described in
Section 7.
23 Slacken and remove the retaining bolt(s)
and remove the idler pulley(s) from the engine.
If necessary, unbolt the pulley mounting
bracket and remove it from the cylinder block.
10.3 Removing a camshaft bearing cap
3510 Vauxhall/Opel Omega
3
1 Remove the relevant camshaft sprocket as
described in Section 8.
2 Carefully punch or drill two small holes
opposite each other in the oil seal. Screw a
self-tapping screw into each, and pull on the
screws with pliers to extract the seal.
Alternatively carefully lever the oil seal out of
position.
3 Clean the seal housing, and polish off any
burrs or raised edges which may have caused
the seal to fail in the first place.
4 Lubricate the lips of the new seal with clean
engine oil, and press it into position using a
suitable tubular drift (such as a socket) which
bears only on the hard outer edge of the seal.
Take care not to damage the seal lips during
fitting; note that the seal lips should face
inwards.
5 Refit the camshaft sprocket as described in
Section 8.
10 Camshafts and followers removal, inspection and
refitting
4
Removal
1 Remove the timing belt as described in
Section 7. Prior to releasing the timing belt
tension and removing the belt, rotate the
crankshaft backwards by approximately 60°
(4 teeth of movement); this will position the
camshafts so that the valve spring pressure is
evenly exerted along the complete length of
the shaft, reducing the risk of the bearing
caps being damaged on removal/refitting (see
illustration).
2 Remove the camshaft sprockets as
described in Section 8.
3 Starting on the inlet camshaft, working in a
spiral pattern from the outside inwards,
slacken the camshaft bearing cap retaining
bolts by half-a-turn at a time, to relieve the
pressure of the valve springs on the bearing
caps gradually and evenly. Once the valve
spring pressure has been relieved, the bolts
can be fully unscrewed and removed along
with the caps; the bearing caps and the
cylinder head locations are numbered to
ensure the caps are correctly positioned on
refitting (see illustration). Take care not to
loose the locating dowels (where fitted).
2.0 litre DOHC engine in-car repair procedures 2B•9
8 Examine the follower bearing surfaces
which contact the camshaft lobes for wear
ridges and scoring. Check the followers and
their bores in the cylinder head for signs of
wear or damage. If any follower is thought to
be faulty or is visibly worn it should be
renewed.
Refitting
10.6 Using a rubber sucker to remove a
camshaft follower
Caution: If the bearing cap bolts are
carelessly slackened, the bearing caps
might break. If any bearing cap breaks
then the complete cylinder head assembly
must be renewed; the bearing caps are
matched to the head and are not available
separately.
4 Lift the camshaft out of the cylinder head
and slide off the oil seal.
5 Repeat the operations described in paragraphs 3 and 4 and remove the exhaust
camshaft.
6 Obtain sixteen small, clean plastic
containers, and label them for identification.
Alternatively, divide a larger container into
compartments. Lift the followers out from the
top of the cylinder head and store each one in
its respective fitted position (see illustration).
Note: Store all the followers the correct way
up to prevent the oil draining from the
hydraulic valve adjustment mechanisms.
Inspection
7 Examine the camshaft bearing surfaces and
cam lobes for signs of wear ridges and scoring.
Renew the camshaft if any of these conditions
are apparent. Examine the condition of the
bearing surfaces both on the camshaft journals
and in the cylinder head. If the head bearing
surfaces are worn excessively, the cylinder
head will need to be renewed.
9 Where removed, lubricate the followers with
clean engine oil and carefully insert each one
into its original location in the cylinder head.
10 Lubricate the camshaft followers with
clean engine oil then lay the camshafts in
position. Ensure the crankshaft is still
positioned approximately 60° BTDC and
position each camshaft so that the lobes of
No1 cylinder are pointing upwards.
Temporarily refit the sprockets to the
camshafts and position each one so that its
sprocket timing mark is approximately 4 teeth
before its TDC alignment position.
11 Ensure the mating surfaces of the bearing
caps and cylinder head are clean and dry and
lubricate the camshaft journals and lobes with
clean engine oil.
12 Apply a smear of sealant (Vauxhall
recommend the use of sealant 15 03 170 available from your Vauxhall dealer) to the
areas of the cylinder head mating surface
around the sides of the inlet and exhaust
camshaft front bearing cap oil seal apertures
(see illustration).
13 Ensure the locating dowels (where fitted)
are in position then refit the camshaft bearing
caps and the retaining bolts in their original
locations on the cylinder head. The caps are
numbered from front to rear and the
corresponding numbers are marked on the
cylinder head upper surface.
14 Working on the inlet camshaft, tighten the
bearing cap bolts by hand only then, working
in a spiral pattern from the centre outwards,
tighten the bolts by half-a-turn at a time to
gradually impose the pressure of the valve
springs on the bearing caps (see illustration).
10.12 Apply sealant to the shaded areas (arrowed) on each side
of the inlet and exhaust camshaft oil seal apertures
Repeat this sequence until all bearing caps
are in contact with the cylinder head then go
around and tighten the camshaft retaining
bolts to the specified torque.
Caution: If the bearing cap bolts are
carelessly tightened, the bearing caps
might break. If any bearing cap breaks then
the complete cylinder head assembly must
be renewed; the bearing caps are matched
to the head and are not available separately.
15 Tighten the exhaust camshaft bearing cap
bolts as described in paragraph 14.
16 Fit new camshaft oil seals as described in
Section 9.
17 Refit the camshaft sprockets as described
in Section 8.
18 Align all the sprocket timing marks to
bring the camshafts and crankshaft back to
TDC then refit the timing belt as described in
Section 7.
19 Refit the camshaft cover and timing belt
cover as described in Sections 4 and 6.
11 Cylinder head removal and refitting
Removal
Note: The engine must be cold when
removing the cylinder head. New cylinder
head bolts must be used on refitting.
1 Disconnect the battery negative lead. Note:
On models with a Vauxhall anti-theft warning
system (ATWS), the battery negative terminal
must be disconnected within 15 seconds of
the ignition being switched off to prevent the
alarm system being triggered.
2 Drain the cooling system and remove the
spark plugs as described in Chapter 1.
3 Remove the inlet and exhaust manifolds as
described in Chapter 4A. If no work is to be
carried out on the cylinder head, the head can
be removed complete with manifolds once the
following operations have been carried out
(see Chapter 4A).
10.14 Camshaft bearing cap tightening sequence
(exhaust camshaft shown - inlet the same)
3510 Vauxhall/Opel Omega
4
2B
2B•10 2.0 litre DOHC engine in-car repair procedures
the block, but do not lever at the mating
faces. Note the fitted positions of the two
locating dowels, and remove them for safe
keeping if they are loose.
12 Recover the cylinder head gasket, and
discard it.
Preparation for refitting
11.19 Fit the new gasket to the cylinder
block, engaging it with the locating dowels
(arrowed) . . .
11.20 . . . making sure its OBEN/TOP
marking is uppermost
a) Remove the intake duct connecting the
air cleaner to the throttle housing.
b) Disconnect the wiring connectors from
the throttle potentiometer, idle speed
adjuster, EGR valve, purge valve, coolant
temperature sensor, oxygen sensor and
DIS module. Unbolt the earth connection
from the fuel rail and release the wiring
harness from its retaining clips. Lift the
wiring cover squarely off of the injectors
then disconnect the knock sensor and
crankshaft sensor wiring connectors
before positioning the wiring
cover/harness clear of the cylinder head.
c) Depressurise the fuel system then
disconnect the fuel hoses from the fuel rail.
d) Disconnect the various vacuum and
coolant hoses from the inlet
manifold/throttle housing.
e) Unbolt the inlet manifold support bracket
and the alternator upper brackets.
f) Disconnect the accelerator cable.
g) Remove the exhaust system front pipe.
h) Disconnect the air hose from the
secondary air injection system non-return
valve on the exhaust manifold.
4 Remove the timing belt as described in
Section 7. Prior to releasing the timing belt
tension and removing the belt, rotate the
crankshaft backwards by approximately 60°
(4 teeth of movement); this will position the
camshafts so that the valve spring pressure is
evenly exerted along the complete length of
the shafts, preventing the shafts turning and
reducing the risk of the valves contacting the
pistons (see illustration 10.1).
5 Remove the camshafts as described in
Section 10.
6 Undo the retaining bolts securing the timing
belt rear cover to the cylinder head.
7 Release the retaining clips and disconnect
the various coolant hoses from the cylinder
head/thermostat housing, noting each ones
correct fitted location.
8 Unbolt the crankcase breather tube and
remove it from the left-hand side of the
cylinder block. Discard the gasket, a new one
should be used on refitting.
9 Make a final check to ensure that all
relevant hoses, pipes and wires, etc, have
been disconnected.
10 Working in the reverse of the tightening
sequence (see illustration 11.23), progressively
slacken the cylinder head bolts by a quarter of
a turn at a time until all bolts can be unscrewed
by hand. Remove each bolt in turn, along with
its washer.
11 Lift the cylinder head from the cylinder
block. If necessary, tap the cylinder head
gently with a soft-faced mallet to free it from
13 The mating faces of the cylinder head and
block must be perfectly clean before refitting
the head. Use a scraper to remove all traces
of gasket and carbon, and also clean the tops
of the pistons. Take particular care with the
aluminium surfaces, as the soft metal is
damaged easily. Also, make sure that debris
is not allowed to enter the oil and water
channels - this is particularly important for the
oil circuit, as carbon could block the oil supply
to the camshaft or crankshaft bearings. Using
adhesive tape and paper, seal the water, oil
and bolt holes in the cylinder block. To
prevent carbon entering the gap between the
pistons and bores, smear a little grease in the
gap. After cleaning the piston, rotate the
crankshaft so that the piston moves down the
bore, then wipe out the grease and carbon
with a cloth rag. Clean the piston crowns in
the same way.
14 Check the block and head for nicks, deep
scratches and other damage. If slight, they
may be removed carefully with a file. More
serious damage may be repaired by
machining, but this is a specialist job.
15 If warpage of the cylinder head is
suspected, use a straight-edge to check it for
distortion. Refer to Chapter 2D if necessary.
16 Ensure that the cylinder head bolt holes in
the crankcase are clean and free of oil.
Syringe or soak up any oil left in the bolt
holes. This is most important in order that the
correct bolt tightening torque can be applied
and to prevent the possibility of the block
being cracked by hydraulic pressure when the
bolts are tightened.
17 Renew the cylinder head bolts regardless
of their apparent condition.
Refitting
11.23 Cylinder head bolt tightening sequence
3510 Vauxhall/Opel Omega
18 Ensure the crankshaft is till positioned
approximately 60° BTDC and wipe clean the
mating faces of the head and block.
19 Ensure that the two locating dowels are in
position at each end of the cylinder
block/crankcase surface (see illustration).
20 Fit the new cylinder head gasket to the
block, making sure it is fitted with the correct
way up with its OBEN or TOP mark uppermost
and at the front end of the engine (see
illustration).
21 Carefully refit the cylinder head, locating it
on the dowels.
22 Fit the washers to the new cylinder head
bolts then carefully insert them into position
(do not drop), tightening them finger-tight
only at this stage.
23 Working progressively and in the sequence
shown, first tighten all the cylinder head bolts
to the stage 1 torque setting (see illustration).
2.0 litre DOHC engine in-car repair procedures 2B•11
24 Once all bolts have been tightened to the
stage 1 torque, again working in the sequence
shown, tighten each bolt through its specified
stage 2 angle, using a socket and extension
bar. It is recommended that an anglemeasuring gauge is used during this stage of
the tightening, to ensure accuracy.
25 Working in the specified sequence, go
around again and tighten all bolts through the
specified stage 3 angle.
26 Working again in the specified sequence,
go around and tighten all bolts through the
specified stage 4 angle.
27 Finally go around in the specified
sequence again and tighten all bolts through
the specified stage 5 angle.
28 Ensure the mating surfaces are clean and
dry then refit the breather tube to the cylinder
block and tighten its retaining bolts to the
specified torque.
29 Reconnect the coolant hoses, securing
them in position with the retaining clips.
30 Refit the timing belt rear cover retaining
bolts and tighten them to the specified torque.
31 Refit the camshafts as described in
Section 10.
32 Align all the sprocket timing marks to
bring the camshafts and crankshaft back to
TDC then refit the timing belt as described in
Section 7.
33 Refit the camshaft cover and timing belt
cover(s) as described in Sections 4 and 5.
34 Refit/reconnect the inlet and exhaust
manifolds (see Chapter 4A).
35 Ensure all pipes and hoses are securely
reconnected then refill the cooling system and
refit the spark plugs as described in Chapter 1.
36 Reconnect the battery then start the
engine and check for signs of leaks.
12 Sump removal and refitting
4
Note: There are two possible types of sump
fitted to these engines; early models had a onepiece sump made of pressed steel and later
models had a two-piece sump arrangement
with a small pressed steel sump pan being
fitted to the base of the main sump casting
which is made of aluminium alloy. Proceed as
described under the relevant heading
One-piece sump
Note: A new baffle plate will be required on
refitting (the sump gasket is an integral part of
the plate).
Removal
1 Disconnect the battery negative terminal.
Note: On models with a Vauxhall anti-theft
warning system (ATWS), the battery negative
terminal must be disconnected within 15
seconds of the ignition being switched off to
prevent the alarm system being triggered.
2 Firmly apply the handbrake then jack up the
front of the car and support it on axle stands.
Undo the retaining screws and remove the
undercover from beneath the engine.
3 Drain the engine oil as described in Chapter 1, then fit a new sealing washer and refit
the drain plug, tightening it to the specified
torque.
4 Where necessary, disconnect the wiring
connector from the oil level sender unit on the
sump.
5 Slacken and remove the bolts securing the
support brackets to the transmission housing
and sides of the cylinder block. Remove both
brackets from the engine then remove the
flywheel lower cover plate from the base of
the transmission housing.
6 Slacken and remove the nuts securing the
left- and right-hand engine mounting brackets
to the top of the rubber mountings. Unbolt the
right-hand mounting bracket and remove it
from the cylinder block.
7 Attach an engine hoist to the cylinder head
lifting brackets then raise the hoist until it is
supporting the weight of the engine.
8 Progressively slacken and remove the bolts
securing the sump to the base of the cylinder
block/oil pump. Break the sump joint by
striking the sump with the palm of the hand,
then lower the sump away from the engine
and withdraw it. Raise the engine unit slightly
to gain the necessary clearance required for
sump removal, taking care not to place any
excess strain on the engine wiring/hoses or
exhaust system.
9 Undo the retaining bolts and remove the oil
pump pick-up/strainer from the base of the oil
pump housing, noting the sealing ring, then
remove the baffle plate assembly.
10 Check the oil pump pick-up/strainer for
signs of clogging or splitting and renew/clean
as necessary. Note: If the sump is to be
removed for any length of time, refit the
mounting bracket to the cylinder block and
lower the engine back down onto its mounting
rubbers.
Refitting
11 Remove all traces of dirt and oil from the
mating surfaces of the sump, cylinder block
and oil pump housing. Also remove all traces
of locking compound from the threads of the
oil pump pick-up/strainer bolts and the sump
retaining bolts.
12 Apply a smear of suitable sealant
(Vauxhall recommend the use of sealant 15 03
295 - available from your Vauxhall dealer) to
the areas of the cylinder block mating surface
around the areas of the oil pump housing and
rear main bearing cap joints.
13 Fit a new sealing ring to the oil pump pickup/strainer and apply a few drops of locking
compound (Vauxhall recommend the use of
locking compound 15 10 181 - available from
your Vauxhall dealer) to the threads of the
strainer retaining bolts.
14 Offer up the new baffle plate, making sure
it is correctly located, then refit the oil pump
strainer tightening its retaining bolts to the
specified torque.
3510 Vauxhall/Opel Omega
15 Apply a drop of the locking compound to
each of the sump retaining bolts then offer up
the sump to the cylinder block. Refit the
retaining bolts and progressively tighten them
to the specified torque, working out from the
centre in a diagonal sequence.
16 Refit the mounting bracket to the cylinder
block and tighten its retaining bolts to the
specified torque. Lower the engine back down
onto its mountings making sure the brackets
and mounting rubbers are correctly aligned.
Remove the hoist from the engine then refit
the mounting nuts, tightening them to the
specified torque setting.
17 Refit the flywheel lower cover plate to the
transmission housing then refit the support
brackets. Screw in the bolts securing the
brackets to the cylinder block and
transmission housing and tighten them to
their specified torque settings.
18 Reconnect the oil level sender wiring
connector (where fitted).
19 Refit the undercover then lower the
vehicle to the ground then fill the engine with
fresh oil, with reference to Chapter 1.
Two-piece sump
Note: New sump pan retaining bolts and front
suspension subframe mounting bolts will be
required on refitting. New retaining nuts for
the centre tie rod will also be required.
Removal
20 Carry out the operations described in
paragraphs 1 to 3.
21 Referring to Chapter 12, on models with
Xenon headlights, disconnect the wiring
connector from the headlight system front
vehicle level control sensor then unclip the
link rod from the sensor arm balljoint.
22 Remove the steering linkage centre tie rod
as described in Chapter 10, Section 25.
23 Slacken and remove the nuts securing the
engine left- and right-hand mountings to the
subframe.
24 Attach an engine hoist to the cylinder
head lifting brackets then raise the hoist until
it is supporting the weight of the engine.
Alternatively use an engine support bar to
take the weight of the engine.
25 Referring to Chapter 10, unscrew the front
suspension subframe front mounting bolts by
approximately 4 turns. Support the rear of the
subframe with a jack then slacken and remove
the rear mounting bolts. Lower the rear of the
subframe approximately 10 cm to gain access
to the sump pan.
26 If an oil level sensor is fitted, disconnect
the wiring connector from the sensor
connector on the left-hand side of the main
casting then slide off the retaining clip and
push the connector into the sump.
27 Slacken and remove the bolts securing
the sump pan to the main casting then free
the pan and remove it along with its gasket.
On models with an oil level sensor, take care
not to damage the sensor wiring as the pan is
removed.
2B
2B•12 2.0 litre DOHC engine in-car repair procedures
13.7 Undo the retaining screws and
remove the oil pump cover
13.9 Lift the inner and outer gears
(arrowed) out from the pump housing
28 To remove the main casting from the
engine, disconnect the wiring connector from
the oil temperature sensor (where fitted) then
slacken and remove the bolts securing the
exhaust front pipe mounting bracket in
position.
29 Unscrew the bolts securing the main
casting flange to the transmission housing
then progressively slacken and remove the
bolts securing the casting to the base of the
cylinder block/oil pump. Break the joint by
striking the casting with the palm of the hand,
then lower it away from the engine and
withdraw it. Remove the gasket and discard it.
Note: If the sump pan/main casting are to be
removed for any length of time, raise the
subframe back up into position and refit its
mounting bolts then lower the engine back
down onto the subframe.
30 While the sump is removed, take the
opportunity to check the oil pump pickup/strainer for signs of clogging or splitting. If
necessary, unbolt the pick-up/strainer and
remove it from the base of the oil pump
housing along with its sealing ring. The
strainer can then be cleaned easily in solvent
or renewed.
32 Where necessary, position a new sealing
ring on top of the oil pump pick-up/strainer
and fit the strainer. Apply locking compound
(Vauxhall recommend the use of locking
compound 15 10 181 - available from your
Vauxhall dealer) to the threads of the retaining
bolts then fit the bolts and tighten to the
specified torque.
33 Apply a smear of suitable sealant
(Vauxhall recommend the use of sealant 15 03
295 - available from your Vauxhall dealer) to
the areas of the cylinder block mating surface
around the areas of the oil pump housing and
rear main bearing cap joints.
34 Fit a new gasket to the main casting then
apply a drop of locking compound to the
threads of the casting to cylinder block/oil
pump bolts. Manoeuvre the casting into
position, ensuring the gasket is correctly
positioned, then loosely refit all the retaining
bolts and the exhaust front pipe mounting
bracket.
35 Working out from the centre in a diagonal
sequence, progressively tighten the bolts
securing the main casting to the cylinder
block/oil pump to their specified torque
setting.
36 Tighten the bolts securing the main
casting flange to the transmission housing to
their specified torque settings then securely
tighten the exhaust bracket bolts. Where
necessary, reconnect the oil temperature
sensor.
37 Ensure the sump pan and main casting
surfaces are clean and dry, place a new
gasket on the top of the pan and offer it up to
the main casting. On models with an oil level
sensor, fit a new sealing ring to the wiring
connector and seat the wiring connector in
the main casting, securing it in position with
the retaining clip, prior to seating the sump
pan on the main casting.
38 Fit the new sump pan retaining bolts then
go around in a diagonal sequence and tighten
them to the specified stage 1 torque setting.
Once all bolts have been tightened go around
again and angle-tighten them through the
specified stage 2 angle. It is recommended
that an angle-measuring gauge is used during
this stage of the tightening, to ensure
accuracy.
39 Reconnect the oil level sender wiring
connector (where necessary).
Refitting
31 Remove all traces of dirt and oil from the
mating surfaces of the sump pan, main
casting and cylinder block and (if necessary)
the pick-up/strainer and oil pump housing.
Also remove all traces of locking compound
from the main casting bolts and (where
removed) the pick-up/strainer bolts.
13.10 Oil pressure relief valve components
1 Plunger
2 Spring
3 Sealing washer
4 Valve bolt
3510 Vauxhall/Opel Omega
40 Raise the subframe back up into position
making sure the engine mounting lugs engage
correctly with the subframe cutouts. Fit the four
new rear retaining bolts then remove the
subframe front retaining bolts and fit the new
ones. Tighten the subframe mounting bolts to
their specified torque setting and then through
the specified angles as described in Chapter 10.
41 Remove the hoist from the engine then
refit the nuts securing the engine mountings
to the subframe, tightening them to the
specified torque.
42 Refit the steering linkage centre tie rod as
described in Chapter 10
43 On models with Xenon headlights clip the
link rod balljoint back onto the vehicle level
control sensor and reconnect the wiring
connector (see Chapter 12).
44 Refit the undercover then lower the
vehicle to the ground then fill the engine with
fresh oil, with reference to Chapter 1.
13 Oil pump removal, overhaul and refitting
4
Removal
1 Drain the engine oil as described in Chapter 1, then fit a new sealing washer and refit
the drain plug, tightening it to the specified
torque. Remove the oil filter and discard it.
2 Remove the timing belt as described in
Section 7.
3 Remove the rear timing belt cover as
described in Section 6.
4 Remove the sump and oil pump pickup/strainer as described in Section 12.
5 Disconnect the wiring connector from the
oil pressure switch.
6 Slacken and remove the retaining bolts
then slide the oil pump housing assembly off
of the end of the crankshaft, taking great care
not to lose the locating dowels. Remove the
housing gasket and discard it.
Overhaul
7 Undo the retaining screws and lift off the
pump cover from the rear of the housing (see
illustration).
8 Using a suitable marker pen, mark the
surface of both the pump inner and outer
gears; the marks can then be used to ensure
the gears are refitted the correct way around.
9 Lift out the inner and outer gears from the
pump housing (see illustration).
10 Unscrew the oil pressure relief valve bolt
from the front of the housing and withdraw the
spring and plunger from the housing, noting
which way around the plunger is fitted (see
illustration). Remove the sealing washer from
the valve bolt. Note: The pressure relief valve
can be removed with pump in position on the
engine unit. On models with air conditioning it
will be necessary to unbolt the compressor
mounting bracket assembly from the block to
allow the valve to be removed.
2.0 litre DOHC engine in-car repair procedures 2B•13
13.12a Using a feeler blade to check gear
clearance
13.12b Using a straight edge and feeler
blade to measure gear endfloat
13.14 Fitting a new crankshaft oil seal to
the oil pump housing
11 Clean the components, and carefully
examine the gears, pump body and relief
valve plunger for any signs of scoring or wear.
Renew any component which shows signs of
wear or damage; if the gears or pump housing
are marked then the complete pump
assembly should be renewed.
12 If the components appear serviceable,
measure the clearance between the inner and
outer gears using feeler blades. Also measure
the gear endfloat, and check the flatness of
the end cover (see illustrations). If the
clearances exceed the specified tolerances,
the pump must be renewed.
13 If the pump is satisfactory, reassemble the
components in the reverse order of removal,
noting the following.
a) Ensure both gears are fitted the correct
way around.
b) Fit a new sealing ring to the pressure
relief valve bolt and tighten the bolt to the
specified torque.
c) Tighten the pump cover screws to the
specified torque.
d) On completion prime the oil pump by
filling it with clean engine oil whilst
rotating the inner gear.
20 Refit the oil pump pick-up/strainer and
sump as described in Section 12.
21 Refit the rear timing belt cover to the
engine, tightening its retaining bolts to the
specified torque.
22 Refit the timing belt sprockets, idler
pulleys and tensioner then refit the belt as
described in Sections 7 and 8.
23 On completion, fit a new oil filter and fill
the engine with clean oil as described in
Chapter 1.
number 1 cylinder at TDC. With number 1
piston at TDC the flats on the end of each
balancer shaft should be correctly aligned
(see paragraph 5).
3 Evenly and progressively slacken and
remove the retaining bolts then remove the
balancer unit from the base of the cylinder
block along with the spacer plate which is
fitted between the unit and block. The spacer
plate is used to adjust the balancer unit gear
teeth backlash (see paragraph 10).
Refitting
14 Crankshaft balancer unit
(1998 model year onwards) removal, refitting and adjustment
4
Note: New balancer unit retaining bolts will be
required on refitting.
Removal
1 Remove the sump and oil pump pickup/strainer pipe as described in Section 12.
2 Using a socket on the crankshaft sprocket
bolt, rotate the crankshaft in the normal
direction of rotation until the notch on the
pulley rim is correctly aligned with the pointer
on the timing belt cover. This positions
4 If any work has been carried out on the
crankshaft or a new balancer is being
installed, it will be necessary to adjust the
gear teeth backlash prior to refitting. If the
original balancer unit is to be refitted and no
work has being carried out on the crankshaft
it is permissible to refit the unit with the
original spacer plate without checking the
gear backlash.
5 Ensure the crankshaft pulley notch is still
correctly aligned with the pointer on the rear
cover then rotate the balancer unit gears until
the flats on the gear shaft ends are facing
downwards and are in line with each other
(see illustration).
Refitting
14 Prior to refitting, carefully lever out the
crankshaft oil seal using a flat-bladed
screwdriver. Fit the new oil seal, ensuring its
sealing lip is facing inwards, and press it
squarely into the housing using a tubular drift
which bears only on the hard outer edge of
the seal (see illustration). Press the seal into
position so that it is flush with the housing and
lubricate the oil seal lip with clean engine oil.
15 Ensure the mating surfaces of the oil
pump and cylinder block are clean and dry
and the locating dowels are in position.
16 Fit a new gasket to the cylinder block.
17 Carefully manoeuvre the oil pump into
position and engage the inner gear with the
crankshaft end. Locate the pump on the
dowels, taking great care not damage the oil
seal lip.
18 Refit the pump housing retaining bolts in
their original locations and tighten them to the
specified torque.
19 Reconnect the oil pressure sensor wiring
connector.
14.5 With number 1 cylinder at TDC the balancer unit gear shaft flats should be correctly
aligned as shown
3510 Vauxhall/Opel Omega
2B
2B•14 2.0 litre DOHC engine in-car repair procedures
14.12 Using service tool KM-949 to check
the balancer unit gear teeth backlash.
Ensure the dial gauge is positioned at a
right-angle to the arm and is correctly
seated in the arm groove
1 Right-hand
thumbwheel
2 Left-hand
thumbwheel
3 Measuring arm
base
4 Dial gauge
5 Measuring arm
6 Fit the spacer plate to the top of the
balancer unit then refit the balancer unit to the
cylinder block. Ensure the shaft gear is
correctly engaged with the crankshaft gear,
and screw in the new retaining bolts.
7 Tighten all the bolts by hand then check
that the crankshaft pulley mark and balance
shaft flats are still correctly aligned. If not,
remove the balancer unit and make any
necessary adjustments before refitting it to
the cylinder block.
8 Once the balancer unit is correctly timed
with the crankshaft, go around in a diagonal
sequence and tighten the retaining bolts to
the specified stage 1 torque setting. Once all
bolts have been tightened go around again
and angle-tighten them through the specified
stage 2 angle. It is recommended that an
angle-measuring gauge is used during this
stage of the tightening, to ensure accuracy.
9 Refit the oil pump pick-up/strainer and
sump as described in Section 12.
Adjustment
Note: The following procedure can only be
accurately carried out using Vauxhall service
tool KM-949 and a dial gauge.
10 If work has been carried out on the
crankshaft or a new balancer unit is being
fitted, it is necessary to check the balancer unit
gear teeth backlash. The backlash is controlled
by the thickness of the spacer plate which is
fitted in between the balancer unit and the
cylinder block. The spacer is available in the
following thicknesses; the thickness can be
determined by direct measurement or by the
identification marking on the stamped on it.
Plate thickness
Identification
marking
0.535 to 0.565 mm
55
0.565 to 0.595 mm
58
0.595 to 0.625 mm
61
0.625 to 0.655 mm
64
0.655 to 0.685 mm
67
0.685 to 0.715 mm
70
0.715 to 0.745 mm
73
0.745 to 0.775 mm
76
0.775 to 0.805 mm
79
0.805 to 0.835 mm
82
0.835 to 0.865 mm
85
11 The backlash is measured with the
balancer unit correctly installed on the
cylinder block. If a new balancer unit is being
fitted, obtain the thickest spacer plate
available (identification marking 85) and fit the
balancer unit to the cylinder block using the
original retaining bolts (see paragraphs 5 to 8).
12 Position number 1 cylinder at TDC (see
paragraph 2) and fit the service tool KM-949.
Fit the measuring arm to the right-hand (inlet
manifold side) shaft, ensuring the arm is
horizontal, then screw both knurled
thumbwheels into the balancer shafts and
tighten securely. Position the dial gauge so
that it is at a right-angle to the measuring arm
and its pointer is seated correctly in the arm
groove (see illustration).
13 Using the knurled thumbwheel, rotate the
left-hand (exhaust manifold side) balancer
shaft fully clockwise then zero the dial gauge.
Rotate the shaft fully anti-clockwise and
measure the movement of the arm on the
gauge, noting this figure down on paper.
14 Position the dial gauge clear of the
measuring arm then rotate the crankshaft
through 45° (the balance shafts will rotate
90°). Slacken the right-hand thumbwheel and
return the measurement arm to the horizontal
position before tightening it securely then take
the backlash measurement again.
15 Repeat this procedure twice more until a
total of four backlash measurements have
been obtained.
16 All four backlash measurements should
be within the range of 0.02 to 0.06 mm. If any
one of the four measurements is outside this
range then adjustment is necessary.
17 If adjustment is necessary, remove the
balancer unit from the cylinder block and
recover the spacer plate. Identify the
thickness of the spacer plate (see paragraph 10). The backlash measurements are
decreased by fitting a thinner spacer plate
and increased by fitting a thicker plate.
Calculate the correct thickness of spacer
plate required noting that each plate thickness
3510 Vauxhall/Opel Omega
increases/decreases (as applicable) the backlash measurement by approximately 0.02 mm.
For example, if a backlash measurement of
0.07 mm was obtained and a spacer plate
with the identification marking 67 was
installed, fitting a spacer plate with the
identification marking 64 will decrease the
measurement by approximately 0.02 mm and
bring the backlash to within the specified limit.
18 Select the correct thickness of spacer
plate required then refit the balancer unit as
described in paragraphs 5 to 9.
15 Flywheel/driveplate removal, inspection and
refitting
Refer to Chapter 2A, Section 15.
16 Crankshaft oil seals renewal
4
Front (timing belt end) oil seal
1 Remove the crankshaft sprocket as
described in Section 8.
2 Carefully punch or drill two small holes
opposite each other in the oil seal. Screw a
self-tapping screw into each and pull on the
screws with pliers to extract the seal.
Alternatively carefully lever the seal out of
position.
Caution: Great care must be taken to avoid
damage to the oil pump
3 Clean the seal housing and polish off any
burrs or raised edges which may have caused
the seal to fail in the first place.
4 Lubricate the lips of the new seal with clean
engine oil and ease it into position on the end
of the shaft. Press the seal squarely into
position until it is flush with the housing. If
necessary, a suitable tubular drift, such as a
socket, which bears only on the hard outer
edge of the seal can be used to tap the seal
into position. Take great care not to damage
the seal lips during fitting and ensure that the
seal lips face inwards.
5 Wash off any traces of oil, then refit the
crankshaft sprocket as described in Section 8.
Rear (flywheel/driveplate end)
oil seal
6 Remove the flywheel/driveplate as
described in Chapter 2A, Section 15.
7 Renew the seal as described in paragraphs 2
to 4.
8 Refit the flywheel/driveplate as described in
Chapter 2A, Section 15.
17 Engine/transmission
mountings inspection and renewal
Refer to Chapter 2A, Section 17.
2C•1
Chapter 2 Part C:
2.5 and 3.0 litre engine in-car repair procedures
Contents
Camshaft covers - removal and refitting . . . . . . . . . . . . . . . . . . . . . . 4
Camshaft oil seals - renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Camshafts and followers - removal, inspection and refitting . . . . . . 10
Compression test - description and interpretation . . . . . . . . . . . . . . 2
Crankshaft oil seals - renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Crankshaft pulley - removal and refitting . . . . . . . . . . . . . . . . . . . . . . 5
Cylinder heads - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . 11
Engine oil and filter - renewal . . . . . . . . . . . . . . . . . . . . .See Chapter 1
Engine oil level check . . . . . . . . . . . . . . . . . . . . . . .See Weekly checks
Engine/transmission mountings - inspection and renewal . . . . . . . . 17
Flywheel/driveplate - removal, inspection and refitting . . . . . . . . . . . 15
General information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Oil cooler - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Oil pump - removal, overhaul and refitting . . . . . . . . . . . . . . . . . . . . 13
Sump - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Timing belt - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Timing belt covers - removal and refitting . . . . . . . . . . . . . . . . . . . . . 6
Timing belt sprockets, tensioner and guide pulleys - removal and
refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Top dead centre (TDC) for No 1 piston - locating . . . . . . . . . . . . . . . 3
Degrees of difficulty
Easy, suitable for
novice with little
experience
1
Fairly easy, suitable
for beginner with
some experience
2
Fairly difficult,
suitable for competent
DIY mechanic
3
Difficult, suitable for
experienced DIY
mechanic
4
Very difficult,
suitable for expert DIY
or professional
5
2C
Specifications
General
Engine type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Manufacturer’s engine code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Bore . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stroke . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Maximum power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Maximum torque . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Firing order . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Direction of crankshaft rotation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Compression ratio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
V6 water-cooled. Double overhead camshaft, belt-driven
2.5 litre engine
3.0 litre engine
X25XE
X30XE
81.6 mm
86.0 mm
79.6 mm
85.0 mm
2498 cc
2969 cc
125 kW at 6000 rpm
155 kW at 6200 rpm
227 Nm at 3200 rpm
270 Nm at 3600 rpm
1-2-3-4-5-6 (No 1 cylinder at timing belt end of right-hand cylinder bank)
Clockwise (viewed from timing belt end of engine)
10.8:1
Compression pressures
Standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Maximum difference between any two cylinders . . . . . . . . . . . . . . . . . .
12 to 15 bar (174 to 218 psi)
1 bar (15 psi)
Camshaft
Cam lift:
2.5 litre engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.0 litre engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9.2 mm
10.0 mm
Lubrication system
Oil pump type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Minimum permissible oil pressure at idle speed, with engine
at operating temperature (oil temperature of at least 80°C) . . . . . . . .
Oil pump rotor endfloat:
Inner rotor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Outer rotor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rotor-type, driven directly from crankshaft
1.5 bar (22 psi)
Less than 0.08 mm
Less than 0.10 mm
3510 Vauxhall/Opel Omega
2C•2 2.5 and 3.0 litre engine in-car repair procedures
Torque wrench settings
Auxiliary drivebelt tensioner bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Baffle plate bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Camshaft bearing cap bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Camshaft cover bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Camshaft sensor bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Camshaft sprocket bolt:
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Connecting rod big-end bearing cap bolt:
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Coolant pipe (right-hand)-to-cylinder block bolts . . . . . . . . . . . . . . . . .
Coolant pipe/dipstick tube/engine lifting bracket bolt . . . . . . . . . . . . . .
Coolant pump bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Coolant pump pulley bolts:
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Crankcase breather housing bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Crankshaft pulley bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Crankshaft sensor rotor bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Crankshaft sprocket bolt:
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cylinder head bolts:
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cylinder head coolant outlet bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Driveplate bolts:
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine/transmission mounting bolts:
Left- and right-hand mountings:
Mounting-to-subframe nut . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Mounting-to-mounting bracket nut . . . . . . . . . . . . . . . . . . . . . . . . .
Mounting bracket-to-cylinder block bolts . . . . . . . . . . . . . . . . . . . .
Vibration damper bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rear mounting:
Mounting-to-transmission bolts . . . . . . . . . . . . . . . . . . . . . . . . . . .
Mounting-to-crossmember nuts . . . . . . . . . . . . . . . . . . . . . . . . . . .
Crossmember-to-body bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine-to-transmission unit bolts:
Transmission-to-cylinder block bolts . . . . . . . . . . . . . . . . . . . . . . . . .
Transmission-to-sump flange bolts . . . . . . . . . . . . . . . . . . . . . . . . . .
Flywheel bolts:
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Main bearing cap/bridge casting:
Main bearing cap bolts:
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Casting threaded sleeves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Casting-to-cylinder block (M8) bolts . . . . . . . . . . . . . . . . . . . . . . . . .
Oil cooler:
Cover bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cover nuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oil cooler pipe union nuts and bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Nm
35
8
8
8
8
lbf ft
26
6
6
6
6
50
Angle-tighten a further 60°
Angle-tighten a further 15°
37
35
Angle-tighten a further 45°
Angle-tighten a further 15°
20
25
25
26
8
Angle-tighten a further 30°
Angle-tighten a further 30°
8
20
15
15
18
18
6
6
15
11
250
Angle-tighten a further 45°
Angle-tighten a further 15°
185
25
Angle-tighten a further 90°
Angle-tighten a further 90°
Angle-tighten a further 90°
Angle-tighten a further 15°
30
18
22
65
Angle-tighten a further 30°
Angle-tighten a further 15°
48
55
40
60
40
41
30
44
30
40
20
45
30
15
33
60
40
44
30
65
Angle-tighten a further 30°
Angle-tighten a further 15°
48
50
Angle-tighten a further 60°
Angle-tighten a further 15°
8
20
37
6
15
20
30
30
15
22
22
3510 Vauxhall/Opel Omega
2.5 and 3.0 litre engine in-car repair procedures 2C•3
Torque wrench settings (continued)
Oil filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oil pump cover screws . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oil pump retaining bolts - see text for details:
M6 bolts with original timing belt rear cover:
Initial torque . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Final torque . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
M6 bolts with modified timing belt rear cover . . . . . . . . . . . . . . . . . .
M8 bolts:
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oil pump pick-up/strainer bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Power steering pump pulley bolts:
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Sump bolts:
Sump pan bolts:
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Main casting bolts:
Casting-to-cylinder block/oil pump bolts . . . . . . . . . . . . . . . . . . . .
Casting flange-to-transmission bolts . . . . . . . . . . . . . . . . . . . . . . .
Sump drain plug:
Hex-head bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Torx-head bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Timing belt cover bolts:
Outer cover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rear cover:
M6 bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
M8 threaded stud . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Timing belt lower guide pulley bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Timing belt tensioner pulley/upper guide pulley assembly:
Backplate-to-cylinder head bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tensioner pulley nut . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Guide pulley bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Nm
15
8
lbf ft
11
6
8
10
10
6
7
7
12
20
8
9
15
6
20
Angle-tighten a further 30°
Angle-tighten a further 15°
15
8
Angle-tighten a further 30°
6
15
40
11
30
55
10
41
7
8
6
8
10
40
6
7
30
40
20
40
30
15
30
2C
1 General information
How to use this Chapter
1 This Part of Chapter 2 is devoted to in-car
repair procedures for the engine. All
procedures concerning engine removal and
refitting, and engine block/cylinder head
overhaul can be found in Chapter 2D.
2 Most of the operations included in this Part
are based on the assumption that the engine
is still installed in the car. Therefore, if this
information is being used during a complete
engine overhaul, with the engine already
removed, many of the steps included here will
not apply.
Engine description
3 The engine is a double overhead camshaft,
V6 unit, mounted at the front of the car with
the transmission on its rear. The cylinder
banks are arranged at a 54° angle to keep the
engine as compact as possible. This engine is
often referred to as the V6 ECOTEC engine
(Emission
Consumption
Optimized
TEChnology).
4 The cylinder block is of the dry-liner type.
The crankshaft is supported within the cylinder
block on four shell-type main bearings. Thrustwashers are fitted to number 4 (flywheel/
driveplate end) main bearing, to control crankshaft endfloat.
5 The aluminium alloy pistons are of the
slipper type, and are fitted with three piston
rings, comprising two compression rings and
a scraper-type oil control ring. The pistons are
joined to the connecting rods by gudgeon
pins; on 2.5 litre engines the pins are an
interference-fit and on 3.0 litre engines the
pins are secured in position with circlips. On
all engines, the connecting rods are attached
to the crankshaft by horizontally split shelltype big-end bearings.
6 The camshafts run directly in the cylinder
heads, and are driven by the crankshaft via a
toothed rubber timing belt. The camshafts
operate each valve via a follower. Each
follower incorporates a hydraulic selfadjusting valve which automatically adjust the
valve clearances.
7 Lubrication is by pressure-feed from a
rotor-type oil pump, which is mounted on the
front end of the crankshaft. It draws oil
through a strainer located in the sump, and
then forces it through an externally mounted
3510 Vauxhall/Opel Omega
full-flow cartridge-type filter. The oil flows into
galleries in the main bearing cap bridge
arrangement and cylinder block/crankcase,
from where it is distributed to the crankshaft
(main bearings) and camshafts. The big-end
bearings are supplied with oil via internal
drillings in the crankshaft, while the camshaft
bearings also receive a pressurised supply.
The camshaft lobes and valves are lubricated
by splash, as are all other engine
components. An oil cooler is fitted to help
keep the oil temperature stable under arduous
operating temperatures; the cooler is fitted to
the top of the cylinder block where it is
located in between the cylinder banks.
8 A semi-closed crankcase ventilation system
is employed; crankcase fumes are drawn from
cylinder head cover, and passed via a hose to
the inlet manifold.
Repair operations possible with
the engine in the car
9 The following operations can be carried out
without having to remove the engine from the
vehicle.
a) Removal and refitting of the cylinder
heads.
b) Removal and refitting of the timing belt
and sprockets.
2C•4 2.5 and 3.0 litre engine in-car repair procedures
3.5a Align the relevant camshaft sprockets timing marks with the
cutouts on the timing belt rear cover (arrowed) on both the righthand . . .
c) Renewal of the camshaft oil seals.
d) Removal and refitting of the camshafts
and followers.
e) Removal and refitting of the sump.
f) Removal and refitting of the connecting
rods and pistons*.
g) Removal and refitting of the oil pump.
h) Renewal of the crankshaft oil seals.
i) Renewal of the engine mountings.
j) Removal and refitting of the
flywheel/driveplate.
* Although the operation marked with an asterisk can be carried out with the engine in the
car after removal of the sump, it is better for the
engine to be removed, in the interests of cleanliness and improved access. For this reason,
the procedure is described in Chapter 2D.
2 Compression test description and interpretation
Refer to Chapter 2A, Section 2.
3 Top dead centre
(TDC) for No 1 piston locating
3
1 In its travel up and down its cylinder bore,
Top Dead Centre (TDC) is the highest point
that each piston reaches as the crankshaft
rotates. While each piston reaches TDC both
at the top of the compression stroke and
again at the top of the exhaust stroke, for the
purpose of timing the engine, TDC refers to
the piston position (usually number 1) at the
top of its compression stroke.
2 Number 1 piston (and cylinder) is at the
front (timing belt) end of the right-hand
cylinder bank, and its TDC position is located
as follows. Note that the crankshaft rotates
clockwise when viewed from the front of the
vehicle.
3.5b . . . and left-hand cylinder heads (arrowed) . . .
3 Disconnect the battery negative terminal. If
necessary, remove all the spark plugs as
described in Chapter 1 to enable the engine to
be easily turned over.
4 Remove the timing belt outer cover to gain
access to the camshaft sprocket timing marks
(see Section 6).
5 Using a socket and extension bar on the
crankshaft sprocket bolt, rotate the crankshaft
until the relevant timing marks on the
camshaft sprockets are all at the top and are
correctly aligned with the marks on the timing
belt rear cover. Each sprocket has two timing
marks the correct mark to use is as follows
(see illustrations).
Camshaft
Timing mark to be used
Right-hand cylinder head exhaust
1
Right-hand cylinder head inlet
2
Left-hand cylinder head inlet
3
Left-hand cylinder head exhaust
4
6 With the camshaft sprocket marks correctly
positioned, align the notch on the crankshaft
pulley rim with the pointer on the oil pump
housing (see illustration). The engine is now
positioned with No1 piston at TDC on its
compression stroke. Note: If the crankshaft
pulley has been removed, use the mark on the
crankshaft sprocket rim. The mark should be
aligned with the cutout on the base of the oil
pump housing (see Section 7).
4 Camshaft covers removal and refitting
3
Removal
1 Remove the inlet manifold as described in
Chapter 4A.
Right-hand cover
2 Disconnect the plug caps from the plugs
then unclip the HT leads and position them
clear of the cover.
3 Evenly and progressively slacken and
remove the camshaft cover retaining bolts.
4 Lift the camshaft cover away from the
cylinder head and recover the cover seals and
the sealing rings which are fitted to each of
the retaining bolt holes. Examine the seal and
sealing rings for signs of wear or damage and
renew if necessary.
Left-hand cover
3.6 . . . and the crankshaft pulley notch
with the pointer on the oil pump housing
(arrowed) to position No1 piston at TDC on
its compression stroke
3510 Vauxhall/Opel Omega
5 To improve access, remove the windscreen
wiper arms and the water deflector panel (see
Chapter 12, Sections 15 and 16). Access can
be further improved by disconnecting the
engine wiring harness as described in
paragraphs 14 to 16 of Section 11 and
positioning it clear of the cover.
6 On models with air conditioning, unbolt the
air conditioning pipe/hose bracket from the
front of the cylinder head and position the
hose/pipe to one side.
7 Lift the oil filler neck retaining tab then twist
the neck anti-clockwise and remove it from
the top of the cover (see illustrations).
Recover the neck sealing ring and discard it; a
new one should be used on refitting.
2.5 and 3.0 litre engine in-car repair procedures 2C•5
4.7a Lift the retaining tab (arrowed) . . .
8 Remove the cover as described
paragraphs 3 and 4 (see illustration).
4.7b . . . and rotate the oil filler neck anticlockwise to free it from the left-hand
camshaft cover
4.8 Removing the left-hand camshaft
cover
4.9a Fit the new seals securely to the
cover grooves . . .
4.9b . . . and install the sealing rings in the
bolt hole grooves
in
Refitting
Right-hand cover
9 Ensure the cover and cylinder head
surfaces are clean and dry then fit the seals
securely to the cover grooves. Fit the sealing
rings to the recesses around each retaining
bolt hole, holding them in position with a
smear of grease (see illustrations).
10 Apply a smear of suitable sealant
(Vauxhall recommend the use of sealant 15 03
295 - available from your Vauxhall dealer) to
the areas of the cylinder head surface around
the front inlet and exhaust camshaft bearing
caps and also to the semi-circular cutouts on
the rear of the head (see illustrations).
11 Carefully manoeuvre the camshaft cover
into position, taking great care to ensure all
the sealing rings remain correctly seated.
12 Refit the cover retaining bolts and tighten
the retaining bolts to the specified torque,
working in a spiral pattern from the centre
outwards.
13 Securely reconnect the plug caps to the
spark plugs making sure the HT leads are
clipped securely in position.
14 Refit the inlet manifold as described in
Chapter 4A.
Left-hand cover
15 Refit the cover as described in
paragraphs 9 to 12.
16 Fit a new sealing ring to the filler neck
then refit the neck to the cover making sure its
retaining tab is correctly engaged with the
cover retaining bolt.
17 Where necessary, refit the air conditioning
pipe/hose retaining clip and securely tighten
its retaining bolt.
18 Refit the windscreen wiper motor cover
panel and wiper arms as described in Chapter 12. Where necessary, reconnect the
engine wiring harness making sure the wiring
4.10a Apply sealant to the areas at the sides of the camshaft
front bearing caps (arrowed) . . .
is correctly routed and all connectors are
securely connected.
5 Crankshaft pulley removal and refitting
2
Removal
1 Remove the auxiliary drivebelt as described
in Chapter 1. Prior to removal, mark the
direction of rotation on the belt to ensure the
belt is refitted the same way around.
4.10b . . . and also to the semi-circular cut-outs (arrowed) on the
rear of the cylinder head
3510 Vauxhall/Opel Omega
2C
2C•6 2.5 and 3.0 litre engine in-car repair procedures
6.4a Retain the coolant pump shaft with
an open-ended spanner then undo the
retaining bolts . . .
6.4b . . . and remove the pulley from the
engine
2 Using a socket and extension bar on the
crankshaft sprocket bolt, turn the crankshaft
until the notch on the pulley rim is correctly
aligned with the pointer on the cover.
3 Slacken and remove the small retaining
bolts securing the pulley to the crankshaft
sprocket and remove the pulley from the
engine. If necessary, prevent crankshaft
rotation by holding the sprocket retaining bolt
with a suitable socket.
5 Refit the auxiliary drivebelt as described in
Chapter 1 using the mark made prior to
removal to ensure the belt is fitted the correct
way around.
Refitting
Outer cover
4 Check that the crankshaft sprocket mark is
still aligned with the mark on the oil pump
housing then manoeuvre the crankshaft pulley
into position. Align the notch on the pulley rim
with the pointer then seat the pulley on the
sprocket and tighten its retaining bolts to the
specified torque.
Note: New coolant pump and power steering
pump pulley bolts will be required on refitting.
6.5a Insert a socket and extension bar
through the power steering pump pulley
then undo the retaining bolts . . .
6.7b . . . and right-hand covers and
position the wiring harness clear of the
tray
6 Timing belt covers removal and refitting
4
Removal
1 Remove the multi-ram air intake system
pre-volume chamber assembly as described
in Chapter 4A.
2 Remove the secondary air injection system
front connecting pipe as described in Chapter 4B.
3 Remove the auxiliary drivebelt as described
in Chapter 1. Prior to removal, mark the
direction of rotation on the belt to ensure the
belt is refitted the same way around.
4 Slacken and remove the coolant pump
drivebelt pulley retaining bolts whilst retaining
the pump shaft with an open-ended spanner.
Remove the pulley and discard the bolts; new
ones must be used on refitting (see
illustrations).
5 Insert a socket and extension bar in through
the one of the power steering pump pulley
holes and locate it on a pump mounting bolt
to prevent rotation. Slacken and remove the
pulley retaining bolts and remove the pulley,
noting which way around it is fitted (see
illustrations). Discard the bolts; new ones
must be used on refitting.
6 Disconnect the right-hand cylinder bank
knock sensor wiring connector and unclip it
from the front of the timing belt cover.
7 Unclip the covers from the front and righthand end of the wiring harness tray which
runs across the front of the timing belt cover.
Disconnect the wiring connector from the
EGR valve and position the wiring harness
clear of the timing belt cover then undo the
retaining bolts and remove the tray from the
belt cover (see illustrations).
8 Slacken and remove the retaining bolts and
remove the auxiliary drivebelt tensioner
assembly from the right-hand cylinder head
(see illustration).
6.5b . . . and remove the pulley from the
pump
6.7a Unclip the front . . .
6.7c Undo the retaining bolts and remove
the tray from the timing belt cover
6.8 Undo the retaining bolts and remove
the auxiliary drivebelt tensioner
3510 Vauxhall/Opel Omega
2.5 and 3.0 litre engine in-car repair procedures 2C•7
9 Slacken and remove the retaining bolts
then remove the outer cover from the engine
unit along with its seal (see illustration).
Refitting
10 Ensure the seal is firmly fixed to the cover
prior to refitting. If necessary, glue it in
position with a suitable adhesive (Vauxhall
recommend the use of adhesive 08 983 341).
Refit the cover to the engine and tighten its
retaining bolts to the specified torque.
11 Refit the auxiliary drivebelt tensioner and
tighten its retaining bolts to the specified
torque.
12 Refit the wiring harness tray onto the
cover and securely tighten its retaining bolts.
Seat the wiring correctly in the tray then clip
on the front and right-hand covers.
13 Refit the drivebelt pulleys to the coolant
and power steering pump then fit the new
retaining bolts. Tighten the pulley bolts to the
specified stage 1 torque then angle-tighten
through the specified stage 2 and 3 angles. It
is recommended that an angle-measuring
gauge is used during the final stages of the
tightening, to ensure accuracy.
14 Refit the auxiliary drivebelt as described in
Chapter 1 using the mark made prior to
removal to ensure the belt is fitted the correct
way around.
15 Refit the air injection system pipe and the
pre-volume chamber as described in Chapter 4A and 4B.
Rear cover
Removal
16 Remove the timing belt as described in
Section 7.
17 Remove the camshaft sprockets, the
timing belt tensioner pulley/upper guide pulley
assembly and the lower guide pulley as
described in Section 8.
18 Drain the cooling system and remove the
coolant pump (see Chapters 1 and 3).
19 Undo the retaining bolts, noting the
correct fitted location of the threaded stud,
and remove the rear cover from the engine
unit (see illustration).
Refitting
20 Refit the rear cover to the engine and
tighten its retaining bolts and the threaded
stud to their specified torque settings.
21 Refit the coolant pump as described in
Chapter 3.
22 Refit the guide pulley, tensioner assembly,
camshaft sprockets and crankshaft sprocket
as described in Section 8 then refit the timing
belt as described in Section 7.
23 On completion, refill the cooling system
as described in Chapter 1.
7 Timing belt removal and refitting
4
Note: Accurate adjustment of the timing belt
requires the use of the following Vauxhall
service tools; camshaft sprocket locking tools
(KM-800-1 and KM-800-2), crankshaft
sprocket locking tool (KM-800-10), timing belt
locating wedge (KM-800-30) and a camshaft
sprocket timing gauge (KM-800-20) (see
illustration). If the belt is to be refitted without
the use of the service tools, it is
recommended that the belt adjustment is
checked at the earliest possible opportunity
by a Vauxhall dealer.
Note: The timing belt must be removed and
refitted with the engine cold.
Removal
1 Disconnect the battery negative lead then
position No1 cylinder at TDC on its
6.19 Ensure the threaded stud is correctly positioned when
refitting the timing belt rear cover
6.9 Removing the timing belt outer cover
compression stroke as described in Section 3.
Note: On models with a Vauxhall anti-theft
warning system (ATWS), the battery negative
terminal must be disconnected within 15
seconds of the ignition being switched off to
prevent the alarm system being triggered.
2 Remove the crankshaft pulley as described
in Section 5.
3 Check the camshaft sprocket timing marks
are all correctly aligned with the rear cover
marks and the crankshaft sprocket timing
mark is aligned with the cutout on the oil
pump housing.
4 If the Vauxhall service tools are available, fix
the service tool (KM-800-10) to the crankshaft
sprocket and lock the crankshaft in position
by clamping the tool locking arm firmly around
the coolant pump flange. Lock the camshafts
in position by inserting the service tools
making sure the TOP marking on each tool is
uppermost; the sprockets on the right-hand
cylinder head must be locked with KM-800-1
(tool is stamped with numbers 1 and 2 and
handle is coloured red) and the left-hand
cylinder head sprockets with KM-800-2 (tool
is stamped with numbers 3 and 4 and handle
is coloured green) (see illustrations).
7.0 Vauxhall timing belt service tools
1 Timing gauge (KM-800-20)
2 Sprocket locking tool
(KM-800-1)
3 Timing belt wedge (KM-800-30)
3510 Vauxhall/Opel Omega
4 Crankshaft locking tool
(KM-800-10)
5 Sprocket locking tool
(KM-800-2)
2C
2C•8 2.5 and 3.0 litre engine in-car repair procedures
7.4a If the service tools are available,
firmly attach the crankshaft locking tool to
the sprocket . . .
7.4b . . . and clamp its locking arm firmly
around the coolant pump flange
7.4c Insert the locking tools correctly in
between the sprockets . . .
7.4d . . . making sure their TOP markings
are uppermost
7.5a Slacken the tensioner pulley retaining
nut . . .
7.5b . . . then rotate the pulley clockwise,
positioning it just before its stop, and
secure it by retightening the nut
5 Slacken the timing belt tensioner pulley nut.
Using an Allen key fitted to the hexagonal
cutout, rotate the tensioner pulley clockwise
so it is positioned just before its stop and hold
it in position by securely tighten the retaining
nut (see illustrations).
6 Slacken the retaining bolts for the timing
belt upper and lower guide pulleys (see
illustrations).
7 Slide the timing belt off from its sprockets
and remove it from the engine. If the new belt
is not being fitted straight away and the
service tools are not being used, rotate the
crankshaft backwards by approximately 60°;
this will position the pistons approximately
halfway up the bores reducing the risk of the
valves contacting the pistons should the
camshafts move.
8 Check the timing belt carefully for any signs
of uneven wear, splitting or oil contamination,
and renew it if there is the slightest doubt
about its condition. If the fitting markings on
the outside of the original belt are no longer
visible the belt must be renewed regardless of
its apparent condition (see paragraph 12). If
the engine is undergoing an overhaul and has
covered 40 000 miles or it was more than 4
years since the original belt was fitted, renew
the belt as a matter of course, regardless of its
apparent condition (from 1997 onwards the
belt renewal interval was increased to 80 000
miles or 8 years). If signs of oil contamination
are found, trace the source of the oil leak and
rectify it, then wash down the engine timing
belt area and all related components to
remove all traces of oil.
7.6a Slacken the retaining bolts securing
the upper guide pulley . . .
7.6b . . . and lower guide pulley in position
then slide the belt off the sprockets
3510 Vauxhall/Opel Omega
Refitting
Note: There are two different types of timing
belt and tensioner assembly available for this
engine and it is essential that the timing belt is
of the correct type for the tensioner. A
modified tensioner assembly and timing belt
were fitted as standard to later (1997 on
model year) engines, enabling the belt
renewal interval on these engines to be
extended to 80 000 miles or 8 years. The
modified tensioner assembly can be identified
by checking the letter stamped on the
tensioner pulley/upper guide roller backplate;
the original tensioner is marked with D and
the modified assembly marking has an E in it
(EA or EB) (see illustration 7.15). It is most
important to check the tensioner backplate
marking before ordering a timing belt since
the modified tensioner and belt can also be
installed on early (pre 1997 model year)
engines to enable the timing belt renewal
interval to be extended. See your Vauxhall
dealer for further details.
9 On reassembly, thoroughly clean the timing
belt sprockets and tensioner/guide pulleys.
10 Check that the crankshaft sprocket timing
mark is still aligned with the cutout on the oil
pump housing and the camshaft sprocket
marks are aligned with the marks on the rear
cover (see Section 3) (see illustrations). If the
crankshaft was moved back 60°, rotate it
back to TDC to bring the marks into
alignment.
2.5 and 3.0 litre engine in-car repair procedures 2C•9
7.10a Ensure the right-hand cylinder head camshaft sprocket
markings (1 and 2) . . .
7.10b . . . and the left-hand cylinder head camshaft markings
(3 and 4) are all correctly aligned with the rear cover cutouts
(arrowed) . . .
7.10c . . . and the crankshaft sprocket
timing mark is correctly aligned with the oil
pump housing cutout (arrowed)
7.13a Align the double line on the timing
belt with the crankshaft sprocket
timing mark
7.13b If the service tool is available secure
the belt in position with the wedge
11 If the special tools are available lock the
camshaft sprockets and crankshaft sprocket
in position as described in paragraph 4.
12 Examine the fitting marks on the outer
face of the timing belt. The arrows on the belt
must point in the direction of rotation and the
double line on the belt should be aligned with
the crankshaft sprocket mark. The four single
lines on the belt will then align with the
camshaft sprocket timing marks if the belt is
correctly installed.
13 Ensure the arrows on the belt are pointing
in the correct direction of rotation then align
the double line on the belt with the crankshaft
sprocket timing mark and engage the belt
with the sprocket. If the locating wedge (KM800-30) is available secure the belt in position
by inserting the wedge in between the righthand side of the belt and the rear cover (see
illustrations).
14 Check the identification marking stamped
onto the tensioner pulley/upper guide pulley
backplate (see Note at the start of the refitting
procedure).
15 On early engines with the original
tensioner (marked with a D - see illustration),
fit the timing belt over the lower guide pulley
then around the left-hand cylinder head
camshaft sprockets making sure the belt
fitting marks are correctly aligned with the
sprocket marks. Fit the belt around the upper
guide pulley then over the right-hand cylinder
camshaft, again making sure the fitting marks
are correctly aligned and tensioner pulley. Do
not twist the belt sharply while refitting it.
16 On all engines fitted with the modified
tensioner (marked with an E - see illustration
7.15), fit the belt behind the tensioner pulley
and then over the right-hand cylinder head
camshaft sprockets ensuring that the fitting
marks are both correctly aligned with the
sprocket marks. Fit the belt around the upper
guide pulley then over the left-hand cylinder
camshaft sprockets, again making sure the
fitting marks are correctly aligned, and finally
over the lower guide pulley (see
illustrations). Do not twist the belt sharply
while refitting it.
7.15 Checking the marking (location
arrowed) on the tensioner/upper guide
pulley backplate to identify which type of
tensioner assembly is fitted to your engine
- see text
7.16a On engines with a modified
tensioner, work around in a clockwise
direction and engage the belt first with the
right-hand cylinder head sprockets . . .
3510 Vauxhall/Opel Omega
2C
2C•10 2.5 and 3.0 litre engine in-car repair procedures
7.16b . . . and then the left-hand head sprockets (directional
fitting arrows arrowed), making sure the fitting lines are all
correctly aligned with the sprockets . . .
17 On all engines, ensure that the belt teeth
are correctly seated centrally in the sprockets
and the sprocket timing marks/belt fitting
marks are correctly aligned. If adjustment is
necessary, disengage the belt from the
sprockets and make any necessary
adjustments.
7.18a Remove all slack from the left-hand
run of the belt by rotating the lower guide
pulley whilst making sure the sprocket
timing marks remain in alignment (timing
gauge shown) . . .
7.18b . . . then hold the pulley stationary
and tighten its retaining bolt to the
specified torque
7.16c . . . and finally over the lower guide pulley
18 Slacken the lower guide pulley retaining
bolt. Rotate the pulley anti-clockwise to
remove all slack from the left-hand run of the
belt without placing any excess strain on the
belt. Ensure that all the sprocket timing marks
remain in alignment as the pulley is moved; if
the service tools are available, remove the
locking tools and use the timing gauge (KM800-20) to check the sprocket mark positions.
Once the pulley is correctly positioned, hold it
stationary and tighten its retaining bolt to the
specified torque (see illustrations).
19 Slacken the upper guide pulley retaining
bolt. Rotate the pulley anti-clockwise to
remove all slack from the top run of the belt
without placing any excess strain on the belt.
Ensure that all the sprocket timing marks
remain in alignment as the pulley is moved.
Once the pulley is correctly positioned, hold it
stationary and tighten its retaining bolt to the
specified torque (see illustration).
20 Slacken the timing belt tensioner pulley
nut then, using an Allen key, rotate the
tensioner arm anti-clockwise until the gap
between the tensioner plate and its stop is 0.5
to 1.5 mm (see illustration). Hold the
tensioner pulley in this position and securely
tighten its retaining nut.
21 Remove all the service tools (where fitted)
then using a socket on the crankshaft
sprocket bolt, rotate the crankshaft smoothly
through two complete turns (720°) in the
normal direction of rotation to settle the timing
belt in position.
22 Check that all the camshaft and
crankshaft sprocket timing marks are
correctly realigned then slacken the tensioner
nut again. Note: The belt fitting lines will not
be realigned with the sprocket marks; they
serve no purpose once the belt has been
installed.
23 Using an Allen key, position the tensioner
pulley so that the index mark on the tensioner
plate is positioned 3 to 4 mm above the mark
on the backplate stop (see illustration). Hold
the tensioner correctly in position and tighten
its retaining nut to the specified torque.
24 Rotate the crankshaft smoothly through
7.19 Remove all slack from the top run of
the belt then hold the upper pulley
stationary and tighten its retaining bolt to
the specified torque
7.20 Rotate the tensioner pulley anticlockwise until the gap (arrowed) is 0.5 to
1.5 mm then securely tighten its retaining
nut
3510 Vauxhall/Opel Omega
2.5 and 3.0 litre engine in-car repair procedures 2C•11
7.23 Adjust the tensioner pulley so that its index mark (A) is
positioned 3 to 4 mm above backplate mark (B) then tighten its
retaining nut to the specified torque
another two complete turns (720°) in the
normal direction of rotation to bring the
sprocket timing marks back into alignment.
25 If the service tools are available, lock the
crankshaft in position (KM-800-10) and check
the camshaft sprocket timing marks are
correctly positioned using the timing gauge
(KM-800-20).
26 If the service tools are not available,
ensure the crankshaft sprocket timing mark is
correctly aligned with the cutout on the oil
pump housing and all the camshaft sprocket
timing marks are exactly aligned with the
cutouts on the rear cover.
27 If adjustment is necessary repeat the
operations described in paragraphs 18 to 26.
28 Once the timing marks are all correctly
aligned, refit the timing belt cover and
crankshaft pulley as described in Sections 5
and 6. Note: If refitting has been carried out
without the use of the service tools, it is
advisable to have the belt adjustment checked
by a Vauxhall dealer at the earliest possible
opportunity.
8.2b If the camshaft cover has been
removed, the camshaft can be held with an
open-ended spanner on the flats provided
8.2a Using a home-made tool to prevent rotation as the camshaft
sprocket bolt is slackened
8 Timing belt sprockets,
tensioner and guide pulleys removal and refitting
4
Camshaft sprockets
Note: New sprocket retaining bolt(s) will be
required on refitting.
Removal
1 Remove the timing belt as described in
Section 7. Once the belt has been removed,
rotate the crankshaft backwards by
approximately 60°; this will position the
pistons approximately halfway up the bores
reducing the risk of the valves contacting the
pistons.
2 The camshaft must be prevented from
turning as the sprocket bolt is unscrewed, and
this can be achieved in one of two ways.
a) Make up a sprocket-holding tool using
two lengths of steel strip (one long, the
other short), and three nuts and bolts; one
8.3a Unscrew the retaining bolt and
washer . . .
3510 Vauxhall/Opel Omega
nut and bolt forms the pivot of a forked
tool, with the remaining two nuts and
bolts at the tips of the ‘forks’ to engage
with the sprocket spokes (see
illustration).
b) Remove the camshaft cover as described
in Section 4 and hold the camshaft with
an open-ended spanner on the flats
provided (see illustration).
3 Unscrew the retaining bolt and washer and
remove the sprocket from the end of the
camshaft (see illustrations). If the sprocket
locating pin is a loose fit in the camshaft end,
remove it and store it with the sprocket for
safe-keeping.
4 If necessary, remove the remaining
sprocket(s) using the same method.
Refitting
5 Prior to refitting check the oil seal(s) for
signs of damage or leakage. If necessary,
renew as described in Section 9.
6 Ensure the locating pin is in position in the
camshaft end.
8.3b . . . and remove the sprocket from the
camshaft
2C
2C•12 2.5 and 3.0 litre engine in-car repair procedures
8.7a Right-hand cylinder head camshaft sprocket. Ensure timing
mark and slot 1 are used on the exhaust camshaft and 2 on the
inlet camshaft
8.7b Left-hand cylinder head camshaft sprocket. Ensure timing
mark and slot 3 are used on the inlet camshaft and 4 on the
exhaust camshaft
8.8a Ensure the locating pins are engaged in the correct sprocket
slots (arrowed) . . .
8.8b . . . and the relevant sprocket timing marks are correctly
aligned with the rear cover cutouts (arrowed)
7 Note that there are two pairs of camshaft
sprockets, one for the right-hand cylinder
head and the other for the left-hand cylinder
head; the right-hand cylinder head sprockets
carry the identification marks 1 and 2 and the
left-hand cylinder head sprockets the marks 3
and 4. The inlet and exhaust camshaft
sprockets on each head are the same but
each one is equipped with two locating pin
cutouts and two timing marks. On refitting is
vital that the sprocket locating pin is engaged
in the correct sprocket slot as follows and the
correct timing mark is used (see
illustrations).
8.9a Retaining the sprocket/camshaft then
tighten the retaining bolt first to the stage
1 torque . . .
8.9b . . . and then through the specified
stage 2 and 3 angles
3510 Vauxhall/Opel Omega
Camshaft
Sprocket slot/timing
mark number to be used
Right-hand cylinder head exhaust
1
Right-hand cylinder head inlet
2
Left-hand cylinder head inlet
3
Left-hand cylinder head exhaust
4
8 Ensure the camshaft locating pin is engaged
in the correct sprocket cutout then fit the washer
and new retaining bolt (see illustrations).
9 Retain the sprocket by the method used on
removal, and tighten the sprocket retaining bolt
to the specified stage 1 torque setting then
angle-tighten the bolt through the specified
stage 2 angle, using a socket and extension
bar, and finally through the specified stage 3
angle (see illustrations). It is recommended
that an angle-measuring gauge is used during
the final stages of the tightening, to ensure
accuracy. If a gauge is not available, use white
paint to make alignment marks between the
bolt head and sprocket prior to tightening; the
marks can then be used to check that the bolt
has been rotated through the correct angle.
2.5 and 3.0 litre engine in-car repair procedures 2C•13
8.13 Home-made tool for preventing
crankshaft rotation as the sprocket bolt is
slackened
8.14a Unscrew the retaining bolt . . .
10 Ensure the relevant camshaft sprocket
timing marks are all correctly aligned with the
cutouts on the rear cover then carefully rotate
the crankshaft in the normal direction of
rotation until the sprocket mark is correctly
realigned with the notch on the oil pump
housing.
11 Refit the timing belt as described in
Section 7 then (where necessary) refit the
camshaft cover as described in Section 4.
crankshaft. Discard the bolt; a new one must
be used on refitting. If necessary, slide the
spacer out from the oil seal and remove it
from the crankshaft; if the outer surface of the
spacer is damaged it should be renewed (see
illustrations).
Refitting
12 Remove the timing belt as described in
Section 7.
13 The crankshaft must be prevented from
turning as the sprocket bolt is unscrewed (the
bolt is very tight), and this can be achieved in
anyone of the following ways.
a) Use the holding tool described in
paragraph 2 securing the tool to the
sprocket with two bolts screwed into
opposite pulley retaining bolt holes (see
illustration).
b) On manual transmission models have an
assistant select top gear and apply the
brakes firmly.
c) If the engine is removed from the vehicle
or the transmission unit has been
removed the flywheel/driveplate can be
locked (see Section 15).
14 Unscrew the retaining bolt and remove
the crankshaft sprocket from the end of the
15 Prior to refitting, examine the oil seal for
signs of damage or deterioration and renew if
necessary (see Section 16).
16 Slide the spacer (where removed) onto the
crankshaft and into position taking care not to
damage the oil seal lip.
17 Align the sprocket with the crankshaft slot
and slide it into position, ensuring the
sprocket flange is facing outwards. Fit the
new retaining bolt.
18 Lock the crankshaft by the method used
on removal, and tighten the sprocket retaining
bolt to the specified stage 1 torque setting
then angle-tighten the bolt through the
specified stage 2 angle, using a socket and
extension bar, and finally through the
specified stage 3 angle. It is recommended
that an angle-measuring gauge is used during
the final stages of the tightening, to ensure
accuracy (see illustrations). If a gauge is not
available, use white paint to make alignment
marks between the bolt head and sprocket
prior to tightening; the marks can then be
used to check that the bolt has been rotated
through the correct angle.
19 Refit the timing belt as described in
Section 7.
8.18a Tighten the crankshaft sprocket bolt
to the specified stage 1 torque setting . . .
8.18b . . . then tighten it through the
specified stage 2 and 3 angles
Crankshaft sprocket
Note: A new crankshaft sprocket retaining
bolt will be required on refitting.
Removal
8.14b . . . then slide off the crankshaft
sprocket . . .
3510 Vauxhall/Opel Omega
8.14c . . . and, if necessary, withdraw the
spacer from the oil seal
Tensioner pulley/
upper guide pulley assembly
Note: The tensioner pulley/upper guide pulley
assembly must be renewed as a complete
unit. It is not possible to renew the individual
components of the assembly separately.
Removal
20 Remove the timing belt as described in
Section 7.
21 Slacken and remove the retaining bolts
securing the backplate to the cylinder head
and remove the assembly from the engine
(see illustrations).
Refitting
22 Fit the tensioner pulley/upper guide pulley
assembly to the cylinder head and tighten its
retaining bolts to the specified torque.
8.21a Undo the retaining bolts
(arrowed) . . .
2C
2C•14 2.5 and 3.0 litre engine in-car repair procedures
9.2a Carefully drill/punch holes in the oil
seal . . .
1 Remove the camshaft cover as described in
Section 4.
2 Remove the camshaft sprockets as
described in Section 8. If the right-hand
cylinder head camshafts are to be removed,
rotate both the inlet and exhaust camshaft
backwards approximately 60°; this will
minimise the valve spring pressure being
exerted on the bearing caps and so lessen the
risk of damage as the caps are removed. The
left-hand cylinder head camshafts are best
left positioned at TDC.
3 Starting on the inlet camshaft, working in a
spiral pattern from the outside inwards,
slacken the camshaft bearing cap retaining
bolts by half-a-turn at a time, to relieve the
pressure of the valve springs on the bearing
caps gradually and evenly. Once the valve
spring pressure has been relieved, the bolts
can be fully unscrewed and removed along
with the caps. The bearing caps and the
cylinder head locations are numbered to
ensure the caps are correctly positioned on
refitting; an identification letter is also
stamped on each cap (see illustration).
Caution: If the bearing cap bolts are
carelessly slackened, the bearing caps
might break. If any bearing cap breaks
then the complete cylinder head assembly
must be renewed; the bearing caps are
matched to the head and are not available
separately.
4 Lift the camshaft out of the cylinder head
and slide off the oil seal. Using a dab of paint
or a suitable marker pen, make an
identification mark on the inlet camshaft to
avoid getting the camshafts mixed up on
refitting; the inlet and exhaust camshafts are
the same but it is important they are not
interchanged as this will increase the rate of
wear.
5 Repeat the operations described in
paragraphs 3 and 4 and remove the exhaust
camshaft. If the work is being carried out on
the left-hand cylinder head, prior to removing
the bearing caps, unbolt the camshaft sensor
(see Chapter 4A, Section 14) and position it
clear of the front bearing cap and free the
knock sensor wiring.
6 Obtain twelve small, clean plastic
containers, and label them for identification.
Alternatively, divide a larger container into
compartments. Lift the followers out from the
9.2b . . . then screw in a self-tapping
screw and pull out the oil seal with
pliers/grips
9.4 Tap the new seal into position using a
socket which bears only on the seal outer
edge as a drift
10.3 Prior to removal note the
identification markings on the camshaft
caps and cylinder head (arrowed)
8.21b . . . and remove the tensioner
pulley/upper guide pulley assembly from
the cylinder head
23 Refit the timing belt as described in
Section 7. If a new tensioner assembly has
been fitted, fit a new timing belt ensuring it is
of the correct type for the tensioner.
Lower guide pulley
Removal
24 Remove the timing belt as described in
Section 7.
25 Slacken and remove the retaining bolt and
remove the lower guide pulley and its spacer
from the engine (see illustration).
Refitting
26 Position the spacer behind the guide
pulley then refit the pulley retaining bolt,
tightening it lightly only at this stage.
27 Refit the timing belt as described in
Section 7.
8.25 Unscrew the retaining bolt and
remove the lower guide pulley and its
spacer (arrowed) from the engine
9 Camshaft oil seals renewal
4
1 Remove the relevant camshaft sprocket as
described in Section 8.
2 Carefully punch or drill two small holes
opposite each other in the oil seal. Screw a
self-tapping screw into each, and pull on the
screws with pliers to extract the seal (see
illustrations). Alternatively carefully lever the
oil seal out of position.
3 Clean the seal housing, and polish off any
burrs or raised edges which may have caused
the seal to fail in the first place.
4 Lubricate the lips of the new seal with clean
engine oil, and press it into position using a
suitable tubular drift (such as a socket) which
bears only on the hard outer edge of the seal
(see illustration). Take care not to damage
the seal lips during fitting; note that the seal
lips should face inwards.
5 Refit the camshaft sprocket as described in
Section 8.
10 Camshafts and followers removal, inspection and
refitting
4
Removal
3510 Vauxhall/Opel Omega
2.5 and 3.0 litre engine in-car repair procedures 2C•15
10.6 Removing a camshaft follower
10.11a Lay the camshafts in position . . .
10.11b . . . then temporarily refit the
sprockets to position the shafts correctly
(see text)
top of the cylinder head and store each one in
its respective fitted position (see illustration).
Note: Store all the followers the correct way
up to prevent the oil draining from the
hydraulic valve adjustment mechanisms.
7 If necessary, repeat the operations
described in paragraphs 1 to 6 and remove
the camshafts and followers from the other
cylinder head. If all the camshafts are to be
removed at the same time, make identification
marks on the shafts to ensure they are refitted
in their original locations, and note the
camshaft bearing caps identification letter
locations to ensure the caps are refitted to the
correct cylinder head.
10 Where removed, lubricate the followers
with clean engine oil and carefully insert each
one into its original location in the cylinder
head.
11 Lubricate the camshaft followers with
clean engine oil then lay the camshafts in
position. Ensure the crankshaft is still
positioned approximately 60° BTDC then
temporarily refit the sprockets (see Section 8
for details) to the camshafts (see
illustrations). On the left-hand cylinder head
position each shaft so that its sprocket timing
mark is aligned with cutouts on the rear cover
and on the right-hand cylinder head position
each shaft so that its sprocket timing mark is
approximately 60∞ before the rear cover
cutouts. This will position each camshaft so
that the valve spring pressure will be equally
exerted along its length as the bearing caps
are tightened.
12 Ensure the mating surfaces of the bearing
caps and cylinder head are clean and dry and
lubricate the camshaft journals and lobes with
clean engine oil.
13 Apply a smear of sealant (Vauxhall
recommend the use of sealant 15 03 170 available from your Vauxhall dealer) to
cylinder mating surfaces on each side of the
camshaft oil seal apertures (see illustration).
14 Refit the camshaft bearing caps and the
retaining bolts in their original locations on the
cylinder head. The exhaust camshaft caps are
numbered 1 to 4 from front to rear and the
inlet camshaft caps 5 to 8 from front to rear
with the corresponding numbers being
marked on the cylinder head upper surface
(see illustration).
15 Working on the exhaust camshaft, tighten
the bearing cap bolts by hand only then,
working in a spiral pattern from the centre
outwards, tighten the bolts by half-a-turn at a
time to gradually impose the pressure of the
valve springs on the bearing caps. Repeat this
sequence until all bearing caps are in contact
with the cylinder head then go around and
tighten the camshaft retaining bolts to the
specified torque (see illustration).
Caution: If the bearing cap bolts are
carelessly tightened, the bearing caps
might break. If any bearing cap breaks
then the complete cylinder head assembly
must be renewed; the bearing caps are
matched to the head and are not available
separately.
16 Tighten the inlet camshaft bearing cap
bolts as described in paragraph 15.
17 If necessary, repeat the operations in
paragraphs 10 to 15 and refit the camshafts to
the opposite cylinder head.
18 Fit new camshaft oil seals as described in
Section 9.
19 Refit the camshaft sprockets as described
in Section 8.
20 Ensure the camshaft sprocket timing
marks are all correctly aligned with the
cutouts on the rear cover then carefully rotate
the crankshaft in the normal direction of
rotation until the sprocket mark is correctly
realigned with the notch on the oil pump
housing.
21 Refit the timing belt as described in
Section 7.
22 Refit the camshaft cover(s) and timing belt
cover as described in Sections 4 and 6.
10.13 Apply sealant to the cylinder head
surface on each side of the camshaft oil
seal apertures (arrowed)
10.14 Use the identification markings
(arrowed) to ensure that the bearing caps
are refitted in their original locations
10.15 Carefully tighten the camshaft
bearing cap bolts as described in text
Inspection
8 Examine the camshaft bearing surfaces and
cam lobes for signs of wear ridges and scoring.
Renew the camshaft if any of these conditions
are apparent. Examine the condition of the
bearing surfaces both on the camshaft journals
and in the cylinder head. If the head bearing
surfaces are worn excessively, the cylinder
head will need to be renewed.
9 Examine the follower bearing surfaces
which contact the camshaft lobes for wear
ridges and scoring. Check the followers and
their bores in the cylinder head for signs of
wear or damage. If any follower is thought to
be faulty or is visibly worn it should be
renewed.
Refitting
3510 Vauxhall/Opel Omega
2C
2C•16 2.5 and 3.0 litre engine in-car repair procedures
11.5 Disconnect the wiring connectors
(arrowed) from the coolant temperature
sender and sensor . . .
11.6 . . . then release the retaining clips
and disconnect the coolant hoses from the
outlet elbow
11.7 Unscrew the retaining bolts then
remove the coolant outlet elbow from
between the cylinder heads and recover
the sealing washers (arrowed)
3 Remove the complete inlet manifold
assembly, including the manifold flange, as
described in Chapter 4A.
4 Drain the cooling system and remove the
spark plugs as described in Chapter 1.
5 Disconnect the wiring connectors from the
coolant temperature gauge sender and the
engine
management
system
coolant
temperature sensor which are screwed into
the coolant outlet which links the rear of the
cylinder heads (see illustration).
6 Slacken the retaining clips and disconnect
the coolant hoses from the cylinder head
outlet (see illustration).
7 Unscrew the retaining bolts and remove the
coolant outlet from the cylinder heads.
Recover the sealing rings and discard them;
new ones must be used on refitting (see
illustration).
8 Remove the timing belt as described in
Section 7.
9 Remove the camshaft sprockets, the timing
belt tensioner pulley/upper guide pulley
assembly and the lower guide pulley as
described in Section 8.
10 Remove the coolant pump as described in
Chapter 3.
11 Undo the retaining bolts and remove the
timing belt rear cover from the engine unit
(see Section 6). Proceed as described under
the relevant sub-heading.
11.14 Disconnecting the wiring connector
from the engine management ECU
12 Remove the camshaft cover as described
in Section 4.
13 Disconnect the wiring connector and the
right-hand cylinder head plug leads from the
DIS module so the module is free to be
removed with the head. Also unbolt the earth
connections from the rear of the left-hand
cylinder head.
14 Remove the cover from the relay box in the
left-hand corner of the engine compartment.
Lift out the engine management electronic
control unit (ECU) then release the retaining clip
and disconnect its wiring connector (see
Chapter 4A, Section 14) (see illustration). The
ECU can be left in position in the box.
15 Trace the engine wiring harness back
from the left-hand cylinder head to the engine
compartment relay box. Unclip the injection
system relay connectors from the box then
disconnect the harness connector and free
the sealing grommet from the relay box (see
illustrations).
16 Disconnect the harness connectors which
are located at the rear of the battery then
disconnect the camshaft sensor and left-hand
cylinder bank knock sensor wiring
connectors. Free the engine wiring harness
auxiliary connections from the battery positive
terminal and position the harness clear of the
cylinder head. On some models the harness is
connected to the fusible link housing instead
of the battery terminal; where this is the case,
remove the fusible link and unclip the
connector
from
the
housing
(see
illustrations).
17 Remove the exhaust system left-hand
front pipe as described in Chapter 4A.
11.15a Unclip the injection system
relays . . .
11.15b . . . then disconnect the wiring
connector . . .
11.15c . . . and free the wiring harness
from the relay box
11 Cylinder head removal and refitting
4
Removal
Note: The engine must be cold when
removing the cylinder head. New cylinder
head bolts must be used on refitting.
1 Remove the battery as described in
Chapter 5A. Note: On models with a Vauxhall
anti-theft warning system (ATWS), the battery
negative terminal must be disconnected within
15 seconds of the ignition being switched off
to prevent the alarm system being triggered.
2 Remove the windscreen wiper arms and the
water deflector panel (see Chapter 12,
Sections 15 and 16).
Left-hand cylinder head
3510 Vauxhall/Opel Omega
2.5 and 3.0 litre engine in-car repair procedures 2C•17
11.16a Disconnect the harness
connectors located at the rear of the
battery
11.16b Where the engine harness is
connected to the fusible link housing,
remove the fusible link . . .
18 Remove the power steering pump as
described in Chapter 10.
19 Slacken the retaining clip and disconnect
the radiator upper coolant hose from the pipe
at the front of the left-hand cylinder head.
20 Unscrew the bolt and spacer securing the
coolant pipe and engine lifting bracket to the
cylinder head and remove the lifting bracket.
Move the coolant pipe to the left to free it from
the thermostat housing then manoeuvre it out
of position (see illustrations). Remove the
sealing rings from the inner end of the pipe
and discard them; new ones must be used on
refitting.
21 Remove the dipstick then free the dipstick
tube from the cylinder block and remove it
from the engine. Discard the tube sealing
rings; new ones should be used on refitting.
22 Remove the exhaust camshaft as
described in Section 10.
23 Working in the reverse of the tightening
sequence
(see
illustration
11.41a),
progressively slacken the cylinder head bolts
by a quarter of a turn at a time until all bolts
can be unscrewed by hand (see illustration).
Remove each bolt in turn, along with its
washer.
24 Lift the cylinder head from the cylinder
block (see illustration). If necessary, tap the
cylinder head gently with a soft-faced mallet
to free it from the block, but do not lever at
the mating faces. Note the fitted positions of
the two locating dowels, and remove them for
safe keeping if they are loose.
25 Recover the cylinder head gasket, and
discard it.
11.16c . . . then unclip the connector from
the housing
11.16d Once all the wiring has been
disconnected, position the harness clear
of the cylinder head
11.20a Slacken and remove the retaining
bolt and spacer . . .
11.20b . . . then remove the coolant pipe
from the thermostat housing (shown with
engine removed)
removal tool if necessary, and drain the oil
into the container. If the oil filter is damaged or
distorted during removal, it must be renewed.
Given the low cost of a new oil filter relative to
the cost of repairing the damage which could
result if a re-used filter springs a leak, it is
probably a good idea to renew the filter in any
case.
27 Unscrew the union nuts securing the oil
cooler pipes to the cylinder block then
unscrew the union bolts securing the pipes to
the cooler. Recover the sealing washers from
each side of the oil cooler unions and move
the pipes to the rear (see illustrations).
28 Release the retaining clips and disconnect
the radiator bottom hose, expansion tank
hose and heater hose from the coolant pipe
which runs along the right-hand side of the
engine. Slacken and remove the retaining
bolts then remove the pipe from the engine.
11.23 Evenly and progressively slacken
and remove the cylinder head bolts . . .
11.24 . . . then lift the cylinder head off
the block
11.27a Unscrew the union nuts (arrowed)
securing the oil pipes to the cylinder
block . . .
Right-hand cylinder head
26 Position a suitable container beneath the
oil filter. Unscrew the filter using an oil filter
3510 Vauxhall/Opel Omega
2C
2C•18 2.5 and 3.0 litre engine in-car repair procedures
11.27b . . . then remove the union bolts
and sealing washers (arrowed) and free
the pipes from the oil cooler
11.28a Disconnect the expansion tank
hose . . .
Recover the sealing ring and discard it; a new
one should be used on refitting (see
illustrations).
29 Remove the exhaust system right-hand
front pipe as described in Chapter 4A.
30 Remove the exhaust camshaft as
described in Section 10.
31 Remove the cylinder head as described in
paragraphs 23 to 25 (see illustration).
with a cloth rag. Clean the piston crowns in
the same way.
33 Check the block and head for nicks, deep
scratches and other damage. If slight, they
may be removed carefully with a file. More
serious damage may be repaired by
machining, but this is a specialist job.
34 If warpage of the cylinder head is
suspected, use a straight-edge to check it for
distortion. Refer to Chapter 2D if necessary.
35 Ensure that the cylinder head bolt holes in
the crankcase are clean and free of oil.
Syringe or soak up any oil left in the bolt
holes. This is most important in order that the
correct bolt tightening torque can be applied
and to prevent the possibility of the block
being cracked by hydraulic pressure when the
bolts are tightened. Renew the cylinder head
bolts regardless of their apparent condition.
Preparation for refitting
32 The mating faces of the cylinder head and
block must be perfectly clean before refitting
the head. Use a scraper to remove all traces
of gasket and carbon, and also clean the tops
of the pistons. Take particular care with the
aluminium surfaces, as the soft metal is
damaged easily. Also, make sure that debris
is not allowed to enter the oil and water
channels - this is particularly important for the
oil circuit, as carbon could block the oil supply
to the camshaft or crankshaft bearings. Using
adhesive tape and paper, seal the water, oil
and bolt holes in the cylinder block. To
prevent carbon entering the gap between the
pistons and bores, smear a little grease in the
gap. After cleaning the piston, rotate the
crankshaft so that the piston moves down the
bore, then wipe out the grease and carbon
Refitting
Left-hand cylinder head
36 Ensure the crankshaft is till positioned
approximately 60° BTDC and wipe clean the
mating faces of the head and block.
37 Ensure that the two locating dowels are in
position at each end of the cylinder
block/crankcase surface.
11.31 Removing the right-hand cylinder head assembly
11.28b . . . and heater hose (arrowed) from
the coolant pipe . . .
11.28c . . . then undo the retaining bolts
and remove the pipe from the engine
38 Fit the new cylinder head gasket to the
block, making sure it is fitted with the correct
way up with its OBEN or TOP mark
uppermost and at the front end of the engine
(see illustration).
39 Carefully refit the cylinder head (complete
with exhaust manifold), locating it on the
dowels.
40 Lightly lubricate the threads and heads of
the new cylinder head bolts with engine oil
then carefully insert them into position (do not
drop), tightening them finger-tight only at this
stage.
11.38 Ensure the locating dowels (arrowed) are in position then fit
the new head gasket
3510 Vauxhall/Opel Omega
2.5 and 3.0 litre engine in-car repair procedures 2C•19
11.41a Cylinder head bolt tightening sequence
(left-hand head shown)
41 Working progressively and in the
sequence shown, first tighten all the cylinder
head bolts to the stage 1 torque setting (see
illustrations).
42 Once all bolts have been tightened to the
stage 1 torque, again working in the sequence
shown, tighten each bolt through its specified
stage 2 angle, using a socket and extension
bar. It is recommended that an anglemeasuring gauge is used during this stage of
the tightening, to ensure accuracy (see
illustration).
43 Working in the specified sequence, go
around again and tighten all bolts through the
specified stage 3 angle.
44 Working again in the specified sequence,
go around and tighten all bolts through the
specified stage 4 angle.
45 Finally go around in the specified
sequence again and tighten all bolts through
the specified stage 5 angle.
46 The remainder of the refitting procedure is
the reverse of removal noting the following
points
a) If the right-hand cylinder head has also
been removed, refit this to the block
before connecting any ancillaries.
b) Fit new sealing rings to the dipstick tube
and thermostat housing coolant pipe.
Ensure the coolant pipe, dipstick tube and
lifting bracket are correctly positioned
before refitting the retaining bolt and
spacer and tightening to the specified
torque.
c) Ensure the engine wiring harness is
correctly routed and securely reconnect
all the wiring connectors. Also make sure
the earth lead retaining bolts are securely
tightened.
d) Refit the camshaft, timing belt and
associated components as described in
Sections 6 to 10.
e) Use new sealing rings when refitting the
coolant outlet to the cylinder heads and
11.41b Working in the specified sequence, tighten the cylinder
head bolts to the specified stage 1 torque . . .
tighten the retaining bolts to the specified
torque.
f) Ensure all coolant hoses are correctly
reconnected and securely retained by
their clips.
g) Refit the exhaust front pipe and inlet
manifold as described in Chapter 4A.
h) On completion refill the cooling system
and power steering fluid reservoir (see
Chapter 1 and Weekly checks).
Right-hand cylinder head
47 Refit the cylinder head as described in
paragraphs 36 to 45 noting that the cylinder
head gasket OBEN or TOP mark must be
uppermost and at the rear end of the engine.
48 The remainder of the refitting procedure is
the reverse of removal noting the following
points
a) If the left-hand cylinder head has also
been removed, refit this to the block
before connecting any ancillaries.
b) Fit a new sealing ring to coolant pipe and
securely tighten the pipe retaining bolts.
c) Fit new sealing washers to each side of
the oil cooler pipe unions and tighten the
pipe union nuts and bolts to the specified
torque.
11.42 . . . and then through the specified
stage 2 to 5 angles using an angle
measuring gauge for accuracy
3510 Vauxhall/Opel Omega
d) Refit the camshaft, timing belt and
associated components as described in
Sections 6 to 10.
e) Use new sealing rings when refitting the
coolant outlet to the cylinder heads and
tighten the retaining bolts to the specified
torque.
f) Ensure all coolant hoses are correctly
reconnected and securely retained by
their clips.
g) Refit the exhaust front pipe and inlet
manifold as described in Chapter 4A.
h) Fit a new oil filter and refill the cooling
system as described in Chapter 1.
i) On completion, check the engine oil level
as described in Weekly checks.
12 Sump removal and refitting
4
Removal
Sump pan
Note: New sump pan retaining bolts will be
required on refitting.
1 Disconnect the battery negative terminal.
Note: On models with a Vauxhall anti-theft
warning system (ATWS), the battery negative
terminal must be disconnected within 15
seconds of the ignition being switched off to
prevent the alarm system being triggered.
2 Firmly apply the handbrake then jack up the
front of the car and support it on axle stands.
Undo the retaining screws and remove the
undercover from beneath the engine.
3 Drain the engine oil as described in Chapter 1, then fit a new sealing washer and refit
the drain plug, tightening it to the specified
torque.
4 Disconnect the wiring connector from the
oil level sensor connector on the right-hand
2C
2C•20 2.5 and 3.0 litre engine in-car repair procedures
12.4 Slide off the retaining clip and push
the oil level sensor wiring connector into
the sump
12.16 Fit a new sealing ring to the oil
pump pick-up/strainer before refitting
12.18 On refitting, locate the oil level
sensor wiring connector in the main casting
before bolting the sump pan in position
side of the main casting then slide off the
retaining clip and push the connector into the
sump (see illustration).
5 Slacken and remove the sump pan
retaining bolts then free it from the main
casting and remove it along with its gasket.
Take care not to damage the oil level sensor
wiring as the pan is removed.
6 If necessary, undo the retaining bolts (one
is tricky to reach) and remove the oil pump
pick-up/strainer from the base of the oil pump
housing along with its sealing ring. Check the
oil pump pick-up/strainer for signs of clogging
or splitting and renew/clean as necessary.
12 Attach an engine hoist to the engine lifting
brackets then raise the hoist until it is
supporting the weight of the engine.
Alternatively use an engine support bar to
take the weight of the engine.
13 Referring to Chapter 10, unscrew the front
suspension subframe front mounting bolts by
approximately 4 turns. Support the rear of the
subframe with a jack then slacken and remove
the rear mounting bolts. Lower the rear of the
subframe approximately 10 cm to gain access
to the main casting.
14 Unscrew the bolts securing the main
casting flange to the transmission housing
then progressively slacken and remove the
bolts securing the main casting to the base of
the cylinder block/oil pump. Break the joint by
striking the casting with the palm of the hand,
then lower it away from the engine and
withdraw it. Remove the seal and discard it.
Note: If the main casting is to be removed for
any length of time, raise the subframe back up
into position and refit its mounting bolts then
lower the engine back down onto the
subframe.
then refit the strainer, tightening its retaining
bolts to the specified torque (see illustration).
17 Ensure the sump pan and main casting
surfaces are clean and dry and fit a new
sealing ring to the oil level sensor wiring
connector.
18 Place a new gasket on the top of the pan
and offer it up to the main casting. Seat the oil
level sensor wiring connector in the main
casting, securing it in position with the
retaining clip, then seat the sump pan on the
main casting (see illustration).
19 Fit the new sump pan retaining bolts then
go around in a diagonal sequence and tighten
them to the specified stage 1 torque setting.
Once all bolts have been tightened go around
again and angle-tighten them through the
specified stage 2 angle. It is recommended
that an angle-measuring gauge is used during
this stage of the tightening, to ensure
accuracy.
20 Reconnect the oil level sender wiring
connector then refit the undercover.
21 Lower the vehicle to the ground then fill
the engine with fresh oil, with reference to
Chapter 1.
Main casting
Note: New front suspension subframe
mounting bolts will be required on refitting.
New retaining nuts for the centre tie rod will
also be required.
7 Remove the sump pan and oil pickup/strainer as described in paragraphs 1 to 6.
8 Referring to Chapter 12, on models with
Xenon headlights, disconnect the wiring
connector from the headlight system front
vehicle level control sensor then unclip the
link rod from the sensor arm balljoint.
9 Remove the steering linkage centre tie rod
as described in Chapter 10, Section 25.
10 Slacken and remove the mounting bolts
and remove the vibration dampers from the
left- and right-hand engine mountings
11 Slacken and remove the nuts securing the
engine left- and right-hand mountings to the
subframe.
12.23 Apply a bead of sealant (arrowed) to
the main casting seal groove in between
the lines shown . . .
Refitting
Sump pan
15 Remove all traces of dirt and oil from the
mating surfaces of the sump pan, main
casting and (if necessary) the pick-up/strainer
and oil pump housing.
16 Where necessary, position a new sealing
ring on top of the oil pump pick-up/strainer
12.24a . . . then locate the new seal in the
casting groove
3510 Vauxhall/Opel Omega
Main casting
22 Remove all traces of dirt and oil from the
mating surfaces of the main casting and
cylinder block.
23 Ensure the main casting seal groove is
completely dry then apply a bead of sealant
(Vauxhall recommend the use of sealant 15 03
298 - available from your Vauxhall dealer) to
the areas of the groove shown (see
illustration). Note: If the Vauxhall sealant is
being used, the main casting must be bolted
in position on the cylinder block within ten
minutes of applying the sealant.
24 Locate the new seal correctly in its groove
then apply a bead of the sealant,
approximately 3mm in diameter, to the main
casting surface as shown (see illustrations).
The sealant should go around the outside of
the seal around the front of the casting and
the inside at the rear, making sure the sealant
overlaps at the points shown.
25 Apply a smear of suitable sealant (Vauxhall
recommend the use of sealant 15 03 295 available from your Vauxhall dealer) to the
areas of the cylinder block mating surface
2.5 and 3.0 litre engine in-car repair procedures 2C•21
around the areas of the oil pump housing and
rear main bearing cap joints (see illustrations).
26 Manoeuvre the casting into position and
loosely refit all its retaining bolts.
27 Working out from the centre in a diagonal
sequence, progressively tighten the bolts
securing the main casting to the cylinder
block/oil pump to their specified torque
setting.
28 Tighten the bolts securing the casting
flange to the transmission housing to their
specified torque settings.
29 Raise the subframe back up into position
making sure the engine mounting lugs engage
correctly with the subframe cutouts. Fit the
four new rear retaining bolts then remove the
subframe front retaining bolts and fit the new
ones. Tighten the subframe mounting bolts to
their specified torque setting and then through
the specified angles as described in Chapter
10.
30 Remove the hoist/support bar from the
engine then refit the nuts securing the engine
mountings to the subframe, tightening them
to the specified torque. Refit the vibration
dampers to the mountings and tighten their
mounting bolts to the specified torque.
31 Refit the steering linkage centre tie rod as
described in Chapter 10
32 On models with Xenon headlights clip the
link rod balljoint back onto the vehicle level
control sensor and reconnect the wiring
connector (see Chapter 12).
33 Refit the sump pan as described in
paragraphs 15 to 21.
13 Oil pump removal, overhaul and refitting
2C
4
Removal
1 Remove the timing belt as described in
Section 7.
2 Remove all the camshaft sprockets, the
crankshaft sprocket, the belt tensioner
pulley/upper guide pulley assembly and the
lower guide pulley as described in Section 8.
3 Undo the retaining bolts and remove the
rear timing belt cover from the front of the
engine (see Section 6).
4 Remove the sump pan, oil pump pickup/strainer and main casting as described in
Section 12.
5 Slacken and remove the alternator lower
mounting bolt then slacken the upper bolt and
pivot the alternator clear of the oil pump
housing.
6 Disconnect the wiring connector from the
oil pressure switch then unscrew the bolt
securing the wiring guide to the front of the
pump housing.
7 Slacken and remove the retaining bolts
then slide the oil pump housing assembly off
of the end of the crankshaft, taking great care
not to lose the locating dowels. Remove the
housing gasket and discard it.
12.24b Apply beads of sealant to the main casting mating surface as shown
12.25a Apply a smear of sealant to the
joints between the oil pump housing and
cylinder block . . .
3510 Vauxhall/Opel Omega
12.25b . . . and the rear main bearing cap
and block
2C•22 2.5 and 3.0 litre engine in-car repair procedures
13.8 Undo the retaining screws and
remove the cover from the oil pump
13.9 Note the identification markings
(where present) on the pump rotors . . .
13.10 . . . then lift both rotors out of the
housing
13.11a Slacken and remove the oil
pressure relief valve bolt and sealing
washer . . .
13.11b . . . then remove the valve plunger
and spring from the pump
13.11c Slacken and remove the safety
valve bolt and sealing washer . . .
9 Using a suitable marker pen, mark the
surface of both the pump inner and outer
rotors; the marks can then be used to ensure
the rotors are refitted the correct way around.
On some pump identification marks may
already exist on the rotors (see illustration).
10 Lift out the inner and outer rotors from the
pump housing (see illustration).
11 Unscrew the oil pressure relief valve and
the safety valve bolts from the top of the
housing and withdraw the valve springs and
plungers from the housing, noting which way
around the plungers are fitted. Remove the
sealing washers from the valve bolts (see
illustrations). Note: The pressure relief valve
can be removed with pump in position on the
engine unit once the timing belt front cover
has been removed.
12 Clean the components, and carefully
examine the rotors, pump body and valve
plungers for any signs of scoring or wear.
Renew any component which shows signs of
wear or damage; if the rotors or pump
housing are marked then the complete pump
assembly should be renewed.
13 If the components appear serviceable,
measure the rotor endfloat, and check the
flatness of the end cover. If the clearances
exceed the specified tolerances, the pump
must be renewed.
14 If the pump is satisfactory, reassemble the
components in the reverse order of removal,
noting the following.
a) Ensure both rotors are fitted the correct
way around.
b) Tighten the pump cover screws to the
specified torque.
c) Fit new sealing rings to the valve bolts and
ensure the plungers and springs are fitted
the correct way around (see illustrations).
13.11d . . . and withdraw the spring and
plunger from the pump
Overhaul
8 Undo the retaining screws and lift off the
pump cover from the rear of the housing (see
illustration).
13.14a Oil pressure relief valve components
1 Spring
2 Plunger
3 Sealing washer
4 Valve bolt
13.14b Safety valve components
1 Plunger
2 Spring
3510 Vauxhall/Opel Omega
3 Sealing washer
4 Valve bolt
2.5 and 3.0 litre engine in-car repair procedures 2C•23
d) On completion prime the oil pump by
filling it with clean engine oil whilst
rotating the inner rotor.
Refitting
15 Prior to refitting it is necessary to determine
which of the three possible types of oil pump
assembly is fitted to your engine. The first step
is to check the diameter of the oil pump
retaining bolts; during the 1999 model year the
pump retaining bolt diameter was increased
from M6 to M8. If M6 retaining bolts are used, it
will then be necessary to determine whether
the engine is fitted with an original oil pump
and timing belt rear cover arrangement or the
modified arrangement (see illustration). The
modified cover has an additional hole through
which the oil pump upper bolt (number 6 in the
tightening sequence) can be reached and this
affects the refitting procedure. Proceed as
described under the relevant sub-heading.
Oil pump with M6 retaining bolts and
the original timing belt rear cover
16 Prior to refitting, carefully lever out the
crankshaft oil seal using a flat-bladed
screwdriver. Fit the new oil seal, ensuring its
sealing lip is facing inwards, and press it
squarely into the housing using a tubular drift
which bears only on the hard outer edge of
the seal (see illustrations). Press the seal into
position so that it is flush with the housing and
lubricate the oil seal lip with clean engine oil.
17 Ensure the mating surfaces of the oil
pump and cylinder block are clean and dry
and the locating dowels are in position.
18 Apply a thin coat of sealant (Vauxhall
recommend the use of sealant 15 03 170 available from your Vauxhall dealer),
approximately 0.2 mm thick, to the shaded
areas of the oil pump side of the new pump
gasket as shown (see illustration).
19 Fit the gasket to the cylinder block then
carefully manoeuvre the oil pump into position
and engage the inner rotor with the crankshaft
end. Locate the pump on the dowels, taking
great care not damage the oil seal lip (see
illustrations).
20 Refit the pump housing retaining bolts in
their original locations and tighten them to the
initial specified torque in the order shown (see
illustration).
13.18 Apply sealant (see text) to the
shaded areas of the oil pump side of the
new gasket
13.15 Oil pump and timing belt rear cover identification details (pump retained by M6 bolts)
A Original pump and timing belt cover
B Modified pump and timing belt cover (shaded areas show differences) which allow
access to the bolt shown with the cover in position
2C
13.16a Lever out the oil seal out from the
pump with a large flat-bladed
screwdriver . . .
13.16b . . . and tap the new seal squarely
into position, using a socket which bears
only on the seal outer edge
13.19a Locate the pump gasket on the
dowels . . .
13.19b . . . then refit the oil pump
assembly
3510 Vauxhall/Opel Omega
2C•24 2.5 and 3.0 litre engine in-car repair procedures
13.20 Oil pump bolt tightening sequence pump with M6 retaining bolts
21 Fit the timing belt lower guide pulley to the
pump and tighten its retaining bolt to the
specified torque.
22 Refit the alternator lower mounting bolt
and tighten to the specified torque (see
Chapter 5A).
23 Wait approximately 10 minutes to allow
the sealant on the pump gasket to cure then
go around again in the specified sequence
and tighten them to the final specified torque
setting.
24 Remove the lower guide pulley from the
oil pump and refit the timing belt rear cover
(see Section 6), tightening its retaining bolts to
the specified torque.
25 Reconnect the oil pressure sensor wiring
connector and secure the wiring guide in
position with the bolt.
26 Refit the sump main casting, oil pump
pick-up/strainer and sump pan as described
in Section 12.
27 Refit the timing belt sprockets, guide
pulleys and tensioner then refit the belt as
described in Sections 7 and 8.
28 On completion, fit a new oil filter and fill
the engine with clean oil as described in
Chapter 1.
13.40 Oil pump bolt tightening sequence pump with M8 retaining bolts
position with the retaining bolt.
34 Refit the sump main casting, oil pump
pick-up/strainer and sump pan as described
in Section 12.
35 Refit the timing belt sprockets, guide
pulleys and tensioner then refit the belt as
described in Sections 7 and 8. Prior to
refitting the timing belt outer cover, go around
in the specified sequence (see illustration
13.20) and retighten all the oil pump retaining
bolts to the specified torque.
36 On completion, fit a new oil filter and fill
the engine with clean oil as described in
Chapter 1.
Oil pump with M8 retaining bolts
37 Remove all traces of locking compound
from the oil pump retaining bolt threads.
38 Carry out the operations described in
paragraphs 16 to 19.
39 Apply a drop of locking compound
(Vauxhall recommend the use of locking
compound 15 10 181 - available from your
Vauxhall dealer) to the thread of each pump
retaining bolt then refit the bolts in their
original locations, tightening them by hand
only.
14 Oil cooler removal and refitting
Oil pump with M6 retaining bolts and
the modified timing belt rear cover
29 Carry out the operations described in
paragraphs 16 to 19.
30 Refit the pump housing retaining bolts in
their original locations and tighten them to the
specified torque in the order shown (see
illustration 13.20).
31 Refit the alternator lower mounting bolt
and tighten to the specified torque (see
Chapter 5A).
32 Refit the timing belt rear cover (see
Section 6) and tighten its retaining bolts to the
specified torque.
33 Reconnect the oil pressure sensor wiring
connector and secure the wiring guide in
40 Go around in the specified sequence and
tighten all the pump retaining bolts to the
specified stage 1 torque setting (see
illustration).
41 Refit the alternator lower mounting bolt
and tighten to the specified torque (see
Chapter 5A).
42 Go around again in the specified
sequence and tighten all the pump retaining
bolts to the specified stage 2 torque setting.
43 Reconnect the oil pressure sensor wiring
connector and secure the wiring guide in
position with the retaining bolt.
44 Refit the timing belt rear cover (see
Section 6) and tighten its retaining bolts to the
specified torque.
45 Refit the sump main casting, oil pump
pick-up/strainer and sump pan as described
in Section 12.
46 Refit the timing belt sprockets, guide
pulleys and tensioner then refit the belt as
described in Sections 7 and 8.
47 On completion, fit a new oil filter and fill
the engine with clean oil as described in
Chapter 1.
4
Removal
14.3 Disconnect the wiring connectors
(arrowed) from the coolant temperature
sender and sensor . . .
3510 Vauxhall/Opel Omega
1 Drain the cooling system as described in
Chapter 1.
2 Remove the complete inlet manifold,
including the manifold flange, as described in
Chapter 4A.
3 Disconnect the wiring connectors from the
coolant temperature gauge sender and the
engine
management
system
coolant
temperature sensor which are screwed into
the coolant outlet which links the rear of the
cylinder heads (see illustration).
2.5 and 3.0 litre engine in-car repair procedures 2C•25
14.4 . . . then release the retaining clips and disconnect the
coolant hoses from the outlet elbow
4 Slacken the retaining clips and disconnect
the coolant hoses from the cylinder head
outlet (see illustration).
5 Unscrew the retaining bolts and remove the
coolant outlet from the cylinder heads.
Recover the sealing rings and discard them;
new ones must be used on refitting (see
illustration).
6 Undo the retaining bolts and remove the
upper heatshield from the left-hand cylinder
bank exhaust manifold. If necessary, to
improve access to the rear bolt remove the
14.5 Unscrew the retaining bolts then remove the coolant outlet
elbow from between the cylinder heads and recover the sealing
washers (arrowed)
exhaust system front pipe as described in
Chapter 4A.
7 Position a suitable container beneath the oil
filter. Unscrew the filter using an oil filter
removal tool if necessary, and drain the oil
into the container. If the oil filter is damaged or
distorted during removal, it must be renewed.
Given the low cost of a new oil filter relative to
the cost of repairing the damage which could
result if a re-used filter springs a leak, it is
probably a good idea to renew the filter in any
case.
8 Unscrew the union nuts securing the oil
cooler pipes to the cylinder block then unscrew
the union bolts securing the pipes to the
cooler. Recover the sealing washers from each
side of the oil cooler unions and position the
pipes clear of the oil cooler (see illustrations).
9 Unscrew the large nuts securing the oil
cooler unions to the cover then undo the
retaining bolts and remove the cover from the
top of the cylinder block (see illustrations).
Recover the gasket (where fitted) and discard
it; sealant will be needed to replace the gasket
on refitting.
10 Lift out the oil cooler and remove it from
the engine, keeping it upright to prevent oil
spillage (see illustration). Recover the sealing
rings from the cooler unions and discard
them; new ones must be used on refitting.
11 If the oil cooler shows signs of damage it
must be renewed.
Refitting
14.8a Slacken the union nuts (arrowed)
securing the oil pipes to the block . . .
14.8b . . . then remove the union bolts and
sealing washers (arrowed) and free the
pipes from the oil cooler
12 Ensure the mating surfaces of the oil
cooler, cover and cylinder block are clean and
dry.
13 Fit new sealing rings to the oil cooler
unions then refit the cover and screw on the
large nuts, tightening them by hand only at
this stage.
14.9a Unscrew the large nuts from the
cooler unions . . .
14.9b . . . then undo the retaining bolts
and lift off the oil cooler cover
14.10 Removing the oil cooler from the
cylinder block
3510 Vauxhall/Opel Omega
2C
2C•26 2.5 and 3.0 litre engine in-car repair procedures
14.14 Apply a bead of sealant to the groove in the oil cooler cover
14 Apply a bead of suitable sealant (Vauxhall
recommend the use of sealant 15 03 296 available from your Vauxhall dealer), approximately 2 mm in diameter, to the groove on the
oil cooler cover (see illustration).
15 Refit the cooler assembly to the cylinder
block and refit the cover retaining bolts,
tightening them evenly and progressively to
their specified torque. Once the cover bolts
are correctly tightened, tighten the cooler nuts
to their specified torque (see illustration).
16 Manoeuvre the oil cooler pipes into
position and screw their union nuts into the
cylinder block by a few turns each. Position a
new sealing washer on each side of the pipe
unions then refit the union bolts. Tighten the
union bolts to the specified torque then
tighten the pipe union nuts to the specified
torque.
17 Fit new sealing rings to each side of the
coolant outlet then refit it to the cylinder
heads, tightening its retaining bolts to the
specified torque. Reconnect the hoses to the
outlet, securing them in position with the
retaining clips, and the temperature sensor
wiring connectors.
18 Refit the inlet manifold as described in
Chapter 4A and install the exhaust manifold
heatshield and (where necessary) front pipe.
14.15 Tighten the cover retaining bolts to the specified torque
then tighten the cooler nuts to their specified torque
19 Fit a new oil filter and refill the cooling
system as described in Chapter 1.
20 On completion, check the engine oil level
as described in Weekly checks.
15 Flywheel/driveplate removal, inspection and
refitting
4
Note: New flywheel/driveplate retaining bolts
will be required on refitting.
Removal
Manual transmission models
1 Remove the transmission as described in
Chapter 7A then remove the clutch assembly
as described in Chapter 6.
2 Prevent the flywheel from turning by locking
the ring gear teeth with a similar arrangement
to that shown (see illustration). Alternatively,
bolt a strap between the flywheel and the
cylinder block/crankcase. Make alignment
marks between the flywheel and crankshaft
using paint or a suitable marker pen.
3 Slacken and remove the retaining bolts and
remove the flywheel. Do not drop it, as it is
very heavy.
Automatic transmission models
4 Remove the transmission as described in
Chapter 7B.
5 Lock the driveplate as described in
paragraph 2 then slacken the driveplate
retaining bolts.
6 Unscrew the retaining bolts and remove the
retaining plate, centering ring and driveplate
from the end of the crankshaft, noting each
components correct fitted location.
Inspection
15.2 Lock the flywheel/driveplate ring gear
with a tool similar to that shown
7 On manual transmission models, examine
the flywheel for scoring of the clutch face. If
the clutch face is scored, the flywheel may be
surface-ground, but renewal is preferable.
3510 Vauxhall/Opel Omega
Check for wear or chipping of the ring gear
teeth, if the teeth are damaged the flywheel
must be renewed (ring gear renewal is not
possible).
8 On automatic transmission models closely
examine the driveplate for ring gear teeth for
signs of wear or damage and check the
driveplate surface for any signs of cracks.
9 If there is any doubt about the condition of
the flywheel/driveplate, seek the advice of a
Vauxhall dealer or engine reconditioning
specialist. They will be able to advise if it is
possible to recondition it or whether renewal
is necessary.
Refitting
Manual transmission models
10 Clean the mating surfaces of the flywheel
and crankshaft and remove all traces of
locking compound from the flywheel retaining
bolt threads in the crankshaft.
11 Offer up the flywheel and fit the new
retaining bolts. If the original is being refitted
align the marks made prior to removal.
12 Lock the flywheel by the method used on
removal, and tighten the retaining bolts to the
specified stage 1 torque setting then angletighten the bolts through the specified stage 2
angle, using a socket and extension bar, and
finally through the specified stage 3 angle. It is
recommended that an angle-measuring
gauge is used during the final stages of the
tightening, to ensure accuracy. If a gauge is
not available, use white paint to make
alignment marks between the bolt head and
flywheel prior to tightening; the marks can
then be used to check that the bolt has been
rotated through the correct angle.
13 Refit the clutch as described in Chapter 6
then remove the locking tool, and refit the
transmission as described in Chapter 7A.
Automatic transmission models
14 Clean the mating surfaces of the
driveplate and crankshaft and remove all
2.5 and 3.0 litre engine in-car repair procedures 2C•27
traces of locking compound from the
driveplate retaining bolt threads in the
crankshaft.
15 Offer up the driveplate complete with the
centering ring and retaining plate, making
sure all components are fitted the correct way
around, then screw in the new retaining bolts.
16 Tighten the retaining bolts through the
specified torque and angles as described in
paragraph 12 then remove the locking tool
and refit the transmission as described in
Chapter 7B.
16 Crankshaft oil seals renewal
4
Front (timing belt end) oil seal
1 Remove the crankshaft sprocket and
spacer as described in Section 8.
2 Carefully punch or drill two small holes
opposite each other in the oil seal. Screw a
self-tapping screw into each and pull on the
screws with pliers to extract the seal.
Alternatively carefully lever the seal out of
position.
Caution: Great care must be taken to avoid
damage to the oil pump
3 Clean the seal housing and polish off any
burrs or raised edges which may have caused
the seal to fail in the first place.
4 Lubricate the lips of the new seal with clean
engine oil and ease it into position on the end
of the shaft. Press the seal squarely into
position until it is flush with the housing. If
necessary, a suitable tubular drift, such as a
socket, which bears only on the hard outer
edge of the seal can be used to tap the seal
into position. Take great care not to damage
the seal lips during fitting and ensure that the
seal lips face inwards.
5 Wash off any traces of oil, then refit the
spacer and crankshaft sprocket as described
in Section 8.
levering against it to check for free play;
where this is not possible, enlist the aid of an
assistant to move the engine/transmission
unit back and forth, or from side to side, while
you watch the mounting. While some free play
is to be expected even from new
components, excessive wear should be
obvious. If excessive free play is found, check
first that the fasteners are correctly secured,
then renew any worn components as
described below.
16.7 Fitting a new crankshaft rear oil seal
Rear (flywheel/driveplate end)
oil seal
6 Remove the flywheel/driveplate as
described in Section 15.
7 Renew the seal as described in paragraphs 2
to 4 (see illustration).
8 Refit the flywheel/driveplate as described in
Section 15.
17 Engine/transmission
mountings inspection and renewal
3
Inspection
1 If improved access is required, raise the
front of the car and support it securely on axle
stands. Undo the retaining bolts and remove
the undercover from beneath the engine unit.
2 Check the mounting rubber to see if it is
cracked, hardened or separated from the
metal at any point; renew the mounting if any
such damage or deterioration is evident.
3 Check that all the mounting’s fasteners are
securely tightened; use a torque wrench to
check if possible.
4 Using a large screwdriver or a pry bar,
check for wear in the mounting by carefully
17.8a Slacken and remove the upper and lower nuts . . .
Renewal
Left- and right-hand engine
mountings
Note: It is recommended that the engine
mountings are replaced as a matched pair.
5 Firmly apply the handbrake then jack up the
front of the vehicle and support it on axle
stands. If necessary, to improve access undo
the retaining screws and remove the
undercover from beneath the engine unit.
6 Support
the
weight
of
the
engine/transmission using a trolley jack with a
block of wood placed on its head.
Alternatively attach an engine hoist/support
bar to the lifting brackets on the cylinder head
and use this to support the engine.
7 Slacken and remove the mounting bolts
and remove the vibration damper (where
fitted) from the mounting assembly.
8 Unscrew the upper and lower nuts securing
the relevant engine mounting to the cylinder
block bracket and subframe then raise the
engine unit slightly and manoeuvre the
mounting out of position (see illustrations). If
necessary the mounting bracket can be
unbolted and removed from the cylinder
block. Note: Take great care not to place any
excess stress on any engine wiring/hoses or
the exhaust system or when raising the
engine.
9 Check all components for signs of wear or
damage, and renew as necessary.
17.8b . . . then lift the engine slightly until there is sufficient
clearance to manoeuvre the mounting out of position
3510 Vauxhall/Opel Omega
2C
2C•28 2.5 and 3.0 litre engine in-car repair procedures
10 On refitting, refit the mounting to the
subframe aligning its locating lug with the
subframe slot then refit the lower nut and
tighten to the specified torque.
11 Refit the mounting bracket (where
removed) to the cylinder block and tighten its
retaining bolts to the specified torque.
12 Lower the engine unit back down onto the
mounting then refit the upper retaining nut to
the mounting, tightening it to the specified
torque.
13 Where necessary, refit the vibration
damper to the mounting bracket and
subframe and tighten its mounting bolts to the
specified torque.
14 Refit the undercover (where removed)
then lower the vehicle to the ground.
Transmission unit rear mounting
15 Firmly apply the handbrake then jack up
the front of the vehicle and support it on axle
stands.
16 Place a jack with a block of wood beneath
the transmission, and raise the jack to take
the weight of the transmission.
17 With the transmission securely supported,
slacken and remove the bolts securing the
transmission unit rear mounting crossmember
to the vehicle body. Unscrew the nuts
securing the crossmember to the mounting
and remove it from the vehicle.
18 Slacken and remove the bolts and remove
the mounting from the base of the
transmission unit.
19 Check all components for signs of wear or
3510 Vauxhall/Opel Omega
damage, and renew as necessary. Remove all
traces of locking compound from the
crossmember to body bolt threads.
20 Fit the mounting to the transmission unit
and tighten its retaining bolts to the specified
torque.
21 Refit the crossmember to the mounting
and lightly tighten its retaining nuts.
22 Apply a few drops of thread locking
compound (Vauxhall recommend the use of
locking compound 15 10 181 - available from
your Vauxhall dealer) to the threads of each
crossmember to body bolt then refit both
bolts and tighten them to the specified torque.
23 Remove the jack from underneath the
transmission unit then tighten the mounting to
crossmember nuts to the specified torque
before lowering the vehicle to the ground.
2D•1
Chapter 2 Part D:
General engine overhaul procedures
Contents
Crankshaft - inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Crankshaft - refitting and main bearing running clearance check . . . 17
Crankshaft - removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Cylinder block - cleaning and inspection . . . . . . . . . . . . . . . . . . . . . 11
Cylinder head - dismantling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Cylinder head - reassembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Cylinder head and valves - cleaning and inspection . . . . . . . . . . . . . 7
Engine - initial start up after overhaul . . . . . . . . . . . . . . . . . . . . . . . . 19
Engine - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Engine overhaul - dismantling sequence . . . . . . . . . . . . . . . . . . . . . . 5
Engine overhaul - general information . . . . . . . . . . . . . . . . . . . . . . . . 2
Engine overhaul - reassembly sequence . . . . . . . . . . . . . . . . . . . . . . 15
Engine removal - methods and precautions . . . . . . . . . . . . . . . . . . . 3
General information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Main and big-end bearings - inspection . . . . . . . . . . . . . . . . . . . . . . 14
Piston rings - refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Piston/connecting rod assembly - inspection . . . . . . . . . . . . . . . . . . 12
Piston/connecting rod assembly - refitting and big-end running
clearance check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Piston/connecting rod assembly - removal . . . . . . . . . . . . . . . . . . . . 9
Degrees of difficulty
Easy, suitable for
novice with little
experience
1
Fairly easy, suitable
for beginner with
some experience
2
Fairly difficult,
suitable for competent
DIY mechanic
3
Difficult, suitable for
experienced DIY
mechanic
Specifications
Cylinder head
2.0 litre engine
Maximum gasket face distortion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cylinder head height:
SOHC engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DOHC engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Valve seat width:
SOHC engine:
Inlet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exhaust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DOHC engine:
Inlet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exhaust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Valve guide height in cylinder head:
SOHC engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DOHC engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.5 and 3.0 litre engine
Maximum gasket face distortion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cylinder head height . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Valve seat width:
Inlet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exhaust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Valve guide height in cylinder head . . . . . . . . . . . . . . . . . . . . . . . . . . . .
0.05 mm
95.75 to 96.25 mm
134 mm
1.0 to 1.5 mm
1.7 to 2.2 mm
1.0 to 1.4 mm
1.4 to 1.8 mm
83.25 to 84.05 mm
13.70 to 14.00 mm
0.05 mm
134 mm
1.0 to 1.4 mm
1.4 to 1.8 mm
13.7 to 14.0 mm
3510 Vauxhall/Opel Omega
4
Very difficult,
suitable for expert DIY
or professional
5
2D
2D•2 General engine overhaul procedures
Valves and guides
2.0 litre engine
Valve stem diameter*:
SOHC engine:
Inlet:
Standard (GM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1st oversize (0.075 mm - GM K1) . . . . . . . . . . . . . . . . . . . . . . . .
2nd oversize (0.150 mm - GM K2) . . . . . . . . . . . . . . . . . . . . . . .
3rd oversize (0.250 mm - A) . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exhaust:
Standard (GM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1st oversize (0.075 mm - GM K1) . . . . . . . . . . . . . . . . . . . . . . . .
2nd oversize (0.150 mm - GM K2) . . . . . . . . . . . . . . . . . . . . . . .
3rd oversize (0.250 mm - A) . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DOHC engine:
Inlet:
Standard (GM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1st oversize (0.075 mm - GM K1) . . . . . . . . . . . . . . . . . . . . . . . .
2nd oversize (0.150 mm - GM K2) . . . . . . . . . . . . . . . . . . . . . . .
Exhaust:
Standard (GM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1st oversize (0.075 mm - GM K1) . . . . . . . . . . . . . . . . . . . . . . . .
2nd oversize (0.0150 mm - GM K2) . . . . . . . . . . . . . . . . . . . . . .
Valve stem runout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Valve guide bore diameter:
SOHC engine:
Standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1st oversize (0.075 mm) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2nd oversize (0.150 mm) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3rd oversize (0.250 mm) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DOHC engine:
Standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1st oversize (0.075 mm) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2nd oversize (0.150 mm) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stem-to-guide clearance:
SOHC engine:
Inlet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exhaust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DOHC engine:
Inlet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exhaust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Valve length:
SOHC engine:
Inlet:
Standard valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oversize valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exhaust:
Standard valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oversize valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DOHC engine:
Inlet:
Standard valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oversize valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exhaust:
Standard valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oversize valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Valve stem fitted height:
SOHC engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DOHC engine:
Standard valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oversize valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Valve head diameter:
SOHC engine:
Inlet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exhaust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DOHC engine:
Inlet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exhaust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.998 to 7.012 mm
7.073 to 7.087 mm
7.148 to 7.162 mm
7.248 to 7.262 mm
6.978 to 6.992 mm
7.053 to 7.067 mm
7.128 to 7.142 mm
7.228 to 7.262 mm
5.955 to 5.970 mm
6.030 to 6.045 mm
6.105 to 6.120 mm
5.945 to 5.960 mm
6.020 to 6.035 mm
6.095 to 6.110 mm
Less than 0.03 mm
7.030 to 7.050 mm
7.105 to 7.125 mm
7.180 to 7.200 mm
7.280 to 7.300 mm
6.000 to 6.012 mm
6.075 to 6.090 mm
6.150 to 6.165 mm
0.018 to 0.052 mm
0.038 to 0.072 mm
0.030 to 0.057 mm
0.040 to 0.067 mm
104.0 to 104.4 mm
103.6 to 104.0 mm
103.75 to 104.25 mm
103.35 to 103.85 mm
101.9 to 102.3 mm
101.5 to 101.9 mm
92.05 to 92.45 mm
91.65 to 92.05 mm
17.85 to 18.25 mm
39.6 to 40.2 mm
39.2 to 39.8 mm
41.8 mm
36.5 mm
31.9 to 32.1 mm
28.9 to 29.1 mm
3510 Vauxhall/Opel Omega
General engine overhaul procedures 2D•3
Valves and guides (continued)
2.5 and 3.0 litre engine
Valve stem diameter*:
Inlet:
Standard (GM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1st oversize (0.075 mm - GM K1) . . . . . . . . . . . . . . . . . . . . . . . . . .
2nd oversize (0.150 mm - GM K2) . . . . . . . . . . . . . . . . . . . . . . . . .
Exhaust:
Standard (GM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1st oversize (0.075 mm - GM K1) . . . . . . . . . . . . . . . . . . . . . . . . . .
2nd oversize (0.0150 mm - GM K2) . . . . . . . . . . . . . . . . . . . . . . . .
Valve stem runout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Valve guide bore diameter:
Standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1st oversize (0.075 mm) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2nd oversize (0.150 mm) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stem-to-guide clearance:
Inlet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exhaust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Valve length:
Inlet:
Standard valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oversize valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exhaust:
Standard valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oversize valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Valve head diameter:
Inlet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exhaust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
*Identification marking in brackets
5.955 to 5.970 mm
6.030 to 6.045 mm
6.105 to 6.120 mm
5.945 to 5.960 mm
6.020 to 6.035 mm
6.095 to 6.110 mm
Less than 0.03 mm
6.000 to 6.012 mm
6.075 to 6.090 mm
6.150 to 6.165 mm
0.030 to 0.057 mm
0.040 to 0.067 mm
101.9 to 102.3 mm
101.5 to 101.9 mm
92.05 to 92.45 mm
91.65 to 92.05 mm
31.9 to 32.1 mm
28.9 to 29.1 mm
Cylinder block
2.0 litre engine
Maximum gasket face distortion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cylinder bore diameter:
Standard:
Size group 8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Size group 99 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Size group 00 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Size group 01 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Size group 02 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oversize (0.5 mm) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Maximum cylinder bore ovality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Maximum cylinder bore taper . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.5 and 3.0 litre engine
Maximum gasket face distortion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cylinder bore diameter:
2.5 litre engine:
Standard:
Size group 8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Size group 99 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Size group 00 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Size group 01 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Size group 02 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oversize (0.5 mm) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.0 litre engine:
Standard:
Size group 8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Size group 99 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Size group 00 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Size group 01 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Size group 02 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oversize (0.5 mm) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Maximum cylinder bore ovality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Maximum cylinder bore taper . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
0.05 mm
2D
85.975 to 85.985 mm
85.985 to 85.995 mm
85.995 to 86.005 mm
86.005 to 86.015 mm
86.015 to 86.025 mm
86.465 to 86.475 mm
0.013 mm
0.013 mm
0.05 mm
81.575 to 81.585 mm
81.585 to 81.595 mm
81.595 to 81.605 mm
81.605 to 81.615 mm
81.615 to 81.625 mm
82.065 to 82.075 mm
85.975 to 85.985 mm
85.985 to 85.995 mm
85.995 to 86.005 mm
86.005 to 86.015 mm
86.015 to 86.025 mm
86.465 to 86.475 mm
0.013 mm
0.013 mm
3510 Vauxhall/Opel Omega
2D•4 General engine overhaul procedures
Pistons and rings
2.0 litre engine
Piston diameter:
Standard:
Size group 8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Size group 99 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Size group 00 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Size group 01 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Size group 02 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oversize (0.5 mm) - size group 7 + 0.5 . . . . . . . . . . . . . . . . . . . . . . . .
Piston-to-bore clearance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Piston ring end gaps (fitted in bore):
Top and second compression rings . . . . . . . . . . . . . . . . . . . . . . . . . .
Oil control ring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Piston ring thickness:
Top and second compression ring . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oil control ring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Piston ring-to-groove clearance:
Top and second compression ring . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oil control ring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.5 and 3.0 litre engine
Piston diameter:
2.5 litre engine:
Standard:
Size group 8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Size group 99 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Size group 00 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Size group 01 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Size group 02 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oversize (0.5 mm) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.0 litre engine:
Standard:
Size group 8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Size group 99 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Size group 00 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Size group 01 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Size group 02 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oversize (0.5 mm) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Piston-to-bore clearance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Piston ring end gaps (fitted in bore):
Top and second compression rings . . . . . . . . . . . . . . . . . . . . . . . . . .
Oil control ring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Piston ring thickness:
Top and second compression ring . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oil control ring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Piston ring-to-groove clearance:
Top and second compression ring . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oil control ring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
85.945 to 85.955 mm
85.955 to 85.965 mm
85.965 to 85.975 mm
85.975 to 85.985 mm
85.985 to 85.995 mm
86.435 to 86.445 mm
0.02 to 0.04 mm
0.3 to 0.5 mm
0.4 to 1.4 mm
1.5 mm
3.0 mm
0.02 to 0.04 mm
0.01 to 0.03 mm
81.540 to 81.550 mm
81.550 to 81.560 mm
81.560 to 81.570 mm
81.570 to 81.580 mm
81.580 to 81.590 mm
82.030 to 82.040 mm
85.940 to 85.950 mm
85.950 to 85.960 mm
85.960 to 85.970 mm
85.970 to 85.980 mm
85.980 to 85.990 mm
86.430 to 86.440 mm
0.025 to 0.045 mm
0.3 to 0.5 mm
0.4 to 1.4 mm
1.5 mm
3.0 mm
0.02 to 0.04 mm
0.01 to 0.03 mm
Gudgeon pins
2.0 litre engine
Diameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Gudgeon pin-to-piston clearance . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.5 and 3.0 litre engine
Diameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Length:
2.5 litre engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.0 litre engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Gudgeon pin-to-piston clearance:
2.5 litre engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.0 litre engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Gudgeon pin-to-connecting rod clearance:
2.5 litre engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.0 litre engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
20.990 to 21.000 mm
61.2 to 61.8 mm
0.011 to 0.014 mm
20.990 to 21.000 mm
55.7 to 56.0 mm
57.7 to 58.0 mm
0.011 to 0.014 mm
0.001 to 0.015 mm
Interference-fit
0.014 to 0.030 mm
3510 Vauxhall/Opel Omega
General engine overhaul procedures 2D•5
Crankshaft
2.0 litre engine
Endfloat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Main bearing journal diameter:
Standard:
1st size group (white) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2nd size group (green) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3rd size group (brown) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1st (0.25 mm) undersize . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2nd (0.50 mm) undersize . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Big-end bearing journal (crankpin) diameter:
Standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1st (0.25 mm) undersize . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2nd (0.50 mm) undersize . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Journal out-of round . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Journal taper . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Crankshaft runout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Main bearing running clearance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Big-end bearing (crankpin) running clearance . . . . . . . . . . . . . . . . . . . .
2.5 and 3.0 litre engine
Endfloat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Main bearing journal diameter:
Standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1st (0.25 mm) undersize . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2nd (0.50 mm) undersize . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Big-end bearing journal (crankpin) diameter:
2.5 litre engine:
Standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1st (0.25 mm) undersize . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2nd (0.50 mm) undersize . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.0 litre engine:
Standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1st (0.25 mm) undersize . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2nd (0.50 mm) undersize . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Journal out-of round . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Journal taper . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Crankshaft runout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Main bearing running clearance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Big-end bearing (crankpin) running clearance . . . . . . . . . . . . . . . . . . . .
0.05 to 0.15 mm
57.974 to 57.981 mm
57.981 to 57.988 mm
57.988 to 57.995 mm
57.732 to 57.745 mm
57.482 to 57.495 mm
48.970 to 48.988 mm
48.720 to 48.738 mm
48.470 to 48.488 mm
0.04 mm
0.04 mm
Less than 0.03 mm
0.015 to 0.043 mm
0.006 to 0.031 mm
0.01 to 0.76 mm
67.980 to 67.996 mm
67.730 to 67.746 mm
67.480 to 67.496 mm
48.971 to 48.990 mm
48.721 to 48.740 mm
48.471 to 48.490 mm
53.971 to 53.990 mm
53.721 to 53.740 mm
53.471 to 53.490 mm
0.04 mm
0.04 mm
Less than 0.03 mm
0.014 to 0.043 mm
0.010 to 0.061 mm
2D
Torque wrench settings
2.0 litre engine
SOHC engine - Refer to Chapter 2A Specifications
DOHC engine - Refer to Chapter 2B Specifications
2.5 and 3.0 litre engine
Refer to Chapter 2C Specifications
1 General information
1 Included in this Part of Chapter 2 are details
of removing the engine from the vehicle and
general overhaul procedures for the cylinder
head, cylinder block and all other engine
internal components.
2 The information given ranges from advice
concerning preparation for an overhaul and
the purchase of replacement parts, to detailed
step-by-step procedures covering removal,
inspection, renovation and refitting of engine
internal components.
3 After Section 5, all instructions are based
on the assumption that the engine has been
removed from the car. For information
concerning in-car engine repair, as well as the
removal and refitting of those external
components necessary for full overhaul, refer
to the relevant in-car repair procedure section
(Chapter 2A to 2C) of this Chapter and to
Section 7. Ignore any preliminary dismantling
operations described in the relevant in-car
repair sections that are no longer relevant
once the engine has been removed from the
car.
4 Apart from torque wrench settings, which
are given at the beginning of the relevant incar repair procedure Chapter (2A to 2C), all
specifications relating to engine overhaul are
at the beginning of this Part of Chapter 2.
3510 Vauxhall/Opel Omega
2 Engine overhaul general information
1 It is not always easy to determine when, or
if, an engine should be completely
overhauled, as a number of factors must be
considered.
2 High mileage is not necessarily an
indication that an overhaul is needed, while
low mileage does not preclude the need for an
overhaul. Frequency of servicing is probably
the most important consideration. An engine
which has had regular and frequent oil and
filter changes, as well as other required
maintenance, should give many thousands of
2D•6 General engine overhaul procedures
miles of reliable service. Conversely, a
neglected engine may require an overhaul
very early in its life.
3 Excessive oil consumption is an indication
that piston rings, valve seals and/or valve
guides are in need of attention. Make sure
that oil leaks are not responsible before
deciding that the rings and/or guides are
worn. Perform a compression test, as
described in Part A of this Chapter, to
determine the likely cause of the problem.
4 Check the oil pressure with a gauge fitted in
place of the oil pressure switch, and compare
it with that specified. If it is extremely low, the
main and big-end bearings, and/or the oil
pump, are probably worn out.
5 Loss of power, rough running, knocking or
metallic engine noises, excessive valve gear
noise, and high fuel consumption may also
point to the need for an overhaul, especially if
they are all present at the same time. If a
complete service does not remedy the
situation, major mechanical work is the only
solution.
6 An engine overhaul involves restoring all
internal parts to the specification of a new
engine. During an overhaul, the pistons and
the piston rings are renewed. New main and
big-end bearings are generally fitted; if
necessary, the crankshaft may be
reground/renewed, to restore the journals.
The valves are also serviced as well, since
they are usually in less-than-perfect
condition at this point. While the engine is
being overhauled, other components, such
as the starter and alternator, can be
overhauled as well. The end result should be
an as-new engine that will give many troublefree miles. Note: Critical cooling system
components such as the hoses, thermostat
and coolant pump should be renewed when
an engine is overhauled. The radiator should
be checked carefully, to ensure that it is not
clogged or leaking. Also, it is a good idea to
renew the oil pump whenever the engine is
overhauled.
7 Before beginning the engine overhaul, read
through the entire procedure, to familiarise
yourself with the scope and requirements of
the job. Overhauling an engine is not difficult
if you follow carefully all of the instructions,
have the necessary tools and equipment, and
pay close attention to all specifications. It
can, however, be time-consuming. Plan on
the car being off the road for a minimum of
two weeks, especially if parts must be taken
to an engineering works for repair or
reconditioning. Check on the availability of
parts and make sure that any necessary
special tools and equipment are obtained in
advance. Most work can be done with typical
hand tools, although a number of precision
measuring tools are required for inspecting
parts to determine if they must be renewed.
Often the engineering works will handle the
inspection of parts and offer advice
concerning reconditioning and renewal.
Note: Always wait until the engine has been
completely dismantled, and until all
components (especially the cylinder block
and the crankshaft) have been inspected,
before deciding what service and repair
operations must be performed by an
engineering works. The condition of these
components will be the major factor to
consider when determining whether to
overhaul the original engine, or to buy a
reconditioned unit. Do not, therefore,
purchase parts or have overhaul work done
on other components until they have been
thoroughly inspected. As a general rule, time
is the primary cost of an overhaul, so it does
not pay to fit worn or sub-standard parts.
8 As a final note, to ensure maximum life and
minimum trouble from a reconditioned engine,
everything must be assembled with care, in a
spotlessly-clean environment.
3 Engine removal methods and precautions
1 If you have decided that the engine must be
removed for overhaul or major repair work,
several preliminary steps should be taken.
2 Locating a suitable place to work is
extremely important. Adequate work space,
along with storage space for the car, will be
needed. If a workshop or garage is not
available, at the very least, a flat, level, clean
work surface is required.
3 Cleaning the engine compartment and
engine/transmission before beginning the
removal procedure will help keep tools clean
and organised.
4 An engine hoist or A-frame will also be
necessary. Make sure the equipment is rated
in excess of the weight of the engine. Safety is
of primary importance, considering the
potential hazards involved in lifting the engine
out of the car.
5 If this is the first time you have removed an
engine, an assistant should ideally be
available. Advice and aid from someone more
experienced would also be helpful. There are
many instances when one person cannot
simultaneously perform all of the operations
required when lifting the engine out of the
vehicle.
6 Plan the operation ahead of time. Before
starting work, arrange for the hire of or obtain
all of the tools and equipment you will need.
Some of the equipment necessary to perform
engine removal and installation safely and
with relative ease (in addition to an engine
hoist) is as follows: a heavy duty trolley jack,
complete sets of spanners and sockets as
described in the front of this manual, wooden
blocks, and plenty of rags and cleaning
solvent for mopping up spilled oil, coolant and
fuel. If the hoist must be hired, make sure that
you arrange for it in advance, and perform all
of the operations possible without it
beforehand. This will save you money and
time.
3510 Vauxhall/Opel Omega
7 Plan for the car to be out of use for quite a
while. An engineering works will be required
to perform some of the work which the do-ityourselfer cannot accomplish without special
equipment. These places often have a busy
schedule, so it would be a good idea to
consult them before removing the engine, in
order to accurately estimate the amount of
time required to rebuild or repair components
that may need work.
8 Always be extremely careful when removing
and refitting the engine. Serious injury can
result from careless actions. Plan ahead and
take your time, and a job of this nature,
although major, can be accomplished
successfully.
4 Engine removal and refitting
4
Note: On 2.5 and 3.0 litre engine models with
air conditioning, it will be necessary to
disconnect the refrigerant lines in order to
remove the engine unit from the vehicle (see
Warnings in Chapter 3). Have the refrigerant
discharged by an air conditioning specialist
before starting work and have ready some
caps/plugs to plug the hose/pipe end fittings
whilst the engine is removed. On completion it
will be necessary to have the system
recharged by an air conditioning specialist. Do
not operate the air conditioning system whilst
it is discharged.
Removal
1 Park the vehicle on firm, level ground then
remove the bonnet as described in Chapter 11.
2 Remove the battery as described in
Chapter 5A.
3 Chock the rear wheels, then firmly apply the
handbrake. Apply the handbrake, then jack up
the front of the vehicle. Securely support it on
axle stands then undo the retaining screws
and remove the undercover from beneath the
engine unit.
4 Drain the cooling system as described in
Chapter 1. If the engine is to be dismantled,
also drain the engine oil and remove the oil
filter.
5 Working as described in Chapter 4A,
depressurise the fuel system then remove the
engine management electronic control unit
(ECU).
6 Remove the lid from the engine
compartment relay box and trace the engine
wiring harness into the box. Unclip the
injection system relay connectors from the
box then disconnect the harness connector(s)
(see illustrations). Free the sealing grommet
and position the harness clear of the relay
box.
7 Disconnect the engine wiring harness
connectors which are located at the rear of
the battery (see illustration).
General engine overhaul procedures 2D•7
4.6a Unclip the injection system relays . . .
4.6b . . . and disconnect the engine wiring
harness connector from the relay box
8 Free the engine wiring harness auxiliary
connections connector from the battery positive
terminal so the harness is free to be removed
with the engine and (where necessary) unbolt
the earth lead from the front of the engine. On
some models the harness is connected to the
fusible link housing instead of the battery
terminal; where this is the case, remove the
fusible link and unclip the connector from the
housing (see illustrations). Proceed as
described under the relevant sub-heading.
disconnect the radiator top hose from the
cylinder head.
12 Remove the cooling fan from the rear of
the radiator as described in Chapter 3.
13 Referring to Chapter 10, unbolt the power
steering pump and position it clear of the
engine unit with its hoses still attached.
14 On models with air conditioning, unbolt the
compressor and position it clear of the engine
with its pipes/hoses still attached. Do not open
the refrigerant system (see Chapter 3).
15 Attach the hoist to the engine lifting
brackets then remove the transmission unit as
described in Chapter 7A or 7B, as applicable.
16 Make a final check that any components
which would prevent the removal of the
engine from the car have been removed or
disconnected. Ensure all wiring/hoses are
secured so that they cannot be damaged on
removal.
17 Slacken and remove the nuts securing the
left- and right-hand engine mounting brackets
to the top of the mountings
18 With the aid of assistant, lift the engine
until the brackets are clear of the mountings
then carefully move the engine forwards
sufficiently to allow it to be lifted cleanly out of
position and clear of the vehicle. Great care
must be taken to ensure that no components
are trapped and damaged during the removal
procedure.
19 Lower the engine onto a suitable work
area and detach the hoist.
2.0 litre SOHC engine
9 Referring to Chapter 4A, carry out the
following procedures.
a) Remove the air cleaner housing and
intake ducts.
b) Remove the exhaust front pipe.
c) Disconnect the fuel feed and return hoses
from the fuel rail.
d) Disconnect the accelerator cable and
(where necessary) cruise control cable
from the throttle linkage then unbolt the
cable mounting bracket and position it
clear of the engine.
e) Disconnect the brake servo hose and
various vacuum hoses and from the inlet
manifold, noting each hoses correct fitted
location. Also disconnect the coolant
hose from the throttle housing.
10 Remove the DIS module as described in
Chapter 5B. Once the module has been
removed, refit the lifting bracket to the cylinder
head and securely tighten the retaining bolt.
11 Disconnect the engine coolant hose from
the rear of the coolant pipe on the right-hand
side of the engine compartment. Also
4.8a Where necessary, remove the fusible
link . . .
4.7 Disconnect the engine wiring harness
connectors which are located at the rear
of the battery
a) Remove the air cleaner housing and
intake ducts.
b) Remove the throttle housing.
c) Remove the exhaust front pipe.
d) Disconnect the fuel feed and return hoses
from the fuel rail.
e) Disconnect the brake servo hose and
various vacuum hoses and from the inlet
manifold, noting each hoses correct fitted
location. Also disconnect the hose from
the secondary air injection valve on the
exhaust manifold.
21 Disconnect the engine coolant hose from
the rear of the coolant pipe on the right-hand
side of the engine compartment. Also
disconnect the radiator top hose from the
cylinder head and the hose from the DIS
module mounting bracket on the rear of the
cylinder head.
22 Remove the engine as described in
paragraphs 12 to 19.
2.5 and 3.0 litre engine
20 Referring to Chapter 4A, carry out the
following procedures.
23 Remove the windscreen wiper motor as
described in Chapter 12.
24 Remove the radiator as described in
Chapter 3.
25 Slacken the retaining clip and disconnect
the radiator top hose from the coolant pipe on
the left-hand cylinder head.
26 Wipe clean the area around the hose/pipe
unions on the power steering pump (see
illustration). Slacken the retaining clip then
disconnect the fluid supply hose from the
pump and drain the reservoir contents into a
suitable container. Unscrew the union nut and
4.8b . . . and unclip the engine harness
connector from the fusible link housing
4.26 On 2.5 and 3.0 litre engines,
disconnect the fluid supply hose (A) and the
feed pipe (B) from the power steering pump
2.0 litre DOHC engine
3510 Vauxhall/Opel Omega
2D
2D•8 General engine overhaul procedures
4.27a Slacken the union nuts and
disconnect the fuel hoses from the fuel rail
4.27b Disconnecting the hose from the
secondary air injection non-return valve
4.27c Disconnect the multi-ram intake
system vacuum hoses from the servo unit
pipe
disconnect the feed pipe from the pump then
plug the hose and pump unions to minimise
fluid loss and prevent the entry of dirt into the
system.
27 Referring to Chapter 4A, carry out the
following procedures.
a) Remove the air cleaner housing and
intake ducts.
b) Disconnect the accelerator cable and
(where necessary) cruise control cable
from the throttle linkage and free them
from the mounting bracket.
c) Remove the exhaust front pipes.
d) Disconnect the fuel feed and return hoses
from the fuel rail (see illustration).
e) Disconnect the brake servo hose from the
inlet manifold then disconnect the
breather hoses from the rear of the
manifold and position the servo hose
clear of the engine.
f) Disconnect the air hose from the
secondary air injection non-return valve at
the front of the engine (see illustration).
g) Disconnect the carbon canister hose from
the purge valve and multi-ram intake
system vacuum hoses from the servo unit
vacuum pipe (see illustration).
28 Release the retaining clips and disconnect
the engine coolant hoses from the expansion
tank. Remove the retaining clip and slide the
tank out of the engine compartment,
disconnecting the wiring connector from the
level sender as it becomes accessible (see
illustrations).
29 Locate the heater matrix coolant hose
unions on the bulkhead. Pull back on the
quick-release fitting collars and detach both
hoses from their unions. Disconnect the
vacuum hose from the heater cut-off valve
(see illustrations).
30 On models with air conditioning,
disconnect the wiring connector from the
compressor. Referring to Chapter 3, having
had the refrigerant discharged by a specialist,
disconnect the compressor refrigerant pipes
at their unions on the receiver/drier damper
and directly above the left-hand cylinder
head. On models with quick-release fittings,
separate the unions by sliding back the dust
seal and releasing the locking collar tabs by
inserting a collar (special tools KM-917-1 and
KM-917-2 are designed for this task) into the
fitting and on models with screw-type fittings,
unscrew the union nuts then disconnect the
pipes and recover the union sealing rings.
Immediately fit the closure cap/plugs to the
pipe/union ends to keep moisture out of the
system. Unscrew the mounting clamp bolts
and position the damper clear of the engine
unit (see illustrations).
4.28a Disconnect the engine coolant
hoses from the expansion tank . . .
4.28b . . . and remove the tank retaining
clip
4.28c Free the expansion tank from its
mountings and remove it, disconnecting
the wiring connector from the level sender
4.29a Pull back on the locking collars and
detach the heater matrix coolant hoses
from their unions on the bulkhead . . .
4.29b . . . then disconnect the vacuum
hose from the heater cut-off valve
3510 Vauxhall/Opel Omega
4.30a On models with air conditioning
disconnect the wiring connector from the
compressor . . .
General engine overhaul procedures 2D•9
4.30b . . . and separate the air refrigerant
pipes at the unions above the left-hand
cylinder head . . .
4.30c . . . and at the front of the engine
(quick-release fitting pipes shown)
31 Attach the hoist to the engine lifting
brackets then remove the transmission unit as
described in Chapter 7A or 7B, as applicable
(see illustration).
32 Make a final check that any components
which would prevent the removal of the
engine from the car have been removed or
disconnected. Ensure all wiring/hoses are
secured so that they cannot be damaged on
removal.
33 Unscrew the mounting bolts and remove
the vibration dampers (where fitted) from the
left- and right-hand engine mountings.
34 Slacken and remove the nuts securing the
left- and right-hand engine mountings to the
subframe and engine brackets.
35 With the aid of assistant, lift the engine
until the brackets are clear of the mountings
then remove both mountings from the vehicle.
Carefully move the engine forwards
sufficiently to allow it to be lifted cleanly out of
position and clear of the vehicle (see
illustration). Great care must be taken to
ensure that no components are trapped and
damaged during the removal procedure.
36 Lower the engine onto a suitable work
area and detach the hoist.
the engine onto its mounting rubbers. Ensure
the brackets are correctly engaged with the
mountings then refit the mounting nuts and
tighten to the specified torque setting.
39 The remainder of the refitting procedure is
a direct reversal of removal, noting the
following.
Refitting
37 Reconnect the hoist to the engine lifting
brackets and, with the aid of an assistant,
carefully lift the assembly into position the
engine compartment taking great care not to
trap any components.
38 Align the engine mounting brackets with
the left- and right-hand mountings and lower
4.31 Remove the covers from the engine
lifting brackets and attach the hoist
a) Refit the transmission unit as described in
Chapter 7A or 7B, as applicable.
b) On 2.5 and 3.0 litre models with air
conditioning, fit new sealing rings to the
compressor pipe unions and securely
tighten the union nuts (screw-type fittings)
or ensure the pipes are pushed securely
together until an audible click is emitted
(quick-release fittings). On completion
have the refrigerant system recharged by
an air conditioning specialist before using
the vehicle.
c) Ensure that all wiring is correctly routed
and retained by all the relevant retaining
clips and that all connectors are correctly
and securely reconnected.
d) Ensure that all disturbed hoses are
correctly reconnected, and securely
retained by their retaining clips. Ensure all
the cooling system quick-release fittings
are securely retained by their collars.
e) Adjust the accelerator cable as described
in the Chapter 4A.
f) Fit a new oil filter (where necessary) and
refill the engine with fresh oil as described
in Chapter 1.
g) Refill the cooling system as described in
Chapter 1.
4.35 Lifting the engine unit out of position
3510 Vauxhall/Opel Omega
4.30d Release the receiver/drier damper
mounting bracket and position the damper
clear of the engine
5 Engine overhaul dismantling sequence
1 It is much easier to dismantle and work on
the engine if it is mounted on a portable engine
stand. These stands can often be hired from a
tool hire shop. Before the engine is mounted
on a stand, the flywheel/driveplate should be
removed, so that the stand bolts can be
tightened into the end of the cylinder block.
2 If a stand is not available, it is possible to
dismantle the engine with it blocked up on a
sturdy workbench, or on the floor. Be extracareful not to tip or drop the engine when
working without a stand.
3 If you are going to obtain a reconditioned
engine, all the external components must be
removed first, to be transferred to the
replacement engine (just as they will if you are
doing a complete engine overhaul yourself).
These components include the following:
a) Inlet and exhaust manifolds (Chapter 4A).
b) Alternator/power steering pump/air
conditioning compressor bracket(s) (as
applicable).
c) Coolant pump (Chapter 3).
d) Fuel system components (Chapter 4A).
e) Wiring harness and all electrical switches
and sensors.
f) Oil filter (Chapter 1).
g) Flywheel/driveplate (relevant part of this
Chapter).
Note: When removing the external
components from the engine, pay close
attention to details that may be helpful or
important during refitting. Note the fitted
position of gaskets, seals, spacers, pins,
washers, bolts, and other small items.
4 If you are obtaining a ‘short’ engine (which
consists of the engine cylinder block, crankshaft, pistons and connecting rods all
assembled), then the cylinder head(s), sump,
oil pump, and timing belt will have to be
removed also.
5 If you are planning a complete overhaul, the
engine can be dismantled, and the internal
components removed, in the order given
below, referring to the relevant part of this
Chapter unless otherwise stated.
2D
2D•10 General engine overhaul procedures
6.4a Using a valve spring compressor
6.4b Pull off the valve stem seals using a
pair of pliers
6.6 Removing a valve
a) Inlet and exhaust manifolds (Chapter 4A).
b) Timing belt, sprockets and tensioner.
c) Cylinder head(s).
d) Flywheel/driveplate.
e) Sump.
f) Oil pump.
g) Piston/connecting rod assemblies.
h) Crankshaft.
6 Before beginning the dismantling and
overhaul procedures, make sure that you have
all of the correct tools necessary. Refer to the
Tools and working facilities Section of this
manual for further information.
1 On 2.0 litre SOHC engines, referring to Part A
of this Chapter, remove the cylinder head from
the engine then lift the camshaft followers,
thrust pads and hydraulic tappets out from the
cylinder head.
2 On 2.0 litre DOHC engines remove the camshafts and followers as described in Part B of
this Chapter then remove the cylinder head
from the engine.
3 On 2.5 and 3.0 litre engines remove the camshafts and followers as described in Part C of
this Chapter then remove the cylinder head(s)
from the engine.
4 On all models, using a valve spring
compressor, compress each valve spring in
turn until the split collets can be removed.
Release the compressor, and lift off the spring
retainer and spring. Using a pair of pliers,
carefully extract the valve stem seal from the
top of the guide then slide off the spring seat
(see illustrations).
5 If, when the valve spring compressor is
screwed down, the spring retainer refuses to
free and expose the split collets, gently tap
the top of the tool, directly over the retainer,
with a light hammer. This will free the retainer.
6 Withdraw the valve through the combustion
chamber (see illustration). It is essential that
each valve is stored together with its collets,
retainer, spring, and spring seat. The valves
should also be kept in their correct sequence,
unless they are so badly worn that they are to
be renewed (see Haynes hint).
combustion chambers and ports, then wash
the cylinder head thoroughly with paraffin or a
suitable solvent. Scrape off any heavy carbon
deposits that may have formed on the valves,
then use a power-operated wire brush to
remove deposits from the valve heads and
stems.
4 Ensure the cylinder head oilways are clean
and free of obstructions. If you have access to
compressed air, use it to blow out the oilways
and galleries. To ensure a thorough job is
done, remove all oil gallery plugs prior to
cleaning. Once the galleries are clean, apply
suitable sealant to the oil gallery plugs and
refit them to the cylinder head, tightening
them securely.
6 Cylinder head dismantling
4
Note: New and reconditioned cylinder heads
are available from the manufacturer, and from
engine overhaul specialists. Be aware that
some specialist tools are required for the
dismantling and inspection procedures, and
new components may not be readily available.
It may therefore be more practical and
economical for the home mechanic to
purchase a reconditioned head, rather than
dismantle, inspect and recondition the original
head.
7 Cylinder head and valves cleaning and inspection
If the components are to be refitted,
place each valve and its associated
components in a labelled polythene bag
or similar small container. Mark the
bag/container with the relevant valve
number to ensure that it is refitted in its
original location
4
Warning: Wear eye protection
when using compressed air!
Inspection
Note: Be sure to perform all the following
inspection procedures before concluding that
the services of a machine shop or engine
overhaul specialist are required. Make a list of
all items that require attention.
Cylinder head
5 Inspect the head very carefully for cracks,
evidence of coolant leakage, and other
damage. If cracks are found, a new cylinder
head should be obtained.
6 Use a straight-edge and feeler blade to
check that the cylinder head surface is not
distorted (see illustration). If it is, it may be
possible to resurface it, provided that the
cylinder head is not reduced to less than the
minimum specified height.
1 Thorough cleaning of the cylinder head and
valve components, followed by a detailed
inspection, will enable you to decide how
much valve service work must be carried out
during the engine overhaul. Note: If the
engine has been severely overheated, it is best
to assume that the cylinder head is warped check carefully for signs of this.
Cleaning
2 Scrape away all traces of old gasket
material from the cylinder head.
3 Scrape away the carbon from the
3510 Vauxhall/Opel Omega
7.6 Checking the cylinder head surface for
distortion
General engine overhaul procedures 2D•11
7 Examine the valve seats in each of the
combustion chambers. If they are severely
pitted, cracked or burned, then they will need
to be renewed (if possible) or recut by an
engine overhaul specialist. If they are only
slightly pitted, this can be removed by
grinding-in the valve heads and seats with fine
valve-grinding compound, as described below.
8 If the valve guides are worn (indicated by a
side-to-side motion of the valve, and
accompanied by excessive blue smoke in the
exhaust when running) new guides must be
fitted. Measure the diameter of the existing
valve stems (see below) and the bore of the
guides, then calculate the clearance and
compare the result with the specified value. If
the clearance is not within the specified limits,
renew the valves and/or guides as necessary.
9 The renewal of valve guides is best carried
out by an engine overhaul specialist. If the
work is to be carried out at home, however,
use a stepped, double-diameter drift to drive
out the worn guide towards the combustion
chamber. On fitting the new guide, place it
first in a deep-freeze for one hour, then drive it
into its cylinder head bore from the camshaft
side until it projects the specified amount
above the cylinder head surface.
10 If the valve seats are to be re-cut this
must be done only after the guides have been
renewed.
Valves
Caution: On 3.0 litre engines, the exhaust
valves are filled with sodium and must
therefore be disposed of carefully. Wearing
protective goggles, gloves and some
overalls, cut the exhaust valves in half then
immerse them in water noting that the
sodium will react violently as soon as it
contacts the water. When the reaction
between the sodium and water has
finished, the valves can then be disposed
of normally. Dispose of the water bearing
in mind that it will contain sodium
hydroxide (caustic soda) which is highly
corrosive.
11 Examine the head of each valve for
pitting, burning, cracks and general wear, and
check the valve stem for scoring and wear
ridges. Rotate the valve, and check for any
obvious indication that it is bent. Look for
pitting and excessive wear on the tip of each
valve stem. Renew any valve that shows any
such signs of wear or damage.
12 If the valve appears satisfactory at this
stage, measure the valve stem diameter at
several points using a micrometer (see
illustration). Any significant difference in the
readings obtained indicates wear of the valve
stem. Should any of these conditions be
apparent, the valve(s) must be renewed.
13 If the valves are in satisfactory condition,
they should be ground (lapped) into their
respective seats, to ensure a smooth gastight seal. If the seat is only lightly pitted, or if
it has been re-cut, fine grinding compound
only should be used to produce the required
7.12 Using a micrometer to measure valve
stem diameter
finish. Coarse valve-grinding compound
should not be used unless a seat is badly
burned or deeply pitted; if this is the case, the
cylinder head and valves should be inspected
by an expert to decide whether seat recutting, or even the renewal of the valve or
seat insert, is required.
14 Valve grinding is carried out as follows.
Place the cylinder head upside-down on a
bench.
15 Smear a trace of the appropriate grade of
valve-grinding compound on the seat face,
and press a suction grinding tool onto the
valve head. With a semi-rotary action, grind
the valve head to its seat, lifting the valve
occasionally to redistribute the grinding
compound (see illustration). A light spring
placed under the valve head will greatly ease
this operation.
16 If coarse grinding compound is being
used, work only until a dull, matt even surface
is produced on both the valve seat and the
valve, then wipe off the used compound and
repeat the process with fine compound. When
a smooth unbroken ring of light grey matt
finish is produced on both the valve and seat,
the grinding operation is complete. Do not
grind in the valves any further than absolutely
necessary, or the seat will be prematurely
sunk into the cylinder head.
17 When all the valves have been ground-in,
carefully wash off all traces of grinding
compound using paraffin or a suitable solvent
before reassembly of the cylinder head.
8.1 Lubricate the valve stem with engine
oil and insert it into the correct guide
3510 Vauxhall/Opel Omega
7.15 Grinding in a valve
Valve components
18 Examine the valve springs for signs of
damage and discoloration; if possible; also
compare the existing spring free length with
new components.
19 Stand each spring on a flat surface, and
check it for squareness. If any of the springs
are damaged, distorted or have lost their
tension, obtain a complete new set of springs.
8 Cylinder head reassembly
4
1 Lubricate the stems of the valves, and
insert them into their original locations (see
illustration). If new valves are being fitted,
insert them into the locations to which they
have been ground.
2 Working on the first valve, refit the spring
seat. Dip the new valve stem seal in fresh
engine oil, then carefully locate it over the
valve and onto the guide. Take care not to
damage the seal as it is passed over the valve
stem. Use a suitable socket or metal tube to
press the seal firmly onto the guide (see
illustrations). Note: If genuine seals are being
fitted there maybe an oil seal protector
supplied with the seals; the protector fits over
the valve stem and prevents the oil seal lip
being damaged on the valve.
3 Locate the spring on the seat and fit the
spring retainer (see illustration).
8.2a Fit the spring seat . . .
2D
2D•12 General engine overhaul procedures
8.2b . . . then fit the seal protector (where
provided) . . .
8.2c . . . and install the valve stem oil seal
8.3 Fit the valve spring and spring retainer
8.4 Compress the valve and locate the
collets in the recess on the valve stem
4 Compress the valve spring, and locate the
split collets in the recess in the valve stem
(see illustration). Release the compressor,
then repeat the procedure on the remaining
valves.
8 On 2.5 and 3.0 litre engines, working as described in Part C, refit the cylinder head to the
engine and install the followers and camshafts.
Use a little dab of grease to hold the
collets in position on the valve stem
while the spring compressor is released
5 With all the valves installed, using a
hammer and interposed block of wood, tap
the end of each valve stem to settle the
components.
6 On 2.0 litre SOHC engine, working as
described in Part A, Sections 11 and 12, refit
the hydraulic tappets, thrust pads and followers to the head then refit the cylinder head.
7 On 2.0 litre DOHC engine, working as
described in Part B, refit the cylinder head to
the engine and install the followers and
camshafts.
9 Piston/connecting rod
assembly removal
4
Note: New connecting rod big-end cap bolts
will be needed on refitting
1 On 2.0 litre SOHC engines, working as
described in Part A of this Chapter, remove
the cylinder head and sump then unbolt the
pick-up/strainer and remove the baffle plate.
2 On 2.0 litre DOHC engines, referring to Part
B of this Chapter, remove the cylinder head,
sump and oil pick-up/strainer. On later (1998
model year onwards) engines, remove the
crankshaft balancer unit. On early (pre 1998
model year) engines with a two-piece sump,
9.3 Removing the baffle plate 2.5 and 3.0 litre engine
3510 Vauxhall/Opel Omega
8.2d Press the oil seal fully onto the guide
with a suitable socket
unscrew the retaining bolts and remove the
baffle plate from the base of the cylinder
block; discard the retaining bolts new ones
should be used on refitting.
3 On 2.5 and 3.0 litre engines remove the
cylinder heads and sump as described in Part
C of this Chapter. Unbolt the baffle plate and
remove it from the base of the main bearing
bridge casting (see illustration).
4 On all models, if there is a pronounced wear
ridge at the top of any bore, it may be
necessary to remove it with a scraper or ridge
reamer, to avoid piston damage during
removal. Such a ridge indicates excessive
wear of the cylinder bore.
5 Using a hammer and centre-punch, paint or
similar, mark each connecting rod and its
bearing cap with its respective cylinder
number on the flat machined surface
provided; if the engine has been dismantled
before, note carefully any identifying marks
made previously (see illustration). On 2.0 litre
engines No 1 cylinder is at the timing belt end
of the engine and on 2.5 and 3.0 litre engines
No1 cylinder it is at the timing belt end of the
right-hand cylinder bank.
6 Turn the crankshaft to bring piston 1 to
BDC (bottom dead centre).
7 Unscrew the bolts from No 1 piston big-end
bearing cap. Take off the cap and recover the
bottom half bearing shell. If the bearing shells
are to be re-used, tape the cap and the shell
together.
9.5 Make identification markings on the
connecting rods and bearing caps
(circled). Note that the lug on the bearing
cap faces towards the flywheel/driveplate
end of the engine
General engine overhaul procedures 2D•13
Caution: On some engines, the connecting
rod/bearing cap mating surfaces are not
machined flat; the big-end bearing caps
are ‘cracked’ off from the rod during
production and left untouched to ensure
the cap and rod mate perfectly. Where this
type of connecting rod is fitted, great care
must be taken to ensure the mating
surfaces of the cap and rod are not marked
or damaged in anyway. Any damage to the
mating surfaces will adversely affect the
strength of the connecting rod and could
lead to premature failure.
8 Using a hammer handle, push the piston up
through the bore, and remove it from the top
of the cylinder block. Recover the bearing
shell, and tape it to the connecting rod for
safe-keeping.
9 Loosely refit the big-end cap to the
connecting rod, and secure with the bolts this will help to keep the components in their
correct order.
10 On 2.0 litre engines, remove No 4 piston
assembly in the same way then turn the
crankshaft through 180° to bring pistons 2
and 3 to BDC (bottom dead centre), and
remove them in the same way.
11 On 2.5 and 3.0 litre engines, remove the
remaining five piston assemblies in the same
way, positioning the crankshaft as necessary
to gain access to the bearing cap bolts.
10 Crankshaft removal
4
10.5 The main bearing caps should be
numbered (No 1 cap shown)
10.7 Removing the centre (No 3) main
bearing cap. Note the thrust flanges
incorporated into the bearing shell
or a suitable marker pen, number the caps
from 1 to 5 from the timing belt end of the
engine and mark each cap to indicate its
correct fitted direction to avoid confusion on
refitting.
6 Working in a diagonal sequence, evenly
and progressively slacken the ten main
bearing cap retaining bolts by half a turn at a
time until all bolts are loose. Remove all bolts.
7 Carefully remove each cap from the
cylinder block, ensuring that the lower main
bearing shell remains in position in the cap
(see illustration).
8 Carefully lift out the crankshaft, taking care
not to displace the upper main bearing shells
(see illustration). Remove the flywheel/
driveplate end oil seal and discard it.
9 Recover the upper bearing shells from the
cylinder block, and tape them to their
respective caps for safe-keeping (see
illustration).
12 Check the crankshaft endfloat as
described in Section 13, then proceed as
follows.
13 Prior to removal, check the main bearing
bridge casting fitting mark is clearly visible.
There should be an arrow on the casting
which points towards the timing belt end of
the engine.
14 With the cylinder block upside down,
slacken and remove the four bolts securing
the main bearing bridge casting to the
cylinder block.
15 Working in a diagonal sequence, evenly
and progressively slacken the eight main
bearing cap/bridge retaining bolts by half a
turn at a time until all bolts are loose. Remove
the bolts then lift off the bridge casting from
the cylinder block.
16 The main bearing caps should be
numbered 1 to 3 from the timing belt end of
the engine; the flywheel/driveplate end
bearing cap is not numbered but is easily
identified anyway. If the bearing caps are not
marked, using a hammer and punch or a
suitable marker pen, number the caps from 1
to 3 from the timing belt end of the engine and
mark each cap to indicate its correct fitted
direction to avoid confusion on refitting.
17 Carefully remove each cap from the
cylinder block, ensuring that the lower main
bearing shell remains in position in the cap. If
the rear cap is a tight-fit, screw two M8 bolts
into the threaded holes and use the bolts to
pull the cap out (see illustration).
18 Carefully lift out the crankshaft, taking
care not to displace the upper main bearing
2.0 litre engine
2.5 and 3.0 litre engines
Note: New main bearing cap bolts will be
required on refitting.
1 Remove
the
oil
pump
and
flywheel/driveplate. Refer to Part A for
information on SOHC engine and Part B for
information on the DOHC engine.
2 Remove the piston and connecting rod
assemblies as described in Section 9. If no
work is to be done on the pistons and
connecting rods, unbolt the caps and push
the pistons far enough up the bores that the
connecting rods are positioned clear of the
crankshaft journals.
3 On earlier DOHC engines with a two-piece
sump, evenly and progressively slacken the
remaining bolts and remove the main bearing
ladder casting from the base of the block.
Discard the retaining bolts; new ones must be
used on refitting.
4 Check the crankshaft endfloat as described
in Section 13, then proceed as follows.
5 The main bearing caps should be
numbered 1 to 5 from the timing belt end of
the engine (see illustration). Note: On some
engines the flywheel/driveplate end (number
5) bearing cap may not be numbered but is
easily identified anyway. If the bearing caps
are not marked, using a hammer and punch
Note: New main bearing cap/bridge bolts will
be required on refitting.
10 Remove the oil pump and flywheel/
driveplate as described in Part C of this
Chapter.
11 Remove the piston and connecting rod
assemblies as described in Section 9. If no
work is to be done on the pistons and
connecting rods, unbolt the caps and push
the pistons far enough up the bores that the
connecting rods are positioned clear of the
crankshaft journals.
10.8 Remove the crankshaft . . .
3510 Vauxhall/Opel Omega
10.9 . . . and lift out the upper main
bearing shells from the cylinder block
2D
2D•14 General engine overhaul procedures
10.17 If the rear cap is tight, screw two M8
bolts into the cap and use them to work
the cap free
10.18 Removing the crankshaft 2.5 and 3.0 litre engine
shells (see illustration). Remove the
flywheel/driveplate end oil seal and discard it.
19 Recover the upper bearing shells from the
cylinder block, and tape them to their
respective caps for safe-keeping.
with a pair of grips or a slide hammer. On 2.5
and 3.0 litre engines the core plugs are
screwed in position.
2 Scrape all traces of gasket from the cylinder
block taking care not to damage the
gasket/sealing surfaces.
3 Remove all oil gallery plugs (where fitted).
The plugs are usually very tight - they may have
to be drilled out, and the holes re-tapped. Use
new plugs when the engine is reassembled. On
2.5 and 3.0 litre engines, it is recommended
that the oil bypass valve is also removed; the
valve is located behind the oil filter (a new one
will be needed on refitting). To remove the
bypass valve, cut a thread into the centre of the
valve bore with an M10 tap; use the finishing
(blunt-ended) tap to ensure the valve is
threaded right up to the ball. Draw the valve out
from the block using an M10 bolt and washers
and a socket as a spacer (see illustrations).
4 If any of the castings are extremely dirty, all
should be steam-cleaned.
5 After the castings are returned, clean all oil
holes and oil galleries one more time. Flush all
internal passages with warm water until the
water runs clear. Dry thoroughly, and apply a
light film of oil to all mating surfaces, to
prevent rusting. Also oil the cylinder bores. If
you have access to compressed air, use it to
speed up the drying process, and to blow out
all the oil holes and galleries (see illustration).
11 Cylinder block cleaning and inspection
4
Cleaning
1 Remove all external components and
electrical switches/sensors from the block.
For complete cleaning, the core plugs should
ideally be removed. On 2.0 litre engines the
core plugs are a press-fit; to remove a plug,
drill a small hole then insert a self-tapping
screw into the hole and pull out the plug either
you can stand!), soapy water and a stiff brush.
Take plenty of time, and do a thorough job.
Regardless of the cleaning method used, be
sure to clean all oil holes and galleries very
thoroughly, and to dry all components well.
Protect the cylinder bores as described
above, to prevent rusting.
7 All threaded holes must be clean, to ensure
accurate torque readings during reassembly.
To clean the threads, run the correct-size tap
into each of the holes to remove rust,
corrosion, thread sealant or sludge, and to
restore damaged threads. If possible, use
compressed air to clear the holes of debris
produced by this operation. A good
alternative is to inject aerosol-applied waterdispersant lubricant into each hole, using the
long spout usually supplied.
Warning: Wear eye protection
when cleaning out these holes in
this way!
8 Apply suitable sealant to the new oil gallery
plugs, and insert them into the holes in the
block. Tighten them securely.
9 If the engine is not going to be reassembled
right away, cover it with a large plastic bag to
keep it clean; protect all mating surfaces and
the cylinder bores as described above, to
prevent rusting.
Inspection
11.3a On 2.5 and 3.0 litre engines cut an
M10 thread into the oil bypass valve . . .
6 If the castings are not very dirty, you can do
an adequate cleaning job with hot (as hot as
10 Visually check the castings for cracks and
corrosion. Look for stripped threads in the
threaded holes. If there has been any history
of internal water leakage, it may be worthwhile
having an engine overhaul specialist check
the cylinder block/crankcase with special
equipment. If defects are found, have them
repaired if possible, or renew the assembly.
11 Check the bore of each cylinder for
scuffing and scoring.
12 Measure the diameter of each cylinder
bore at the top (just below the wear ridge),
centre and bottom of the bore, both parallel to
the crankshaft axis and at right angles to it, so
that a total of six measurements are taken.
Note that there are various size groups of
standard bore diameter to allow for
manufacturing tolerances; the size group
markings are stamped on the cylinder block
upper surface.
13 Compare
the
results
with
the
Specifications at the beginning of this
11.3b . . . then use an M10 bolt and washer
and a suitable socket . . .
11.3c . . . to draw the valve assembly out
from the cylinder block
11.5 Use compressed air to blow out all
the cylinder block internal drillings and
oilways
Warning: Wear eye protection
when using compressed air!
3510 Vauxhall/Opel Omega
General engine overhaul procedures 2D•15
Chapter; if any measurement exceeds the
service limit specified, the cylinder block must
be rebored if possible, or renewed and new
piston assemblies fitted.
14 If the cylinder bores are badly scuffed or
scored, or if they are excessively worn, out-ofround or tapered, or if the piston-to-bore
clearances is excessive (see Section 12), the
cylinder block must be rebored (if possible) or
renewed and new pistons fitted. Oversize (0.5
mm) pistons are available for all engines.
15 If the bores are in reasonably good
condition and not worn to the specified limits,
then the piston rings should be renewed. If
this is the case, the bores should be honed to
allow the new rings to bed in correctly and
provide the best possible seal. The
conventional type of hone has spring-loaded
stones, and is used with a power drill. You will
also need some paraffin (or honing oil) and
rags. The hone should be moved up and
down the bore to produce a crosshatch
pattern, and plenty of honing oil should be
used. Ideally, the crosshatch lines should
intersect at approximately a 60° angle. Do not
take off more material than is necessary to
produce the required finish. If new pistons are
being fitted, the piston manufacturers may
specify a finish with a different angle, so their
instructions should be followed. Do not
withdraw the hone from the bore while it is still
being turned – stop it first. After honing a
bore, wipe out all traces of the honing oil. If
equipment of this type is not available, or if
you are not sure whether you are competent
to undertake the task yourself, an engine
overhaul specialist will carry out the work at
moderate cost.
16 On 2.5 and 3.0 litre engines, on
completion fit a new oil bypass valve to the
cylinder block and tap it fully into position
using a hammer and tubular drift (a 15 mm
socket is ideal) (see illustrations).
12 Piston/connecting rod
assembly inspection
4
1 Before the inspection process can begin,
the piston/connecting rod assemblies must
be cleaned, and the original piston rings
removed from the pistons.
2 Carefully expand the old rings over the top
of the pistons (see illustration). The use of
two or three old feeler blades will be helpful in
preventing the rings dropping into empty
grooves. Be careful not to scratch the piston
with the ends of the ring. The rings are brittle,
and will snap if they are spread too far.
They’re also very sharp - protect your hands
and fingers. Note that the third (oil control)
ring consists of a spacer and two side rails.
Always remove the rings from the top of the
piston. Keep each set of rings with its piston if
the old rings are to be re-used.
3 Scrape away all traces of carbon from the
top of the piston. A hand-held wire brush (or a
11.16a On 2.5 and 3.0 litre engines, insert
the new bypass valve into the cylinder
block . . .
11.16b . . . and tap it fully into position
using a hammer and socket
piece of fine emery cloth) can be used, once
the majority of the deposits have been
scraped away. The piston identification
markings should now be visible.
4 Remove the carbon from the ring grooves
in the piston, using an old ring. Break the ring
in half to do this (be careful not to cut your
fingers - piston rings are sharp). Be careful to
remove only the carbon deposits - do not
remove any metal, and do not nick or scratch
the sides of the ring grooves.
5 Once the deposits have been removed,
clean the piston/connecting rod assembly
with paraffin or a suitable solvent, and dry
thoroughly. Make sure that the oil return holes
in the ring grooves are clear.
6 If the cylinder bores are not damaged or
worn excessively, and if the cylinder block
does not need to be rebored (see Section 11),
check the pistons as follows.
7 Carefully inspect each piston for cracks
around the skirt, around the gudgeon pin
holes, and at the piston ring ‘lands’ (between
the ring grooves).
8 Look for scoring and scuffing on the piston
skirt, holes in the piston crown, and burned
areas at the edge of the crown. If the skirt is
scored or scuffed, the engine may have been
suffering from overheating, and/or abnormal
combustion which caused excessively high
operating temperatures. The cooling and
lubrication systems should be checked
thoroughly. Scorch marks on the sides of the
pistons show that blow-by has occurred. A
hole in the piston crown, or burned areas at
the edge of the piston crown, indicates that
abnormal
combustion
(pre-ignition,
knocking, or detonation) has been occurring.
If any of the above problems exist, the
causes must be investigated and corrected,
or the damage will occur again. The causes
may include incorrect ignition timing or a
faulty injector.
9 Corrosion of the piston, in the form of
pitting, indicates that coolant has been
leaking into the combustion chamber and/or
the crankcase. Again, the cause must be
corrected, or the problem may persist in the
rebuilt engine.
10 Measure the piston diameter at right
angles to the gudgeon pin axis; compare the
results with the Specifications at the
beginning of this Chapter. Note that there are
various size groups of standard piston
diameter to allow for manufacturing
tolerances; the size group markings are
stamped on the piston crown.
11 To measure the piston-to-bore clearance,
either measure the bore (see Section 11) and
piston skirt as described and subtract the skirt
diameter from the bore measurement, or
insert each piston into its original bore, then
select a feeler gauge blade and slip it into the
bore along with the piston. The piston must
be aligned exactly in its normal attitude, and
the feeler gauge blade must be between the
piston and bore, on one of the thrust faces,
just up from the bottom of the bore. If the
clearance is excessive, a new piston will be
required. If the piston binds at the lower end
of the bore and is loose towards the top, the
bore is tapered. If tight spots are encountered
as the piston/feeler gauge blade is rotated in
the bore, the bore is out-of-round.
12 Repeat this procedure for the remaining
pistons and cylinder bores. Any piston which
is worn beyond the specified limits must be
renewed.
13 Examine each connecting rod carefully for
signs of damage, such as cracks around the
big-end and small-end bearings. Check that
the rod is not bent or distorted. Damage is
highly unlikely, unless the engine has been
seized or badly overheated. Detailed checking
of the connecting rod assembly can only be
carried out by a Vauxhall dealer or engine
repair specialist with the necessary
equipment.
3510 Vauxhall/Opel Omega
12.2 Using a feeler blade to remove a
piston ring
2D
2D•16 General engine overhaul procedures
result can be compared with the specified
amount, and will give an indication as to
whether new main bearing shells are required.
3 If a dial gauge is not available, feeler
gauges can be used (see illustration). First
push the crankshaft fully towards the
flywheel/driveplate end of the engine, then
use feeler gauges to measure the gap
between the web of the crankpin and the side
of thrustwasher which is incorporated into
number 3 main bearing shells on 2.0 litre
engines and number 4 shell on 2.5 and 3.0
litre engines.
12.20a Ensure the piston and connecting
rod are assembled so the arrow on the
piston crown (circled) is pointing away
from . . .
14 On 2.0 and 2.5 litre engines, the gudgeon
pins are an interference fit in the connecting
rod small-end bearing. Therefore, piston
and/or connecting rod renewal should be
entrusted to a Vauxhall dealer or engine repair
specialist, who will have the necessary tooling
to remove and install the gudgeon pins. If new
pistons are to be fitted, ensure that the
correct size group pistons are fitted to each
bore (see Section 12). Note: Vauxhall state
that the piston/connecting rod assemblies
should not be disassembled. If any
components requires renewal, then the
complete assembly must be renewed. Do not
fit a new piston to an old connecting rod or
vice versa.
15 On 3.0 litre engines, the gudgeon pins are
of the floating type, secured in position by two
circlips. On these engines, the pistons and
connecting rods can be separated as follows.
16 Using a small flat-bladed screwdriver,
prise out the circlips, and push out the
gudgeon pin. Hand pressure should be
sufficient to remove the pin. Identify the piston
and rod to ensure correct reassembly.
Discard the circlips - new ones must be used
on refitting.
17 Examine the gudgeon pin and connecting
rod small-end bearing for signs of wear or
damage. Wear will require the renewal of both
the pin and connecting rod.
18 The connecting rods themselves should
not be in need of renewal, unless seizure or
some other major mechanical failure has
occurred. Check the alignment of the
13.2 Checking crankshaft endfloat with a
dial gauge
12.20b . . . the assembly mark (circled) on
the side of the connecting rod
connecting rods visually, and if the rods are
not straight, take them to an engine overhaul
specialist for a more detailed check.
19 Examine all components, and obtain any
new parts from your Vauxhall dealer. If new
pistons are purchased, they will be supplied
complete with gudgeon pins and circlips.
Circlips can also be purchased individually.
20 Assemble the piston and connecting rod
so that the arrow on the piston crown is
pointing away from the assembly mark which
is cast onto one side of the connecting rod, on
the top of the big-end bore (see illustrations).
21 Apply a smear of clean engine oil to the
gudgeon pin. Slide it into the piston and
through the connecting rod small-end. Check
that the piston pivots freely on the rod, then
secure the gudgeon pin in position with two
new circlips, ensuring that each circlip is
correctly located in its groove in the piston.
Inspection
4 Clean the crankshaft using paraffin or a
suitable solvent, and dry it, preferably with
compressed air if available. Be sure to clean
the oil holes with a pipe cleaner or similar
probe, to ensure that they are not obstructed.
Warning: Wear eye protection
when using compressed air.
1 If the crankshaft endfloat is to be checked,
this must be done when the crankshaft is still
installed in the cylinder block, but is free to
move (see Section 10).
2 Check the endfloat using a dial gauge in
contact with the end of the crankshaft (see
illustration). Push the crankshaft fully one way,
and then zero the gauge. Push the crankshaft
fully the other way, and check the endfloat. The
5 Check the main and big-end bearing
journals for uneven wear, scoring, pitting and
cracking.
6 Big-end bearing wear is accompanied by
distinct metallic knocking when the engine is
running (particularly noticeable when the
engine is pulling from low speed) and some
loss of oil pressure.
7 Main bearing wear is accompanied by
severe engine vibration and rumble - getting
progressively worse as engine speed
increases - and again by loss of oil pressure.
8 Check the bearing journal for roughness by
running a finger lightly over the bearing
surface. Any roughness (which will be
accompanied by obvious bearing wear)
indicates that the crankshaft requires
regrinding (where possible) or renewal.
9 Check for burrs around the crankshaft oil
holes (the holes are usually chamfered, so
burrs should not be a problem unless
regrinding has been carried out carelessly).
Remove any burrs with a fine file or scraper,
and thoroughly clean the oil holes as
described previously.
10 Using a micrometer, measure the diameter
of the main and big-end bearing journals, and
compare the results with the Specifications
(see illustration). By measuring the diameter
13.3 Using a feeler blade to measure
crankshaft endfloat (2.0 litre engine shown)
13.10 Using a micrometer to measure a
main bearing journal
13 Crankshaft inspection
4
Checking crankshaft endfloat
3510 Vauxhall/Opel Omega
General engine overhaul procedures 2D•17
at a number of points around each journal’s
circumference, you will be able to determine
whether or not the journal is out-of-round.
Take the measurement at each end of the
journal, near the webs, to determine if the
journal is tapered. Compare the results
obtained with those given in the
Specifications. If the crankshaft paint markings
are still visible, the bearing journal size can be
determined from these.
11 Check the oil seal contact surfaces at
each end of the crankshaft for wear and
damage. If the seal has worn a deep groove in
the surface of the crankshaft, consult an
engine overhaul specialist; repair may be
possible, but otherwise a new crankshaft will
be required.
12 Set the crankshaft up in V-blocks, and
position a dial gauge on the top of the
crankshaft number 1 main bearing journal.
Zero the dial gauge, then slowly rotate the
crankshaft through two complete revolutions,
noting the journal run-out. Repeat the
procedure on the remaining main bearing
journals, so that a run-out measurement is
available for all main bearing journals. If the
difference between the run-out of any two
journals exceeds the service limit given in the
Specifications, the crankshaft must be
renewed.
13 Undersize big-end and main bearing shells
are produced by Vauxhall for all engines. If the
crankshaft journals have not already been
reground, it may be possible to have the
crankshaft reconditioned, and to fit undersize
shells. Main bearing shells are available in 0.25
and 0.50 mm undersizes and the big-end
bearing shells are available in 0.25 and 0.50 mm
undersizes for the 2.5 and 3.0 litre engines and
0.25 mm undersize for 2.0 litre engine.
14 Main and big-end bearings inspection
14.1 Typical main bearing shell
identification marking
general position as their location in the
engine. This will enable you to match any
bearing problems with the corresponding
crankshaft journal.
4 Dirt and other foreign matter gets into the
engine in a variety of ways. It may be left in
the engine during assembly, or it may pass
through filters or the crankcase ventilation
system. It may get into the oil, and from there
into the bearings. Metal chips from machining
operations and normal engine wear are often
present. Abrasives are sometimes left in
engine components after reconditioning,
especially when parts are not thoroughly
cleaned using the proper cleaning methods.
Whatever the source, these foreign objects
often end up embedded in the soft bearing
material, and are easily recognised. Large
particles will not embed in the bearing, and
will score or gouge the bearing and journal.
The best prevention for this cause of bearing
failure is to clean all parts thoroughly, and
keep everything spotlessly-clean during
engine assembly. Frequent and regular engine
oil and filter changes are also recommended.
5 Lack of lubrication (or lubrication
4
1 Even though the main and big-end bearings
should be renewed during the engine
overhaul, the old bearings should be retained
for close examination, as they may reveal
valuable information about the condition of
the engine. The identification number
stamped on the rear of the bearing shells can
be used by a Vauxhall dealer to identify the
size group of the bearing (see illustration).
2 Bearing failure can occur due to lack of
lubrication, the presence of dirt or other
foreign particles, overloading the engine, or
corrosion (see illustration). Regardless of the
cause of bearing failure, the cause must be
corrected (where applicable) before the
engine is reassembled, to prevent it from
happening again.
3 When examining the bearing shells, remove
them from the cylinder block, the main
bearing caps, the connecting rods and the
connecting rod big-end bearing caps. Lay
them out on a clean surface in the same
breakdown) has a number of interrelated
causes. Excessive heat (which thins the oil),
overloading (which squeezes the oil from the
bearing face) and oil leakage (from excessive
bearing clearances, worn oil pump or high
engine speeds) all contribute to lubrication
breakdown. Blocked oil passages, which
usually are the result of misaligned oil holes in
a bearing shell, will also oil-starve a bearing,
and destroy it. When lack of lubrication is the
cause of bearing failure, the bearing material
is wiped or extruded from the steel backing of
the bearing. Temperatures may increase to
the point where the steel backing turns blue
from overheating.
6 Driving habits can have a definite effect on
bearing life. Full-throttle, low-speed operation
(labouring the engine) puts very high loads on
bearings, tending to squeeze out the oil film.
These loads cause the bearings to flex, which
produces fine cracks in the bearing face
(fatigue failure). Eventually, the bearing
material will loosen in pieces, and tear away
from the steel backing.
7 Short-distance driving leads to corrosion of
bearings, because insufficient engine heat is
produced to drive off the condensed water
and corrosive gases. These products collect
in the engine oil, forming acid and sludge. As
the oil is carried to the engine bearings, the
acid attacks and corrodes the bearing
material.
8 Incorrect bearing installation during engine
assembly will lead to bearing failure as well.
Tight-fitting bearings leave insufficient bearing
running clearance, and will result in oil
starvation. Dirt or foreign particles trapped
behind a bearing shell result in high spots on
the bearing, which lead to failure.
9 As mentioned at the beginning of this
Section, the bearing shells should be renewed
as a matter of course during engine overhaul;
to do otherwise is false economy.
15 Engine overhaul reassembly sequence
14.2 Typical bearing failures
3510 Vauxhall/Opel Omega
1 Before reassembly begins, ensure that all
new parts have been obtained, and that all
necessary tools are available. Read through
the entire procedure to familiarise yourself
with the work involved, and to ensure that all
items necessary for reassembly of the engine
are at hand. In addition to all normal tools and
materials, thread-locking compound will be
needed. A good quality tube of liquid sealant
will also be required for the joint faces that are
fitted without gaskets (the numbers of the
Vauxhall recommended sealants are given in
the text).
2 In order to save time and avoid problems,
engine reassembly can be carried out in the
following order:
a) Crankshaft.
b) Piston/connecting rod assemblies.
c) Oil pump.
2D
2D•18 General engine overhaul procedures
its groove. Check the ring-to-groove
clearance of each ring using feeler gauges
and check that the clearance is within the
specified range then position the ring end
gaps as shown (see illustrations).
17 Crankshaft refitting and main bearing
running clearance check
16.4 Measuring a piston ring end gap
using a feeler gauge
d)
e)
f)
g)
Sump.
Flywheel/driveplate.
Cylinder head(s).
Timing belt tensioner and sprockets, and
belts.
h) Inlet and exhaust manifolds (Chapter 4A).
i) Engine external components.
3 At this stage, all engine components should
be absolutely clean and dry, with all faults
repaired. The components should be laid out
(or in individual containers) on a completely
clean work surface.
16 Piston rings refitting
4
1 Before fitting new piston rings, the ring end
gaps must be checked as follows.
2 Lay out the piston/connecting rod
assemblies and the new piston ring sets, so
that the ring sets will be matched with the
same piston and cylinder during the end gap
measurement and subsequent engine
reassembly.
3 Insert the top ring into the first cylinder, and
push it down the bore using the top of the
piston. This will ensure that the ring remains
square with the cylinder walls. Push the ring
16.11b Piston ring end gap positions
I Top and second compression rings
II Oil control ring side rails
16.11a Checking the piston ring-to-groove
clearance using a feeler gauge
down into the bore until it is positioned 15 to
20 mm down from the top edge of the bore,
then withdraw the piston.
4 Measure the end gap using feeler gauges,
and compare the measurements with the
figures given in the Specifications (see
illustration).
5 If the gap is too small (unlikely if genuine
Vauxhall parts are used), it must be enlarged,
or the ring ends may contact each other
during engine operation, causing serious
damage. Ideally, new piston rings providing
the correct end gap should be fitted. As a last
resort, the end gap can be increased by filing
the ring ends very carefully with a fine file.
Mount the file in a vice with soft jaws, slip the
ring over the file with the ends contacting the
file face, and slowly move the ring to remove
material from the ends. Take care, as piston
rings are sharp, and are easily broken.
6 With new piston rings, it is unlikely that the
end gap will be too large. If the gaps are too
large, check that you have the correct rings
for your engine and for the particular cylinder
bore size.
7 Repeat the checking procedure for each
ring in the first cylinder, and then for the rings
in the remaining cylinders. Remember to keep
rings, pistons and cylinders matched up.
8 Once the ring end gaps have been checked
and if necessary corrected, the rings can be
fitted to the pistons.
9 Fit the piston rings using the same
technique as for removal. Fit the bottom (oil
control) spacer first then install both the side
rails, noting that both the spacer and side rails
can be installed either way up.
10 The second and top compression rings
are different and can be identified by their
cross-sections; the top ring is square whilst
the second ring is tapered. Fit the second and
top compression rings ensuring that each ring
is fitted the correct way up with its
identification (TOP) mark uppermost. Note:
Always follow any instructions supplied with
the new piston ring sets - different
manufacturers
may
specify
different
procedures. Do not mix up the top and
second compression rings. On some engines
the top ring will not have an identification
marking and can be fitted either way up.
11 With the piston rings correctly installed,
check that each ring is free to rotate easily in
3510 Vauxhall/Opel Omega
4
Note: It is recommended that new main
bearing shells are fitted regardless of the
condition of the original ones.
Selection of bearing shells
1 Although the original bearing shells fitted at
the factory maybe of various grades, all
replacement bearing shells sold are of the
same grade. Vauxhall supply both standard
size bearing shells and undersize shells for
use when the crankshaft has been reground.
The required size of shell required can be
determined by measuring the crankshaft
journals (see Section 13).
Main bearing running clearance
check
2 Clean the backs of the bearing shells and
the bearing locations in both the cylinder
block and the main bearing caps.
3 Press the bearing shells into their locations,
ensuring that the tab on each shell engages in
the notch in the cylinder block or main bearing
cap (see illustration). If the original bearing
shells are being used for the check ensure
they are refitted in their original locations.
When fitting new shells on 2.5 and 3.0 litre
engines, note that No1 bearing is wider than
No2 and 3 and that the grooved shell of No2
and 3 bearing should be fitted in the upper
location. The clearance can be checked in
either of two ways.
4 One method (which will be difficult to
achieve without a range of internal
micrometers or internal/external expanding
calipers) is to refit the main bearing caps to
the cylinder block, with bearing shells in
place. With the cap retaining bolts correctly
tightened (use the original bolts for the check,
not the new ones), measure the internal
diameter of each assembled pair of bearing
17.3 Fit each main bearing shell making
sure its tab is correctly seated in the notch
(arrowed)
General engine overhaul procedures 2D•19
17.7 Plastigauge in place on a crankshaft
journal
17.10 Measure the width of the crushed
Plastigauge using the scale on the card
provided
shells. If the diameter of each corresponding
crankshaft journal is measured and then
subtracted from the bearing internal diameter,
the result will be the main bearing running
clearance.
5 The second (and more accurate) method is
to use a product known as Plastigauge. This
consists of a fine thread of perfectly round
plastic which is compressed between the
bearing shell and the journal. When the shell is
removed, the plastic is deformed and can be
measured with a special card gauge supplied
with the kit. The running clearance is
determined from this gauge. Plastigauge is
sometimes difficult to obtain but enquiries at
one of the larger specialist quality motor
factors should produce the name of a stockist
in your area. The procedure for using
Plastigauge is as follows.
6 With the main bearing upper shells in place,
carefully lay the crankshaft in position. Do not
use any lubricant; the crankshaft journals and
bearing shells must be perfectly clean and
dry.
7 Cut several lengths of the appropriate size
Plastigauge (they should be slightly shorter
than the width of the main bearings) and place
one length on each crankshaft journal axis
(see illustration).
8 With the main bearing lower shells in
position, refit the main bearing caps, using the
identification marks to ensure each one is
correctly positioned. On 2.5 and 3.0 litre
engines also refit the main bearing bridge
casting ensuring the arrow cast on it is
pointing towards the timing belt end of the
engine.
9 Refit the original main bearing retaining bolts
and tighten them to the specified stage 1 torque
and then through the stage 2 and 3 angles (see
paragraphs 22 and 23). Take care not to disturb
the Plastigauge and do not rotate the
crankshaft at any time during this operation.
Evenly and progressively slacken and remove
the main bearing cap bolts then lift off the caps
again taking great care not to disturb the
Plastigauge or rotate the crankshaft.
10 Compare the width of the crushed
Plastigauge on each journal to the scale
printed on the Plastigauge envelope to obtain
the main bearing running clearance (see
illustration). Compare the clearance
measured with that given in the Specifications
at the start of this Chapter.
17.15 Crankshaft sensor rotor is secured to the crankshaft by
four bolts (three arrowed)
11 If the clearance is significantly different
from that expected, the bearing shells may be
the wrong size (or excessively worn if the
original shells are being re-used). Before
deciding that the crankshaft is worn, make
sure that no dirt or oil was trapped between
the bearing shells and the caps or block when
the clearance was measured. If the
Plastigauge was wider at one end than at the
other, the crankshaft journal may be tapered.
12 Before condemning the components
concerned, seek the advice of your Vauxhall
dealer or suitable engine repair specialist.
They will also be able to inform as to the best
course of action or whether renewal will be
necessary.
13 Where necessary, obtain the correct size
of bearing shell and repeat the running
clearance checking procedure as described
above.
14 On completion, carefully scrape away all
traces of the Plastigauge material from the
crankshaft and bearing shells using a
fingernail or other object which is unlikely to
score the bearing surfaces.
Final crankshaft refitting
2.0 litre engine
15 Carefully lift the crankshaft out of the
cylinder block once more. If a new crankshaft
is being fitted, do not forget to transfer the
crankshaft sensor rotor over from the original
crankshaft to the new one. Secure the rotor in
position with new retaining bolts, tightening
them to the specified torque (see
illustration).
16 Place the bearing shells in their locations
as described above in paragraphs 2 and 3
(see illustration). If new shells are being
fitted, ensure that all traces of the protective
grease are cleaned off using paraffin. Wipe
dry the shells and caps with a lint-free cloth.
17.16 The bearing shells which incorporate the thrust flanges (A)
must be fitted to the centre (No 3) bearing on 2.0 litre engines and
the rear (No 4) bearing on 2.5 and 3.0 litre engine. All other shells
have no flanges (B)
3510 Vauxhall/Opel Omega
2D
2D•20 General engine overhaul procedures
17.17 Lubricate the upper bearing shells
with clean engine oil then lower the
crankshaft into position
17.19 Refit the bearing caps number 1 to 4
ensuring each one is refitted in its original
location
17.20 Fill the side grooves of the rear
(number 5) bearing cap with sealant prior
to refitting it to the engine
17 Lubricate the upper shells with clean
engine oil then lower the crankshaft into
position (see illustration).
18 Ensure the crankshaft is correctly seated
then check the endfloat as described in
Section 13.
19 Ensure the bearing shells are correctly
located in the caps and refit the caps number
1 to 4 to the cylinder block (see illustration).
Ensure the caps are fitted in their correct
locations, with number 1 cap at the timing belt
end.
20 Ensure the rear (number 5) bearing cap is
clean and dry then fill the groove on each side
of the cap with sealing compound (Vauxhall
recommend the use of sealant 15 03 295 available from your Vauxhall dealer) (see
illustration). Fit the bearing cap to the engine,
ensuring it is fitted the correct way around.
bolts to the casting centre retaining holes (the
outer bolts are fitted later with the baffle plate)
and tighten them first to the specified stage 1
torque setting then tighten them through the
specified stage 2 angle.
27 On all engines refit/reconnect the piston
connecting rod assemblies to the crankshaft
as described in Section 18.
28 Referring to Part A (SOHC engine) or Part
B (DOHC engine), fit a new crankshaft oil seal
then refit the flywheel/driveplate, oil pump,
cylinder head, timing belt sprocket(s) and fit a
new timing belt.
17.21 Lubricate the threads of the new
main bearing cap bolts . . .
21 Apply a smear of clean engine to oil to the
threads and underneath the heads of the new
main bearing cap bolts. Fit the bolts
tightening them all by hand (see illustration).
22 Working in a diagonal sequence from the
centre outwards, tighten the main bearing cap
bolts to the specified Stage 1 torque setting
(see illustration).
23 Once all bolts are tightened to the specified
Stage 1 torque, go around again and tighten all
bolts through the specified Stage 2 angle then
go around for once more and tighten all bolts
through the specified Stage 3 angle. It is
recommended that an angle-measuring gauge
is used during the final stages of the tightening,
to ensure accuracy (see illustration). If a
gauge is not available, use white paint to make
alignment marks between the bolt head and
cap prior to tightening; the marks can then be
used to check that the bolt has been rotated
through the correct angle.
24 Once all the bolts have been tightened,
inject more sealant down the grooves in the
rear main bearing cap until sealant is seen to
be escaping through the joints. Once you are
sure the cap grooves are full of sealant, wipe
off all excess sealant using a clean cloth.
25 Check that the crankshaft is free to rotate
smoothly; if excessive pressure is required to
turn the crankshaft, investigate the cause
before proceeding further.
26 On earlier DOHC engines with a two-piece
sump, ensure the mating surfaces are clean
and dry then refit the main bearing ladder
casting to the block. Fit the new retaining
17.22 . . . then tighten the bolts to the
specified stage 1 torque setting . . .
17.23 . . . and then through the specified
stage 2 and 3 angles
3510 Vauxhall/Opel Omega
2.5 and 3.0 litre petrol engines
29 Refit the crankshaft as described in
paragraphs 15 to 18.
30 Ensure the bearing shells are correctly
located in the caps and refit the caps number
1 to 3 to the cylinder block (see illustration).
Ensure the caps are fitted in their correct
locations, with number 1 cap at the timing belt
end.
31 Ensure the rear bearing cap is clean and
dry then fill the groove on each side of the cap
with sealing compound (Vauxhall recommend
the use of sealant 15 03 295 - available from
your Vauxhall dealer). Fit the bearing cap to
the engine, ensuring it is fitted the correct way
around (see illustrations).
32 Back off the threaded sleeves until they
no longer protrude from the main bearing
bridge casting then refit the casting, making
sure the arrow is pointing towards the timing
belt end of the engine (see illustration).
17.30 Refit the bearing caps number 1 to 3
ensuring each one is refitted in its original
location
General engine overhaul procedures 2D•21
17.31a Fill the side grooves of the rear
(number 4) bearing cap with sealant . . .
17.31b . . . then refitting it to the cylinder
block
17.32 Refit the main bearing bridge casting
making sure the arrow (circled) is pointing
towards the timing belt end of the engine
17.33 Lubricate the threads of the new
main bearing cap bolts . . .
17.34 . . . then tighten the bolts to the
specified stage 1 torque setting . . .
17.35 . . . and then through the specified
stage 2 and 3 angles
33 Apply a smear of clean engine to oil to the
threads and underneath the heads of the new
main bearing cap bolts (see illustration). Fit
the bolts tightening them all by hand.
34 Working in a diagonal sequence from the
17.36 Inject sealant down each of the rear
main bearing cap grooves until it is seen to
be escaping through the joints (arrowed)
centre outwards, evenly and progressively
tighten the main bearing cap bolts to the
specified Stage 1 torque setting (see
illustration).
35 Once all bolts are tightened to the
specified Stage 1 torque, go around again and
tighten all bolts through the specified Stage 2
angle then go around for once more and
tighten all bolts through the specified Stage 3
angle. It is recommended that an anglemeasuring gauge is used during the final
stages of the tightening, to ensure accuracy
(see illustration). If a gauge is not available,
use white paint to make alignment marks
between the bolt head and cap prior to
tightening; the marks can then be used to
check that the bolt has been rotated through
the correct angle.
36 Once all the bolts have been tightened,
inject more sealant down the grooves in the
rear main bearing cap until sealant is seen to
be escaping through the joints (see
illustration). Once you are sure the cap
grooves are full of sealant, wipe off all excess
sealant using a clean cloth.
37 Check that the crankshaft is free to rotate
smoothly; if excessive pressure is required to
turn the crankshaft, investigate the cause
before proceeding further.
38 Tighten the threaded sleeves to the main
bearing bridge casting and tighten them to the
specified torque. Once the sleeves are tight,
refit the bolts securing the casting to the
cylinder block and tighten them to the
specified torque (see illustrations).
39 Refit/reconnect the piston connecting rod
assemblies to the crankshaft as described in
Section 18.
40 Referring to Part C, fit a new crankshaft oil
seal then refit the flywheel/driveplate, oil
pump, cylinder heads, timing belt sprockets
and fit a new timing belt.
17.38a Tighten the main bearing bridge
casting threaded sleeves (arrowed) to the
specified torque . . .
17.38b . . . then refit the bolts securing the
casting to the cylinder block . . .
17.38c . . . and tighten them (arrowed) to
their specified torque setting
3510 Vauxhall/Opel Omega
2D
2D•22 General engine overhaul procedures
18.3 Fit the bearing shells to the connecting rod and cap making
sure their tabs are correctly seated in the cutouts
18 Piston/connecting rod
assembly - refitting and bigend running clearance check
4
Note: It is recommended that new piston rings
and big-end bearing shells are fitted
regardless of the condition of the original
ones.
Selection of bearing shells
1 Although the original bearing shells fitted at
the factory maybe of various grades, all
replacement bearing shells sold are of the
same grade. Vauxhall supply both standard
size bearing shells and undersize shells for
use when the crankshaft has been reground.
The required size of shell required can be
determined by measuring the crankshaft
journals (see Section 13).
Big-end bearing running
clearance check
2 Clean the backs of the bearing shells and
the bearing locations in both the connecting
rod and bearing cap.
3 Press the bearing shells into their locations,
ensuring that the tab on each shell engages in
the notch in the connecting rod and cap (see
18.8 Ensure the piston ring end gaps are correctly positioned
then clamp them in position with a ring compressor
illustration). If the original bearing shells are
being used for the check ensure they are
refitted in their original locations. The clearance
can be checked in either of two ways.
4 One method is to refit the big-end bearing
cap to the connecting rod, with bearing shells
in place. With the cap retaining bolts (use the
original bolts for the check) correctly tightened,
use an internal micrometer or vernier caliper to
measure the internal diameter of each
assembled pair of bearing shells. If the
diameter of each corresponding crankshaft
journal is measured and then subtracted from
the bearing internal diameter, the result will be
the big-end bearing running clearance.
5 The second method is to use Plastigauge
as described in Section 17, paragraphs 5 to
14. Place a strand of Plastigauge on each
(cleaned) crankpin journal and refit the (clean)
piston/connecting rod assemblies, shells and
big-end bearing caps. Tighten the bolts (see
paragraphs 13 - use the original bolts for the
check) correctly taking care not to disturb the
Plastigauge. Dismantle the assemblies
without rotating the crankshaft and use the
scale printed on the Plastigauge envelope to
obtain the big-end bearing running clearance.
On completion of the measurement, carefully
scrape off all traces of Plastigauge from the
journal and shells using a fingernail or other
object which will not score the components.
position with a piston ring compressor (see
illustration).
9 Insert the piston/connecting rod assembly
into the top of cylinder No 1, ensuring that the
arrow marking on the piston crown is pointing
towards the timing belt end of the engine.
Using a block of wood or hammer handle
against the piston crown, tap the assembly
gently (do not force it) into the cylinder until
the piston crown is flush with the top of the
cylinder (see illustration). As the piston is
fitted make sure the connecting rod lower end
remains correctly aligned with the crankshaft
to avoid damage.
10 Taking care not to mark the cylinder bore,
liberally lubricate the crankpin and both
bearing shells, then pull the piston/connecting
rod assembly down the bore and onto the
crankpin.
11 Ensure the connecting rod and bearing
cap mating surfaces are completely clean and
dry; this is most important on engines where
the bearing caps are ‘cracked’ off of the rod.
12 Refit the big-end bearing cap, using the
markings to ensure it is fitted the correct way
around (the lug on the bearing cap base
should be facing the flywheel/driveplate end
of the engine), then screw in the new retaining
bolts (see illustrations).
Final piston/connecting rod
assembly refitting
18.9 Insert the piston into the correct
bore, tapping it gently into position with
the handle of a hammer
6 Ensure the bearing shells are correctly
refitted as described above in paragraphs 2
and 3. If new shells are being fitted, ensure
that all traces of the protective grease are
cleaned off using paraffin. Wipe dry the shells
and connecting rods with a lint-free cloth.
7 Lubricate the bores, the pistons and piston
rings then lay out each piston/connecting rod
assembly in its respective position.
8 Starting with assembly number 1, make
sure that the piston rings are still spaced as
described in Section 16, then clamp them in
3510 Vauxhall/Opel Omega
18.12a Refit the bearing cap making sure
the lug is facing towards the
flywheel/driveplate end of the engine . . .
General engine overhaul procedures 2D•23
18.12b . . . and screw in the new retaining
bolts
18.13a Tighten both bolts to the specified
stage 1 torque setting . . .
13 Tighten both bearing cap bolts to the
specified Stage 1 torque setting then tighten
them through the specified Stage 2 angle, and
finally through the specified Stage 3 angle. It
is recommended that an angle-measuring
gauge is used during the final stages of the
tightening, to ensure accuracy (see
illustrations). If a gauge is not available, use
white paint to make alignment marks between
the bolt head and cap prior to tightening; the
marks can then be used to check that the bolt
has been rotated through the correct angle.
14 Refit the remaining piston and connecting
rod assemblies in the same way.
15 Rotate the crankshaft, and check that it
turns freely, with no signs of binding or tight
spots.
16 On 2.0 litre SOHC engines, working as
described in Part A of this Chapter, fit the
baffle plate, oil pump pick-up/strainer and
sump to the cylinder block then refit the
cylinder head.
17 On 2.0 litre DOHC engines carry out the
following:
a) On early (pre 1998 model year) engines
with a two-piece sump, refit the baffle
plate to the main bearing ladder casting
and screw in the new retaining bolts.
Working in a diagonal sequence from the
centre outwards, tighten the bolts first to
the specified stage 1 torque and then
tighten them through the specified stage
2 angle.
b) On later engines refit the crankshaft
balancer unit as described in Part B.
c) On all engines refit the oil pump pickup/strainer and sump then refit the
cylinder head as described in Part B.
18 On 2.5 and 3.0 litre engines refit the baffle
plate to the base of the main bearing bridge
casting and tighten its retaining bolts to the
specified torque (see illustration). Working as
described in Part C of this Chapter, refit the
sump then install the cylinder heads.
18.13b . . . then tighten them through the
specified stage 2 and 3 angles
19 Engine initial start up after overhaul
1 With the engine refitted in the vehicle,
double-check the engine oil and coolant
levels. Make a final check that everything has
been reconnected, and that there are no tools
or rags left in the engine compartment.
2 Ensure the ignition is switched off then
disable the ignition system by disconnecting
the wiring connector from the DIS module
(see Chapter 5A) and the fuel system by
removing the fuel pump relay from the engine
compartment relay box (see Chapter 4A,
Section 13).
3 Turn the engine on the starter until the oil
pressure warning light goes out then stop.
Ensure the ignition is switched off then
securely refit the relay and reconnect the
wiring connector.
4 Start the engine as normal noting that this
may take a little longer than usual, due to the fuel
system components having been disturbed.
3510 Vauxhall/Opel Omega
18.18 On 2.5 and 3.0 litre engines, refit the
baffle plate and tighten its retaining bolts
to the specified torque
5 While the engine is idling, check for fuel,
water and oil leaks. Don’t be alarmed if there
are some odd smells and smoke from parts
getting hot and burning off oil deposits.
6 Assuming all is well, keep the engine idling
until hot water is felt circulating through the
top hose, then switch off the engine.
7 Allow the engine to cool then recheck the
oil and coolant levels as described in Weekly
checks, and top-up as necessary.
8 If new pistons, rings or crankshaft bearings
have been fitted, the engine must be treated
as new, and run-in for the first 500 miles (800
km). Do not operate the engine at full-throttle,
or allow it to labour at low engine speeds in
any gear. It is recommended that the oil and
filter be changed at the end of this period.
2D
3•1
Chapter 3
Cooling, heating and ventilation systems
Contents
Air conditioning system - description and precautions . . . . . . . . . . . 11
Air conditioning system components - removal and refitting . . . . . . 12
Antifreeze mixture - general . . . . . . . . . . . . . . . . . . .See Weekly checks
Blower motor and series resistor - removal and refitting . . . . . . . . . 10
Coolant pump - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . 5
Cooling system - draining, flushing and refilling . . . . . . .see Chapter 1
Electric cooling fans - removal and refitting . . . . . . . . . . . . . . . . . . . 3
Electronic Climate Control (ECC) components - removal and
refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Expansion tank - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . 6
General description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Heater control system components - removal and refitting . . . . . . . 8
Heater matrix - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . 9
Pollen filter - renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . .see Chapter 1
Radiator - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Temperature gauge sender unit - removal and refitting . . . . . . . . . . 7
Thermostat - removal, testing and refitting . . . . . . . . . . . . . . . . . . . . 4
Degrees of difficulty
Easy, suitable for
novice with little
experience
1
Fairly easy, suitable
for beginner with
some experience
2
Fairly difficult,
suitable for competent
DIY mechanic
3
Difficult, suitable for
experienced DIY
mechanic
4
Very difficult,
suitable for expert DIY
or professional
5
Specifications
System type
All models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pressurised, with cross-flow radiator, centrifugal water pump driven
by timing belt, bypass thermostat, and remote expansion tank.
Thermostatically controlled electric main cooling fan, with one or two
auxiliary electric cooling fans, depending on specification.
Thermostat
Opening commences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fully open . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
92ºC (198ºF)
107ºC (225ºF)
Coolant
Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Refer to Weekly checks
Refer to Chapter 1
3510 Vauxhall/Opel Omega
3
3•2 Cooling, heating and ventilation systems
Torque wrench settings
Nm
lbf ft
35
20
26
15
All models
Air conditioning compressor:
Front mounting bracket bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rear mounting bracket bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Air conditioning refrigerant lines unions:
To bulkhead flange . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
To compressor (M10) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
To condenser . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
To expansion valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
To pulsation damper . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
To receiver/dryer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Air conditioning tri-switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Coolant pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Steering column bracing strut:
To steering column . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
To floorpan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
20
40
20
9
27
20
7
25
15
30
15
7
20
15
5
28
22
22
16
16
4-cylinder models
Coolant pipe to thermostat cover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Temperature gauge sender unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Thermostat housing cover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8
11
15
6
8
11
6-cylinder models
Coolant bridge to cylinder head . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Coolant intake pipe to cylinder block . . . . . . . . . . . . . . . . . . . . . . . . . . .
Coolant intake pipe to exhaust manifold . . . . . . . . . . . . . . . . . . . . . . . .
Coolant pipe to cylinder head . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Temperature gauge sender unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Thermostat housing cover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
30
20
6
25
18
20
22
15
4
18
13
15
1 General description
1 The cooling system comprises a radiator,
timing belt driven coolant pump (depending
on engine), a waxstat-type bypass
thermostat, and a remotely-mounted plastic
expansion tank. A thermostatically-controlled
electric cooling fan is fitted to all models,
between the front of the engine and the
radiator. An auxiliary cooling fan is also fitted,
in front of the radiator. Models with air
conditioning also have a second electric
auxiliary cooling fan, to cope with the extra
demand of cooling the refrigerant condenser.
2 Cold water from the coolant pump is forced
around the cylinder block, cylinder head and
heater matrix during the warm up cycle. When
2.2 Lift out the radiator upper cover panel
the engine reaches a predetermined
temperature, the thermostat starts to open
and the coolant then circulates through the
radiator via a transfer pipe, to provide extra
cooling. The main cooling fan is controlled by
the temperature of air behind the radiator.
2 Radiator removal and refitting
3
Removal
Models with 6-cylinder engines
1 Ensure that the engine has cooled
completely before starting work. Drain the
cooling system as described in Chapter 1.
2 Remove the screws and lift out the radiator
upper cover panel (see illustration).
2.5a Disconnect the wiring from cooling
fan thermo-switches . . .
3510 Vauxhall/Opel Omega
3 Disconnect the negative and positive cables
from the battery terminals, then remove the
battery as described in Chapter 5A.
4 Refer to Chapter 4A and remove multi-ram
air intake pre-volume chamber.
5 Disconnect the wiring from cooling fan
thermo-switches, secondary air-cut-off valve,
and auxiliary coolant pump (as applicable)
(see illustrations). Label each connector
carefully, to aid correct refitting.
6 Disconnect all coolant hoses from the
radiator; these include the expansion tank
hose, the radiator top and bottom hoses, and
the auxiliary coolant pump hose (where
applicable) (see illustrations).
7 Release the securing clips and disconnect
the air hoses from secondary air cut-off valve.
8 On models with air conditioning, unscrew the
securing bolts and disconnect the refrigerant
condenser from radiator (see illustration).
2.5b . . . secondary air-cut-off valve . . .
Cooling, heating and ventilation systems 3•3
2.5c . . . and auxiliary coolant pump
2.6c Disconnect the coolant expansion
tank hose from the radiator
9 On models with automatic transmission,
release the hose clips and disconnect the
narrow bore hoses from the transmission fluid
cooler (see illustration). Plug the pipes to
prevent excessive fluid loss and the ingress of
debris.
10 Release the spring clips at the top of the
radiator, then withdraw radiator complete with
the cooling fan from engine compartment
(see illustrations).
Models with 4-cylinder engines
11 Ensure that the engine has cooled
completely before starting work. Drain the
cooling system as described in Chapter 1.
12 Disconnect the negative cable from the
battery and position it away from the terminal.
13 Disconnect the wiring from main cooling
fans and is associated thermo-switch. Label
the connector(s), to aid correct refitting.
2.6a Disconnect the top hose from the
radiator
2.6b Disconnect the bottom hose from the
engine coolant transfer pipe
2.8 Unscrew the securing bolts and
disconnect the air conditioning refrigerant
condenser from radiator
2.9 Disconnect the narrow bore
transmission fluid cooler hoses from the
radiator
14 Disconnect all coolant hoses from the
radiator, including the expansion tank hose,
and the radiator top and bottom hoses.
15 On models with air conditioning, undo the
screws and disconnect the refrigerant heat
exchanger from radiator.
16 On models with automatic transmission,
release the hose clips and disconnect the
narrow bore pipes from the transmission fluid
cooler. Plug the pipes to prevent excessive
fluid loss and the ingress of debris.
17 Release the spring clips at the top of the
radiator, then withdraw radiator complete with
the cooling fan from engine compartment.
b) On models with automatic transmission,
use new union seals when reconnecting
the automatic transmission fluid cooler
pipes.
c) On models with air conditioning, secure
the heat exchanger to the base of the
radiator and tighten the retaining bolts
securely.
d) Refill the cooling system as described in
Chapter 1.
e) Where applicable, top up the level of
automatic transmission fluid as described
in Chapter 1.
Refitting
3 Electric cooling fan(s) removal and refitting
18 Refitting is a reversal of the removal
procedure, noting the following points:.
a) Ensure that all coolant hose clips are
securely tightened.
2
Main cooling fan
Removal Models with 4-cylinder engines
2.10a Release the spring clips at the top of
the radiator . . .
2.10b . . . then withdraw radiator complete
with the cooling fan from engine
compartment
3510 Vauxhall/Opel Omega
1 Disconnect the battery negative cable and
position it away from the terminal.
2 Unplug the wiring from the rear of the fan
motor, at the connector.
3 Remove the two screws that secure the
fan/cowling assembly to the rear of the
radiator.
4 Disengage the fan housing from its lower
mounting, then lift the fan and housing from of
the engine bay, taking care not to damage the
cooling fins of the radiator (and airconditioning heat exchanger, where fitted).
5 The fan motor can be separated from the
3
3•4 Cooling, heating and ventilation systems
3.12 Slacken and remove the securing
screws . . .
housing by slackening and removing the three
securing nuts.
Removal Models with 6-cylinder engines
6 Disconnect the negative and positive cables
from the battery terminals, then remove the
battery as described in Chapter 5A.
7 Release the mounting bracket and detach
secondary air cut-off valve from the fan
housing.
8 Remove the screws and lift off the radiator
upper cover panel.
9 Refer to Chapter 4A and remove multi-ram
air intake pre-volume chamber.
10 Disconnect the wiring from the rear of the
fan motor. Label each connector carefully, to
aid correct refitting.
11 Release the mounting bracket and detach
the auxiliary coolant pump from the side of
the fan housing (where applicable).
3.13 . . . and remove the cooling fan
together with its housing from the radiator
(shown with radiator removed for clarity)
12 Remove the three screws that secure the
fan/cowling assembly to the rear of the
radiator (see illustration).
13 Disengage the fan housing from its lower
mounting, then lift the fan and housing from of
the engine bay, taking care not to damage the
cooling fins of the radiator (and airconditioning heat exchanger, where fitted)
(see illustration).
14 The fan motor can be separated from the
housing by slackening and removing the three
securing nuts (see illustration).
Refitting (all models)
15 Refit the cooling fan by following the
removal procedure in reverse.
Auxiliary cooling fan(s)
3.14 Fan motor securing nuts (arrowed)
17 With reference to Chapter 11, remove the
radiator grille, then unbolt and remove the
cross-member from the front of the engine
compartment.
18 Undo the securing screws and detach the
air intake duct from the crossmember (see
illustration).
19 Unclip the cover panel then unplug the
wiring harness from the auxiliary fan at the
multi-way connector. Release the harness
from the cable ties (see illustrations).
20 To improve access, unclip the wiring
harness conduit from the bodywork (see
illustration).
21 Slacken and remove the securing screws
then withdraw the fan and motor from its
housing (see illustrations).
Refitting
16 Disconnect the battery negative cable and
position it away from the terminal.
Refitting
22 Refitting is a reversal of removal.
3.18 Undo the securing screws and detach
the air intake duct from the crossmember
3.19a Unclip the cover panel . . .
3.19b . . . then unplug the wiring harness
from the auxiliary fan at the multi-way
connector
3.20 Unclip the wiring harness conduit
from the bodywork
3.21a Slacken and remove the securing
screws . . .
3.21b . . . then withdraw the fan and motor
from its housing
3510 Vauxhall/Opel Omega
Cooling, heating and ventilation systems 3•5
4 Thermostat removal, testing and refitting
3
Models with 4-cylinder engines
Removal
1 Drain the cooling system as described in
Chapter 1.
2 Loosen the clip and disconnect the coolant
hose from the thermostat housing cover.
3 Unscrew the bolts and remove the cover.
Note that the thermostat is integral with the
cover.
4 Carefully clean the mating surface of the
thermostat housing.
Refitting
5 Refitting is a reversal of the removal
procedure. Use a new thermostat housing
cover sealing ring and ensure that the
securing screws are tightened to the specified
torque. On completion, refill the cooling
system as described in Chapter 1.
Models with 6-cylinder engines
Removal
6 Drain the cooling system as described in
Chapter 1.
7 Release the clip and disconnect the
radiator top hose from the engine coolant
transfer pipe.
8 Slacken and remove the bolt securing the
coolant transfer pipe to the cylinder head.
Note that this bolt also secures one of the
engine lifting eyelets and the dipstick tube.
9 Carefully pull the coolant transfer pipe from
the thermostat housing, using just enough
effort to disengage the O-ring seals (see
illustrations).
10 Remove the upper half of the inlet
manifold, with reference to Chapter 4A.
11 Unscrew the bolts and remove the cover.
Note that the thermostat is integral with the
cover (see illustration).
Refitting
12 Refitting is a reversal of the removal
procedure, noting the following points (see
illustration):.
a) Fit a new sealing ring to the thermostat
cover.
b) Ensure that the thermostat cover securing
screws are tightened to the specified
torque.
c) Use new O-ring seals when refitting the
coolant transfer pipe to the thermostat
housing.
d) On completion, refill the cooling system
as described in Chapter 1.
4.9a Carefully pull the coolant transfer pipe
from the thermostat housing . . .
4.9b . . . using just enough effort to
disengage the O-ring seals
thermostat begins to open. If a suitably
graduated thermometer is available, the
temperature at which the thermostat begins to
open may be determined and then compared
with the figure given in the Specifications.
Note that as tap water begins to boil as its
temperature approaches 100º, it will not be
possible to test the thermostat in its fully open
position. Using additives to raise the boiling
point of the water may adversely affect the
operation of thermostat, hence this is not
recommended.
14 A thermostat which fails to close as the
water cools must also be considered faulty
and should be renewed.
the fitted position of each bolt to ensure
correct refitting.
5 Lift the coolant pump away from the engine
and recover the seal.
5 Coolant pump removal and refitting
4
Models with 4-cylinder engines
Removal
1 Drain the cooling system as described in
Chapter 1.
2 Remove the camshaft timing belt tensioner
pulley, as described in Chapter 2A/B.
3 Release the crankshaft sensor wiring from
the timing belt cover, noting its routing ensure
correct refitting.
4 Progressively slacken and remove the
water pump retaining bolts. Note that the
bolts are of different lengths; make a note of
Refitting
6 Refit the coolant pump by following the
removal procedure in reverse, noting these
points:.
a) Use a new coolant pump sealing ring.
b) Coat the new sealing ring and the pump
mating surface with silicon grease before
fitting.
c) The lug on the side of the coolant pump
flange must be aligned with the
corresponding recess in the cylinder
block.
d) Tighten the coolant pump securing bolts
to the specified torque.
e) Refit the timing belt tensioner pulley,
according to the information given in
Chapter 2A/B (as applicable).
f) On completion, refill the cooling system
with the specified quantity of correctlymixed coolant.
Models with 6-cylinder engines
Removal
7 Drain the cooling system as described in
Chapter 1.
8 Remove the camshaft timing belt front
cover, as described in Chapter 2C. Note that
this entails the removal of the auxiliary
drivebelt (see Chapter 1) and the coolant
pump pulley.
Thermostat testing
13 A rough test of the thermostat may be
made by suspending it on the end of a piece
of string in a saucepan full of water. Bring the
water to the boil and check that the
4.11 Unscrew the bolts, then remove the
cover and integral thermostat
3510 Vauxhall/Opel Omega
4.12 Fit a new sealing ring to the
thermostat cover
3
3•6 Cooling, heating and ventilation systems
disconnect the radiator vent hose.
4 Unclip the expansion tank from the front
suspension turret.
5 Loosen the clips and disconnect the
coolant supply and return hoses.
6 Withdraw the expansion tank from the
engine compartment.
Refitting
7 Refitting is a reversal of the removal
procedure. On completion, refill the cooling
system with reference to Chapter 1 .
5.9 Progressively slacken and remove the
water pump retaining bolts
9 Progressively slacken and remove the
water pump retaining bolts (see illustration).
Note that the bolts are of different lengths;
make a note of the fitted position of each bolt
to ensure correct refitting.
10 Lift the coolant pump away from the engine
and recover the seal (see illustrations).
Refitting
11 Refit the coolant pump by following the
removal procedure in reverse, noting these
points:.
a) Use a new coolant pump sealing ring..
b) Coat the new sealing ring and the pump
mating surface with silicon grease before
fitting.
c) Tighten the coolant pump securing bolts
to the specified torque.
d) Refit the timing belt cover, coolant pump
pulley and auxiliary drive belt, according
to the information given in Chapter 2C
and Chapter 1 (as applicable).
e) On completion, refill the cooling system
with the specified quantity of correctlymixed coolant.
6 Expansion tank removal and refitting
2
7 Temperature gauge
sender unit removal and refitting
2
Removal
Warning: If the engine is hot,
allow it to cool before attempting
to remove the unit.
1 On all models, the temperature gauge
sender unit is located on the rear of the
cylinder block between the cylinder heads.
Note that the gauge sender has a single
electrical terminal; do not confuse it with the
engine management coolant temperature
sensor which has a two-way electrical
connector. To gain access, refer to Chapter
4A and remove the upper section of the inlet
manifold.
2 Remove the filler cap from the radiator or
expansion tank to release any remaining
pressure, then refit the cap - the vacuum will
help to reduce the loss of coolant.
3 Disconnect the wiring from the terminal on
the sender unit.
4 Unscrew and remove the sender unit,
recovering the sealing ring (where fitted).
Temporarily plug the aperture with a suitable
bung. Note: Be prepared for an amount of
coolant loss - position a container under the
thermostat housing and pad the area with
absorbent rags .
Refitting
Removal
1 Drain the cooling system as described in
Chapter 1.
2 Remove the filler cap.
3 Where applicable, loosen the clip and
5 Refitting is a reversal of the removal
procedure. Use a new sealing ring and tighten
the sender to the specified torque. On
completion, top up the cooling system as
detailed in Weekly checks.
8 Heater/ventilation
system components removal and refitting
3
Note: For models equipped with Electronic
Climate Control, refer to the information given
in Section 13.
Heater control panel switches
Removal
1 Disconnect the battery negative cable and
position it away from the terminal.
2 The number and types of switches fitted will
vary with model specification, but the removal
method for each switch is identical.
3 Obtain two small flat bladed screwdrivers.
Pad the ends of the blades with insulating
tape.
4 Insert the screwdrivers into the recesses at
either side of the switch to be removed.
Carefully depress the locking tabs and lever
the switch button away from the switch body.
5 Squeeze the locking tabs at either side of
the switch body together, then slide the
switch body from the heater control panel.
Refitting
6 Refitting is a reversal of the removal
procedure.
Heater control panel
Removal
7 Remove the switches from the heater
control panel as described in the previous
sub-Section.
8 Pull the rotary knobs from the four heat and
air distribution control shafts.
9 Remove radio unit from the facia as
described in Chapter 12.
10 Unclip and remove the storage
compartment adjacent to the radio aperture.
11 Slacken and remove the five heater
control panel securing screws; one at the rear
of the radio aperture, one at the rear of the
storage compartment aperture, and one
below each heat/air distribution control shaft.
12 Withdraw the heater control panel from
heater control unit.
13 At the rear of the control panel, slide the
locking bars to one side and unplug the
electrical connectors from the panel. Also
unplug the wiring for the panel illumination
bulbs and the cigarette lighter.
Refitting
14 Refitting is a reversal of the removal
procedure.
Heater control unit
5.10a Lift the coolant pump away from the
engine . . .
5.10b . . . and recover the seal
3510 Vauxhall/Opel Omega
15 Remove the heater control panel as
described in the previous sub-Section.
16 Remove the screws and detach the heater
control unit from the facia.
17 Prise open the retaining brackets and
release both air temperature control cables
from the control shafts.
Cooling, heating and ventilation systems 3•7
18 Unplug the wiring connector from the rear
of the fan control switch.
19 Disconnect the vacuum control hose
manifold from the rear of the control panel.
20 Remove the control panel from the
vehicle.
38 Working inside the car, unscrew and
remove the last distribution unit securing bolt.
39 Pull the unit up and away from the facia,
the lift it over the facia wiring harness and
remove it from the vehicle.
Refitting
40 Refitting is a reversal of the removal
procedure, noting the following points:.
a) Use new O-ring seals when reconnecting
the heater matrix coolant pipes.
b) Use new O-ring seals when reconnecting
the air conditioning refrigerant pipes to
the bulkhead.
c) Observe the correct tightening torques
when reconnecting the steering column
bracing strut (see Chapter 10).
d) On model with air conditioning, have the
refrigerant circuit evacuated and
recharged by an air conditioning specialist
or a Vauxhall dealer.
e) Ensure that all vacuum and electrical
connections are securely re-made
f) On completion, refill the cooling system
as described in Chapter 1.
21 Refitting is a reversal of the removal
procedure.
Air distribution unit
Note: On models with air conditioning, this
procedure involves having the refrigerant
circuit discharged by a Vauxhall dealer or an
air conditioning specialist.
Removal
22 Drain the coolant as described in Chapter 1.
23 Remove the facia as described in Chapter 11.
24 On models with air conditioning, the
refrigerant circuit must be now be discharged
by an air conditioning specialist or a Vauxhall
dealer, to allow the air conditioning lines to be
disconnected from the engine compartment
bulkhead. Refer to the precautions given in
Section 11 before proceeding.
25 Unclip and remove the duct for the face
level air vent on the drivers side of the vehicle.
26 With reference to Chapter 10, unbolt and
remove the steering column bracing strut,
from the steering column and the floorpan.
27 Undo the bolt and release the earth cable
from the bulkhead.
28 Unplug the wiring connector from the
blower motor resistor pack, at the connector.
29 Place a suitable container beneath the
point where the heater matrix coolant pipes
enter the air distribution unit.
30 Unscrew the bolt to release the pipe
retaining plate, then disconnect the coolant
pipes from the heater matrix, at the right hand
side of the air distribution unit. Allow the
escaping coolant to drain into the container.
Press the coolant pipes back towards the
engine compartment, clear of the air
distribution unit.
31 On models with air conditioning,
disconnect the black vacuum hose from the
coolant cut-off valve.
32 Unplug the wiring connector from the
recirculation valve solenoid.
33 On models without electronic climate
control, disconnect the yellow vacuum hose
from the air distribution unit.
34 Undo the securing screws and detach the
rear passenger compartment footwell ducts
from the distribution unit.
35 Disconnect the blue vacuum hose from
the recirculation valve vacuum unit.
36 On models with automatic transmission,
release the cable ties and separate the
selector cable from the recirculation valve
solenoid.
37 Working in the engine compartment,
slacken and withdraw the two distribution unit
securing bolts, located near the upper edge of
the bulkhead.
Refitting
Heater matrix
41 See Section 9.
Blower motor and fan
42 See Section 10.
Heater control cable driver’s side
Removal
43 Release the facia from the bulkhead, with
reference to Chapter 11. Pull it away from the
bulkhead just far enough to gain access to the
rear of the air distribution unit.
44 Prise open the retaining clip and then
disconnect the cable inner from the operating
lever on the air distributor unit.
45 Remove the heater control panel as
described earlier in this Section.
46 Prise open the retaining clip and then
disconnect the cable inner from the quadrant
at the end of the control shaft.
47 Remove the cable from the vehicle.
Refitting
48 Refitting is a reversal of the removal
procedure. Set the operating lever on the air
distributor unit in the vertical position before
reconnecting the control cable inner.
Heater control cable passenger side
49 Proceed as described for the driver’s side
control cable, in the previous sub-Section,
noting that the air duct for the passenger
footwell vent must be removed to gain access
to the cable.
Recirculation air valve solenoid
Removal
50 Disconnect the battery negative cable and
position it away from the terminal.
3510 Vauxhall/Opel Omega
51 On right hand drive models, remove the
glove compartment from the facia, as
described in Chapter 11, then unclip and
remove the air duct for the passenger footwell
vent.
52 On left hand drive models, remove the
lower trim panel from the drivers side of the
facia, then unclip and remove the air duct for
the drivers footwell vent.
53 The solenoid is mounted on the left hand
side of the air distributor unit. Note the
connection order of each of the vacuum
hoses, then disconnect them from the
solenoid valve ports.
54 Unplug the wiring connector from the
solenoid valve.
55 Slacken and withdraw the securing screw
then remove the solenoid valve from the
vehicle.
Refitting
56 Refitting is a reversal of the removal
procedure. Ensure that the valve sits squarely
in its guide slots, and that the vacuum hoses
are correctly reconnected according to the
notes made during removal.
Recirculation air valve vacuum
unit
Removal
57 Remove the glove compartment from the
facia, as described in Chapter 11.
58 Release the cable ties, then depress the
locking tabs and disengage the wiring
harness support from the facia. Unclip and
remove the air ducting.
59 The recirculation air valve vacuum unit is
located on the left hand side of the blower
motor housing, and is distinguished by the
blue vacuum hose leading to it.
60 Disconnect the vacuum hose from the
side of the vacuum unit.
61 Lever the unit from its mounting boss.
Disconnect the actuator arm from the lever at
the base of the vacuum unit, then remove the
vacuum unit from the vehicle.
Refitting
62 Refitting is a reversal of the removal
procedure.
Defroster valve vacuum unit
63 Proceed as described for the recirculation
valve vacuum unit, in the previous subSection. The defroster valve vacuum unit is
located on the right hand side of the air
distributor unit and is distinguished by the
brown vacuum hose leading to it.
Footwell valve vacuum unit
64 Proceed as described for the recirculation
valve vacuum unit, in the previous subSection. The footwell valve vacuum unit is
located on the right hand side of the air
distributor unit and is distinguished by the
green vacuum hose leading to it.
3
3•8 Cooling, heating and ventilation systems
Vacuum control circuit
General information
65 The heating and ventilation system is
controlled by a series of valves which direct
air through the required air ducts, according
to the position of the control knobs on the
heater control panel. The valves are actuated
by vacuum supplied engine inlet manifold.
The following diagram is provided to show the
order of vacuum hose and vacuum unit
connection (see illustration).
9 Heater matrix removal and refitting
4
Removal
1 Disconnect the battery negative cable and
position it away from the terminal.
2 Drain the coolant as described in Chapter 1.
3 Refer to Chapter 11 and remove the facia.
4 With reference to Chapter 10, unbolt the
lower end of the steering column bracing strut
and pivot it upwards away from the floorpan.
5 Remove the securing screw and unclip the
air duct for the drivers footwell vent from the
side of the air distributor unit.
6 Detach the drivers side control cable from
the air distributor unit, as described in the
previous Section.
7 Place a suitable container beneath the point
where the heater matrix coolant pipes enter
the air distribution unit.
8 Unscrew the bolt to release the pipe
retaining plate, then disconnect the coolant
pipes from the heater matrix, at the right hand
side of the air distribution unit, and recover
the O-ring seals. Allow the escaping coolant
to drain into the container. Press the coolant
pipes back towards the engine compartment,
clear of the air distribution unit.
9 Slacken and remove the securing screws
then withdraw the heater matrix from the side
of the air distribution unit, recover the rubber
seal (see illustration). If a new heater matrix
is to be fitted, extract the captive nut (for the
coolant pipe retaining plate) from the plastic
casing of the old matrix and transfer it to the
new one.
8.65 Heating/ventilation system vacuum control circuit
1
2
3
4
5
6
7
8
Vacuum reservoir
Blue vacuum hose
Vacuum unit, recirculating air valve
Vacuum unit, defroster valve
Brown vacuum hose
Vacuum unit, footwell valve
Green vacuum hose
Connector, vacuum hoses
9
10
11
12
13
14
15
16
Refitting
10 Refitting is a reversal of the removal
procedure, noting the following points:.
a) Use new O-ring seals when reconnecting
the heater matrix coolant pipes.
b) Observe the correct tightening torques
when reconnecting the steering column
bracing strut (see Chapter 10).
c) On completion, refill the cooling system
as described in Chapter 1.
10 Blower motor
and series resistor removal and refitting
3
Heater controls
Recirculating air switch
Solenoid valve wiring, recirculating air valve
Blue vacuum hose
Solenoid valve, recirculating air valve
Yellow vacuum hose
Bulkhead
Vacuum supply hose
4 Disconnect the vacuum hose from the side
of the air recirculation valve vacuum unit then
remove the unit from its mounting bracket
(see Section 8).
5 Unplug the wiring harness leading to the
blower motor series resistor.
6 Slacken and remove the securing screws,
then withdraw the blower motor and fan
assembly from its housing (see illustrations).
Refitting
7 Refitting is a reversal of the removal
procedure.
Blower motor
Removal
9.9 Heater matrix securing screw (A) and
coolant pipe retaining plate bolt (B)
1 Disconnect the battery negative cable and
position it away from the terminal.
2 Remove the glove compartment from the
facia as described in Chapter 11.
3 Release the cable ties, then depress the
locking tabs and disengage the wiring
harness support from the facia. Unclip and
remove the air ducting.
3510 Vauxhall/Opel Omega
10.6a Slacken and remove the securing
screws . . .
Cooling, heating and ventilation systems 3•9
form a highly poisonous gas. It is therefore
extremely dangerous to disconnect any
part of the air conditioning system without
specialised knowledge and equipment.
7 Uncontrolled discharging of the refrigerant
can also be damaging to the environment, as
certain refrigerants contain CFCs.
8 Do not operate the air conditioning system
if it is known to be short of refrigerant, as this
will damage the compressor.
Series resistor
Removal
8 Proceed as described in paragraphs 1 to 3
inclusive in the previous sub-Section.
9 Unplug the wiring harness from the blower
motor series resistor at the connector (see
illustration).
10 Depress the retaining tabs and withdraw
the resistor from the fan/motor housing (see
illustration).
Refitting
11 Refitting is a reversal of removal.
10.6b . . . then withdraw the blower motor
and fan assembly from its housing
11 Air conditioning system description and precautions
temperature in the passenger compartment.
On models with Electronic Climate control,
the cabin temperature is regulated
automatically by a system of air valves
controlled by servo motors.
4 The heating side of the system works in the
same way as on models without air
conditioning (see Section 8).
5 The operation of the system is controlled by
an electronic control unit, which controls the
electric cooling fan, the compressor, and the
facia-mounted warning light. Any problems
with the system should be referred to a
Vauxhall dealer.
General information
1 An air conditioning system is available on
certain models. When activated, the air
conditioning system allows air entering the
passenger to be cooled giving greater control
over the temperature inside the car and
leading to increased comfort. The cooled air is
also dehumidified, enabling faster windscreen
demisting.
2 The cooling side of the system works in the
same way as a domestic refrigerator.
Refrigerant gas, contained in a sealed network
of alloy pipes, is drawn into a belt-driven
compressor, and is forced through a condenser
mounted on the front of the radiator. On
entering the condenser, the refrigerant changes
state from gas to liquid and releases heat,
which is absorbed by the air flowing into the
engine compartment through the condenser.
The liquid refrigerant passes through an
expansion valve to an evaporator, where it
changes from liquid under high pressure to gas
under low pressure. This change in state is
accompanied by a drop in temperature, which
cools the evaporator. Air passing through the
evaporator is cooled before flowing into the air
distribution unit. The refrigerant then returns to
the compressor, and the cycle begins again.
3 Cool air passes to the air distribution unit,
where it is mixed with hot air blown through
the heater matrix, to achieve the desired
Precautions
6 When an air conditioning system is fitted, it
is necessary to observe special precautions
whenever dealing with any part of the system,
or its associated components. If for any
reason the system must be disconnected, you
must entrust this task to a Vauxhall dealer or
an air conditioning specialist. Similarly, the
system can only be evacuated and recharged
by a dealer or air conditioning specialist.
Warning: The air conditioning
system contains a pressurised
liquid refrigerant. If the system is
discharged in an uncontrolled manner
without the aid of specialist equipment, the
refrigerant will boil as soon as it is exposed
to the atmosphere, causing severe
frostbite if it comes into contact with
unprotected skin. In addition, certain
refrigerants, in the presence of a naked
flame (including a lit cigarette), will burn to
12 Air conditioning
system components removal and refitting
3
Warning: Do not attempt to
discharge the refrigerant circuit
yourself - refer to the precautions
given in Section 11. Have the air
conditioning system discharged by a
qualified engineer.
On completion, have the refrigerant
engineer fit new O-rings to the line
connections and evacuate and re-charge
the system.
Auxiliary coolant pump
Removal
1 Drain the coolant as described in Chapter 1.
2 Remove the battery as described in
Chapter 5A.
3 Remove the screws and lift the upper cover
from the top of the radiator.
4 Unplug the wiring from the auxiliary coolant
pump at the connector.
5 Release the securing clips and detach the
auxiliary coolant pump from the radiator.
Refitting
6 Refitting is a reversal of removal. On
completion, top up the cooling system as
described in Weekly checks.
Compressor
Removal Models with 4-cylinder engines
7 Have the air conditioning system
discharged by a qualified engineer.
8 Remove the battery as described in Chapter 5A.
9 Remove the auxiliary drivebelt as described
in Chapter 1.
10 Unbolt the refrigerant lines from the
compressor.
11 Unplug the wiring connector from the
clutch unit at the underside of the compressor.
12 Unscrew the three securing bolts from the
front of the compressor.
13 Unscrew the three securing bolts from the
rear of the compressor, then remove the
compressor from its mounting bracket.
Refitting Models with 4-cylinder engines
10.9 Unplug the wiring harness from the
blower motor series resistor at the
connector
10.10 Withdraw the resistor from the
fan/motor housing
3510 Vauxhall/Opel Omega
14 Refitting is a reversal of the removal
procedure; ensure that all fixings are tightened
to the specified torque, where given. On
3
3•10 Cooling, heating and ventilation systems
completion, have the refrigerant engineer fit
new O-rings to the line connections and
evacuate and re-charge the refrigerant circuit.
Evaporator
Removal Models with 6-cylinder engines
34 Remove the expansion valve as described
in previous sub-Section, then withdraw the
evaporator from the air distributor unit.
15 Have the air conditioning system
discharged by a qualified engineer.
16 Remove the battery as described in
Chapter 5A.
17 Remove the auxiliary drivebelt as
described in Chapter 1.
18 Uncouple the low pressure refrigerant
pipe at the service union. Work along the
length of the pipe that remains connected to
the compressor and release it from any
retaining brackets.
19 Uncouple the high pressure refrigerant
pipe at the pulsation damper unit. Work along
the length of the pipe that remains connected
to the compressor and release it from any
retaining brackets.
20 Unplug the wiring connector from the
clutch unit at the underside of the compressor.
21 Unscrew the three securing bolts from the
front of the compressor.
22 Unscrew the two securing bolts from the
rear of the compressor.
23 Rotate the compressor so that the fluid
filler bolt faces towards the engine sump, then
remove the compressor from its mounting
bracket.
Removal
Refitting
35 Refitting is a reversal of removal.
Condenser
Removal Models with 4 cylinder engines
36 Have the air conditioning system
discharged by a qualified engineer.
37 Disconnect the battery negative cable and
position it away from the terminal.
38 Remove the radiator as described in
Section 2.
39 Slacken and separate the unions, then disconnect the refrigerant lines from the
condenser and tape over or plug them.
40 Carefully lift the condenser from its rubber
guide and withdraw it from the vehicle.
Refitting
41 Refitting is a reversal of removal. Have a
refrigerant engineer fit new O-rings to the line
connections and then evacuate and re-charge
the refrigerant circuit. On completion, refill the
cooling system with reference to Chapter 1.
Refitting Models with 6-cylinder engines
Removal Models with 6 cylinder engines
24 Refitting is a reversal of the removal
procedure; ensure that all fixings are
tightened to the specified torque, where
given. On completion, have the refrigerant
engineer fill the compressor with lubricant, fit
new O-rings to the line connections and then
evacuate and re-charge the refrigerant circuit.
42 Have the air conditioning system
discharged by a qualified engineer.
43 Disconnect the battery negative cable and
position it away from the terminal.
44 Remove the radiator as described in
Section 2.
45 Slacken and separate the unions, then disconnect the refrigerant lines from the
condenser and tape over or plug them.
46 Carefully lift the condenser from its rubber
guide and tilt it backwards towards the
engine.
47 Slacken and separate the unions, then disconnect the refrigerant lines from the receiver/
dryer unit and tape over or plug them.
48 Undo the screws and detach the
receiver/dryer unit mounting bracket from the
condenser.
49 Carefully lift the condenser from its rubber
guide and withdraw it from the vehicle,
together with the receiver/dryer unit.
Expansion valve
25 Have the air conditioning system
discharged by a qualified engineer.
26 Disconnect the battery negative cable and
position it away from the terminal.
27 Refer to Chapter 11 and remove the glove
compartment.
28 Refer to Section 10 and remove the
blower motor.
29 Disconnect the refrigerant lines at the
engine compartment bulkhead.
30 Unbolt the solenoid valves from the evaporator housing and position them to one side.
31 Remove the six securing screws and lift
the evaporator cover from the air distributor
unit.
32 Unbolt the retainer plate, disconnect the
refrigerant lines, then unbolt the expansion
valve from the evaporator.
Refitting
33 Refitting is a reversal of removal. Ensure
that all fixings are tightened to the specified
torque, where given. On completion, have the
refrigerant engineer fit new O-rings to the line
connections and then evacuate and re-charge
the refrigerant circuit.
52 Disconnect the battery negative cable and
position it away from the terminal.
53 Refer to Chapter 11 and remove the
radiator grille.
54 Detach the filler neck from the top of the
windscreen washer fluid reservoir. On models
with 6-cylinder engines, unbolt and remove
the crossmember from the front of the engine
compartment.
55 Punch out the pre-stressed holes in the
cooling fan casing to gain access to the
refrigerant line unions, at the top of the
receiver/dryer unit.
56 Slacken and separate the unions, then disconnect the refrigerant lines from the receiver/
dryer unit and tape over or plug them.
57 Undo the screws and detach the
receiver/dryer unit mounting bracket from the
front of the vehicle. Remove the unit from the
engine compartment, together with its
mounting bracket.
Refitting
58 Refitting is a reversal of removal. On
completion, have a refrigerant engineer fit new
O-rings to the line connections and then
evacuate and re-charge the refrigerant circuit.
Tri-switch
Removal
59 The tri-switch is located beneath
receiver/dryer unit at the front left hand corner
of the engine compartment. Have the air
conditioning system discharged by a qualified
engineer.
60 Disconnect the battery negative cable and
position it away from the terminal.
61 Unplug the wiring from the tri-switch at
the multi-way connector.
62 Counterhold the refrigerant line union and
unscrew the tri-switch.
Refitting
63 Refitting is a reversal of removal. On
completion, have a refrigerant engineer fit new
O-rings to the line connections and then
evacuate and re-charge the refrigerant circuit.
Cooling fan thermo-switches
Main radiator fan
50 Refitting is a reversal of removal. Have a
refrigerant engineer fit new O-rings to the line
connections and then evacuate and re-charge
the refrigerant circuit. On completion, refill the
cooling system with reference to Chapter 1.
64 The main radiator fan thermo-switch is
located at the lower edge of the radiator.
65 Drain the cooling system as described in
Chapter 1.
66 Disconnect the battery negative cable and
position it away from the terminal.
67 Unplug the wiring from the switch at the
multi-way connector.
68 Unscrew the switch from the radiator.
69 Refitting is a reversal of removal, but use a
new switch sealing ring. On completion refill
the cooling system as described in Chapter 1.
Receiver/dryer
Auxiliary fan
Refitting Models with 6 cylinder engines
Removal
51 Have the air conditioning
discharged by a qualified engineer.
3510 Vauxhall/Opel Omega
system
70 The auxiliary radiator fan thermo-switch is
located at the left hand side of the radiator.
71 Drain the cooling system as described in
Chapter 1.
Cooling, heating and ventilation systems 3•11
13.4 Slacken and remove the securing
screws from the lower edge of the ECC
panel
72 Disconnect the battery negative cable and
position it away from the terminal.
73 Unplug the wiring from the switch at the
multi-way connector.
74 Unscrew the switch from the radiator.
75 Refitting is a reversal of removal, but use a
new switch sealing ring. On completion refill
the cooling system as described in Chapter 1.
13 Electronic Climate Control
(ECC) components removal and refitting
3
ECC control panel and switches
Removal
1 Disconnect the battery negative cable and
position it away from the terminal.
2 Remove ashtray from the facia as
described in Chapter 11.
3 Remove radio unit from the facia as
described in Chapter 12, then remove the
radio mounting frame.
4 Slacken and remove the securing screws
from the lower edge of the control panel (see
illustration).
5 Reach through the radio aperture and pull
down on the aluminium locking bar at the rear
of the upper edge of the control panel (see
illustrations).
6 Remove the panel from the facia. At the
rear of the control panel, slide the locking bars
to one side and unplug the electrical
connectors from the panel. Also unplug the
wiring for the control panel and ashtray
illumination bulbs (see illustrations).
7 If required, the ECC switch controls can be
detached from the control panel by removing
the relevant securing screws.
13.5a Reach through the radio aperture . . .
Defroster air valve servo motor
Removal
9 Disconnect the battery negative cable and
position it away from the terminal. Remove
the lower trim panel from the drivers side of
the facia, then unclip and remove the air duct
for the drivers footwell vent.
10 The servo motor is mounted on the right
hand side of the air distributor unit (see
illustration).
11 Unplug the wiring harness from the servo
motor at the multiway connector.
12 Undo the securing screws and withdraw
the servo motor from the air distributor unit.
13 Disengage the motor spindle arm from the
actuator rod.
Refitting
14 Refitting is a reversal of removal. On
completion, synchronise the air valve servo
13.5b . . . and pull down on the aluminium
locking bar at the rear of the upper edge of
the control panel (shown with panel
removed for clarity)
motors as follows: turn the ignition switch to
the On position, then depress and hold the
Auto and Off keys on the ECC control panel
for more than 5 seconds.
Footwell air valve servo motor
Removal
15 Refer to the previous sub-Section and
remove the defroster air valve servo motor.
16 The servo motor is mounted on the right
hand side of the air distributor unit, in front of
the defroster air valve servo motor (see
illustration).
17 Unplug the wiring harness from the servo
motor at the multiway connector.
18 Undo the securing screws and withdraw
the servo motor from the air distributor unit.
3
13.6a Unplug the wiring harness
connectors . . .
13.6b . . . and remove the ECC panel from
the facia
13.10 Location of the ECC defroster air
valve servo
13.16 Location of the ECC footwell air
valve servo
Refitting
8 Refitting is a reversal of removal, noting the
following points:.
a) Ensure that locking bar at the rear upper
edge of the control panel is correctly
engaged.
b) On completion, synchronise the air valve
servo motors as follows: Switch the
ignition to the On position, then depress
and hold the Auto and Off keys on the
ECC control panel for more than 5
seconds.
3510 Vauxhall/Opel Omega
3•12 Cooling, heating and ventilation systems
13.32 Unclip the cover panel to expose the
right hand vent servo motor
Refitting
19 Turn the servo motor spindle gear fully
clockwise to the end of its stop. Similarly, turn
the spindle gear air distributor housing fully
clockwise to the end of its stop.
20 Refit the motor and tighten its securing
screws. Reconnect the wiring harness.
21 Refit the defroster air valve servo motor as
described in the previous sub-Section. Refit
all components removed for access.
22 On completion, synchronise the air valve
servo motors as follows: turn the ignition
switch to the On position, then depress and
hold the Auto and Off keys on the ECC control
panel for more than 5 seconds.
Centre vent servo motor
Removal
23 Disconnect the battery negative cable and
position it away from the terminal.
24 Remove the lower trim panel from the
drivers side of the facia, then unclip and remove
the air duct for the drivers footwell vent.
25 The servo motor is mounted on the right
hand side of the air distributor unit, above the
defroster air valve servo motor.
26 Unplug the wiring harness from the servo
motor at the multiway connector.
27 Undo the securing screws and withdraw
the servo motor from the air distributor unit.
28 Disengage the motor spindle arm from the
actuator rod.
Refitting
29 Refitting is a reversal of removal. On
completion, synchronise the air valve servo
motors as follows: turn the ignition switch to
the On position, then depress and hold the
Auto and Off keys on the ECC control panel
for more than 5 seconds.
Right hand vent
temperature sensor
Right hand vent servo motor
Removal
Removal
44 Remove the footwell air valve servo motor
as described earlier in this Section.
45 Unplug the wiring from the sensor at the
connector.
46 Carefully prise the sensor body away from
its mounting clip and withdraw the probe from
the air ducting (see illustration).
30 Disconnect the battery negative cable and
position it away from the terminal.
31 Remove the lower trim panel from the
drivers side of the facia, then unclip and remove
the air duct for the drivers footwell vent.
32 Unclip the cover panel to expose the
servo motor (see illustration).
33 Unplug the wiring harness from the servo
motor at the multiway connector.
34 Undo the securing screws and withdraw
the servo motor from the air distributor unit.
35 Disengage the motor spindle arm from the
actuator rod and actuator lever.
Refitting
36 Refitting is a reversal of removal. On
completion, synchronise the air valve servo
motors as follows: turn the ignition switch to
the On position, then depress and hold the
Auto and Off keys on the ECC control panel
for more than 5 seconds.
Left hand vent servo motor
Removal
37 Disconnect the battery negative cable and
position it away from the terminal. Remove
the glove compartment from the facia, as
described in Chapter 11.
38 Release the cable ties, then depress the
locking tabs and disengage the wiring
harness support from the facia. Unclip and
remove the air ducting.
39 Unclip the cover panel to expose the
servo motor.
40 Unplug the wiring harness from the servo
motor at the multiway connector.
41 Undo the securing screws and withdraw
the servo motor from the air distributor unit.
42 Disengage the motor spindle arm from the
actuator rod and actuator lever.
Refitting
47 Refitting is a reversal of removal. On
completion, refit the footwell air valve servo
motor, then synchronise the air valve servo
motors as follows: turn the ignition switch to
the On position, then depress and hold the
Auto and Off keys on the ECC control panel
for more than 5 seconds.
Left hand vent
temperature sensor
Removal
48 Disconnect the battery negative cable and
position it away from the terminal. Remove
the glove compartment from the facia, as
described in Chapter 11.
49 Release the cable ties, then depress the
locking tabs and disengage the wiring
harness support from the facia. Unclip and
remove the air ducting.
50 Note the direction that the wiring
connector is facing, then pull the sensor to
release it from the air distributor unit, then
rotate it clockwise through half a turn and
unplug the wiring connector.
51 Tilt the sensor to the left and withdraw it
from its aperture.
Refitting
52 Refitting is a reversal of removal. Ensure
that when the sensor is refitted, the wiring
connector faces the right hand side of the
vehicle, as noted during removal.
Blower motor regulator
Refitting
Removal
43 Refitting is a reversal of removal. On
completion, synchronise the air valve servo
motors as follows: turn the ignition switch to
the On position, then depress and hold the
Auto and Off keys on the ECC control panel
for more than 5 seconds.
53 Disconnect the battery negative cable and
position it away from the terminal. Remove
the glove compartment from the facia, as
described in Chapter 11.
54 Depress the retaining lugs and withdraw
the regulator from the fan housing. Unplug the
wiring from the regulator at the connector.
Refitting
55 Refitting is a reversal of removal.
Sun sensor
Removal
56 Carefully lever the sensor from the facia
using blunt soft bladed instrument (see
illustration).
57 Secure a cable tie around the wiring
harness to prevent it from falling back into the
facia, then disconnect it from the sensor.
13.46 Location of the ECC right hand vent
temperature sensor
13.56 Carefully lever the sun sensor from
the upper surface of the facia
3510 Vauxhall/Opel Omega
Refitting
58 Refitting is a reversal of removal.
4A•1
Chapter 4 Part A:
Fuel and exhaust systems
Contents
Accelerator cable - removal and refitting . . . . . . . . . . . . . . . . . . . . . 3
Accelerator pedal - removal and refitting . . . . . . . . . . . . . . . . . . . . . 4
Air cleaner assembly and intake ducts - removal and refitting . . . . . 2
Air cleaner filter element renewal . . . . . . . . . . . . . . . . . .See Chapter 1
Exhaust manifold - removal and refitting . . . . . . . . . . . . . . . . . . . . . . 16
Exhaust system - general information, removal and refitting . . . . . . 18
Exhaust system check . . . . . . . . . . . . . . . . . . . . . . . . . . .See Chapter 1
Fuel filter renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .See Chapter 1
Fuel gauge sender unit - removal and refitting . . . . . . . . . . . . . . . . . 9
Fuel injection system - depressurisation . . . . . . . . . . . . . . . . . . . . . . 7
Fuel injection system - testing and adjustment . . . . . . . . . . . . . . . . . 12
Fuel injection system components (2.0 litre engine) - removal and
refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Fuel injection system components (2.5 and 3.0 litre engines) - removal
and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Fuel injection systems - general information . . . . . . . . . . . . . . . . . . . 6
Fuel pump - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Fuel tank - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
General information and precautions . . . . . . . . . . . . . . . . . . . . . . . . 1
Inlet manifold - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . 15
Multi-ram air intake system - information and component removal
and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Throttle housing - removal and refitting . . . . . . . . . . . . . . . . . . . . . . 11
Unleaded petrol - general information and usage . . . . . . . . . . . . . . . 5
Degrees of difficulty
Easy, suitable for
novice with little
experience
1
Fairly easy, suitable
for beginner with
some experience
4A
2
Fairly difficult,
suitable for competent
DIY mechanic
3
Difficult, suitable for
experienced DIY
mechanic
4
Very difficult,
suitable for expert DIY
or professional
Specifications
System type
2.0 litre SOHC engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.0 litre DOHC engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.5 and 3.0 litre engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
*See Section 6 for further information
Bosch Motronic M1.5.4*
Simtec 56.1 or 56.5*
Bosch Motronic M2.8.1 or M2.8.3*
Fuel system data
Fuel pump type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel pump regulated pressure (approximate) . . . . . . . . . . . . . . . . . . . . .
Specified idle speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Idle mixture CO content . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Electric, immersed in tank
3.0 bar
Not adjustable - controlled by ECU
Not adjustable - controlled by ECU
Recommended fuel
Minimum octane rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
95 RON* unleaded (UK unleaded premium).
Leaded fuel must not be used
*91 RON unleaded fuel can be used but a slight power loss maybe noticeable.
3510 Vauxhall/Opel Omega
5
4A•2 Fuel and exhaust systems
Torque wrench settings
Auxiliary drivebelt tensioner mounting bolts - 2.5 and 3.0 litre engines .
Braking system vacuum hose union nut . . . . . . . . . . . . . . . . . . . . . . . .
Camshaft sensor bolt:
2.0 litre DOHC engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.5 and 3.0 litre engines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Crankshaft sensor bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
EGR pipe union nuts - 2.5 and 3.0 litre engine . . . . . . . . . . . . . . . . . . . .
Exhaust manifold heatshield bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exhaust manifold nuts:
2.0 litre engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.5 and 3.0 litre engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exhaust system fasteners:
Front pipe to manifold bolts:
2.0 litre engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.5 and 3.0 litre engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Front pipe to mounting bracket bolt . . . . . . . . . . . . . . . . . . . . . . . . . .
Front pipe to intermediate pipe bolts . . . . . . . . . . . . . . . . . . . . . . . . .
Intermediate pipe to tailpipe clamp . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel hose union nuts/bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel pressure regulator clamp screw . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel rail bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel tank retaining strap bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inlet manifold nuts and bolts:
2.0 litre engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.5 and 3.0 litre engines:
Flange to cylinder head bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Lower section:
Retaining bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel pipe adaptor mounting bolts . . . . . . . . . . . . . . . . . . . . . . . .
Upper section retaining bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Knock sensor bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oil cooler pipe union nuts and bolts - 2.5 and 3.0 litre engines . . . . . . .
Spark plug heatshields - 2.0 litre SOHC engine . . . . . . . . . . . . . . . . . . .
Throttle housing nuts/bolts:
2.0 litre engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.5 and 3.0 litre engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1 General information and
precautions
1 The fuel system consists of a fuel tank
(which is mounted under the rear of the car,
with an electric fuel pump immersed in it), a
fuel filter and the fuel feed and return lines.
The fuel pump supplies fuel to the fuel rail,
which acts as a reservoir for the fuel injectors
(one for each cylinder) which inject fuel into
the inlet tracts. In addition, there is an
Electronic Control Unit (ECU) and various
sensors, electrical components and related
wiring.
2 Refer to Section 6 for further information on
the operation of each fuel injection system,
and to Section 18 for information on the
exhaust system.
Warning: Many of the procedures
in this Chapter require the
removal of fuel lines and
connections, which may result in some fuel
spillage. Before carrying out any operation
Nm
35
20
Ibf ft
26
15
6
8
8
25
8
4
6
6
18
6
22
20
16
15
25
30
20
18
17
15
18
22
15
13
13
11
8
30
6
22
22
16
20
15
20
8
8
20
30
25
15
6
6
15
22
18
9
8
7
6
on the fuel system, refer to the precautions
given in Safety first! at the beginning of
this manual, and follow them implicitly.
Petrol is a highly-dangerous and volatile
liquid, and the precautions necessary
when handling it cannot be overstressed.
Note: Residual pressure will remain in the fuel
lines long after the vehicle was last used.
Before disconnecting any fuel line, first
depressurise the fuel system as described in
Section 7.
2 Air cleaner assembly
and intake ducts removal and refitting
2
Removal
Note: On 2.5 and 3.0 litre engines, refer to
Section 17 for information on the multi-ram air
intake system.
1 To remove the air cleaner housing slacken
the retaining clip and disconnect the duct
from the outlet then unclip the housing from
3510 Vauxhall/Opel Omega
its mounting rubbers. Free the housing from
the intake duct and remove it from the engine
compartment.
2 The various ducts can be disconnected and
removed once the retaining clips have been
slackened. In some cases it will be necessary
to disconnect breather hoses and wiring
connectors to allow the duct to be removed;
some duct sections are also bolted to a
support bracket.
Refitting
3 Refitting is the reverse of removal, noting
the following.
a) Examine the housing mounting rubbers
for signs of damage or deterioration and
renew if necessary.
b) On refitting, remove the mounting rubbers
from the body and fit them to the housing
pins. Ease installation by lubricating the
mounting rubbers with a spray-based
silicone lubricant.
c) Ensure all ducts are securely joined and
retained by the necessary clips and
screws.
Fuel and exhaust systems 4A•3
3 Accelerator cable removal and refitting
3
Removal
1 Working in the engine compartment, unclip
the inner cable retaining clip then slide the clip
out of the end fitting and release the cable
from the throttle cam (see illustration).
2 Free the accelerator outer cable from its
mounting bracket, taking care not to lose the
adjusting clip (see illustration). Work back
along the length of the cable, free it from any
retaining clips or ties, noting its correct
routing. On models with automatic
transmission it will be necessary to
disconnect the wiring from the kickdown
switch which is built into the cable.
3 To improve access, remove the windscreen
wiper arms and the water deflector panel from
the base of the windscreen (see Chapter 12,
Sections 15 and 16).
4 From inside the vehicle, release the
retaining clips (rotate them through 90º) then
remove the undercover panel from the drivers’
side of the facia. Remove the fastener (prise
out the centre pin then pull out the fastener
outer section) then unclip and remove the
heater/ventilation duct to improve access to
the accelerator pedal (see illustrations).
5 Reaching up behind the facia, unclip the
accelerator inner cable from the top of the
accelerator pedal (see illustration).
3.4a Release the retaining clips and
remove the undercover panel from the
driver’s side of the facia
3.4b Prise out the centre pin then remove
the fastener outer section . . .
3.1 Remove the retaining clip and detach
the inner cable from the throttle cam . . .
6 Return to the engine compartment then free
the cable sealing grommet from the bulkhead
and remove the cable and grommet from the
vehicle.
7 Examine the cable for signs of wear or
damage and renew if necessary.
Refitting
8 Feed the cable into position from the
engine compartment and seat the outer cable
grommet in the bulkhead.
9 From inside the vehicle, clip the inner cable
end fitting into position in the pedal end and
check to make sure the grommet is correctly
located in the bulkhead. Check that the cable
is securely retained, then refit the
heater/ventilation duct and undercover to the
facia.
10 From within the engine compartment,
ensure the outer cable is correctly seated in
the bulkhead, then work along the cable,
securing it in position with the retaining clips
and ties, and ensuring that the cable is
correctly routed. On models with automatic
transmission, reconnect the kickdown switch
wiring connector making sure the wiring is
correctly routed.
11 Refit the water deflector panel and install
both wiper arms (see Chapter 12).
12 Connect the inner cable to the throttle
cam and secure it in position with the
retaining clip. Clip the outer cable into its
mounting bracket and adjust the cable as
described below.
3.4c . . . and unclip the heater/ventilation
duct
3510 Vauxhall/Opel Omega
3.2 . . . then free the outer cable from the
mounting bracket
Adjustment
13 Working in the engine compartment, slide
off the adjustment clip from accelerator outer
cable.
14 With the clip removed, ensure that the
throttle cam is fully against its stop. Gently
pull the cable out of its grommet until all free
play is removed from the inner cable.
15 With the cable held in this position, refit
the spring clip to the last exposed outer cable
groove in front of the rubber grommet. When
the clip is refitted and the outer cable is
released, there should be only a small amount
of free play in the inner cable.
16 Have an assistant depress the accelerator
pedal, and check that the throttle cam opens
fully and returns smoothly to its stop.
4 Accelerator pedal removal and refitting
3
Removal
1 From inside the vehicle, release the retaining
clips (rotate them through 90º) then remove the
undercover panel from the drivers’ side of the
facia. Remove the fastener (prise out the centre
pin then pull out the fastener outer section) then
unclip and remove the heater/ventilation duct to
improve access to the accelerator pedal (see
illustrations 3.4a to 3.4c).
3.5 Unhook the accelerator cable
(arrowed) from the upper end of the pedal
4A
4A•4 Fuel and exhaust systems
4.3 Undo the retaining nuts (arrowed) and
remove the accelerator pedal from the
vehicle
2 Reaching up behind the facia, unclip the
accelerator inner cable end fitting from the top
of the accelerator pedal (see illustration 3.5).
3 Unscrew the retaining nuts and remove the
pedal assembly from the bulkhead (see
illustration).
4 Inspect the pedal assembly for signs of
wear, paying particular attention to the pedal
bushes, and renew as necessary. To
dismantle the assembly, unhook the return
spring then slide off the retaining clip and
separate the pedal, mounting bracket, return
spring and pivot bushes.
Refitting
5 If the assembly has been dismantled, apply
a smear of multi-purpose grease to the pedal
pivot shaft and bushes. Fit the bushes and
return spring to the mounting bracket and
insert the pedal, making sure it passes
through the return spring bore. Secure the
pedal in position with the retaining clip and
hook the return spring back behind the pedal.
6 Refit the pedal assembly and securely
tighten its retaining nuts.
7 Clip the accelerator cable end fitting into
the pedal then refit the heater/ventilation duct
and undercover to the facia.
8 On completion, adjust the accelerator cable
as described in Section 3.
5 Unleaded petrol general information and usage
Note: The information given in this Chapter is
correct at the time of writing. If updated
information is thought to be required, check
with a Vauxhall dealer. If travelling abroad,
consult one of the motoring organisations (or a
similar authority) for advice on the fuel
available.
1 The fuel recommended by Vauxhall is given
in the Specifications Section of this Chapter,
followed by the equivalent petrol currently on
sale in the UK.
2 All petrol models are designed to run on
fuel with a minimum octane rating of 95
(RON). Lower octane fuel, down to minimum
of rating 91 (RON), can be safely used since
the engine management system automatically
adjusts the ignition timing to suit (using the
information supplied by the knock sensor).
However, a slight power loss is likely if fuel
with a octane rating of less than 95 (RON) is
used. Vauxhall state that if 91 octane fuel is to
be used, as a precautionary measure, it is
wise to avoid placing the engine under severe
loads for any length of time (eg. towing or full
throttle driving).
3 All UK models have a catalytic converter,
and so must be run on unleaded fuel only.
Under no circumstances should leaded fuel
(UK 4-star) be used, as this may damage the
converter.
4 Super unleaded petrol (98 octane) can also
be used in all models if wished, though there
is no advantage in doing so.
6 Fuel injection systems general information
2.0 litre SOHC engine models Bosch Motronic M1.5.4 system
1 All 2.0 litre SOHC engine models are
equipped with a Bosch Motronic engine
management (fuel injection/ignition) system
(see illustration). On UK models the system
incorporates
a
closed-loop
catalytic
converter, an evaporative emission control
system and an exhaust gas recirculation
(EGR) system and complies with the latest
emission control standards. The fuel injection
side of the system operates as follows; refer
to Chapter 5B for information on the ignition
system.
2 The fuel pump, immersed in the fuel tank,
pumps fuel from the fuel tank to the fuel rail,
via a filter mounted underneath the rear of the
vehicle. Fuel supply pressure is controlled by
the pressure regulator which allows excess
fuel to be returned to the tank.
3 The electrical control system consists of the
ECU, along with the following sensors.
a) Throttle potentiometer - informs the ECU
of the throttle position, and the rate of
throttle opening or closing.
b) Coolant temperature sensor - informs the
ECU of engine temperature.
c) Airflow meter - informs the ECU of the
amount of air entering the inlet manifold.
d) Intake air temperature sensor - informs
the ECU of the temperature of the air
entering the manifold.
e) Crankshaft sensor - informs the ECU of
engine speed and crankshaft position.
f) Knock sensor - informs the ECU when
pre-ignition (pinking) is occurring.
g)
Oxygen sensor (UK models) informs the ECU of the oxygen content of
the exhaust gases (explained in greater
detail in Part B of this Chapter).
h) ABS control unit - informs the ECU of the
vehicle speed.
3510 Vauxhall/Opel Omega
i) Air conditioning system compressor
switch (where fitted) - informs ECU when
the air conditioning system is switched
on.
4 All the above information is analysed by the
ECU and, based on this, the ECU determines
the appropriate ignition and fuelling
requirements for the engine. The ECU
controls the fuel injector by varying its pulse
width - the length of time the injector is held
open - to provide a richer or weaker mixture,
as appropriate. The mixture is constantly
varied by the ECU, to provide the best setting
for cranking, starting (with either a hot or cold
engine), warm-up, idle, cruising, and
acceleration.
5 The ECU also has full control over the
engine idle speed, via the idle speed adjuster
which is fitted to the throttle housing. The
adjuster controls the opening of an air
passage which bypasses the throttle valve.
When the throttle valve is closed (accelerator
pedal released), the ECU uses the adjuster to
vary the amount of air entering the engine and
so controls the idle speed.
6 The ECU also controls the exhaust and
evaporative emission control systems, which
are described in detail in Part B of this
Chapter.
7 If there is an abnormality in any of the
readings obtained from any sensor, the ECU
enters its back-up mode. In this event, the
ECU ignores the abnormal sensor signal, and
assumes a pre-programmed value which will
allow the engine to continue running (albeit at
reduced efficiency). If the ECU enters this
back-up mode, the warning light on the
instrument panel will come on, and the
relevant fault code will be stored in the ECU
memory.
8 If the warning light comes on, the vehicle
should be taken to a Vauxhall dealer at the
earliest opportunity. A complete test of the
engine management system can then be
carried out, using a special electronic
diagnostic test unit which is simply plugged
into the system’s diagnostic connector. The
connector is located behind the fusebox
cover panel on the drivers’ side of the facia.
2.0 litre DOHC engine models Simtec 56.1 or 56.5 system
9 All 2.0 litre DOHC engine models are
equipped with a Simtec engine management
(fuel injection/ignition) system (see illustration
overleaf). The system is almost identical in
operation to the Motronic system fitted to
SOHC engines (see paragraphs 1 to 8). The
only major change to the system is that a
camshaft sensor is also incorporated into the
system. The camshaft sensor informs the ECU
of the speed and position of the exhaust
camshaft.
10 In order to reduce exhaust emissions even
further, a secondary air system is also
incorporated. This is explained in greater
detail in Part B of this Chapter.
Fuel and exhaust systems 4A•5
4A
6.1 Engine management system component locations - 2.0 litre SOHC engine
1 Idle speed adjuster valve
2 Throttle potentiometer
3 Evaporative emission system purge
valve
4 Exhaust gas recirculation (EGR) valve
5
6
7
8
9
Fuel pressure regulator
DIS module
Fuel pump relay
Injection system relay
Electronic control unit (ECU)
3510 Vauxhall/Opel Omega
10
11
12
13
14
Crankshaft sensor
Coolant temperature sensor
Knock sensor
Intake air temperature sensor
Airflow meter
4A•6 Fuel and exhaust systems
2.5 and 3.0 litre engines - Bosch
Motronic M2.8.1 or 2.8.3 system
11 All 2.5 and 3.0 litre engine models are
equipped with a Bosch Motronic engine
management (fuel injection/ignition) system
(see illustration). The system is almost
identical in operation to the Motronic system
fitted to 2.0 litre SOHC engine (see paragraphs
1 to 8). The only major change to the system is
that a camshaft sensor is also incorporated
into the system. The camshaft sensor is fitted
to the left-hand cylinder bank informs the ECU
of the speed and position of the exhaust
camshaft. Due to the V6 layout of the engine
there are two knock sensors and two oxygen
sensors, one for each bank of cylinders.
12 In order to reduce exhaust emissions even
6.9 Engine management system component locations - 2.0 litre DOHC engine
1
2
3
4
5
Exhaust gas recirculation (EGR) valve
DIS module
Evaporative emission system purge valve
Coolant temperature sensor
Electronic control unit (ECU)
6
7
8
9
10
Fuel pump relay
Injection system relay
Crankshaft sensor
Camshaft sensor
Knock sensor
3510 Vauxhall/Opel Omega
11
12
13
14
15
Intake air temperature sensor
Airflow meter
Idle speed adjuster valve
Throttle potentiometer
Fuel pressure regulator
Fuel and exhaust systems 4A•7
further, a secondary air system is also
incorporated. This is explained in greater
detail in Part B of this Chapter.
13 The ECU also has full control over the multiram air intake system described in Section 17.
14 On some later models the original M2.8.1
system was replaced with the later M2.8.3
system. The M2.8.3 system is identical in
operation to the earlier system but
incorporates an additional power steering
system sensor which informs the ECU when
load is being placed on the steering pump.
Modifications to the injection/ignition settings
within the ECU also result in more efficient
engine operation.
4A
6.11 Engine management system component locations - 2.5 and 3.0 litre engine
1
2
3
4
5
6
Right-hand cylinder bank knock sensor
Evaporative emission system purge valve
Coolant temperature sensor
DIS module
Fuel pressure regulator
Inlet manifold switchover valve solenoid valve
7
8
9
10
11
12
Inlet manifold switchover valve
Idle speed adjuster valve
Fuel pump relay
Injection system relay
Electronic control unit (ECU)
Left-hand cylinder bank knock sensor
3510 Vauxhall/Opel Omega
13
14
15
16
17
18
Camshaft sensor
Intake duct switchover valve
Intake duct switchover valve solenoid valve
Airflow meter
Intake air temperature sensor
Exhaust gas recirculation (EGR) valve
4A•8 Fuel and exhaust systems
7.2b On 2.5 and 3.0 litre engines the fuel
valve (arrowed) is located at the rear of the
inlet manifold
7.3 Place a wad of rag around the valve
and depress the valve with a screwdriver
to relieve the pressure in the fuel system
4 Once all pressure is relieved, securely refit
the valve cap.
Warning: Refer to the warning
note in Section 1 before proceeding. The following procedure
will merely relieve the pressure in the fuel
system - remember that fuel will still be
present in the system components, and
take precautions accordingly before
disconnecting any of them.
1 The fuel system referred to in this Section is
defined as the tank-mounted fuel pump, the
fuel filter, the fuel injectors and the pressure
regulator, and the metal pipes and flexible
hoses of the fuel lines between these
components. All these contain fuel which will
be under pressure while the engine is running,
and/or while the ignition is switched on. The
pressure will remain for some time after the
ignition has been switched off, and it must be
relieved in a controlled fashion when any of
these components are disturbed for servicing
work.
2 Locate the valve assembly which is fitted to
the fuel rail on the inlet manifold. On 2.0 litre
engines it can be found on the top of the rail
and on 2.5 and 3.0 litre engines it is located at
the rear of the fuel rail, directly below the
breather hose connections on the rear of the
inlet manifold upper section (see illustrations).
3 Unscrew the cap from the valve and
position a container beneath the valve. Hold a
wad of rag over the valve and relieve the
pressure in the fuel system by depressing the
valve core with a suitable screwdriver (see
illustration). Be prepared for the squirt of fuel
as the valve core is depressed and catch it
with the rag. Hold the valve core down until no
more fuel is expelled from the valve.
8.4 Undo the retaining screws (arrowed)
and remove the access cover . . .
8.5 . . . then disconnect the wiring
connector from the fuel pump cover
8.6 Release the retaining clips and
disconnect the fuel hoses from the pump
cover
8.7 Unscrew and remove the locking
ring . . .
7.2a On 2.0 litre DOHC engines the fuel
valve is located on the top of the fuel rail
7 Fuel injection system depressurisation
2
3510 Vauxhall/Opel Omega
8 Fuel pump removal and refitting
3
Warning: Refer to the warning
note in Section 1 before proceeding.
Note: A new fuel pump cover sealing ring will
be required on refitting.
Removal
1 Depressurise the fuel system as described in
Section 7 then disconnect the battery negative
lead. Note: On models with a Vauxhall antitheft warning system (ATWS), the battery
negative terminal must be disconnected within
15 seconds of the ignition being switched off to
prevent the alarm system being triggered.
2 On Saloon models lift up the luggage
compartment carpet/floor to reveal the fuel
pump access cover.
3 On Estate models lift up the luggage
compartment floor then undo the fasteners
and lift up the right-hand side section of the
carpet to gain access to the fuel pump cover.
If necessary, remove the CD autochanger as
described in Chapter 12, Section 19.
4 Undo the retaining screws and remove the
access cover from the floor to expose the fuel
pump (see illustration). Recover the cover
gasket; it should be renewed if it is damaged.
5 Disconnect the wiring connector from the
fuel pump cover and tape the connector to
the vehicle body to prevent it disappearing
behind the tank (see illustration).
6 Mark the fuel hoses for identification
purposes. Release the retaining clips and
disconnect both hoses from the pump cover
then plug the hose ends to minimise fuel loss
(see illustration). Where the hoses are fitted
with quick-release fittings, compress the clips
located on each side of the fitting and ease
the fitting off of its union.
7 Unscrew the locking ring and remove it
from the tank (see illustration). This is best
accomplished by using a screwdriver on the
raised ribs of the locking ring. Tap the
screwdriver to turn the ring anti-clockwise
until it can be unscrewed by hand.
Fuel and exhaust systems 4A•9
8.8a . . . then lift up pump cover and
disconnect the wiring connector . . .
8.8b . . . and fuel hoses and remove the
cover from the vehicle
8 Carefully lift the fuel pump cover away from
tank then make alignment marks between the
cover and hoses/wiring. Release the retaining
clips then disconnect both the hose and
wiring connectors and remove the cover from
the vehicle along with its sealing ring (see
illustrations). Discard the sealing ring; a new
one must be used on refitting.
9 Release the three retaining clips by
pressing them inwards then lift the fuel pump
housing assembly out of the fuel tank using a
piece of hooked welding rod engaged with the
hole if the housing lug. As the pump is
removed take great care not to displace the
fuel filter which is fitted to the pump base and
also try not to spill fuel onto the interior of the
vehicle (see illustrations).
10 Inspect the fuel filter for signs of damage
or deterioration and renew if necessary.
11 If necessary the pump housing assembly
can be dismantled and the pump removed,
noting the wiring connectors correct
locations.
Removal
Refitting
Refitting
12 Where necessary, reassembly the pump
and housing components ensuring the wiring
connectors are correctly and securely
reconnected.
13 Ensure the filter is securely fitted to the
base of the pump then carefully manoeuvre
the pump assembly into position, making sure
it clips securely into position.
14 Fit a new sealing ring to the tank.
15 Reconnect the fuel hoses and wiring
connectors to the pump cover, using the
marks made on removal to ensure they are
correctly reconnected. Secure the hoses in
position with the retaining clips then seat the
pump cover on the tank.
16 Refit the locking ring to the fuel tank and
tighten it securely.
17 Reconnect the fuel hoses to the pump
cover, ensuring each fitting clicks securely
into position, and reconnect the wiring
connector.
18 Reconnect the battery then start the
engine and check for fuel leaks. If all is well,
refit the access cover and gasket then lay the
luggage compartment carpet/floor back in
position.
4 Manoeuvre the sender unit carefully in
through the tank aperture and slide it into
position on the side of the fuel pump
reservoir.
5 Ensure the sender unit is clipped securely in
position then refit the fuel pump cover as
described in paragraphs 14 to 18 of Section 8.
9 Fuel gauge sender unit removal and refitting
8.9a Release the retaining clips and
withdraw the pump housing assembly
from the tank with a piece of welding rod
3
Warning: Refer to the warning
note in Section 1 before proceeding.
Note: A new fuel pump cover sealing ring will
be required on refitting.
1 Carry out the operations described in
paragraphs 1 to 8 of Section 8 to remove the
fuel pump cover.
2 The fuel gauge sender unit is clipped to the
side of the fuel pump mounting reservoir.
Carefully release the retaining clip then slide
the sender unit upwards to release it from its
mounting.
3 Manoeuvre the sender unit through the fuel
tank aperture, taking great care not damage
the float arm (see illustration).
10 Fuel tank removal and refitting
3
8.9b Ensure the pump filter is clean and
undamaged
2 Before removing the fuel tank, all fuel must
be drained from the tank. Since a fuel tank
drain plug is not provided, it is therefore
preferable to carry out the removal operation
when the tank is nearly empty. The remaining
fuel can then be siphoned or hand-pumped
from the tank.
3 Open up the fuel filler flap and remove the
rubber cover from around the filler neck
aperture.
4 Chock the front wheels then jack up the
rear of the vehicle and support it on axle
stands. Remove the right-hand rear
roadwheel.
5 Remove the retaining screws and fasteners
and remove the wheelarch liner from the rear,
right-hand arch then proceed as described
under the relevant sub-heading.
Warning: Refer to the warning
note in Section 1 before proceeding.
Removal
1 Depressurise the fuel system as described
in Section 7 then disconnect the battery
negative terminal. Note: On models with a
Vauxhall anti-theft warning system (ATWS),
the battery negative terminal must be
disconnected within 15 seconds of the
ignition being switched off to prevent the
alarm system being triggered.
3510 Vauxhall/Opel Omega
9.3 Removing the fuel gauge sender unit
4A
4A•10 Fuel and exhaust systems
10.6 On Saloon models disconnect the pump/gauge sender unit
wiring connector (1) which is located at the front of the fuel tank
(2 is tank mounting bolt)
Saloon models
6 Locate the fuel pump/gauge sender unit
wiring connector at the front of the fuel tank and
disconnect the connector (see illustration).
7 Trace the filler neck vent hose back to its
connection on the right-hand side of the tank.
Slacken the retaining clip and disconnect the
hose so that it is free to be removed with the
tank.
8 Trace the fuel feed and return hoses from
the tank to their unions in front of the tank
then mark the fuel hoses for identification
purposes. The hoses are equipped with
quick-release fittings to ease removal. To
disconnect each hose, compress the clips
located on each side of the fitting and ease
the fitting off of its union. Disconnect both
hoses from the top of the pump, noting the
correct fitted position of the sealing rings and
plug the hose ends to minimise fuel loss.
9 Place a trolley jack with an interposed block
of wood beneath the tank, then raise the jack
until it is supporting the weight of the tank.
10 Slacken and remove the retaining nut and
bolts and remove the two retaining straps
from underneath the fuel tank.
11 Slowly lower the fuel tank out of position,
disconnecting any other relevant vent pipes as
they become accessible (where necessary),
and remove the tank from underneath the
vehicle.
12 If the tank is contaminated with sediment or
water, remove the fuel pump cover (Section 8),
and swill the tank out with clean fuel. The tank is
injection-moulded from a synthetic material - if
seriously damaged, it should be renewed.
However, in certain cases, it may be possible to
have small leaks or minor damage repaired.
Seek the advice of a specialist before
attempting to repair the fuel tank.
10.16 On Estate models locate the vent hose T-piece (arrowed)
and disconnect the tank hoses
retaining screws and remove access cover
from the floor to expose the fuel pump cover.
Recover the cover gasket; it should be
renewed if it is damaged.
14 Disconnect the wiring connector from the
fuel pump cover and tape the connector to
the vehicle body to prevent it disappearing
behind the tank.
15 Release the retaining clip and disconnect
the vent hose from the rear of the fuel tank.
16 Locate the vent hose T-piece on the front,
left-hand corner of the fuel tank. Free the Tpiece from its retaining clip then slacken the
clips and detach both the tank hoses (see
illustration).
17 Remove the fuel tank as described in
paragraphs 7 to 13 (see illustration).
Refitting
18 Refitting is the reverse of the removal
procedure, noting the following points:
a) When lifting the tank back into position,
take care to ensure that none of the hoses
become trapped between the tank and
vehicle body. Refit the retaining straps
and tighten the nut and bolts to the
specified torque.
b) Ensure all pipes and hoses are correctly
routed and all hoses unions are securely
joined.
Estate models
13 Lift up the luggage compartment floor
then remove the fasteners and lift up the righthand side section of the carpet to gain access
to the fuel pump access cover. Undo the
10.17 Fuel tank retaining bolt Estate model
3510 Vauxhall/Opel Omega
c) On completion, refill the tank with a small
amount of fuel, and check for signs of
leakage prior to taking the vehicle out on
the road.
11 Throttle housing removal and refitting
4
2.0 litre SOHC engine models
Removal
1 Disconnect the battery negative terminal.
Note: On models with a Vauxhall anti-theft
warning system (ATWS), the battery negative
terminal must be disconnected within 15
seconds of the ignition being switched off to
prevent the alarm system being triggered.
2 Disconnect the wiring connectors from the
intake air temperature sensor and the airflow
meter.
3 Slacken the retaining clips then disconnect
the intake duct from the air cleaner and
throttle housing and remove the duct
assembly from the engine compartment.
4 Remove the retaining clip and detach the
accelerator cable from the throttle cam
balljoint and unclip the cable from its
mounting bracket. On models with cruise
control it will also be necessary to remove the
second retaining clip and detach the cruise
control cable.
5 Undo the retaining bolts and free the cable
mounting bracket from the manifold noting
the correct fitted location of the spring.
6 Clamp the coolant hoses which are
connected to the rear of the throttle body then
release the retaining clips and disconnect
both hoses. Wipe away any spilt coolant.
7 Disconnect the wiring connectors from the
throttle potentiometer and the idle speed
adjuster.
8 Disconnect the vacuum/breather hoses
from the throttle body, noting their correct
Fuel and exhaust systems 4A•11
11.11 Disconnect the wiring connectors
from the intake air temperature sensor and
the airflow meter (arrowed)
11.12a Disconnect the breather hose from
the cylinder head cover . . .
11.12b . . . then release the retaining clips
and remove the intake duct assembly from
the engine compartment
fitted locations, then undo the retaining nuts
and remove the housing from the manifold.
Remove the gasket and discard it, a new one
should be used on refitting.
11 Disconnect the wiring connectors from
the intake air temperature sensor and the
airflow meter (see illustration).
12 Slacken the retaining clip and disconnect
the intake duct breather hose from the
cylinder head cover. Slacken the retaining
clips then disconnect the intake duct from the
air cleaner and throttle housing and remove
the duct assembly from the engine
compartment (see illustrations).
13 Remove the retaining clip and detach the
accelerator cable from the throttle cam
balljoint and unclip the cable from its
mounting bracket. On models with cruise
control it will also be necessary to remove the
second retaining clip and detach the cruise
control cable.
14 Unscrew the nut and disconnect the fuel
feed hose from its union on the rear of the fuel
rail. As the union nut is slackened, retain the
pipe end fitting with an open-ended spanner
to prevent any excess strain being placed on
the pipe. Plug the hose and pipe ends to
minimise fuel loss and prevent the entry of dirt
then undo the retaining bolt securing the fuel
pipe to the throttle housing bracket (see
illustration).
15 Clamp the coolant hoses which are
connected to the throttle housing then release
the retaining clips and disconnect both hoses
(see illustration). Wipe away any spilt
coolant.
16 Disconnect the wiring connectors from
the throttle potentiometer and the idle speed
adjuster.
17 Disconnect the vacuum hose(s) from the
throttle body, noting their correct fitted
locations, then undo the retaining nuts and
remove the housing from the manifold.
Remove the gasket and discard it, a new one
should be used on refitting.
Refitting
9 Refitting is the reverse of removal, bearing
in mind the following points.
a) Ensure the mating surfaces are clean and
dry then fit a new gasket and tighten the
housing nuts to the specified torque.
b) Ensure all hoses are correctly and
securely reconnected.
c) On completion adjust the accelerator
cable as described in Section 3.
2.0 litre DOHC engine models
Warning: Refer to the warning
note in Section 1 before proceeding.
Removal
10 Disconnect the battery negative terminal
then depressurise the fuel system as
described in Section 7. Note: On models with
a Vauxhall anti-theft warning system (ATWS),
the battery negative terminal must be
disconnected within 15 seconds of the
ignition being switched off to prevent the
alarm system being triggered.
11.14 Unscrew the fuel feed pipe union nut (A) then undo the pipe
retaining bolt (B)
Refitting
18 Refitting is the reverse of removal, bearing
in mind the following points.
a) Ensure the mating surfaces are clean and
dry then fit a new gasket and tighten the
housing nuts to the specified torque.
b) Ensure all hoses are correctly and
securely reconnected.
c) On completion adjust the accelerator
cable as described in Section 3.
2.5 and 3.0 litre engines
Removal
19 Remove the inlet manifold upper section
as described in Section 15.
11.15 Release the retaining clips and disconnect the coolant
hoses (arrowed) from the throttle housing
3510 Vauxhall/Opel Omega
4A
4A•12 Fuel and exhaust systems
2 If these checks fail to reveal the cause of
the problem, the vehicle should be taken to a
suitably-equipped Vauxhall dealer for testing.
A wiring block connector is incorporated in
the engine management circuit, into which a
special electronic diagnostic tester can be
plugged (see Section 6). The tester will locate
the fault quickly and simply, alleviating the
need to test all the system components
individually, which is a time-consuming
operation that carries a risk of damaging the
ECU.
11.20 Removing the throttle housing 2.5 and 3.0 litre engines
20 Slacken and remove the retaining bolts
and separate the throttle body from the
manifold (see illustration). Recover the large
sealing rings from the throttle body bores and
the small rings from the manifold breather
passages and discard them; new sealing rings
should be used on refitting.
Refitting
21 Fit new sealing rings to the manifold
breather passages and the throttle body
bores then carefully ease the throttle housing
assembly into position on the manifold upper
section, ensuring all the sealing rings remain
correctly seated (see illustration).
22 Tighten the throttle body retaining bolts to
the specified torque then refit the manifold
upper section as described in Section 15.
12 Fuel injection system testing and adjustment
Testing
1 If a fault appears in the fuel injection system,
first ensure that all the system wiring
connectors are securely connected and free of
corrosion. Ensure that the fault is not due to
poor maintenance; ie, check that the air
cleaner filter element is clean, the spark plugs
are in good condition and correctly gapped,
the cylinder compression pressures are
correct, and that the engine breather hoses are
clear and undamaged, referring to Chapters 1
and 2A, 2B or 2C for further information (as
applicable).
11.21 On refitting, fit new sealing rings to
the throttle housing recesses
Adjustment
3 Experienced home mechanics with a
considerable amount of skill and equipment
(including a tachometer and an accurately
calibrated exhaust gas analyser) may be able
to check the exhaust CO level and the idle
speed. However, if these are found to be in
need of adjustment, the car will have to be
taken to a suitably-equipped Vauxhall dealer
who has access to the necessary diagnostic
equipment required to test and (where
possible) adjust the settings.
13 Fuel injection system
components (2.0 litre engine)
- removal and refitting
4
Fuel injector
Warning: Refer to the warning
note in Section 1 before proceeding.
Note: If a faulty injector is suspected, before
condemning the injector, it is worth trying the
effect of one of the proprietary injectorcleaning treatments.
6 Release the retaining clips and disconnect
the wiring connectors from the injectors.
7 Unscrew the nut and detach the earth lead
from the fuel rail rear retaining bolt.
8 Slacken and remove the retaining bolts
then carefully ease the fuel rail and injector
assembly out of position and remove it from
the manifold. Remove the lower sealing rings
from the injectors and discard them; they
must be renewed whenever they are
disturbed.
9 Slide off the relevant retaining clip and
withdraw the injector from the fuel rail.
Remove the upper sealing ring from the
injector and discard it; all disturbed sealing
rings must be renewed.
10 Refitting is a reversal of the removal
procedure, noting the following points.
a) Renew all disturbed sealing rings and
apply a smear of engine oil to them to aid
installation.
b) Ease the injector(s) into the fuel rail,
ensuring that the sealing ring(s) remain
correctly seated, and secure in position
with the retaining clips.
c) On refitting the fuel rail, take care not to
damage the injectors and ensure that all
sealing rings remain in position. Once the
fuel rail is correctly seated, tighten its
retaining bolts to the specified torque.
d) Fit new sealing washers to each side of
the fuel feed and return hose unions then
screw in the union bolts. Ensure both
hose unions are correctly positioned then
tighten the unions bolts to the specified
torque.
e) On completion start the engine and check
for fuel leaks. Adjust the accelerator cable
as described in Section 3.
SOHC engine
DOHC engine
1 Depressurise the fuel system as described
in Section 7 then disconnect the battery
negative terminal. Note: On models with a
Vauxhall anti-theft warning system (ATWS),
the battery negative terminal must be
disconnected within 15 seconds of the
ignition being switched off to prevent the
alarm system being triggered.
2 Disconnect the vacuum hoses from the inlet
manifold and fuel pressure regulator and
position the hose clear of the fuel rail.
3 Remove the retaining clip and detach the
accelerator cable from the throttle cam
balljoint and unclip the cable from its
mounting bracket. On models with cruise
control it will also be necessary to remove the
second retaining clip and detach the cruise
control cable.
4 Undo the retaining bolts and free the cable
mounting bracket from the manifold noting
the correct fitted location of the spring.
5 Unscrew the union bolts and disconnect
the fuel feed and return hoses from the fuel
rail. Recover the sealing washers from each
hose union and discard; new ones should be
used on refitting.
11 Depressurise the fuel system as
described in Section 7 then disconnect the
battery negative terminal. Note: On models
with a Vauxhall anti-theft warning system
(ATWS), the battery negative terminal must be
disconnected within 15 seconds of the
ignition being switched off to prevent the
alarm system being triggered.
12 Release the retaining clips and disconnect
the breather hoses from the right-hand side of
the cylinder head cover. Also disconnect the
vacuum hose from the fuel pressure regulator.
13 Disconnect the wiring connectors from
the intake air temperature sensor and the
airflow meter.
14 Slacken the retaining clips then
disconnect the intake duct from the air
cleaner and throttle housing and remove the
duct assembly from the engine compartment,
freeing it from the wiring harness.
15 Remove the retaining clip and detach the
accelerator cable from the throttle cam
balljoint and unclip the cable from its
mounting bracket. On models with cruise
control it will also be necessary to detach the
cruise control cable.
3510 Vauxhall/Opel Omega
Fuel and exhaust systems 4A•13
16 Unscrew the nuts and disconnect the fuel
feed hose from its union on the rear of the fuel
rail and the return pipe from the front end of
the fuel rail. As the union nuts are slackened,
retain the pipe end fitting with an open-ended
spanner to prevent any excess strain being
placed on the pipe. Plug the hose and pipe
ends to minimise fuel loss and prevent the
entry of dirt then undo the retaining bolt
securing the fuel feed rail pipe to the throttle
housing bracket (see illustrations).
17 Disconnect the wiring connector from the
idle control stepper motor then undo the
retaining bolts and free the cable mounting
bracket from the throttle housing, noting the
correct fitted location of the spring.
18 Unscrew the retaining nut and detach the
earth lead from the fuel rail front retaining bolt.
19 Carefully release the retaining clips and lift
off the injector wiring cover assembly squarely
away from the top of the injectors; the wiring
connectors are an integral part of the cover.
Disconnect the crankshaft sensor and knock
sensor wiring connectors (where necessary)
from the underside of the injector wiring cover
then position the cover assembly clear of the
fuel rail.
20 Slacken and remove the retaining bolts
then carefully ease the fuel rail and injector
assembly out of position and remove it from
the manifold. Remove the lower sealing rings
from the injectors and discard them; they
must be renewed whenever they are
disturbed.
21 Slide off the relevant retaining clip and
withdraw the injector from the fuel rail.
Remove the upper sealing ring from the
injector and discard it; all disturbed sealing
rings must be renewed.
22 Refitting is a reversal of the removal
procedure, noting the following points.
a) Renew all disturbed sealing rings and
apply a smear of engine oil to them to aid
installation.
b) Ease the injector(s) into the fuel rail,
ensuring that the sealing ring(s) remain
correctly seated, and secure in position
with the retaining clips. Ensure that the
retaining clips are correctly positioned
otherwise it will not be possible to refit the
wiring cover assembly.
c) On refitting the fuel rail, take care not to
damage the injectors and ensure that all
sealing rings remain in position. Once the
fuel rail is correctly seated, tighten its
retaining bolts to the specified torque.
d) On completion, adjust the accelerator
cable as described in Section 3 then start
the engine and check for fuel leaks.
13.16a Unscrew the fuel feed pipe union
nut (A) and bolt (B) . . .
(ATWS), the battery negative terminal must be
disconnected within 15 seconds of the
ignition being switched off to prevent the
alarm system being triggered.
24 Disconnect the vacuum hose from the
regulator (see illustration).
25 Slacken the retaining clamp then carefully
ease the pressure regulator out from the top
of the fuel rail. Remove the both sealing rings
from the regulator and discard them; new
ones must be used on refitting.
26 Refitting is the reverse of removal, using
new sealing rings and lubricating them with a
smear of engine oil to ease installation. Ensure
the regulator is correctly positioned then
tighten the retaining clamp screw to the
specified torque. On completion start the
engine and check for signs of fuel leakage.
Idle speed adjuster valve
27 On DOHC engines, disconnect the wiring
connectors from the intake air temperature
sensor and the airflow meter then slacken the
retaining clips then disconnect the intake duct
from the air cleaner and throttle housing.
Position the duct assembly clear of the
throttle housing to improve access to the
adjuster valve.
28 On all engines, disconnect the wiring
connector then undo the retaining screws and
remove the motor assembly from the side of
the throttle housing. Remove the gasket and
discard it; a new one should be used on
refitting.
29 Refitting is the reverse of removal using a
new gasket.
13.16b . . . and the fuel return pipe union
nut
Throttle potentiometer
30 Ensure the ignition is switched off then
disconnect the wiring connector from the
throttle potentiometer which is fitted to the
throttle housing.
31 Slacken and remove the retaining screws
then remove the potentiometer from the
housing (see illustration).
32 Refitting is the reverse of removal making
sure the potentiometer is correctly engaged
with the throttle valve spindle.
Coolant temperature sensor
SOHC engine
33 The coolant temperature sensor is screwed
into the front, right-hand end of the cylinder
head. Refer to Chapter 3, Section 7 for removal
and refitting details noting that it maybe
necessary to unbolt the upper mounting
brackets and pivot the alternator away from the
cylinder block to gain the necessary clearance
required to remove the sensor.
DOHC engine
34 The coolant temperature sensor is
screwed into the rear of the cylinder head
where it is located beneath the DIS module.
Refer to Chapter 3, Section 7 for removal and
refitting details.
Intake air temperature sensor
35 Ensure ignition is switched off then disconnect the wiring connector from the sensor.
36 Slacken the retaining clips then detach
the intake duct from the airflow meter and air
Fuel pressure regulator
Warning: Refer to the warning
note in Section 1 before proceeding.
23 Depressurise the fuel system as
described in Section 7 then disconnect the
battery negative terminal. Note: On models
with a Vauxhall anti-theft warning system
13.24 Fuel pressure regulator vacuum
hose (1) and retaining clamp (2)
3510 Vauxhall/Opel Omega
13.31 Disconnect the wiring connector (1)
then undo the retaining screws (2) and
remove the throttle potentiometer
4A
4A•14 Fuel and exhaust systems
13.36a Disconnect the wiring connector
from the intake air temperature sensor . . .
13.36b . . . then slacken the retaining clips
and remove the intake duct
cleaner housing and remove it from the
vehicle (see illustrations).
37 Carefully ease the sensor out of position,
taking great care not to damage the duct.
38 Refitting is the reverse of removal noting
that the sensor must be fitted so that its flat
edge aligns with the flat on the intake duct.
Aid installation by lubricating the duct with a
silicone-based spray.
45 On models with air conditioning, to
improve access to the sensor remove the
engine/transmission left-hand mounting and
mounting bracket from the cylinder block (see
Chapter 2A).
46 Work back along the sensor wiring and
release it from all the relevant clips and ties
whilst noting its correct routing. Disconnect
the wiring connector so the wiring is free to be
removed with the sensor.
47 Unscrew the retaining bolt and remove
the sensor from the front of the cylinder block,
along with its sealing ring. Discard the sealing
ring, a new one should be used on refitting.
48 Refitting is the reverse of removal using a
new sealing ring and tightening the sensor
bolt to the specified torque. Ensure the wiring
is correctly routed and retained by all the
necessary clips before refitting the timing belt
cover (see Chapter 2A).
Airflow meter
39 Ensure the ignition is switched off then
disconnect the wiring connector from the
airflow meter and intake air temperature
sensor (see illustration).
40 Slacken the retaining clips then detach the
intake duct from the airflow meter and air
cleaner housing and remove it from the vehicle.
41 Slacken the retaining clip then remove the
airflow meter from the vehicle (see
illustration). Inspect the meter for signs of
damage and renew if necessary.
42 Refitting is the reverse of removal
ensuring the intake ducts are correctly
engaged with the meter recesses.
Crankshaft sensor
SOHC engine
43 Remove the timing belt front cover as
described in Chapter 2A. The sensor is
mounted on the left-hand side of the cylinder
block, beneath the power steering pump.
44 To improve access, firmly apply the
handbrake then jack up the front of the
vehicle and support it securely on axle stands.
Undo the retaining screws and remove the
undercover from beneath the engine.
13.39 Disconnect the wiring connector
from the airflow meter
DOHC engine
49 The sensor is fitted to the left-hand side of
the cylinder block, beneath the power steering
pump. Removal and refitting is as follows.
50 Firmly apply the handbrake then jack up
the front of the vehicle and support it securely
on axle stands. Undo the retaining screws and
remove the undercover from beneath the
engine.
51 Trace the wiring back from the sensor,
over the top of the cylinder head to its wiring
connector. On early models the connector is
connected to the underside of the front of the
injector wiring cover assembly whereas on
later models it is connected to the engine
harness connector on the front of the engine.
52 Release the retaining clip and disconnect
13.41 Removing the airflow meter
3510 Vauxhall/Opel Omega
the crankshaft sensor connector from the
injector cover/engine harness (as applicable)
(see illustration). On early models if the
connector proves difficult to disconnect, free
the injector wiring cover from the injectors as
described earlier in this section then
disconnect the connector.
53 Work along the sensor wiring, releasing it
from all the relevant clips and ties whilst
noting its correct routing.
54 On models with air conditioning, to
improve access to the sensor remove the
engine/transmission left-hand mounting and
mounting bracket from the cylinder block (see
Chapter 2B).
55 Unscrew the retaining bolt and remove
the sensor from the front of the cylinder block,
along with its sealing ring. Discard the sealing
ring, a new one should be used on refitting.
56 Refitting is the reverse of removal using a
new sealing ring and tightening the sensor
bolt to the specified torque. Ensure the wiring
is correctly routed and retained by all the
necessary clips and ties.
Knock sensor
SOHC engine
57 The knock sensor is mounted onto the
centre of the right-hand side of the cylinder
block. To improve access, firmly apply the
handbrake then jack up the front of the
vehicle and support it on axle stands so the
sensor can also be reached from below.
58 Ensure the ignition is switched off then
disconnect the wiring connector from the
sensor.
59 Slacken and remove the retaining bolt and
remove the sensor from the engine.
60 On refitting ensure the mating surfaces
are clean and dry. Fit the sensor then tighten
its retaining bolt to the specified torque and
reconnect the wiring connector.
DOHC engine
61 The sensor is fitted to the centre of the
right-hand side of the cylinder block. Removal
and refitting is as follows.
62 Firmly apply the handbrake then jack up
the front of the vehicle and support it securely
on axle stands. Undo the retaining screws and
remove the undercover from beneath the
engine.
13.52 On later models the crankshaft
sensor wiring connector (arrowed) is easily
accessible
Fuel and exhaust systems 4A•15
13.75a Slide out the ECU then lift the
retaining clip . . .
13.75b . . . and disconnect its wiring
connector
63 If necessary, to improve access, remove
the starter motor as described in Chapter 5A.
64 Trace the wiring back from the sensor to
its wiring connector. On early models the
connector is connected to the underside of
the injector wiring cover assembly (in between
number 3 and 4 injectors) whereas on later
models it is connected to the engine harness
connector located on the underside of the
inlet manifold.
65 Release the retaining clip and disconnect
the crankshaft sensor connector from the
injector cover/engine harness (as applicable).
On early models if the connector proves
difficult to disconnect, free the injector wiring
cover from the injectors as described earlier in
this section then disconnect the connector.
66 Work along the sensor wiring, releasing it
from all the relevant clips and ties whilst
noting its correct routing.
67 Slacken and remove the retaining bolt and
remove the sensor from the engine.
68 On refitting ensure the mating surfaces
are clean and dry then fit the sensor and
tighten its retaining bolt to the specified
torque. Ensure the wiring is correctly routed
and securely reconnected.
72 Unscrew the retaining bolt and remove
the camshaft sensor from the top of the
cylinder head.
73 Refitting is the reverse of removal
tightening the sensor retaining bolt to the
specified torque.
Camshaft sensor - DOHC engine
69 Undo the retaining screws and remove
the spark plug cover from the top of the
cylinder head cover.
70 Ensure the ignition is switched off then
disconnect the wiring connector from the
camshaft sensor.
71 Remove the timing belt front cover as
described in Chapter 2B.
13.79 Removing the fuel pump relay
Electronic control unit (ECU)
74 Disconnect the battery negative terminal
then unclip the lid from the engine
compartment relay box. Note: On models
with a Vauxhall anti-theft warning system
(ATWS), the battery negative terminal must be
disconnected within 15 seconds of the
ignition being switched off to prevent the
alarm system being triggered.
75 Slide the ECU out of position until access
to the wiring connector retaining clip can be
gained. Lift the retaining clip and carefully
disconnect the wiring connector then remove
the ECU from the vehicle (see illustrations). If
necessary, undo the retaining nuts and
separate the ECU from its mounting plate.
76 Refitting is the reverse of removal making
sure the wiring connector is correctly
reconnected. On later DOHC engines (with
Simtec 56.5 system) if a new ECU has been
fitted it will be necessary to take the vehicle to
a Vauxhall dealer to have the unit coded to
match the performance of your engine.
13.78 The fuel pump relay (1) and injection
system relay (2) are located in the engine
compartment relay box
relay is the right-hand (inner) relay of the two
and the injection system/protection relay is
the left-hand (outer) relay (see illustration).
79 Ensure the ignition is switched off then
pull the relevant relay out of its socket and
remove it from the vehicle (see illustration).
80 Refitting is the reverse of removal.
Air conditioning system switch
81 The air conditioning system switch is
screwed into one of the refrigerant pipes and
cannot be removed without first discharging
the refrigerant (see Chapter 3). Renewal of the
switch should therefore be entrusted to a
suitably equipped garage.
14 Fuel injection system components
(2.5 and 3.0 litre engines) removal and refitting
4
Fuel injector
77 The injection system relays are located in
the engine compartment relay box.
78 Unclip the lid from the relay box. The
injection system relays are the two relays
situated at the rear of the box; the fuel pump
Warning: Refer to the warning
note in Section 1 before proceeding.
Note: If a faulty injector is suspected, before
condemning the injector, it is worth trying the
effect of one of the proprietary injectorcleaning treatments.
1 Remove the lower section of the inlet
manifold as described in Section 15.
2 Depress the retaining clips and disconnect
the wiring connectors from the six injectors.
Unclip the wiring harness cover from the top
of the fuel rail and remove it from the manifold
(see illustrations).
14.2a Disconnect the wiring connectors
from the injectors . . .
14.2b . . . then unclip the cover assembly
from the fuel rail
Injection system relays
3510 Vauxhall/Opel Omega
4A
4A•16 Fuel and exhaust systems
14.3a Slacken the union nuts . . .
14.3b . . . then undo the retaining bolts
(arrowed) . . .
14.3c . . . and remove the fuel pipes from
the manifold
3 Slacken the union nuts securing the fuel
pipes to the fuel rail whilst (where possible)
retaining the fuel rail with an open-ended
spanner. Unscrew the retaining bolts and
remove the pipe assembly from the manifold
lower section (see illustrations).
4 Slacken and remove the retaining bolts
then carefully ease the fuel rail and injector
assembly out from the manifold. Remove the
lower sealing rings from the injectors and
discard them. Slide off the relevant retaining
clip and withdraw the injector from the fuel
rail. Remove the upper sealing ring from the
injector and discard it. All disturbed sealing
rings must be renewed (see illustrations).
5 Refitting is a reversal of the removal
procedure, noting the following points.
a) Renew all disturbed sealing rings and
apply a smear of engine oil to them to aid
installation (see illustration).
b) Ease the injector(s) into the fuel rail,
ensuring that the sealing ring(s) remain
correctly seated, and secure in position
with the retaining clips.
c) On refitting the fuel rail, take care not to
damage the injectors and ensure that all
sealing rings remain in position. Once the
fuel rail is correctly seated, tighten its
retaining bolts to the specified torque.
d) Tighten the fuel pipe union nuts and
retaining bolts to the specified torque
then refit the wiring cover assembly
making sure all the wiring connectors are
securely reconnected.
e) Refit the manifold as described in Section
15. On completion start the engine and
check for fuel leaks.
6 Depressurise the fuel system as described
in Section 7 then disconnect the battery
negative terminal. Note: On models with a
Vauxhall anti-theft warning system (ATWS),
the battery negative terminal must be
disconnected within 15 seconds of the
ignition being switched off to prevent the
alarm system being triggered.
7 To gain access to the pressure regulator,
remove the windscreen wiper arms and the
water deflector panel from the base of the
windscreen (see Chapter 12, Sections 15
and 16) (see illustration).
8 Unclip the wiring connector holder from the
lifting bracket on the rear of the cylinder head
and position the wiring clear of the regulator.
9 Disconnect the vacuum hose from the fuel
pressure regulator.
10 Slacken the retaining clamp then carefully
ease the pressure regulator out from the fuel
rail. Remove both sealing rings from the
Fuel pressure regulator
Warning: Refer to the warning
note in Section 1 before proceeding.
14.4a Undo the retaining bolts
(arrowed) . . .
14.4b . . . and ease the fuel rail and
injector assembly out of position
14.4c Slide off the relevant retaining
clip . . .
14.4d . . . then ease the injector out from
the fuel rail
14.5 On refitting be sure to renew all
injector sealing rings
14.7 The fuel pressure regulator is located
at the rear of the inlet manifold
(shown with engine removed)
3510 Vauxhall/Opel Omega
Fuel and exhaust systems 4A•17
14.12 Disconnect the wiring connector
from the idle speed adjuster valve . . .
14.13 . . . then release the retaining clip
and detach the air hose
14.15 Disconnecting the throttle
potentiometer wiring connector
regulator and discard them; new ones must
be used on refitting.
11 Refitting is the reverse of removal, using
new sealing rings and lubricating them with a
smear of engine oil to ease installation. Ensure
the regulator is correctly positioned then
securely tighten the retaining clamp screw.
On completion start the engine and check for
signs of fuel leakage.
16 Slacken and remove the retaining screws
then remove the potentiometer from the
housing.
17 Refitting is the reverse of removal making
sure the potentiometer is correctly engaged
with the throttle valve spindle.
airflow meter and intake air temperature
sensor.
24 Slacken the retaining clips then detach
the intake duct from the airflow meter and air
cleaner housing and remove it from the
vehicle.
25 Slacken the retaining clip then remove the
airflow meter from the vehicle. Inspect the
meter for signs of damage and renew if
necessary.
26 Refitting is the reverse of removal
ensuring the intake ducts are correctly
engaged with the meter recesses.
Idle speed adjuster valve
12 Ensure the ignition is switched off then
disconnect the wiring connector from the
valve which is fitted to the left-hand side of
the inlet manifold (see illustration).
13 Slacken the retaining clip and disconnect
the hose from the valve then carefully ease
the valve assembly out from the manifold (see
illustration). If necessary separate the valve
and its mounting rubber. Inspect the
mounting rubber for signs of damage or
deterioration and renew if necessary.
14 Refitting is the reverse of removal making
sure the mounting rubber grommet is correctly
positioned. Aid installation by lubricating the
grommet with a silicone-based spray.
On completion start the engine and check for
air leaks.
Throttle potentiometer
15 Ensure the ignition is switched off then
disconnect the wiring connector from the
throttle potentiometer which is fitted to the
left-hand side of the throttle housing (see
illustration).
14.18 The coolant temperature sensor is
screwed into the coolant outlet (shown
with inlet manifold removed)
Coolant temperature sensor
18 The coolant temperature sensor is
screwed into the coolant outlet which links the
rear of the cylinder heads. Refer to Chapter 3
for removal and refitting details noting that it
will be necessary to remove the inlet manifold
to gain access to the sensor (see
illustration).
Crankshaft sensor
23 Ensure the ignition is switched off then
disconnect the wiring connectors from the
27 The sensor is mounted on the left-hand
side of the cylinder block, directly below the
oil filter, and its wiring connector is clipped
onto the holder on the rear of the left hand
cylinder head.
28 To gain access to the wiring connector,
remove the windscreen wiper arms and the
water deflector panel from the base of the windscreen (see Chapter 12, Sections 15 and 16).
29 Ensure the ignition is switched off then
unclip the sensor wiring connector from its
holder and disconnect it (see illustration).
30 Firmly apply the handbrake then jack up
the front of the vehicle and support it on axle
stands.
31 Work back along the sensor wiring and
release it from all the relevant clips and ties
whilst noting its correct routing.
32 Unscrew the retaining bolt and remove
the sensor from the cylinder block, along with
14.20 Disconnect the wiring connector
from the intake air sensor then release the
retaining clips (arrowed) and remove the
intake duct
14.29 The crankshaft sensor wiring
connector (arrowed) is clipped onto the
engine rear lifting bracket (shown with
engine removed)
Intake air temperature sensor
19 Ensure ignition is switched off then
disconnect the wiring connector from the
sensor.
20 Slacken the retaining clips then detach
the intake duct from the airflow meter and air
cleaner housing and remove it from the
vehicle (see illustration).
21 Carefully ease the sensor out of position
and recover is sealing grommet. Inspect the
grommet for signs of damage or deterioration
and renew if necessary.
22 Refitting is the reverse of removal making
sure the sensor and grommet are correctly
seated.
Airflow meter
3510 Vauxhall/Opel Omega
4A
4A•18 Fuel and exhaust systems
retained by all the necessary clips so that it is
no danger of contacting the exhaust system
or auxiliary drivebelt. On models with air
conditioning refit the engine mounting bracket
and mounting as described in Chapter 2C.
Camshaft sensor
14.32 Removing the crankshaft sensor
(shown with oil filter removed)
its sealing ring. Discard the sealing ring, a new
one should be used on refitting (see
illustration).
33 Refitting is the reverse of removal using a
new sealing ring and tightening the sensor
bolt to the specified torque. Ensure the wiring
is correctly routed and retained by all the
necessary clips so that it is in no danger of
contacting the exhaust manifold.
Knock sensor right-hand cylinder bank
34 Remove the auxiliary drivebelt as
described in Chapter 1 then unbolt the
drivebelt tensioner pulley assembly from the
side of the cylinder head.
35 Remove the alternator upper mounting
bolt then slacken the lower mounting and
pivot the alternator away from the block (see
Chapter 5A).
36 Trace the wiring back from the sensor to
the front of the timing belt cover, releasing it
from all the relevant clips and ties whilst
noting its correct routing. Ensure the ignition
is switched off then disconnect the sensor
wiring connector.
37 Slacken and remove the retaining bolt and
remove the sensor from the engine (see
illustration).
38 On refitting ensure the mating surfaces
are clean and dry then fit the sensor and
tighten its retaining bolt to the specified
torque. Ensure the wiring is correctly routed
and securely retained by all the necessary
clips so that it is no danger of contacting the
auxiliary drivebelt. Refit the alternator and
14.43 On refitting ensure the knock sensor
is correctly positioned then tighten its
retaining bolt to the specified torque
14.37 Unscrew the retaining bolt and
remove the knock sensor from the righthand side of the cylinder block
drivebelt tensioner, tightening their retaining
bolts to the specified torque settings (see
Chapter 5A) and refit the auxiliary drivebelt
(see Chapter 1).
Knock sensor left-hand cylinder bank
39 The knock sensor is situated on the lefthand side of the cylinder block, just in front of
the oil filter and is wiring connector is
connected to the wiring harness cover above
the left-hand cylinder head. To gain access to
the sensor, firmly apply the handbrake then
jack up the front of the vehicle and support it
on axle stands.
40 On models with air conditioning, to
improve access to the sensor remove the
engine/transmission left-hand mounting and
mounting bracket from the cylinder block (see
Chapter 2C).
41 Trace the wiring back from the sensor,
releasing it from all the relevant clips and ties
whilst noting its correct routing. Disconnect
the wiring connector and tie a length of string
to it; the string can then be used on refitting to
draw the wiring connector up and into
position.
42 Slacken and remove the retaining bolt and
remove the sensor from the engine. Untie the
string and leave in position for use on refitting.
43 On refitting then use the string to draw the
wiring connector up and into position. Ensure
the mating surfaces are clean and dry then fit
the sensor and tighten its retaining bolt to the
specified torque (see illustration). Ensure the
wiring is correctly routed and securely
14.46 Removing the camshaft sensor
3510 Vauxhall/Opel Omega
44 The sensor is mounted onto the top of the
left-hand cylinder bank exhaust camshaft
where it is directly behind the timing belt
cover. On models with air conditioning, to
improve access to the sensor, unbolt the air
conditioning pipe/hose bracket from the
cylinder head and position the hose/pipe to
one side.
45 Ensure the ignition is switched off then
disconnect the wiring connector from the
camshaft sensor
46 Unscrew the retaining bolt and remove
the camshaft sensor from the camshaft
bearing cap (see illustration).
47 Refitting is the reverse of removal
tightening the sensor retaining bolt to the
specified torque.
Electronic control unit (ECU)
48 Refer to Section 13.
Injection system relays
49 Refer to Section 13.
Air conditioning system switch
50 The air conditioning system switch is
screwed into one of the refrigerant pipes and
cannot be removed without first discharging
the refrigerant (see Chapter 3). Renewal of the
switch should therefore be entrusted to a
suitably equipped garage.
15 Inlet manifold removal and refitting
4
Warning: Refer to the warning
note in Section 1 before proceeding.
2.0 litre SOHC engine
Removal
1 Depressurise the fuel system as described
in Section 7 then disconnect the battery
negative terminal. Note: On models with a
Vauxhall anti-theft warning system (ATWS),
the battery negative terminal must be
disconnected within 15 seconds of the
ignition being switched off to prevent the
alarm system being triggered.
2 Remove the auxiliary drivebelt and drain the
cooling system as described in Chapter 1.
3 Disconnect the wiring connectors from the
intake air temperature sensor and the airflow
meter.
4 Slacken the retaining clips then disconnect
the intake duct from the air cleaner and
throttle housing and remove the duct
assembly from the engine compartment.
5 Remove the retaining clip and detach the
Fuel and exhaust systems 4A•19
accelerator cable from the throttle cam
balljoint and unclip the cable from its
mounting bracket. On models with cruise
control it will also be necessary to remove the
second retaining clip and detach the cruise
control cable.
6 Undo the retaining bolts and free the cable
mounting bracket from the manifold noting
the correct fitted location of the spring.
7 Undo the retaining bolts and remove the
support bracket and alternator mounting
bracket from the front of the manifold.
8 Unscrew the union bolts and disconnect
the fuel feed and return hoses from the fuel
rail. Recover the sealing washers from each
hose union and discard; new ones should be
used on refitting. Plug the hose ends to
minimise fuel loss and prevent the entry of dirt
into the system.
9 Disconnect the wiring connectors from the
throttle potentiometer, the idle speed adjuster
valve, the injectors, the purge valve, the DIS
module and the exhaust gas recirculation
(EGR) valve.
10 Unscrew the nut/bolt and detach the earth
leads from the fuel rail rear retaining bolt and
camshaft housing.
11 Note the correct routing of the wiring then
undo the wiring cover retaining bolts and
position the cover assembly clear of the inlet
manifold.
12 Disconnect the various breather/vacuum
hoses from the throttle housing and manifold
(as applicable) noting each ones correct fitted
location.
13 Slacken the retaining clips and disconnect
the coolant hose from the throttle housing.
14 Unscrew the union nut and disconnect the
braking system servo unit hose from the
manifold.
15 Check
that
all
the
necessary
vacuum/breather
hoses
have
been
disconnected then slacken and remove the
manifold retaining nuts.
16 Remove the manifold from the engine and
recover the manifold gasket, noting which
way around it is fitted.
Refitting
17 Refitting is the reverse of removal bearing
in mind the following points.
a) Prior to refitting, check the manifold studs
and renew any that are worn or damaged.
b) Ensure the manifold and cylinder mating
surfaces are clean and dry and fit the new
gasket. Refit the manifold and tighten the
retaining nuts evenly and progressively to
the specified torque.
c) Ensure that all relevant hoses are
reconnected to their original positions,
and are securely held (where necessary)
by their retaining clips.
d) Fit new sealing washers to each side of
the fuel feed and return hose unions then
screw in the union bolts. Ensure both
hose unions are correctly positioned then
tighten the unions bolts to the specified
torque.
e) Tighten all fixings to their specified torque
setting (where given).
f) Refit the auxiliary drivebelt and refill the
cooling system as described in Chapter 1.
g) On completion, adjust the accelerator
cable as described in Section 3.
2.0 litre DOHC engine
Note: New manifold retaining will be required
on refitting.
Removal
18 Remove the auxiliary drivebelt and drain
the cooling system as described in Chapter 1.
19 Remove the throttle housing as described
in Section 11.
20 Unscrew the nut and disconnect the fuel
return pipe from the end of the fuel rail. As the
union nuts are slackened, retain the pipe end
fitting with an open-ended spanner to prevent
any excess strain being placed on the pipe.
Plug the hose and pipe end to minimise fuel
loss and prevent the entry of dirt.
21 Unscrew the retaining nut and detach the
earth lead from the fuel rail front retaining bolt.
22 Carefully release the retaining clips and lift
off the injector wiring cover assembly squarely
away from the top of the injectors; the wiring
connectors are an integral part of the cover.
Disconnect the crankshaft sensor and knock
sensor wiring connectors (where necessary)
from the injector wiring cover then position
the cover assembly clear of the manifold.
23 Unscrew the union nut and disconnect the
braking system servo unit hose from the
manifold.
24 Disconnect all remaining vacuum/breather
hoses from the manifold, noting each ones
correct fitted location.
25 Undo the retaining bolts and remove the
alternator mounting brackets from the front of
the inlet manifold.
26 Undo the retaining bolts and remove the
support bracket from the base of the
manifold.
27 Slacken and remove the retaining nuts
and bolts and manoeuvre the manifold
assembly away from the engine. Remove the
gasket and discard it also discard the
manifold nuts; new ones should be used on
refitting.
15.30 Slacken the retaining clip and
detach the air hose from the idle speed
adjuster valve
e) Refit the auxiliary drivebelt and refill the
cooling system as described in Chapter 1.
f) On completion, adjust the accelerator
cable as described in Section 3.
2.5 and 3.0 litre engines
Removal
Note: If only the upper section is to be
removed carry out the operations described in
paragraphs 29 to 39.
29 Disconnect the battery negative terminal.
Note: On models with a Vauxhall anti-theft
warning system (ATWS), the battery negative
terminal must be disconnected within 15
seconds of the ignition being switched off to
prevent the alarm system being triggered.
30 Slacken the retaining clip and disconnect
the inlet hose from the idle speed adjuster
(see illustration).
31 Slacken the retaining clips securing the
intake ducts to the throttle housing and intake
pre-volume valve and remove both ducts.
32 Remove the retaining clip and detach the
accelerator cable from the throttle cam
balljoint then unclip the cable from its
mounting bracket. On models with cruise
control it will also be necessary to remove the
second retaining clip and detach the cruise
control cable (see illustrations).
33 Clamp the coolant hoses which are
connected to the throttle housing then release
the retaining clips and disconnect both hoses
(see illustration). Wipe away any spilt
coolant.
Refitting
28 Refitting is the reverse of removal noting
the following.
a) Prior to refitting, check the manifold studs
and renew any that are worn or damaged.
b) Ensure the manifold and cylinder mating
surfaces are clean and dry and fit the new
gasket. Refit the manifold then fit the
retaining bolts and new nuts tightening
them evenly and progressively to the
specified torque.
c) Ensure that all relevant hoses are
reconnected to their original positions,
and are securely held (where necessary)
by their retaining clips.
d) Tighten all fixings to their specified torque
setting (where given).
3510 Vauxhall/Opel Omega
15.32a Remove the retaining clip and
detach the accelerator inner cable from
the throttle cam
4A
4A•20 Fuel and exhaust systems
15.32b On models with cruise control
prise off the second retaining clip . . .
15.32c . . . and free the cruise control
cable from the throttle cam and bracket
15.33 Release the retaining clips and
detach the coolant hoses (arrowed) from
the throttle housing
34 Disconnect the wiring connectors from
the throttle valve potentiometer, the idle
speed adjuster, the inlet manifold switchover
valve solenoid and the exhaust gas
recirculation (EGR) valve.
35 Unscrew the union nut and disconnect the
pipe from the EGR valve then unscrew the
retaining bolt and free the pipe bracket from
the valve (see illustrations). Where
necessary, disconnect the connector and free
the knock sensor wiring connector from the
EGR valve bracket.
36 Unscrew the union nut and disconnect the
braking system servo unit vacuum hose from
the manifold upper section (see illustration).
37 Make a note of the correct fitted locations
of the vacuum/breather hoses connected to
the rear of the manifold upper section then
release the retaining clips (where fitted) and
disconnect them (see illustration).
38 Unscrew the retaining bolts and detach
the hose/wiring brackets from the corners of
the manifold upper section (see illustration).
39 Remove the caps from the top of the
manifold then slacken and remove the upper
section retaining bolts. Lift off the manifold
upper section, disconnecting the vacuum
hoses from the manifold switchover solenoid
valve as they become accessible (see
illustrations). Remove the sealing rings from
the top of manifold lower section and discard
them; new ones should be used on refitting.
Caution: Take great care not to allow any
foreign object to drop down into the
cylinder head intake ports.
40 Depressurise the fuel system (Section 7)
then unscrew the nuts and disconnect the fuel
feed and return hoses from their unions on the
right-hand side of the manifold. As each union
nut is slackened, retain the pipe end fitting
with an open-ended spanner to prevent any
excess strain being placed on the pipes (see
illustration). Plug the hose and pipe ends to
minimise fuel loss and prevent the entry of
dirt.
15.35b . . . then remove the bracket
retaining bolt
15.36 Unscrew the union nut and
disconnect the braking system servo unit
hose
15.37 Release the retaining clips and
disconnect the vacuum and breather
hoses from the rear of the manifold
15.38 Undo the retaining bolts and free the
hose/wiring brackets from the manifold
15.39a Remove the caps then unscrew the
retaining bolts . . .
15.39b . . . and remove the manifold upper
section
15.35a Unscrew the union nut and free the
EGR pipe from the EGR valve
3510 Vauxhall/Opel Omega
Fuel and exhaust systems 4A•21
15.40 Unscrew the union nuts and
disconnect the fuel feed and return hoses
from the manifold
15.41 The injector wiring harness
connector (arrowed) is clipped onto the
engine rear lifting bracket (shown with
engine removed)
41 Disconnect the injector wiring harness
connector and the vacuum hose from the fuel
pressure regulator (see illustration).
42 Slacken and remove the retaining bolts
then lift the manifold lower section away from
the cylinder head. Remove the seals from the
manifold flange recesses and discard them;
new ones must be used on refitting (see
illustrations).
43 If necessary, undo the retaining bolts and
remove the intake manifold flange from the
top of the cylinder head (see illustration).
Recover the flange seals and discard them;
new ones must be used on refitting.
Note: New manifold nuts will be required on
refitting.
Refitting
2.0 litre SOHC engine
44 Refitting is the reverse of removal noting
the following.
a) Ensure all the mating surfaces are clean
and dry and the new seals/sealing rings
are correctly seated in their recesses (see
illustration). Tighten all the manifold
retaining bolts evenly and progressively to
their specified torque settings.
b) Ensure that all relevant hoses are
reconnected to their original positions,
and are securely held (where necessary)
by their retaining clips.
c) Tighten the fuel hose and vacuum servo
hose union nuts to their specified torque
settings.
d) Ensure the EGR valve and pipe mating
surfaces are clean and dry and apply a
smear of high-temperature grease to the
threads of the union nut (Vauxhall recommend the use of assembly paste 19 48 569
- available from your Vauxhall dealer).
15.42b . . . and recover the seals (arrowed)
from the flange
Reconnect the pipe to the valve and
tighten its union nut to the specified
torque.
e) On completion, adjust the accelerator
cable as described in Section 3.
16 Exhaust manifold removal and refitting
4
Removal
1 Firmly apply the handbrake then jack up the
front of the vehicle and support it on axle
stands. If necessary, to improve access undo
the retaining bolts and remove the undercover
from beneath the engine.
2 Slacken and remove the bolt(s) securing the
exhaust system front pipe to its mounting
bracket then unscrew the bolts securing the
front pipe to the manifold. Free the pipe from
the manifold taking care not to place any
strain on the oxygen sensor wiring. Discard
the front pipe gasket; a new one should be
used on refitting.
3 Undo the retaining bolts and remove the
heatshield from the exhaust manifold.
4 Remove the engine oil dipstick and pull the
plug caps off from the centre (No 2 and 3)
spark plugs. Unscrew the centre spark plug
heatshields and remove them from the
15.43 Removing the manifold flange
3510 Vauxhall/Opel Omega
15.42a Remove the manifold lower
section . . .
manifold (a special socket, number KM-834, is
available to ease removal of the heatshields).
5 Undo the retaining nuts securing the
manifold to the head. Manoeuvre the manifold
out of the engine compartment, complete with
the gasket. Discard both the gasket and
retaining nuts; new ones should be used on
refitting.
Refitting
6 Examine all the exhaust manifold studs for
signs of damage and corrosion; remove all
traces of corrosion, and repair or renew any
damaged studs.
7 Ensure that the manifold and cylinder head
sealing faces are clean and flat, and fit the
new gasket.
8 Refit the manifold then fit the new retaining
nuts and tighten them to the specified torque.
9 Apply a smear of high-temperature grease
(Vauxhall recommend the use of assembly
paste 19 48 569 - available from your Vauxhall
dealer) to the threads of the spark plug
heatshields then refit the shields and tighten
them to the specified torque. Reconnect the
plug caps and refit the dipstick.
10 Apply the high-temperature grease to the
heatshield bolts then refit the heatshield to the
manifold and securely tighten the bolts.
11 Fit a new gasket to the exhaust front pipe
joint and lubricate the front pipe to manifold
bolts with the high-temperature grease. Refit
the bolts to the manifold, tightening them to
the specified torque, then securely tighten the
bolt(s) securing the front pipe to its mounting
bracket.
15.44 On refitting be sure to renew all
manifold seals and sealing rings
4A
4A•22 Fuel and exhaust systems
16.20 Disconnect the wiring connectors
from the coolant sensor and sender . . .
16.21 . . . then release the retaining clips
and disconnect the coolant hoses
16.22 Unscrew the retaining bolts and
remove the coolant outlet from the engine
(sealing rings arrowed)
15 Refit the manifold as described in
paragraphs 6 to 8.
16 Fit a new gasket to the exhaust front pipe
joint and lubricate the front pipe to manifold
bolts with high-temperature grease (Vauxhall
recommend the use of assembly paste 19 48
569 - available from your Vauxhall dealer).
18 Remove the inlet manifold and flange as
described in Section 15.
19 Drain the cooling system as described in
Chapter 1.
20 Disconnect the wiring connectors from
the coolant temperature gauge sender and
the engine management system coolant
temperature sensor which are screwed into
the coolant outlet which links the rear of the
cylinder heads (see illustration).
16.24a Unscrew the union nuts securing
the oil pipes to the block . . .
16.24b . . . then unscrew the union bolts
and detach the pipes from the oil cooler
(sealing washers arrowed)
21 Slacken the retaining clips and disconnect
the coolant hoses from the cylinder head
outlet (see illustration).
22 Unscrew the retaining bolts and remove
the coolant outlet from the cylinder heads
(see illustration). Recover the sealing rings
and discard them; new ones must be used on
refitting.
23 Position a container beneath the oil filter.
Unscrew the filter using an oil filter removal tool
if necessary, and drain the oil into the container.
If the oil filter is damaged or distorted during
removal, it must be renewed. Given the low cost
of a new oil filter relative to the cost of repairing
the damage which could result if a re-used filter
springs a leak, it is probably a good idea to
renew the filter in any case.
24 Unscrew the union nuts securing the oil
cooler pipes to the cylinder block then
unscrew the union bolts securing the pipes to
the cooler. Recover the sealing washers from
each side of the oil cooler unions and move
the pipes to the rear (see illustrations).
25 Release the retaining clips and disconnect
the radiator bottom hose, expansion tank hose
and heater hose from the coolant pipe on the
right-hand side of the engine. Slacken and
remove the retaining bolts then remove the pipe
from the engine (see illustration). Recover the
sealing ring and discard it; a new one should be
used on refitting. Note that it maybe necessary
to remove the camshaft cover from the righthand cylinder head to gain the clearance
required to remove the coolant pipe.
26 Undo the retaining bolts and remove the
heatshields from the exhaust manifold (see
illustrations).
16.26a Undo the retaining bolts and
remove the lower . . .
16.26b . . . and upper heatshields from the
right-hand exhaust manifold
2.0 litre DOHC engine
Removal
12 Remove the secondary air injection
system air valve and connecting pipe as
described in Chapter 4B.
13 Carry out the operations described in
paragraphs 1 and 2.
14 Undo the retaining nuts then remove the
exhaust manifold and gasket from the cylinder
head. Discard both the gasket and retaining
nuts; new ones should be used on refitting.
Refitting
16.25 Removing the engine coolant pipe
Refit the bolts to the manifold, tightening them
to the specified torque, then securely tighten
the bolt(s) securing the front pipe to its
mounting bracket.
17 Refit the secondary air injection system
connecting pipe and air valve as described in
Chapter 4B.
2.5 and 3.0 litre engine
Right-hand cylinder bank
3510 Vauxhall/Opel Omega
Fuel and exhaust systems 4A•23
27 Slacken and remove the bolt securing the
exhaust system right-hand front pipe to its
mounting bracket then unscrew the bolts
securing the pipe to the manifold. Free the
pipe from the manifold taking care not to
place any strain on the oxygen sensor wiring,
and recover the gasket. Discard the front pipe
gasket; a new one should be used on refitting.
28 Unscrew the union nuts and remove the
pipe connecting the exhaust gas recirculation
(EGR) valve to the manifold.
29 Slacken the clip securing the connecting
hose to the right-hand cylinder bank
secondary air injection system pipe then
unscrew the bolts securing the pipe to the
manifold. Remove the pipe from the vehicle
and discard its gaskets (see illustration).
30 Undo the retaining nuts then remove the
exhaust manifold and gasket from the cylinder
head. Discard both the gasket and retaining
nuts; new ones should be used on refitting.
31 Refitting is the reverse of removal, noting
the following points.
a) Prior to refitting, check the manifold studs
and renew any that are worn or damaged.
b) Ensure all mating surfaces are clean and
dry and use new gaskets, sealing rings
and washers.
c) Secure the manifold in position with new
retaining nuts, tightening them evenly and
progressively to the specified torque.
d) Prior to refitting, lubricate the threads of
the secondary air injection system pipe
bolts, the EGR valve pipe nuts, the front
pipe to manifold bolts and the heatshield
bolts with a smear of high-temperature
grease (Vauxhall recommend the use of
assembly paste 19 48 569 - available from
your Vauxhall dealer).
e) Tighten all fixings to their specified torque
setting (where given).
f) Ensure that all relevant hoses are
reconnected to their original positions,
and are securely held (where necessary)
by their retaining clips.
g) Fit new sealing washers to each side of
the oil cooler pipe unions and tighten the
pipe union nuts and bolts to the specified
torque.
i) Fit a new oil filter and refill the cooling
system as described in Chapter 1.
j) On completion, check the engine oil level
as described in Weekly checks.
16.29 Undo the retaining bolts and remove
the secondary air connecting pipe
the bolt and spacer securing the coolant pipe
and engine lifting bracket to the cylinder head
and remove the lifting bracket. Free the
coolant pipe from the thermostat housing
then manoeuvre it out of position then
withdraw the dipstick and ease the dipstick
tube out from the cylinder block. Discard the
coolant pipe and dipstick tube sealing rings;
new ones should be used on refitting.
35 Undo the retaining bolts and remove the
heatshields from the exhaust manifold.
36 Unscrew the retaining bolts and remove
the secondary air injection system pipe from
the manifold. Recover the gaskets fitted
between the pipe and manifold and discard
them.
37 Undo the retaining nuts then remove the
exhaust manifold and gasket from the cylinder
head. Discard both the gasket and retaining
nuts; new ones should be used on refitting.
38 Refitting is the reverse of removal, noting
the following points.
a) Prior to refitting, check the manifold studs
and renew any that are worn or damaged.
b) Ensure the manifold and cylinder head
mating surfaces are clean and dry then fit
the new gasket. Refit the manifold then fit
the new retaining nuts, tightening them
evenly and progressively to the specified
torque.
c) Lubricate the threads of the secondary air
injection system pipe bolts with a smear of
high-temperature grease (Vauxhall recommend the use of assembly paste 19 48 569
- available from your Vauxhall dealer). Fit
Left-hand cylinder bank
32 It is not possible to remove the exhaust
manifold from the left-hand cylinder bank with
the engine in the vehicle. This leaves two
possible options, the first is to remove the
engine unit from the vehicle and the second is
to remove the cylinder head assembly. Decide
on the course of action which is best suited
then proceed as follows.
33 Working as described in Chapter 2C,
either remove the engine unit from the vehicle
or alternatively remove the cylinder head
assembly from the engine.
34 If the engine has been removed, unscrew
new gaskets to the pipe unions then refit
the pipe to the cylinder head and tighten
the retaining bolts to the specified torque
(see Chapter 4B).
d) Lubricate the manifold heatshield bolts
with the high-temperature grease before
installation.
e) If the engine was removed, fit new sealing
rings to the dipstick tube and thermostat
housing coolant pipe. Ensure the coolant
pipe, dipstick tube and lifting bracket are
correctly positioned before refitting the
retaining bolt and spacer and tightening
to the specified torque.
17 Multi-ram air intake system information and component
removal and refitting
3
Information
1 All 2.5 and 3.0 litre engines are fitted with a
multi-ram air intake system to help increase
torque output at all engine speeds. The
system consists of the pre-volume chamber,
which splits the air cleaner intake duct into
two separate ducts, and two valves, one
linking the intake ducts in between the prevolume chamber and throttle housing, and the
second linking the left- and right-hand
chambers of the inlet manifold upper section.
Each valve is controlled the engine
management ECU via a solenoid valve and
vacuum diaphragm unit.
2 There are four possible combinations of
valve position, each of which is suited to a
particular engine speed range, they are as
follows.
a) Idle speed - intake duct valve closed,
manifold valve open
b) Full load at low engine speeds - intake
duct and manifold valves both closed.
c) Full load at medium engine speeds intake duct valve open, manifold valve
closed.
d) Full load at high engine speeds - intake
valve and manifold valve both open.
3 Testing of the system can only be carried
out using the special electronic diagnostic
test unit which is plugged into the system’s
diagnostic connector (see Section 6). The
multi-ram intake system components can be
removed and refitted as follows.
Component removal and
refitting
Intake duct switchover valve solenoid
valve
17.4 The intake duct switchover valve
solenoid valve (arrowed) is mounted on the
rear of the pre-volume chamber (shown
with chamber removed)
3510 Vauxhall/Opel Omega
4 The intake duct switchover valve solenoid
valve is mounted onto the rear of the prevolume chamber (see illustration).
5 Ensure the ignition is switched off then
disconnect the wiring connector from the
valve.
6 Disconnect the vacuum pipes from the
valve, noting their correct fitted locations,
4A
4A•24 Fuel and exhaust systems
17.11 Undo the retaining screws (arrowed) and remove the
switchover valve assembly from its housing
then undo the retaining screws and remove
the valve from the engine compartment.
7 Refitting is the reverse of removal ensuring
the vacuum hoses are correctly reconnected.
Intake duct switchover valve housing
8 Slacken the retaining clip and disconnect the
idle speed adjuster hose from the intake duct.
9 Slacken the retaining clips securing the
intake ducts to the throttle housing and valve
housing and remove both ducts from the
engine compartment.
10 Disconnect the vacuum hose from the
switchover valve diaphragm then slacken the
lower retaining clips and remove the housing
from the vehicle.
11 If necessary, slacken the retaining screws
and remove the valve assembly from its
housing, along with its sealing ring (see
illustration).
12 Refitting is the reverse of removal
ensuring all the intake ducts are securely
reconnected.
Manifold switchover valve solenoid
valve
13 The manifold switchover valve solenoid
valve is mounted onto the rear of the inlet
manifold upper section on the left-hand side
(see illustration).
17.19 Undo the retaining bolts (arrowed)
and withdraw the switchover valve
assembly from the manifold upper section
17.13 The manifold switchover valve solenoid valve (arrowed) is
mounted onto the rear of the inlet manifold
(shown with engine removed)
14 To gain access to the valve, remove the
windscreen wiper arms and the water
deflector panel from the base of the windscreen (see Chapter 12, Sections 15 and 16).
15 Ensure the ignition is switched off then
disconnect the wiring connector from the
valve.
16 Disconnect the vacuum pipes from the
valve, noting their correct fitted locations,
then undo the retaining screws and remove
the valve from the manifold.
17 Refitting is the reverse of removal
ensuring the vacuum hoses are correctly
reconnected.
Manifold switchover valve assembly
18 Remove the upper section of the inlet
manifold as described in Section 15.
19 Disconnect the vacuum hose from the
diaphragm unit then undo the retaining bolts
and remove the valve assembly from the
manifold ill (see illustration). Recover the
sealing ring and discard it; a new one should
be used on refitting.
20 On refitting fit a new sealing ring to the
valve assembly then refit the valve to the
manifold. Securely tighten the valve retaining
bolts then refit the manifold upper section
(see Section 15).
17.25 Removing the pre-volume chamber
assembly
3510 Vauxhall/Opel Omega
Pre-volume chamber assembly
21 Remove the airflow meter as described in
Section 14.
22 Slacken the retaining clip and disconnect
the idle speed adjuster hose from the intake
duct.
23 Slacken the retaining clips securing the
intake ducts to the throttle housing and
switchover valve and remove both ducts from
the engine compartment.
24 Disconnect the wiring connector and
vacuum hose from the intake duct switchover
valve solenoid valve on the rear of the
chamber.
25 Unscrew the mounting nuts then free the
chamber assembly from its lower mounting
rubber and manoeuvre it out of position (see
illustration).
26 Refitting is the reverse of removal
ensuring the chamber is correctly engaged
with its lower mounting rubber.
18 Exhaust system general information,
removal and refitting
3
General information
1 On 2.0 litre engine models, the exhaust
system consists of three sections: the front
pipe which incorporates the catalytic converter, the intermediate pipe and centre silencer,
and the tailpipe and main silencer box.
2 On 2.5 and 3.0 litre engine models the
exhaust system consists of five sections;
there is a separate front pipe (incorporating a
catalytic converter) and intermediate pipe
(incorporating a centre silencer) for each bank
of cylinders with both exhaust sections being
joined to a single tailpipe and main silencer.
3 The front pipe joints are flange joints which
are secured by bolts and the tailpipe is secured
to the intermediate pipe by a clamping ring.
The system is suspended throughout its entire
length by rubber mountings.
Fuel and exhaust systems 4A•25
Removal
Tailpipe
4 Each exhaust section can be removed
individually, or alternatively, the complete
system can be removed as a unit. Even if only
one part of the system needs attention, it is
often easier to remove the whole system and
separate the sections on the bench.
5 To remove the system or part of the
system, first jack up the front or rear of the car
and support it securely on axle stands.
Alternatively, position the car over an
inspection pit or on car ramps.
12 Slacken the clamp(s) securing the tailpipe
to the intermediate pipe(s) (as applicable) (see
illustration).
13 Free the tailpipe from its mounting rubbers
then disengage it from the intermediate pipe(s)
and remove it from the underneath the vehicle.
Front pipe
6 Trace the wiring back from the oxygen
sensor, noting its correct routing, and disconnect its wiring connector (see illustration).
Free the wiring from any clips so the sensor is
free to be removed with the front pipe.
7 Slacken and remove the bolts securing the
front pipe flange joint to the manifold.
8 Unscrew the bolt(s) securing the front pipe
to its mounting bracket(s) (see illustration).
9 Slacken and remove the bolts securing the
front pipe to the intermediate pipe and
remove the front pipe from the vehicle (see
illustration). Recover the gasket from the
front pipe to manifold joint.
Intermediate pipe
10 Slacken and remove the bolts securing
the intermediate pipe to the front pipe. On 2.5
and 3.0 litre engines also remove the bolts
securing the other intermediate pipe to its
front pipe.
11 Slacken the clamp securing the pipe to
the tailpipe then free the intermediate pipe
from its mounting rubbers. Ease the
intermediate pipe out from the tailpipe and
remove it from underneath the vehicle.
Complete system
14 Trace the wiring back from the oxygen
sensor(s), noting its correct routing, and
disconnect the wiring connector(s). Free the
wiring from any clips so the sensor(s) is free to
be removed with the front pipe.
15 Unscrew the bolts securing the front
pipe(s) to the mounting bracket.
16 Slacken and remove the bolts securing
the front pipe flange joint(s) to the manifold(s)
and recover the gasket(s).
17 Free the exhaust system from all its
mounting rubbers and lower it from
underneath the vehicle.
Heat shield(s)
18 The heat shields are secured to the
underside of the body by various nuts and
bolts. Each shield can be removed once the
relevant exhaust section has been removed. If
a shield is being removed to gain access to a
component located behind it, it may prove
sufficient in some cases to remove the
retaining nuts and/or bolts, and simply lower
the shield, without disturbing the exhaust
system.
Refitting
19 Each section is refitted by reversing the
removal sequence, noting the following
points:
18.6 The oxygen sensor wiring connector
(arrowed) is clipped to the side of the
transmission unit
a) Ensure that all traces of corrosion have
been removed from the flanges.
b) Inspect the rubber mountings for signs of
damage or deterioration, and renew as
necessary.
c) Always renew the front pipe manifold
gasket whenever it is disturbed.
d) Where no gasket is fitted to a joint, apply
a smear of exhaust system jointing paste
to ensure a gas-tight seal.
e) Prior to refitting, lubricate the threads of
the front pipe to manifold bolts with a
smear of high-temperature grease
(Vauxhall recommend the use of assembly
paste 19 48 569 - available from your
Vauxhall dealer).
f) Prior to tightening the exhaust system
fasteners to the specified torque, ensure
that all rubber mountings are correctly
located, and that there is adequate
clearance between the exhaust system
and vehicle underbody.
4A
18.8 Front pipe-to-mounting bracket bolts
- 2.0 litre DOHC engine
18.9 Front pipe-to-intermediate pipe bolts
- 2.0 litre DOHC engine
3510 Vauxhall/Opel Omega
18.12 Tailpipe-to-intermediate pipe clamp
- 2.0 litre DOHC engine
4B•1
Chapter 4 Part B:
Emission control systems
Contents
Catalytic converter - general information and precautions . . . . . . . .
Emission control system testing - general information . . . . . . . . . . .
Evaporative emission control system components - removal and
refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exhaust emission control system components - removal and
refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7
2
4
Exhaust gas recirculation (EGR) system components - removal and
refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
General information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Secondary air injection system components - removal and refitting . 6
3
Degrees of difficulty
Easy, suitable for
novice with little
experience
1
Fairly easy, suitable
for beginner with
some experience
2
Fairly difficult,
suitable for competent
DIY mechanic
3
Difficult, suitable for
experienced DIY
mechanic
4
Very difficult,
suitable for expert DIY
or professional
5
Specifications
Torque wrench settings
EGR valve bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
EGR pipe union nuts - 2.5 and 3.0 litre engine . . . . . . . . . . . . . . . . . . . .
EGR valve adaptor bolts - 2.5 and 3.0 litre engine . . . . . . . . . . . . . . . . .
Exhaust manifold shroud bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oxygen sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Roadwheel bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Secondary air injection system:
Connecting pipe bolts:
M6 bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
M8 bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Non-return valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pump assembly:
Pump/mounting rubber nuts/bolts . . . . . . . . . . . . . . . . . . . . . . . . .
Mounting bracket-to-body nuts . . . . . . . . . . . . . . . . . . . . . . . . . . .
Air filter retaining clamp nut . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1 General information
1 All UK models use unleaded petrol and also
have various other features built into the fuel
system to help minimise harmful emissions.
All models are equipped with a crankcase
emission-control
system,
a
catalytic
converter, an exhaust gas recirculation (EGR)
system and an evaporative emission control
system to keep fuel vapour/exhaust gas
emissions down to a minimum. All models
except those with a 2.0 litre SOHC engine are
also fitted with the secondary air injection
system to further improve the exhaust gas
emissions during engine warm-up.
Crankcase emission control
2 To reduce the emission of unburned
hydrocarbons from the crankcase into the
atmosphere, the engine is sealed and the
blow-by gases and oil vapour are drawn from
Nm
20
25
8
8
30
110
lbf ft
15
18
6
6
22
81
8
20
30
6
15
22
10
20
4
7
15
3
inside the crankcase, through a wire mesh oil
separator, into the inlet tract to be burned by
the engine during normal combustion.
3 Under conditions of high manifold
depression (idling, deceleration) the gases will
be sucked positively out of the crankcase.
Under conditions of low manifold depression
(acceleration, full-throttle running) the gases
are forced out of the crankcase by the
(relatively) higher crankcase pressure; if the
engine is worn, the raised crankcase pressure
(due to increased blow-by) will cause some of
the flow to return under all manifold
conditions.
Exhaust emission control
Note: All 2.5 and 3.0 litre engines have two
catalytic converters and two oxygen sensors;
one for each bank of cylinders.
4 To minimise the amount of pollutants which
escape into the atmosphere, all models are
fitted with a catalytic converter in the exhaust
system. The system is of the closed-loop
type, in which a oxygen sensor in the exhaust
3510 Vauxhall/Opel Omega
system provides the engine management
(fuel-injection/ignition) system ECU with
constant feedback, enabling the ECU to
adjust the mixture to provide the best possible
conditions for the converter to operate.
5 The oxygen sensor’s tip is sensitive to
oxygen and sends the ECU a varying voltage
depending on the amount of oxygen in the
exhaust gases; if the intake air/fuel mixture is
too rich, the exhaust gases are low in oxygen
so the sensor sends a low-voltage signal, the
voltage rising as the mixture weakens and the
amount of oxygen rises in the exhaust gases.
Peak conversion efficiency of all major
pollutants occurs if the intake air/fuel mixture
is maintained at the chemically-correct ratio
for the complete combustion of petrol of 14.7
parts (by weight) of air to 1 part of fuel (the
stoichiometric ratio). The sensor output
voltage alters in a large step at this point, the
ECU using the signal change as a reference
point and correcting the intake air/fuel mixture
accordingly by altering the fuel injector pulse
width.
4B
4B•2 Emission control systems
alleviating the need to test all the system
components individually, which is a timeconsuming operation that carries a risk of
damaging the ECU.
Evaporative emission control
6 To minimise the escape into the
atmosphere of unburned hydrocarbons, an
evaporative emissions control system is also
fitted to all models. The fuel tank filler cap is
sealed and a charcoal canister is mounted
behind the right-hand front wing. The canister
collects the petrol vapours generated in the
tank when the car is parked and stores them
until they can be cleared from the canister
(under the control of the engine management
system ECU) via the purge valve into the inlet
tract to be burned by the engine during
normal combustion.
7 To ensure that the engine runs correctly
when it is cold and/or idling and to protect the
catalytic converter from the effects of an overrich mixture, the purge control valve is not
opened by the ECU until the engine has
warmed up, and the engine is under load; the
valve solenoid is then modulated on and off to
allow the stored vapour to pass into the inlet
tract.
Exhaust gas recirculation (EGR)
system
8 This system is designed to recirculate small
quantities of exhaust gas into the inlet tract,
and therefore into the combustion process.
This process reduces the level of unburnt
hydrocarbons present in the exhaust gas
before it reaches the catalytic converter. The
system is controlled by the Engine
management (fuel-injection/ignition) ECU,
using the information from its various sensors,
via the EGR valve.
9 On 2.0 litre engines the EGR valve
assembly contains the vacuum-operated
valve and the electrical solenoid valve which
is used to switch the valve on and off. On
SOHC engines the valve is mounted onto the
top of the inlet manifold and on DOHC
engines it is mounted onto the rear of the
cylinder head.
10 On 2.5 and 3.0 litre engines the EGR valve
is an electrically-operated valve mounted on
and adaptor situated on the right-hand side of
the engine.
Secondary air injection system 2.0 litre DOHC engine and all
2.5 and 3.0 litre engines
11 The purpose of the secondary air injection
system is to decrease exhaust gas emissions
when the engine is cold. The system achieves
this by raising the temperature of the exhaust
gases which has the effect of quickly warming
the catalytic converter up to its normal
operating temperature. Once the catalytic
converter is up to temperature the air injection
system is switched off.
12 The system consists of the pump, the air
cut-off valve and the solenoid valve and is
controlled by the engine management (fuelinjection/ignition) ECU. When the engine is
cold, the solenoid valve switches the air valve
to open and the pump injects a controlled
amount of air into the cylinder head exhaust
3 Exhaust emission control
system components removal and refitting
3
Note: All 2.5 and 3.0 litre engines have two
catalytic converters and two oxygen sensors;
one for each bank of cylinders.
3.3 Disconnect the wiring connector then
unscrew the oxygen sensor (arrowed) from
the front pipe (2.5 litre engine shown)
ports. The air then mixes with the exhaust
gases, causing any unburned particles of the
fuel in the mixture to be burnt in the exhaust
port/manifold which effectively raises the
temperature of the exhaust gases. Once the
catalytic converter is up to temperature, the
solenoid valve closes the air valve and the
pump is switched off. A non-return valve
prevents the exhaust gases passing through
the air valve.
2 Emission control system
testing general information
1 If any of the emission control systems are
thought to be faulty, first ensure that all the
system wiring connectors are securely
connected and free of corrosion. Ensure that
the fault is not due to poor maintenance; ie,
check that the air cleaner filter element is clean,
the spark plugs are in good condition and
correctly gapped, the cylinder compression
pressures are correct, and that the engine
breather hoses are clear and undamaged,
referring to Chapters 1 and 2A, 2B or 2C for
further information (as applicable).
2 If these checks fail to reveal the cause of
the problem, the vehicle should be taken to a
suitably-equipped Vauxhall dealer for testing.
A wiring block connector is incorporated in
the engine management circuit, into which a
special electronic diagnostic tester can be
plugged (see Chapter 4A, Section 6). The
tester will locate the fault quickly and simply,
Catalytic converter
1 The catalytic converter is an integral part of
the exhaust system front pipe. Refer to
Chapter 4A for removal and refitting details.
Oxygen sensor
Note: The oxygen sensor is delicate and will
not work if it is dropped or knocked, if its
power supply is disrupted, or if any cleaning
materials are used on it.
2 Firmly apply the handbrake then jack up the
front of the vehicle and support it on axle
stands. Disconnect the battery negative
terminal.
3 Trace the wiring back from the oxygen
sensor, which is screwed into the exhaust
front pipe, to its connector which is clipped to
the transmission unit. Disconnect the wiring
connector and free the wiring from any
relevant retaining clips or ties, noting its
correct routing (see illustration).
4 Unscrew the sensor and remove it from the
exhaust system front pipe (see illustration).
Recover the sealing washer and discard it a
new one should be used on refitting.
5 Refitting is a reverse of the removal
procedure using a new sealing washer. Prior
to installing the sensor apply a smear of high
temperature grease to the sensor threads
(Vauxhall recommend the use of special
grease 19 48 602 - available from your
Vauxhall dealer). Tighten the sensor to the
specified torque and ensure that the wiring is
correctly routed and in no danger of
contacting either the exhaust system or
engine.
4 Evaporative emission control
system components removal and refitting
3
Charcoal canister
3.4 Oxygen sensor 2.0 litre DOHC engine
3510 Vauxhall/Opel Omega
1 The charcoal canister is located behind the
right-hand front wing. To gain access to the
canister, firmly apply the handbrake then jack
up the front of the vehicle and support it on
axle stands. Remove the right-hand front
roadwheel.
2 Remove the retaining nuts and fasteners
and remove the wheelarch liner to gain access
to the canister. The fasteners are released by
pressing out their centre pins and then prising
Emission control systems 4B•3
4.2a Unscrew the retaining nuts then
press out the centre pins . . .
out the outer section; the centre pins must be
recovered so they can be reused on refitting
(see illustrations).
3 Slacken and remove the retaining nut and
free the canister from its mounting. Mark the
hoses for identification purposes then
disconnect them and remove the canister
from the vehicle (see illustrations).
4 Refitting is a reverse of the removal
procedure ensuring the hoses are correctly
and securely reconnected.
Purge valve
2.0 litre SOHC engine
5 The purge valve is mounted onto the top of
the inlet manifold.
6 Undo the bolts securing the wiring cover to
the camshaft housing and position the cover
clear of the purge valve.
7 To improve access to the valve, release the
retaining clips and disconnect the breather
hoses from the camshaft housing.
8 Ensure the ignition is switched off then
depress the retaining clip and disconnect the
wiring connector from the valve.
9 Slacken and remove the valve bracket
upper screw then loosen the lower screw and
free the valve bracket from the engine.
Disconnect the hoses from the valve, noting
their correct fitted locations and remove the
valve from the engine. The valve and bracket
can then be separated.
10 Refitting is a reversal of the removal
procedure ensuring the hoses are securely
connected.
4.3a Unscrew the retaining nut . . .
4.2b . . . and remove the fastener outer
sections . . .
2.0 litre DOHC engine
11 The purge valve is mounted on the rear of
the cylinder head, on the right-hand side of
the DIS module.
12 Firmly apply the handbrake then jack up
the front of the vehicle and support it on axle
stands. Access the valve can then be gained
from above and underneath.
13 Ensure the ignition is switched off then
disconnect the wiring connector from the
valve.
14 Release the retaining clip and free the
wiring harness from the purge valve bracket
then undo the retaining screws and free the
purge valve bracket from the cylinder head.
15 Disconnect the vacuum hoses, noting
their correct fitted locations and remove the
purge valve and mounting bracket from the
vehicle. The valve and bracket can then be
separated.
16 Refitting is a reversal of the removal
procedure ensuring the hoses are securely
connected.
4.2c . . . and remove the right-hand front
wheelarch liner
switched off, disconnect the wiring connector
from the valve (see illustration).
20 Disconnect the vacuum hoses, noting
their correct fitted locations and remove the
purge valve and mounting bracket from the
engine. The valve and bracket can then be
separated.
21 Refitting is a reversal of the removal
procedure ensuring the hoses are securely
connected.
5 Exhaust gas recirculation
(EGR) system components removal and refitting
3
EGR valve
2.0 litre SOHC engine
17 The purge valve is located at the rear of
the right-hand cylinder head.
18 Remove the inlet manifold upper section
as described in Chapter 4A. To further
improve access, remove the windscreen
wiper arms and the water deflector panel from
the base of the windscreen (see Chapter 12,
Sections 15 and 16).
19 Slacken and remove the valve bracket
retaining bolt then, ensuring the ignition is
1 On 2.0 litre SOHC engines, to improve
access undo the bolts securing the wiring
cover to the camshaft housing and position
the cover clear of the EGR valve which is
mounted onto the top of the inlet manifold.
2 Ensure the ignition is switched off then
disconnect the wiring connector and vacuum
hose from the valve.
3 Undo the retaining screws and remove the
valve and its gasket, noting which way around
the valve is fitted.
4 Refitting is the reverse of removal using a
new gasket. Ensure the valve is fitted the
correct way around and tighten its retaining
bolts to the specified torque.
4.3b . . . then free the charcoal canister
from its mounting and disconnect it from
its hoses
4.19 On 2.5 and 3.0 litre engines the purge
valve (arrowed) is mounted on the rear of
the right-hand cylinder head (shown with
engine removed)
2.5 and 3.0 litre engines
3510 Vauxhall/Opel Omega
4B
4B•4 Emission control systems
5.7 On 2.5 and 3.0 litre engines,
disconnect the wiring connector . . .
2.0 litre DOHC engine
5 The valve is mounted on the rear of the
cylinder head. Removal and refitting is as
described in paragraphs 2 to 4.
2.5 and 3.0 litre engine
6 The valve is mounted onto an adaptor on
the right-hand cylinder head.
7 Ensure the ignition is switched off then
disconnect the wiring connector from the
valve (see illustration).
8 Undo the retaining screws and remove the
valve and its gasket, noting which way around
the valve is fitted (see illustration).
9 Refitting is the reverse of removal using a
new gasket. Ensure the valve is fitted the
correct way around and tighten its retaining
bolts to the specified torque.
EGR valve pipe 2.5 and 3.0 litre engines
10 Slacken the union nuts and remove the
pipe connecting the valve adaptor to the righthand cylinder bank exhaust manifold (see
illustrations).
11 On refitting, lubricate the threads of the
union nuts with a smear of high-temperature
grease (Vauxhall recommend the use of
assembly paste 19 48 569 - available from
your Vauxhall dealer) and tighten them to the
specified torque.
EGR valve adaptor 2.5 and 3.0 litre engines
12 Remove the EGR valve and pipe as
described earlier in this Section.
6.4a Disconnect the wiring connector . . .
5.8 . . . then undo the retaining bolts
(arrowed) and remove the EGR valve from
its adaptor
5.10a Unscrew the union nuts . . .
13 Unclip the accelerator cable from its
mounting bracket then unbolt and remove the
mounting bracket.
14 Unbolt the bracket from the end of the
adaptor then slacken then remove the
retaining bolts and remove the adaptor and
gasket from the inlet manifold.
15 Refitting is the reverse of removal using a
new gasket. Tighten the retaining bolts to the
specified torque then refit the EGR valve and
pipe (see paragraphs 9 and 11).
6 Secondary air injection
system components removal and refitting
3
Note: This system is not fitted to 2.0 litre
SOHC engines.
2.0 litre DOHC engine
Pump and filter assembly
Note: The filter can be renewed without
removing the pump assembly from the
vehicle. Detach the hose from the filter then
unscrew the nut and remove the retaining
clamp and filter from the bracket.
1 The pump and filter assembly is located
behind the left-hand front wing. To gain
access to the canister, firmly apply the
handbrake then jack up the front of the
vehicle and support it on axle stands. Remove
the left-hand front roadwheel.
2 Remove the retaining nuts and fasteners
6.4b . . . then release the retaining clip and
disconnect the hose from the air pump
3510 Vauxhall/Opel Omega
5.10b . . . and remove the EGR valve pipe
from the engine
and remove the wheelarch liner to gain access
to the canister. The fasteners are released by
pressing out their centre pins and then prising
out the outer section; the centre pins must be
recovered so they can be reused on refitting.
3 Unbolt the horn assembly from the pump
mounting bracket and position it clear.
4 Disconnect the pump wiring connector then
slacken the retaining clip and disconnect the
air hose from the pump (see illustrations).
5 Slacken and remove the pump mounting
bracket retaining nuts then manoeuvre the
assembly out from underneath the vehicle
(see illustration).
6 To separate the pump and bracket first
slacken the retaining clips and disconnect the
hose connecting the pump to its air filter. If
necessary, undo the nut then remove the
retaining clamp and air filter from the bracket
(see illustration).
6.5 Undo the retaining nuts (arrowed) and
remove the pump and filter assembly from
the vehicle
Emission control systems 4B•5
6.8a Undo the retaining bolts (arrowed) . . .
6.6 Release the retaining clip (A) and disconnect the hose then
undo the retaining nut (B) and remove the clamp and filter assembly
Cut-off valve
6.8b . . . and separate the pump from its
mounting bracket
6.8c If necessary, undo the retaining nuts
(arrowed) and remove the mounting plate
and rubber from the bracket
7 Make alignment marks between the pump,
bracket, mounting plate and rubber then free
the pump wiring connector from the bracket.
8 Undo the retaining bolts and remove the
pump from its mounting bracket. If necessary,
unscrew the retaining nuts and remove the
mounting plate and rubber from the bracket
(see illustrations).
9 Refitting is the reverse of removal aligning
the marks made prior to removal and tighten
the mounting nuts and bolts to their specified
torque settings.
6.10 On 2.0 litre DOHC engines disconnect the vacuum hose (1)
then release the retaining clips and free the air hoses (2) from the
cut-off valve
10 The valve is located on the left-hand side
of the engine compartment. Disconnect the
vacuum pipe from the valve then release the
retaining clips and disconnect the air hoses
(see illustration).
11 Slacken and remove the retaining bolts
and remove the valve from the vehicle, noting
which way around it is fitted.
12 Refitting is the reverse of removal making
sure the valve is fitted the correct way around;
the arrow on the valve must point in the
direction of air flow (towards the engine).
Cut-off valve solenoid
13 The solenoid valve is located next to the
cut-off valve on the left-hand side of the
engine compartment (see illustration).
14 Ensure the ignition is switched off then
disconnect the wiring connector from the
valve and detach the vacuum hoses, noting
each ones correct fitted location.
6.13 Disconnect the wiring connector (1) and vacuum hoses (2)
from the cut-off valve solenoid
3510 Vauxhall/Opel Omega
4B
4B•6 Emission control systems
6.18 Release the retaining clip and
disconnect the air hose from the nonreturn valve (arrowed)
6.28a Disconnect the vacuum pipe from
the solenoid valve . . .
6.28b . . . then release the retaining clips
and disconnect the hoses from the cut-off
valve
15 Undo the retaining screws and remove
the valve from the engine compartment.
16 Refitting is the reverse of removal ensuring
the vacuum hoses are correctly reconnected.
the breather hose from the left-hand side of
the cylinder head cover.
24 Undo the retaining bolts and remove the
connecting pipe from the cylinder head/
manifold. Recover the gaskets which are fitted
between the pipe unions and cylinder head
and discard them.
25 Refitting is the reverse of removal, noting
the following.
a) Ensure the mating surfaces are clean and
dry and use new gaskets.
b) Apply a smear of high-temperature grease
(Vauxhall recommend the use of assembly
paste 19 48 569 - available from your
Vauxhall dealer) to the threads of the pipe
retaining bolts and heatshield bolts prior
to refitting.
c) Tighten all bolts to their specified torque
settings (where given).
solenoid valve then release the retaining clips
and disconnect the air hoses from the cut-off
valve (see illustrations).
29 Slacken and remove the retaining bolts
securing the valve mounting bracket to the
radiator and remove the bracket assembly
from the vehicle, disconnecting the valve
wiring connector as it becomes accessible
(see illustration).
30 Undo the retaining bolts and remove the
cut-off valve/solenoid valve (as applicable)
from the bracket, noting which way around it
is fitted (see illustration).
31 Refitting is the reverse of removal. If the
cut-off valve has been removed, make sure it
is fitted the correct way around with the arrow
pointing in the direction of air flow (towards
the engine).
2.5 and 3.0 litre engines
32 The non-return valve is screwed onto the
left-hand end of the front connecting pipe and
is located just in front of the timing belt cover
(see illustration). To improve access to the
valve unbolt the air conditioning pipe/hose
bracket from the cylinder head and position
the hose/pipe to one side.
33 Release the retaining clip and disconnect
the air hose from the pipe then unscrew the
valve and remove it from its pipe.
Non-return valve
17 The non-return valve is located on the top
of the exhaust manifold.
18 Release the retaining clip and disconnect
the air hose from the pipe then unscrew the
valve and remove it from the connecting pipe
(see illustration).
19 On refitting, clean the valve threads and
apply a smear of fresh sealing compound to
them (Vauxhall recommend the use of sealing
compound 15 03 295 - available from your
Vauxhall dealer). Refit the valve to its pipe and
tighten it to the specified torque before
securely reconnecting the air hose.
Connecting pipe
20 Release the retaining clip and disconnect
the air hose from the connecting pipe nonreturn valve.
21 Slacken and remove the retaining bolts
and remove the bracket securing the
connecting pipe to the exhaust manifold.
22 Undo the retaining bolts and remove the
heatshield from the exhaust manifold.
23 Slacken the retaining clip and disconnect
Pump and filter assembly
26 Refer to paragraphs 1 to 9.
Cut-off valve and solenoid valve
27 The cut-off valve and its solenoid are
mounted onto a bracket which is secured to
the rear of the radiator.
28 Disconnect the vacuum pipe from the
6.29 Undo the retaining bolts and disconnect the wiring
connector (arrowed) then remove the bracket assembly from the
vehicle
Non-return valve
6.30 Air cut-off valve (A) and solenoid valve (B) can then be
unbolted from the bracket
3510 Vauxhall/Opel Omega
Emission control systems 4B•7
6.32 Non return valve location 2.5 and 3.0 litre engines
6.36 Disconnect the air hose from the nonreturn valve on the front connecting pipe
6.37b . . . and right-hand retaining nuts then (if necessary)
slacken the alternator mounting nut and pivot the bracket
(arrowed) clear of the pipe . . .
34 On refitting, clean the valve threads and
apply a smear of fresh sealing compound to
them (Vauxhall recommend the use of sealing
compound 15 03 295 - available from your
Vauxhall dealer). Refit the valve to its pipe and
tighten it to the specified torque before
securely reconnecting the air hose.
Front connecting pipe
35 Remove the multi-ram air intake system prevolume chamber as described in Chapter 4A.
36 Release the retaining clip and disconnect
the air hose from the front connecting pipe
non-return valve (see illustration).
37 Unscrew the pipe retaining nuts then
release the retaining clips securing the pipe
ends to the hoses and remove the assembly
from the engine compartment. If necessary,
slacken the alternator upper mounting nut and
pivot the pipe bracket out of position to gain
the necessary clearance required for removal
(see illustrations).
38 Refitting is the reverse of removal
ensuring the hose are correctly and securely
reconnected.
6.37a Slacken and remove the
left-hand . . .
6.37c . . . to allow the front connecting pipe to be removed from
the engine
41 Slacken and remove the bolts securing
the upper and lower heatshields to the lefthand exhaust manifold. Remove the lower
heatshield and position the upper one clear of
the manifold so access can be gained to the
connecting pipe bolts.
42 Slacken and remove the retaining bolts
and free the connecting pipe from the
manifold (see illustration). Release the
retaining clip securing the rubber hose to the
front of the connecting pipe then disconnect
the pipe and manoeuvre it out from
underneath the vehicle. Recover the gaskets
which are fitted between the pipe and
manifold and discard them.
43 Refitting is the reverse of removal, noting
the following points.
a) Ensure the mating surfaces are clean and
dry and use new gaskets (see
illustration).
6.42 Removing the left-hand connecting
pipe from the manifold (shown with engine
removed)
6.43 On refitting, ensure the mating
surfaces are clean and dry and fit new
gaskets to the connecting pipe
the auxiliary drivebelt then unbolt the
compressor and position it clear of its
mounting bracket (see Chapters 1 and 3).
Warning: Do not disconnect any
of the refrigerant pipes/hoses
Left-hand cylinder head connecting
pipe
39 Remove the exhaust system left-hand
front pipe as described in Chapter 4A.
40 On models with air conditioning, remove
3510 Vauxhall/Opel Omega
4B
4B•8 Emission control systems
6.45a Undo the retaining bolts and remove
the lower . . .
6.45b . . . and upper heatshields from the
right-hand exhaust manifold (shown with
engine removed)
6.47 Removing the right-hand connecting
pipe from the manifold
b) Apply a smear of high-temperature grease
(Vauxhall recommend the use of assembly
paste 19 48 569 - available from your
Vauxhall dealer) to the threads of the pipe
retaining bolts and the heatshield bolts
prior to refitting.
c) Tighten all bolts to their specified torque
settings (where given).
dry and use new gaskets.
b) Apply a smear of high-temperature grease
(Vauxhall recommend the use of assembly
paste 19 48 569 - available from your
Vauxhall dealer) to the threads of the pipe
retaining bolts and heatshield bolts prior
to refitting.
c) Tighten all bolts to their specified torque
settings (where given).
d) DO NOT push- or tow-start the car - this
will soak the catalytic converter in
unburned fuel, causing it to overheat
when the engine does start.
e) DO NOT switch off the ignition at high
engine speeds.
f) DO NOT use fuel or engine oil additives these may contain substances harmful to
the catalytic converter.
g) DO NOT continue to use the car if the
engine burns oil to the extent of leaving a
visible trail of blue smoke.
h) Remember that the catalytic converter
operates at very high temperatures. DO
NOT, therefore, park the car in dry
undergrowth, over long grass or piles of
dead leaves after a long run.
i) Remember that the catalytic converter is
FRAGILE - do not strike it with tools
during servicing work.
j) In some cases a sulphurous smell (like
that of rotten eggs) may be noticed from
the exhaust. This is common to many
catalytic converter-equipped cars and
once the car has covered a few thousand
miles the problem should disappear.
k) The catalytic converter, used on a wellmaintained and well-driven car, should
last indefinitely - if the converter is no
longer effective it must be renewed.
Right-hand cylinder head connecting
pipe
44 Slacken and remove the bolt securing the
coolant pipe bracket to the right-hand
cylinder head.
45 Slacken and remove the retaining bolts
then remove the lower and upper heatshields
from the exhaust manifold (see illustrations).
46 Taking care not to place excess strain on
the coolant pipe, slacken and remove the
retaining bolts securing the connecting pipe
to the manifold.
47 Free the connecting pipe from the
manifold then release the retaining clip
securing the rubber hose to the front of the
connecting pipe then disconnect the pipe and
manoeuvre it out of position (see illustration).
Recover the gaskets which are fitted between
the pipe and manifold and discard them.
48 Refitting is the reverse of removal, noting
the following points.
a) Ensure the mating surfaces are clean and
7 Catalytic converter general information
and precautions
1 The catalytic converter is a reliable and
simple device which needs no maintenance in
itself, but there are some facts of which an
owner should be aware if the converter is to
function properly for its full service life.
a) DO NOT use leaded petrol in a car
equipped with a catalytic converter - the
lead will coat the precious metals,
reducing their converting efficiency and
will eventually destroy the converter.
b) Always keep the ignition and fuel systems
well-maintained in accordance with the
manufacturer’s schedule.
c) If the engine develops a misfire, do not
drive the car at all (or at least as little as
possible) until the fault is cured.
3510 Vauxhall/Opel Omega
5A•1
Chapter 5 Part A:
Starting and charging systems
Contents
Alternator - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Alternator - testing and overhaul . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Alternator drivebelt - removal, refitting and tensioning . . . . . . . . . . . 6
Battery - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Battery - testing and charging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Battery check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .See Weekly checks
Charging system - testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Electrical fault finding - general information . . . . . . . . . . . . . . . . . . . 2
General information and precautions . . . . . . . . . . . . . . . . . . . . . . . . 1
Ignition switch - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . 12
Oil level sensor - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . 14
Oil pressure warning light switch - removal and refitting . . . . . . . . . 13
Starter motor - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . 10
Starter motor - testing and overhaul . . . . . . . . . . . . . . . . . . . . . . . . . 11
Starting system - testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Degrees of difficulty
Easy, suitable for
novice with little
experience
1
Fairly easy, suitable
for beginner with
some experience
2
Fairly difficult,
suitable for competent
DIY mechanic
3
Difficult, suitable for
experienced DIY
mechanic
4
Very difficult,
suitable for expert DIY
or professional
5
Specifications
System type
...........................................
12-volt, negative earth
5A
Battery
Charge condition:
Poor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Normal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Good . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
12.5 volts
12.6 volts
12.7 volts
Torque wrench settings
Nm
lbf ft
35
26
18
20
35
8
40
13
15
26
6
30
45
25
60
40
33
18
44
30
Alternator mounting bolts:
2.0 litre engine:
Lower bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Upper bracket bolts:
SOHC engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DOHC engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.5 and 3.0 litre engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oil level sensor bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oil pressure switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Starter motor bolts:
2.0 litre engine:
Lower bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rear mounting bracket to block bolt . . . . . . . . . . . . . . . . . . . . . . .
Upper bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.5 and 3.0 litre engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3510 Vauxhall/Opel Omega
5A•2 Starting and charging systems
1 General information and
precautions
General information
1 The engine electrical system consists
mainly of the charging and starting systems.
Because of their engine-related functions,
these components are covered separately
from the body electrical devices such as the
lights, instruments, etc (which are covered in
Chapter 12). Refer to Part B for information on
the ignition system.
2 The electrical system is of the 12-volt
negative earth type.
3 The battery is of the low maintenance or
maintenance-free (sealed for life) type and is
charged by the alternator, which is belt-driven
from the crankshaft pulley.
4 The starter motor is of the pre-engaged
type incorporating an integral solenoid. On
starting, the solenoid moves the drive pinion
into engagement with the flywheel ring gear
before the starter motor is energised. Once
the engine has started, a one-way clutch
prevents the motor armature being driven by
the engine until the pinion disengages from
the flywheel.
Precautions
5 Further details of the various systems are
given in the relevant Sections of this Chapter.
While some repair procedures are given, the
usual course of action is to renew the
component concerned. The owner whose
interest extends beyond mere component
renewal should obtain a copy of the Automobile
Electrical & Electronic Systems Manual,
available from the publishers of this manual.
6 It is necessary to take extra care when
working on the electrical system to avoid
damage to semi-conductor devices (diodes
and transistors), and to avoid the risk of
personal injury. In addition to the precautions
given in Safety first! at the beginning of this
manual, observe the following when working
on the system:
7 Always remove rings, watches, etc before
working on the electrical system. Even with
the battery disconnected, capacitive
discharge could occur if a component’s live
terminal is earthed through a metal object.
This could cause a shock or nasty burn.
8 Do not reverse the battery connections.
Components such as the alternator, electronic
control units, or any other components having
semi-conductor circuitry could be irreparably
damaged.
9 If the engine is being started using jump
leads and a slave battery, connect the
batteries positive-to-positive and negative-tonegative (see Jump starting). This also applies
when connecting a battery charger.
10 Never disconnect the battery terminals,
the alternator, any electrical wiring or any test
instruments when the engine is running.
11 Do not allow the engine to turn the
alternator when the alternator is not
connected.
12 Never test for alternator output by flashing
the output lead to earth.
13 Never use an ohmmeter of the type
incorporating a hand-cranked generator for
circuit or continuity testing.
14 Always ensure that the battery negative
lead is disconnected before carrying out any
serious work on the electrical system. Note:
On models with a Vauxhall anti-theft warning
system (ATWS), the battery negative terminal
must be disconnected within 15 seconds of
the ignition being switched off to prevent the
alarm system being triggered.
15 Before using electric-arc welding
equipment on the car, disconnect the battery,
alternator and components such as the
engine management electronic control unit to
protect them from the risk of damage.
16 The radio/cassette unit fitted as standard
equipment by Vauxhall is equipped with a builtin security code to deter thieves. If the power
source to the unit is cut, the anti-theft system
will activate. Even if the power source is
immediately reconnected, the radio/ cassette
unit will not function until the correct security
code has been entered. Therefore, if you do not
know the correct security code for the radio/
cassette unit do not disconnect the battery
negative terminal of the battery or remove the
radio/cassette unit from the vehicle. Refer to
Radio/cassette
unit
anti-theft
system
precaution Section for further information.
2 Electrical fault finding general information
Refer to Chapter 12.
3 Battery testing and charging
1
Standard and low maintenance
battery - testing
1 If the vehicle covers a small annual mileage,
3.5 Standard Vauxhall battery with built-in
charge indicator (arrowed)
3510 Vauxhall/Opel Omega
it is worthwhile checking the specific gravity of
the electrolyte every three months to
determine the state of charge of the battery.
Use a hydrometer to make the check and
compare the results with the following table.
Note that the specific gravity readings assume
an electrolyte temperature of 15ºC (60ºF); for
every 10ºC (18ºF) below 15ºC (60ºF) subtract
0.007. For every 10ºC (18ºF) above 15ºC (60ºF)
add 0.007.
Ambient temperature - 25ºC (77ºF)
Above
Below
Charged
1.210 to 1.230 1.270 to 1.290
70% charged 1.170 to 1.190 1.230 to 1.250
Discharged 1.050 to 1.070 1.110 to 1.130
2 If the battery condition is suspect, first
check the specific gravity of electrolyte in
each cell. A variation of 0.040 or more
between any cells indicates loss of electrolyte
or deterioration of the internal plates.
3 If the specific gravity variation is 0.040 or
more, the battery should be renewed. If the
cell variation is satisfactory but the battery is
discharged, it should be charged as
described later in this Section.
Maintenance-free battery testing
4 In cases where a sealed for life
maintenance-free battery is fitted, topping-up
and testing of the electrolyte in each cell is not
possible. The condition of the battery can
therefore only be tested using a battery
condition indicator or a voltmeter.
5 Certain models may be fitted with a Delco or
Vauxhall type maintenance-free battery, with a
built-in charge condition indicator (see
illustration). The indicator is located in the top
of the battery casing, and indicates the
condition of the battery from its colour. If the
indicator shows green, then the battery is in a
good state of charge. If the indicator turns
darker, eventually to black, then the battery
requires charging, as described later in this
Section. If the indicator shows clear/yellow,
then the electrolyte level in the battery is too
low to allow further use, and the battery should
be renewed. Do not attempt to charge, load or
jump start a battery when the indicator shows
clear/yellow.
6 If testing the battery using a voltmeter,
connect the voltmeter across the battery and
compare the result with those given in the
Specifications under charge condition. The
test is only accurate if the battery has not
been subjected to any kind of charge for the
previous six hours. If this is not the case,
switch on the headlights for 30 seconds, then
wait four to five minutes before testing the
battery after switching off the headlights. All
other electrical circuits must be switched off,
so check that the doors and tailgate are fully
shut when making the test.
7 If the voltage reading is less than 12.2 volts,
then the battery is discharged, whilst a
reading of 12.2 to 12.4 volts indicates a
partially discharged condition.
Starting and charging systems 5A•3
8 If the battery is to be charged, remove it
from the vehicle (Section 4) and charge it as
described later in this Section.
Standard and low maintenance
battery - charging
Note: The following is intended as a guide
only. Always refer to the manufacturer’s
recommendations (often printed on a label
attached to the battery) before charging a
battery.
9 Charge the battery at a rate of 3.5 to 4
amps and continue to charge the battery at
this rate until no further rise in specific gravity
is noted over a four hour period.
10 Alternatively, a trickle charger charging at
the rate of 1.5 amps can safely be used
overnight.
11 Specially rapid boost charges which are
claimed to restore the power of the battery in 1
to 2 hours are not recommended, as they can
cause serious damage to the battery plates
through overheating.
12 While charging the battery, note that the
temperature of the electrolyte should never
exceed 37.8ºC (100ºF).
Maintenance-free battery charging
Note: The following is intended as a guide
only. Always refer to the manufacturer’s
recommendations (often printed on a label
attached to the battery) before charging a
battery.
13 This battery type takes considerably
longer to fully recharge than the standard
type, the time taken being dependent on the
extent of discharge, but it can take anything
up to three days.
14 A constant voltage type charger is
required, to be set, when connected, to 13.9
to 14.9 volts with a charger current below 25
amps. Using this method, the battery should
be usable within three hours, giving a voltage
reading of 12.5 volts, but this is for a partially
discharged battery and, as mentioned, full
charging can take considerably longer.
15 If the battery is to be charged from a fully
discharged state (condition reading less than
12.2 volts), have it recharged by your Vauxhall
dealer or local automotive electrician, as the
charge rate is higher and constant supervision
during charging is necessary.
4 Battery removal and refitting
4.3 Where necessary, unclip the fusible
link housing from the relay box and
position it clear of the battery
2 Unclip the cover (where fitted) then slacken
the clamp nut and disconnect the clamp from
the battery negative (earth) terminal. Note: On
models with a Vauxhall anti-theft warning
system (ATWS), the battery negative terminal
must be disconnected within 15 seconds of
the ignition being switched off to prevent the
alarm system being triggered.
3 On models where a fusible link housing is
clipped onto the engine compartment relay
box, unclip the housing and position it clear of
the battery (see illustration).
4 Lift the insulation cover and disconnect the
positive terminal lead in the same way.
5 Unscrew the bolt and remove the battery
retaining clamp and lift the battery out of the
engine compartment.
Refitting
6 Refitting is a reversal of removal, but smear
petroleum jelly on the terminals when reconnecting the leads, and always reconnect the
positive lead first, and the negative lead last.
5 Charging system testing
2
Note: Refer to the warnings given in Safety
first! and in Section 1 of this Chapter before
starting work.
1 If the ignition warning light fails to illuminate
when the ignition is switched on, first check
6 Alternator drivebelt removal, refitting and
tensioning
1 Refer to the procedure given for the
auxiliary drivebelt in Chapter 1.
7 Alternator removal and refitting
1
3
Removal
1 Disconnect the battery negative lead and
proceed as described under the relevant subheading. Note: On models with a Vauxhall
anti-theft warning system (ATWS), the battery
negative terminal must be disconnected within
15 seconds of the ignition being switched off
to prevent the alarm system being triggered.
Note: If a Vauxhall radio/cassette unit is fitted,
refer to Radio/cassette unit anti-theft system precaution.
Removal
1 The battery is located on the left-hand side
of the engine compartment. On some models
the battery will be housed in a protective
casing.
the alternator wiring connections for security.
If satisfactory, check that the warning light
bulb has not blown, and that the bulbholder is
secure in its location in the instrument panel.
If the light still fails to illuminate, check the
continuity of the warning light feed wire from
the alternator to the bulbholder. If all is
satisfactory, the alternator is at fault and
should be renewed or taken to an autoelectrician for testing and repair.
2 If the ignition warning light illuminates when
the engine is running, stop the engine and
check that the drivebelt is correctly tensioned
(see Section 6) and that the alternator
connections are secure. If all is so far
satisfactory, have the alternator checked by
an auto-electrician for testing and repair.
3 If the alternator output is suspect even
though the warning light functions correctly,
the regulated voltage may be checked as
follows.
4 Connect a voltmeter across the battery
terminals and start the engine.
5 Increase the engine speed until the
voltmeter reading remains steady; the reading
should be approximately 12 to 13 volts, and
no more than 14 volts.
6 Switch on as many electrical accessories
(eg, the headlights, heated rear window and
heater blower) as possible, and check that the
alternator maintains the regulated voltage at
around 13 to 14 volts.
7 If the regulated voltage is not as stated, the
fault may be due to worn brushes, weak brush
springs, a faulty voltage regulator, a faulty
diode, a severed phase winding or worn or
damaged slip rings. The alternator should be
renewed or taken to an auto-electrician for
testing and repair.
2.0 litre engine
7.2 On 2.0 litre DOHC engines, disconnect
the wiring connector from the intake air
temperature sensor and airflow meter . . .
3510 Vauxhall/Opel Omega
2 Disconnect the wiring connectors from the
intake air temperature sensor and the airflow
meter (see illustration).
5A
5A•4 Starting and charging systems
7.3a . . . then disconnect the breather hose from the camshaft
cover . . .
3 Slacken the retaining clips then disconnect
the intake duct from the air cleaner and
throttle housing and remove the duct
assembly from the engine compartment. On
DOHC engines it will be necessary to
disconnect the breather hose in order to allow
the duct to be removed (see illustrations).
4 Release the auxiliary drivebelt as described
in Chapter 1 and disengage it from the
alternator pulley.
5 Undo the bolts and remove the support
brackets securing the alternator to the inlet
manifold and cylinder head. Slacken the lower
mounting bolt and pivot the alternator away
from the block to improve access to the wiring
connections.
6 Remove the rubber covers (where fitted)
from the alternator terminals, then unscrew
the retaining nuts and disconnect the wiring
from the rear of the alternator.
7 Unscrew the nut from the lower mounting
bolt then withdraw the bolt and manoeuvre
the alternator out of position.
2.5 and 3.0 litre engines
8 Firmly apply the handbrake then jack up the
front of the vehicle and support it on axle
stands. Undo the retaining screws and
remove the undercover from beneath the
engine so access to the alternator can be
gained from below.
9 Release the auxiliary drivebelt as described
in Chapter 1 and disengage it from the
alternator pulley.
10 Remove the rubber covers (where fitted)
from the alternator terminals, then unscrew
the retaining nuts and disconnect the wiring
from the rear of the alternator (see
illustration).
11 Slacken and remove the upper and lower
mounting nut and bolt then manoeuvre the
alternator out of position.
Refitting
12 Refitting is the reverse of removal
tightening all mounting bolts to their specified
torque settings (where given). Ensure the
7.3b . . . before slackening the retaining clips and removing the
intake duct assembly
drivebelt is correctly refitted and tensioned as
described in Chapter 1.
8 Alternator testing and overhaul
5
1 If the alternator is thought to be suspect, it
should be removed from the vehicle and taken
to an auto-electrician for testing. Most autoelectricians will be able to supply and fit
brushes at a reasonable cost. However, check
on the cost of repairs before proceeding as it
may prove more economical to obtain a new
or exchange alternator.
9 Starting system testing
3
Note: Refer to the precautions given in Safety
first! and in Section 1 of this Chapter before
starting work.
1 If the starter motor fails to operate when the
ignition key is turned to the appropriate
position, the following possible causes may
be to blame.
7.10 Slacken the retaining nuts (arrowed)
and disconnect the wiring from the rear of
the alternator (shown with engine
removed)
3510 Vauxhall/Opel Omega
a) The battery is faulty.
b) The electrical connections between the
switch, solenoid, battery and starter
motor are somewhere failing to pass the
necessary current from the battery
through the starter to earth.
c) The solenoid is faulty.
d) The starter motor is mechanically or
electrically defective.
2 To check the battery, switch on the
headlights. If they dim after a few seconds,
this indicates that the battery is discharged recharge (see Section 3) or renew the battery.
If the headlights glow brightly, operate the
ignition switch and observe the lights. If they
dim, then this indicates that current is
reaching the starter motor, therefore the fault
must lie in the starter motor. If the lights
continue to glow brightly (and no clicking
sound can be heard from the starter motor
solenoid), this indicates that there is a fault in
the circuit or solenoid - see following
paragraphs. If the starter motor turns slowly
when operated, but the battery is in good
condition, then this indicates that either the
starter motor is faulty, or there is considerable
resistance somewhere in the circuit.
3 If a fault in the circuit is suspected,
disconnect the battery leads (including the
earth connection to the body), the
starter/solenoid
wiring
and
the
engine/transmission earth strap. Thoroughly
clean the connections, and reconnect the
leads and wiring, then use a voltmeter or test
lamp to check that full battery voltage is
available at the battery positive lead
connection to the solenoid, and that the earth
is sound. Smear petroleum jelly around the
battery terminals to prevent corrosion corroded connections are amongst the most
frequent causes of electrical system faults.
4 If the battery and all connections are in
good condition, check the circuit by
disconnecting the wire from the solenoid
blade terminal. Connect a voltmeter or test
lamp between the wire end and a good earth
Starting and charging systems 5A•5
(such as the battery negative terminal), and
check that the wire is live when the ignition
switch is turned to the start position. If it is,
then the circuit is sound - if not the circuit
wiring can be checked as described in
Chapter 12, Section 2.
5 The solenoid contacts can be checked by
connecting a voltmeter or test lamp between
the battery positive feed connection on the
starter side of the solenoid, and earth. When the
ignition switch is turned to the start position,
there should be a reading or lighted bulb, as
applicable. If there is no reading or lighted bulb,
the solenoid is faulty and should be renewed.
6 If the circuit and solenoid are proved
sound, the fault must lie in the starter motor.
In this event, it may be possible to have the
starter motor overhauled by a specialist, but
check on the cost of spares before
proceeding, as it may prove more economical
to obtain a new or exchange motor.
10 Starter motor removal and refitting
4
Removal
1 Disconnect the battery negative lead then
firmly apply the handbrake then jack up the
front of the vehicle and support it on axle
stands. Undo the retaining screws and
remove the undercover from beneath the
engine then proceed as described under the
relevant sub-heading. Note: On models with a
Vauxhall anti-theft warning system (ATWS),
the battery negative terminal must be
disconnected within 15 seconds of the
ignition being switched off to prevent the
alarm system being triggered.
2.0 litre engine
2 Slacken and remove the two retaining nuts
and disconnect the wiring from the starter
motor solenoid. Recover the washers under
the nuts. On DOHC engine models, to improve
access to the motor, undo the retaining bolts
and remove the inlet manifold support bracket.
3 Unscrew the retaining bolt securing the
starter motor rear bracket to the cylinder
block.
4 Slacken and remove the upper and lower
retaining bolts, noting the bolts are different
lengths, and remove the starter motor from
the vehicle. The upper bolt comes through
from behind and secures the transmission unit
to the cylinder block.
2.5 and 3.0 litre engine
5 Remove the right-hand engine mounting
and bracket as described in Chapter 2C.
6 Slacken and remove the two retaining nuts
and disconnect the wiring from the starter
motor solenoid. Recover the washers under
the nuts.
7 Slacken and remove the upper and lower
retaining bolts and remove the starter motor
from the vehicle.
Refitting
8 Refitting is a reversal of removal tightening
the retaining bolts to the specified torque.
Ensure all wiring is correctly routed and its
retaining nuts are securely tightened.
14 Oil level sensor removal and refitting
3
2.0 litre SOHC engine
11 Starter motor testing and overhaul
5
1 If the starter motor is thought to be suspect,
it should be removed from the vehicle and
taken to an auto-electrician for testing. Most
auto-electricians will be able to supply and fit
brushes at a reasonable cost. However, check
on the cost of repairs before proceeding as it
may prove more economical to obtain a new
or exchange motor.
12 Ignition switch removal and refitting
1 The ignition switch is integral with the
steering column lock, and can be removed as
described in Chapter 10.
13 Oil pressure
warning light switch removal and refitting
2
Removal
1 The switch is screwed into the oil pump
housing which is located on the front of the
engine, on the end of the crankshaft. On 2.0
litre engines the switched is screwed into the
rear of the housing and on 2.5 and 3.0 litre
engines it is screwed into the front of the
housing.
2 To improve access to the switch, firmly
apply the handbrake then jacked up the front
of the vehicle and support it on axle stands.
Undo the retaining bolts and remove the
undercover from beneath the engine unit.
3 Disconnect the wiring connector then
unscrew the switch and recover the sealing
washer. Be prepared for oil spillage, and if the
switch is to be left removed from the engine
for any length of time, plug the switch
aperture.
Removal
1 The oil level sensor (where fitted) is located
on the right-hand face of the engine sump.
2 To gain access to the sensor, firmly apply
the handbrake then jack up the front of the
vehicle and support it on axle stands. Where
necessary, undo the retaining screws and
remove the undercover from beneath the
engine unit.
3 Drain the engine oil into a clean container
then refit the drain plug and tighten it to the
specified torque setting (see Chapter 1).
4 Disconnect the wiring connector from the
sensor.
5 Unscrew the retaining bolts then ease the
sensor out from the sump and remove it along
with its sealing ring. Discard the sealing ring, a
new one should be used on refitting.
Refitting
6 Refitting is the reverse of removal using a
new sealing ring. On completion refill the
engine with oil (see Chapter 1).
2.0 litre DOHC engine
Engines with a one-piece sump
7 Remove and refit the sensor as described
in paragraphs 1 to 6.
Engines with a two-piece sump
8 Remove and refit the sensor as described
in paragraphs 9 to 11.
2.5 and 3.0 litre engine
Removal
9 Remove the sump pan as described in
Chapter 2C.
10 Unscrew the retaining bolts and remove
the sensor from the sump pan, noting which
way around it is fitted (see illustration).
Refitting
11 Ensure the sensor is correctly positioned
then tighten its retaining bolts to the specified
torque. Refit the sump pan as described in
Chapter 2C.
Refitting
4 Examine the sealing washer for signs of
damage or deterioration and if necessary
renew.
5 Refit the switch and washer, tightening it to
the specified torque, and reconnect the wiring
connector.
6 Refit the undercover then lower the vehicle
to the ground. Check and, if necessary, top
up the engine oil as described in Weekly
checks.
3510 Vauxhall/Opel Omega
14.10 Removing the oil level sensor
(2.5 litre engine shown)
5A
5B•1
Chapter 5 Part B:
Ignition system
Contents
DIS module - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Ignition system - general information . . . . . . . . . . . . . . . . . . . . . . . . 1
Ignition system - testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Ignition timing - checking and adjustment . . . . . . . . . . . . . . . . . . . . 4
Spark plug renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . .See Chapter 1
Degrees of difficulty
Easy, suitable for
novice with little
experience
1
Fairly easy, suitable
for beginner with
some experience
2
Fairly difficult,
suitable for competent
DIY mechanic
3
Difficult, suitable for
experienced DIY
mechanic
4
Very difficult,
suitable for expert DIY
or professional
5
Specifications
System type
...........................................
Distributorless ignition system controlled by engine management ECU
2.0 litre engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.5 and 3.0 litre engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-3-4-2 (No 1 cylinder at timing belt end)
1-2-3-4-5-6 (No1 cylinder at timing belt end of right-hand cylinder bank)
Torque wrench settings
Nm
8
15
Firing order
DIS module bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DIS module bracket bolts - 2.0 litre SOHC engine . . . . . . . . . . . . . . . . .
1 Ignition system general information
Warning: Voltages produced by an
electronic ignition system are
considerably higher than those
produced by conventional ignition systems.
Extreme care must be taken when working
on the system with the ignition switched
on. Persons with surgically-implanted
cardiac pacemaker devices should keep
well clear of the ignition circuits,
components and test equipment.
2.0 litre engine
1 The ignition system is integrated with the
fuel injection system to form a combined
engine management system under the control
of one ECU (See Chapter 4A, Section 13 for
further information). The ignition side of the
system is of the distributorless type, and
consists of the DIS (distributorless ignition
system) module and the knock sensor.
2 The DIS module is actually a four output
ignition coil. The module actually consists of
two separate HT coils which supply two
cylinders each (one coil supplies cylinders 1
and 4, and the other cylinders 2 and 3). Under
the control of the ECU, the module operates
on the wasted spark principle, ie. each spark
plug sparks twice for every cycle of the
engine, once on the compression stroke and
once on the exhaust stroke. The ECU uses its
lbf ft
6
11
inputs from the various sensors to calculate
the required ignition advance setting and coil
charging time.
3 The knock sensor is mounted onto the
cylinder block and informs the ECU when the
engine is pinking under load. The sensor is
sensitive to vibration and detects the
knocking which occurs when the engine starts
to pink (pre-ignite). The knock sensor sends
an electrical signal to the ECU which in turn
retards the ignition advance setting until the
pinking ceases.
2.5 and 3.0 litre engine
4 Refer to the information given in paragraphs 1
to 3 noting that there are two knock sensors
(one for the left-hand bank of cylinders and one
for the right-hand bank) and the DIS module is a
six output coil consisting of three separate HT
coils which supply two cylinders each.
2 Ignition system testing
5
1 If a fault appears in the engine management
(fuel injection/ignition) system first ensure that
the fault is not due to a poor electrical
connection or poor maintenance; ie, check
that the air cleaner filter element is clean, the
spark plugs are in good condition and
correctly gapped, that the engine breather
hoses are clear and undamaged, referring to
Chapter 1 for further information. Also check
3510 Vauxhall/Opel Omega
that the accelerator cable is correctly adjusted
as described in Chapter 4A. If the engine is
running very roughly, check the compression
pressures as described in Chapter 2A. Whilst
checking the spark plugs, also check the HT
leads as follows.
2 Check inside the HT lead end fitting for
signs of corrosion, which will look like a white
crusty powder. Push the end fitting back onto
the spark plug, ensuring that it is a tight fit on
the plug. If not, remove the lead again and use
pliers to carefully crimp the metal connector
inside the end fitting until it fits securely on the
end of the spark plug.
3 Using a clean rag, wipe the entire length of
the lead to remove any built-up dirt and
grease. Once the lead is clean, check for
burns, cracks and other damage. Do not bend
the lead excessively, nor pull the lead
lengthwise - the conductor inside might
break.
4 Disconnect the other end of the lead from
the DIS module (see Section 3) and check for
corrosion and a tight fit in the same manner as
the spark plug end. Ensure that the leads are
numbered before removing them, to avoid
confusion when refitting. Pull the leads from
the plugs by gripping the end fitting, not the
lead, otherwise the lead connection may be
fractured. Refit the lead securely on
completion.
5 Check the remaining leads one at a time, in
the same way. If new spark plug (HT) leads
are required, purchase a set for your specific
car and engine.
5B
5B•2 Ignition system
3.6 DIS module wiring connector (1) and HT leads (2) from the DIS
module - 2.0 litre DOHC engine
6 If these checks fail to reveal the cause of
the problem the vehicle should be taken to a
suitably equipped Vauxhall dealer for testing.
A wiring block connector is incorporated in
the engine management circuit into which a
special electronic diagnostic tester can be
plugged (see Chapter 4A, Section 6). The
tester will locate the fault quickly and simply
alleviating the need to test all the system
components individually which is a time
consuming operation that carries a high risk of
damaging the ECU. If necessary, the system
wiring and wiring connectors can be checked,
ensuring that the ECU wiring connector has
first been disconnected.
3 DIS module removal and refitting
4
Removal
2.0 litre SOHC engine
1 The DIS module is mounted onto the rear of
the cylinder head. Firmly apply the handbrake
then jack up the front of the vehicle and
support it on axle stands; access can then be
gained both from above and below.
2 Ensure the ignition is switched off then
disconnect the wiring connector from the DIS
module.
3 Slacken and remove the bolts securing the
DIS module mounting bracket to the cylinder
head noting the correct fitted location of the
engine lifting bracket. Free the wiring from the
bracket then manoeuvre the module and
bracket assembly out from behind the
cylinder head.
3.8 On 2.5 and 3.0 litre engines the DIS module is mounted on the
rear of the left-hand cylinder head (later model shown with
engine removed)
4 Disconnect the HT leads from the DIS
module and remove the module from the
vehicle. The module HT lead terminals are
numbered (the leads should also be numbered)
with their respective cylinder number to avoid
confusion on refitting. If necessary, undo the
bolts and separate the module and bracket.
2.0 litre DOHC engine
5 Undo the retaining screws and remove the
spark plug cover from the cylinder head
cover.
6 Ensure the ignition is switches off then
disconnect the wiring connector and HT leads
from the DIS module (see illustration). The
module HT lead terminals are numbered (the
leads should also be numbered) with their
respective cylinder number to avoid confusion
on refitting.
7 Slacken and remove the retaining bolts and
remove the DIS module from the rear of the
cylinder head.
2.5 and 3.0 litre engine
8 The DIS module is mounted onto the rear of
the left-hand cylinder head (see illustration).
To gain access to the module remove the
wiper motor as described in Chapter 12. The
module is very awkward to remove; access
can by further improved by unclip the wiring
connector holder from the lifting bracket on
the rear of the cylinder head and
disconnecting the pipes/hoses which pass
over the module.
9 Slacken and remove the retaining bolts and
free the module from cylinder head. On early
models the module is bolted directly onto the
head (as opposed to being mounted on a
bracket on later models), access to the lower
bolts may be easier from below once the
3510 Vauxhall/Opel Omega
vehicle has been raised and supported.
10 Disconnect the wiring connector and HT
leads from the DIS module and remove the
module from the vehicle. The module HT lead
terminals are numbered (the leads should also
be numbered) with their respective cylinder
number to avoid confusion on refitting.
Refitting
11 Refitting is the reverse of removal,
ensuring each HT lead is securely
reconnected to its corresponding terminal on
the DIS module using the numbers on the
leads and module. Tighten the retaining bolts
to the specified torque and securely
reconnect the wiring connector.
4 Ignition timing checking and adjustment
5
1 There are no timing marks on the flywheel
or crankshaft pulley. The timing is constantly
being monitored and adjusted by the engine
management ECU, and nominal values
cannot be given. Therefore, it is not possible
for the home mechanic to check the ignition
timing.
2 The only way in which the ignition timing
can be checked and (where possible)
adjusted is by using special electronic test
equipment, connected to the engine
management system diagnostic connector
(refer to Chapter 4A, Section 6 for further
information). Refer to your Vauxhall dealer for
further information.
6•1
Chapter 6
Clutch
Contents
Clutch assembly - removal, inspection and refitting . . . . . . . . . . . . . 6
Clutch hydraulic system - bleeding . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Clutch pedal - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . 5
Fluid level check . . . . . . . . . . . . . . . . . . . . . . . . . . .See Weekly checks
General information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Master cylinder - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . 3
Release cylinder - removal and refitting . . . . . . . . . . . . . . . . . . . . . . 4
Degrees of difficulty
Easy, suitable for
novice with little
experience
1
Fairly easy, suitable
for beginner with
some experience
2
Fairly difficult,
suitable for competent
DIY mechanic
3
Difficult, suitable for
experienced DIY
mechanic
4
Very difficult,
suitable for expert DIY
or professional
5
Specifications
Type
...................................................
Single dry plate with diaphragm spring, hydraulically operated
Friction plate
Diameter:
2.0 litre engine models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.5 litre engine models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.0 litre engine models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Torque wrench settings
Bleed screw . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Hydraulic pipe union nut . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Master cylinder retaining nuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pedal:
Mounting bracket bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pivot bolt nut . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pressure plate retaining bolts:
M7 bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
M8 bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Release cylinder mounting bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1 General information
1 The clutch consists of a friction plate, a
pressure plate assembly, and the hydraulic
release cylinder and bearing; all of these
components are contained in the large castaluminium alloy bellhousing, sandwiched
between the engine and the transmission.
2 The friction plate is fitted between the
216 mm
228 mm
240 mm
Nm
9
14
20
lbf ft
7
10
15
18
18
13
13
15
28
22
11
21
16
engine flywheel and the clutch pressure plate,
and is allowed to slide on the transmission
input shaft splines.
3 The pressure plate assembly is bolted to
the engine flywheel. When the engine is
running, drive is transmitted from the
crankshaft, via the flywheel, to the friction
plate (these components being clamped
securely together by the pressure plate
assembly) and from the friction plate to the
transmission input shaft.
4 To interrupt the drive, the spring pressure
3510 Vauxhall/Opel Omega
must be relaxed. This is achieved using a
hydraulic release mechanism which consists of
the master cylinder, the release cylinder and the
pipe/hose linking the two components.
Depressing the pedal pushes on the master
cylinder pushrod which hydraulically forces the
release cylinder bearing against the pressure
plate spring fingers. This causes the springs to
deform and releases the clamping force on the
friction plate.
5 The clutch is self-adjusting and requires no
manual adjustment.
6
6•2 Clutch
2 Clutch hydraulic system bleeding
3
Warning: Hydraulic fluid is
poisonous; wash off immediately
and thoroughly in the case of skin
contact, and seek immediate medical
advice if any fluid is swallowed or gets into
the eyes. Certain types of hydraulic fluid
are flammable, and may ignite when
allowed into contact with hot components;
when servicing any hydraulic system, it is
safest to assume that the fluid is
flammable, and to take precautions
against the risk of fire as though it is petrol
that is being handled. Hydraulic fluid is
also an effective paint stripper, and will
attack plastics; if any is spilt, it should be
washed off immediately, using copious
quantities of fresh water. Finally, it is
hygroscopic (it absorbs moisture from the
air) - old fluid may be contaminated and
unfit for further use. When topping-up or
renewing the fluid, always use the
recommended type, and ensure that it
comes from a freshly opened sealed
container.
1 The correct operation of any hydraulic
system is only possible after removing all air
from the components and circuit; this is
achieved by bleeding the system.
2 During the bleeding procedure, add only
clean, unused hydraulic fluid of the recommended type; never re-use fluid that has
already been bled from the system. Ensure
that sufficient fluid is available before starting
work.
3 If there is any possibility of incorrect fluid
being already in the system, the hydraulic
circuit must be flushed completely with
uncontaminated, correct fluid.
4 If hydraulic fluid has been lost from the
system, or air has entered because of a leak,
ensure that the fault is cured before
continuing further.
5 The bleed screw is located on the righthand side of the transmission bellhousing
(see illustration). To gain access, firmly apply
the handbrake then jack up the front of the
vehicle and support it on axle stands so that
the screw can be reached from below.
6 Check that all pipes and hoses are secure,
unions tight and the bleed screw is closed.
Clean any dirt from around the bleed screw.
7 Unscrew the master cylinder fluid reservoir
cap (the clutch shares the same fluid reservoir
as the braking system), and top the master
cylinder reservoir up to the upper (MAX) level
line. Refit the cap loosely, and remember to
maintain the fluid level at least above the
lower (MIN) level line throughout the
procedure, or there is a risk of further air
entering the system.
8 There are a number of one-man, do-ityourself bleeding kits currently available from
motor accessory shops. It is recommended
that one of these kits is used whenever
possible, as they greatly simplify the bleeding
operation, and reduce the risk of expelled air
and fluid being drawn back into the system. If
such a kit is not available, the basic (two-man)
method must be used, which is described in
detail below.
9 If a kit is to be used, prepare the vehicle as
described previously, and follow the kit
manufacturer’s instructions, as the procedure
may vary slightly according to the type being
used; generally, they are as outlined below in
the relevant sub-section.
Bleeding basic (two-man) method
10 Collect a clean glass jar, a suitable length
of plastic or rubber tubing which is a tight fit
over the bleed screw, and a ring spanner to fit
the screw. The help of an assistant will also be
required.
11 Remove the dust cap from the bleed
screw. Fit the spanner and tube to the screw,
place the other end of the tube in the jar, and
pour in sufficient fluid to cover the end of the
tube.
12 Ensure that the fluid level is maintained at
least above the lower level line in the reservoir
throughout the procedure.
13 Have the assistant fully depress the clutch
pedal several times to build up pressure, then
maintain it on the final downstroke.
14 While pedal pressure is maintained,
unscrew the bleed screw (approximately one
turn) and allow the compressed fluid and air to
flow into the jar. The assistant should maintain
pedal pressure and should not release it until
instructed to do so. When the flow stops,
tighten the bleed screw again, have the
assistant release the pedal slowly, and
recheck the reservoir fluid level.
15 Repeat the steps given in paragraphs 13
and 14 until the fluid emerging from the bleed
screw is free from air bubbles. If the master
cylinder has been drained and refilled allow
approximately five seconds between cycles
for the master cylinder passages to refill.
16 When no more air bubbles appear, tighten
the bleed screw to the specified torque,
remove the tube and spanner, and refit the
dust cap. Do not overtighten the bleed screw.
Bleeding using a one-way valve kit
17 As their name implies, these kits consist
of a length of tubing with a one-way valve
fitted, to prevent expelled air and fluid being
drawn back into the system; some kits include
a translucent container, which can be
positioned so that the air bubbles can be
more easily seen flowing from the end of the
tube.
18 The kit is connected to the bleed screw,
which is then opened. The user returns to the
driver’s seat, depresses the clutch pedal with
a smooth, steady stroke, and slowly releases
it; this is repeated until the expelled fluid is
clear of air bubbles.
19 Note that these kits simplify work so
much that it is easy to forget the clutch fluid
reservoir level; ensure that this is maintained
at least above the lower level line at all times.
Bleeding using a pressure-bleeding kit
20 These kits are usually operated by the
reservoir of pressurised air contained in the
spare tyre. However, note that it will probably
be necessary to reduce the pressure to a
lower level than normal; refer to the
instructions supplied with the kit.
21 By connecting a pressurised, fluid-filled
container to the clutch fluid reservoir,
bleeding can be carried out simply by opening
the bleed screw and allowing the fluid to flow
out until no more air bubbles can be seen in
the expelled fluid.
22 This method has the advantage that the
large reservoir of fluid provides an additional
safeguard against air being drawn into the
system during bleeding.
All methods
23 When bleeding is complete, and correct
pedal feel is restored, tighten the bleed screw
to the specified torque and wash off any spilt
fluid. Refit the dust cap to the bleed screw.
24 Check the hydraulic fluid level in the
master cylinder reservoir, and top-up if
necessary (see Weekly checks).
25 Discard any hydraulic fluid that has been
bled from the system; it will not be fit for re-use.
26 Check the operation of the clutch pedal. If
the clutch is still not operating correctly, air
must still be present in the system, and further
bleeding is required. Failure to bleed
satisfactorily after a reasonable repetition of
the bleeding procedure may be due to worn
master cylinder/release cylinder seals.
3 Master cylinder removal and refitting
3
Removal
2.5 Clutch bleed screw location
(arrowed)
3510 Vauxhall/Opel Omega
1 On 2.5 and 3.0 litre right-hand drive models
and all left-hand drive models, to improve
access to the master cylinder remove the
Clutch 6•3
windscreen wiper arms and the water
deflector panel from the base of the windscreen (see Chapter 12, Sections 15 and 16).
2 On all models, remove all traces of dirt from
the outside of the master cylinder and position
some cloth beneath the cylinder to catch any
spilt fluid.
3 Slacken the retaining clip then disconnect
the master cylinder hose from the reservoir
outlet. Plug the reservoir outlet to minimise
fluid loss then wash off any spilt fluid
immediately.
4 Slide out the retaining clip and free the
hydraulic pipe from the front of the master
cylinder. Plug pipe end and master cylinder
port to minimise fluid loss and prevent the
entry of dirt. Refit the retaining clip to the
master cylinder groove, ensuring its is
correctly located.
5 From inside the vehicle, release the retaining
clips (rotate them through 90º) then remove the
undercover panel from the drivers’ side of the
facia. Remove the fastener (prise out the centre
pin then pull out the fastener outer section)
then unclip and remove the heater/ventilation
duct to improve access to the pedal.
6 Slide off the retaining clip and remove the
clevis pin securing the master cylinder
pushrod to the pedal then slacken and
remove the cylinder retaining nuts.
7 Return to the engine compartment and
remove the master cylinder from the vehicle
noting that it maybe necessary to unclip the
brake pipes from the bulkhead to gain the
necessary clearance required. If the master
cylinder is faulty it must be renewed; overhaul
of the unit is not possible.
Refitting
8 Ensure the cylinder and bulkhead mating
surfaces then manoeuvre the master cylinder
into position.
9 From inside the vehicle, ensure the pushrod
clevis is correctly engaged with the pedal then
refit the master cylinder retaining nuts,
tightening them to the specified torque.
10 Apply a smear of multi-purpose grease to
the clevis pin then align the clevis and pedal
and insert the pin. Secure the clevis pin in
position with the retaining clip, making sure it is
correctly located in the pin groove, then refit the
heater/ventilation duct and facia undercover.
11 Working in the engine compartment,
ensure that the retaining clip is correctly
located in the master cylinder groove and the
clutch pipe sealing ring is in good condition.
Ease the pipe union into position until the
retaining clip is heard to click then check that
the pipe is securely retained.
12 Reconnect the master cylinder pipe to the
fluid reservoir outlet and securely tighten its
retaining clip.
13 Where necessary, refit the water deflector
panel and bulkhead sealing strip then refit
both windscreen wiper arms (see Chapter 12).
14 Top up the fluid reservoir and bleed the
clutch hydraulic system (see Section 2).
4 Release cylinder removal and refitting
4
Removal
Note: Refer to the warning concerning the
dangers of asbestos dust at the beginning of
Section 6.
1 Remove the transmission unit as described
in Chapter 7A.
2 Remove the release bearing from the
cylinder noting which way around it is fitted.
3 Wipe clean the outside of the release
cylinder then slacken the union nut securing
the feed pipe to the cylinder. Free the rubber
grommet from the transmission housing and
remove the pipe assembly.
4 Slacken the union nut and free the bleed
screw pipe from the release cylinder. If
necessary, slide off the retaining clip and
remove the bleed screw assembly from the
transmission housing.
5 Unscrew the three retaining bolts and slide
the release the cylinder off from the transmission input shaft. Remove the sealing ring
which is fitted to the rear of the release
cylinder and discard it; a new one must be
used on refitting. Whilst the cylinder is
removed, take care not to allow any debris to
enter the transmission unit.
6 The release cylinder is a sealed unit and
must be renewed if faulty. The only
component which can be replaced is the input
shaft seal which is fitted to the rear of the
cylinder (see Chapter 7A, Section 5).
7 Also check the release bearing noting that it
is often considered worthwhile to renew it as a
matter of course. Check that the contact
surface rotates smoothly and easily, with no
sign of noise or roughness, and that the
surface itself is smooth and unworn, with no
signs of cracks, pitting or scoring. If there is
any doubt about its condition, the bearing
must be renewed.
Refitting
8 If the original cylinder is being refitted it is
recommended that the input shaft oil seal is
renewed, regardless of its apparent condition
(see Chapter 7A, Section 5).
9 Ensure the release cylinder and
transmission mating surfaces are clean and
dry and fit the new sealing ring to the recess
on the rear of the release cylinder.
10 Lubricate the release cylinder seal with a
smear of transmission oil then carefully ease
the cylinder along the input shaft and into
position. Ensure the sealing ring is still
correctly seated in its groove then refit the
release cylinder retaining bolts and tighten
them to the specified torque.
11 Reconnect the bleed screw pipe to the
release cylinder and tighten its union nut to
the specified torque. Where necessary secure
the bleed screw assembly in position with the
retaining clip.
3510 Vauxhall/Opel Omega
12 Reconnect the feed pipe to the release
cylinder and seat the sealing grommet in the
transmission housing. Make sure the pipe is
centrally position in the housing aperture then
tighten the union nut to the specified torque.
13 Lubricate the inner bore of the release
bearing with a smear of high temperature
grease (Vauxhall recommend the use of
lubricating paste 19 42 530 - available from
your Vauxhall dealer); do apply too much or
there is risk of the clutch friction plate
becoming contaminated. Fit the release
bearing to the cylinder making sure it is the
correct way around.
14 Refit the transmission unit as described in
Chapter 7A.
5 Clutch pedal removal and refitting
3
Removal
1 From inside the vehicle, release the
retaining clips (rotate them through 90º) then
remove the undercover panel from the drivers’
side of the facia. Remove the fastener (prise
out the centre pin then pull out the fastener
outer section) then unclip and remove the
heater/ventilation duct to improve access to
the pedals.
2 Slide off the retaining clip and remove the
clevis pin securing the master cylinder
pushrod to the pedal.
3 Where necessary, disconnect the wiring
connector from the clutch pedal switch.
4 Slacken and remove the master cylinder
retaining nuts and free the cylinder pushrod
from the pedal.
5 Fully depress the clutch pedal then slacken
and remove the pedal mounting bracket
upper retaining bolt and manoeuvre the pedal
assembly out from underneath the facia.
6 If necessary, clamp the pedal bracket firmly
in a vice and disassemble as follows.
7 On 2.0 litre engine models unhook the
return spring, noting its correct fitted position.
Remove the retaining clip from the pivot bolt
nut then slacken and remove the nut and
washer. Remove the pivot bolt and separate
the pedal and return spring from the mounting
bracket.
8 On 2.5 and 3.0 litre engine models carefully
unhook the return spring lower end fitting
from the pedal and remove the spring
assembly noting which way around the end
fittings are positioned. Remove the retaining
clip from the pivot bolt nut then slacken and
remove the nut and washer. Remove the pivot
bolt and separate the pedal from the
mounting bracket noting the correct fitted
location of the thrustwasher.
9 On all models check the pedal components
for signs of damage. If any components is
worn or damage it should be renewed.
6
6•4 Clutch
position with the retaining clip, making sure it
is correctly located in the pin groove
15 Reconnect the wiring connector to the
clutch pedal switch (where fitted) then refit the
heater/ventilation duct and facia undercover.
6 Clutch assembly removal, inspection
and refitting
6.3 Vauxhall service tool for depressing
the diaphragm spring on engines with a
normal flywheel
Arrows indicate where pressure plate
retaining clips are fitted
Refitting
10 If the pedal and bracket assembly has
been dismantled, apply a smear of multipurpose grease to the pedal pivot bolt and
bushes prior to reassembly.
11 On 2.0 litre engine models, fit the return
spring to the pedal then refit the assembly to
the mounting bracket. Insert the pivot bolt
then refit the washer and nut, tightening it to
the specified torque. Secure the pivot bolt nut
in position with the retaining clip then hook
the return spring back into position.
12 On 2.5 and 3.0 litre engine models refit the
pedal to the mounting bracket then, making
sure the thrustwasher is correctly positioned,
insert the pivot bolt. Refit the washer and nut to
the pivot bolt then tighten it to the specified
torque and secure in position with the retaining
clip. Ensure the end fittings are correctly seated
on the return spring then refit the assembly to
the pedal and bracket making sure the smaller
end fitting is positioned at the pedal end.
13 On all models, manoeuvre the pedal and
bracket assembly into position and refit the
upper retaining bolt. Engage the master
cylinder pushrod with the pedal then refit the
master cylinder retaining nuts. Tighten both
the master cylinder nuts and the pedal
bracket bolt to their specified torque settings.
14 Apply a smear of multi-purpose grease to
the clevis pin then align the clevis and pedal
and insert the pin. Secure the clevis pin in
6.14 Refit the friction plate making sure its
spring hub assembly faces away from the
flywheel
4
Warning: Dust created by clutch
wear and deposited on the clutch
components
may
contain
asbestos, which is a health hazard. DO
NOT blow it out with compressed air, or
inhale any of it. DO NOT use petrol or
petroleum-based solvents to clean off the
dust. Brake system cleaner or methylated
spirit should be used to flush the dust into
a suitable receptacle. After the clutch
components are wiped clean with rags,
dispose of the contaminated rags and
cleaner in a sealed, marked container.
Note: Although some friction materials may
no longer contain asbestos, it is safest to
assume that they do, and to take precautions
accordingly.
Removal
1 Remove the transmission as described in
Chapter 7A.
2 Before disturbing the clutch, use chalk or a
marker pen to mark the relationship of the
pressure plate assembly to the flywheel.
3 Working in a diagonal sequence, evenly
and progressively slacken the pressure plate
bolts by half a turn at a time, until spring
pressure is released and the bolts can be
unscrewed by hand.
Caution: To avoid the risk of distorting the
pressure plate diaphragm spring it is most
important that the pressure plate bolts are
evenly slackened. To avoid this, on models
with a normal flywheel (it is not possible if
a dual-mass flywheel is fitted) Vauxhall
dealers use a special tool to depress the
diaphragm spring and then hold the spring
in its compressed state by fitting special
clips to the pressure plate assembly (see
illustration). Removal of the clips and
fitting to a new pressure plate will then
6.17 Centralising the friction plate with an
aligning tool
3510 Vauxhall/Opel Omega
require the use of a press. However,
provided adequate care is taken to
unscrew the pressure plate bolts evenly no
distortion should occur.
4 Remove the pressure plate assembly and
collect the friction plate, noting which way
round the friction plate is fitted.
Inspection
Note: Due to the amount of work necessary to
remove and refit clutch components, it is
usually considered good practice to renew the
clutch friction plate, pressure plate assembly
and release bearing as a matched set, even if
only one of these is actually worn enough to
require renewal. It is also worth considering
the renewal of the clutch components on a
preventive basis if the engine and/or
transmission have been removed for some
other reason.
5 Remove the clutch assembly.
6 When cleaning clutch components, read
first the warning at the beginning of this
Section; remove dust using a clean, dry cloth,
and working in a well-ventilated atmosphere.
7 Check the friction plate facings for signs of
wear, damage or oil contamination. If the
friction material is cracked, burnt, scored or
damaged, or if it is contaminated with oil or
grease (shown by shiny black patches), the
friction plate must be renewed.
8 If the friction material is still serviceable,
check that the centre boss splines are
unworn, that the torsion springs are in good
condition and securely fastened, and that all
the rivets are tight. If any wear or damage is
found, the friction plate must be renewed.
9 If the friction material is fouled with oil, this
must be due to an oil leak from the crankshaft
oil seal, from the sump-to-cylinder block joint,
or from the release cylinder assembly (either
the input shaft seal or the sealing ring). Renew
the crankshaft oil seal or repair the sump joint
as described in the relevant part of Chapter 2,
before installing the new friction plate. The
clutch release cylinder is covered in Section 4.
10 Check the pressure plate assembly for
obvious signs of wear or damage; shake it to
check for loose rivets or worn or damaged
fulcrum rings, and check that the drive straps
securing the pressure plate to the cover do
not show signs (such as a deep yellow or blue
discoloration) of overheating. If the diaphragm
spring is worn or damaged, or if its pressure is
in any way suspect, the pressure plate
assembly should be renewed.
11 Examine the machined bearing surfaces
of the pressure plate and of the flywheel; they
should be clean, completely flat, and free from
scratches or scoring. If either is discoloured
from excessive heat, or shows signs of
cracks, it should be renewed - although minor
damage of this nature can sometimes be
polished away using emery paper.
12 Also check that the release cylinder
bearing rotates smoothly and easily, with no
sign of noise or roughness. Also check that
the surface itself is smooth and unworn, with
Clutch 6•5
no signs of cracks, pitting or scoring. If there
is any doubt about its condition, the bearing
should be renewed (see Section 4).
Refitting
13 On reassembly, ensure that the bearing
surfaces of the flywheel and pressure plate
are completely clean, smooth, and free from
oil or grease. Use solvent to remove any
protective grease from new components.
14 Fit the friction plate so that its spring hub
assembly faces away from the flywheel; there
may also be a marking showing which way
round the plate is to be refitted (see illustration).
15 Refit the pressure plate assembly,
aligning the marks made on dismantling (if the
original pressure plate is re-used). Fit the
pressure plate bolts, but tighten them only
finger-tight, so that the friction plate can still
be moved.
16 The friction plate must now be
centralised, so that when the transmission is
refitted, its input shaft will pass through the
splines at the centre of the friction plate.
17 Centralisation can be achieved by passing
a screwdriver or other long bar through the
friction plate and into the hole in the
crankshaft; the friction plate can then be
moved around until it is centred on the
crankshaft hole. Alternatively, a clutchaligning -tool can be used to eliminate the
guesswork; these can be obtained from most
accessory shops (see illustration). A homemade aligning tool can be fabricated from a
length of metal rod or wooden dowel which
fits closely inside the crankshaft hole, and has
insulating tape wound around it to match the
diameter of the friction plate splined hole.
18 When the friction plate is centralised,
tighten the pressure plate bolts evenly and in
a diagonal sequence to the specified torque
setting. Once all the bolts have been
tightened remove the alignment tool. Where
necessary, use the service tool to remove the
retaining clips from the pressure plate.
Caution: To avoid the risk of distorting the
pressure plate diaphragm spring it is most
important that the pressure plate bolts are
evenly and progressively tightened.
19 Refit the transmission as described in
Chapter 7A.
6
3510 Vauxhall/Opel Omega
7A•1
Chapter 7 Part A:
Manual transmission
Contents
Gearchange linkage - adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . .
Gearchange linkage - removal and refitting . . . . . . . . . . . . . . . . . . .
General information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oil seals - renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3
4
1
5
Reversing light switch - testing, removal and refitting . . . . . . . . . . .
Transmission - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . .
Transmission oil - draining, refilling and checking . . . . . . . . . . . . . . .
Transmission overhaul - general information . . . . . . . . . . . . . . . . . .
6
7
2
8
Degrees of difficulty
Easy, suitable for
novice with little
experience
1
Fairly easy, suitable
for beginner with
some experience
2
Fairly difficult,
suitable for competent
DIY mechanic
3
Difficult, suitable for
experienced DIY
mechanic
4
Very difficult,
suitable for expert DIY
or professional
5
Specifications
General
Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Identification code:
2.0 and 2.5 litre engines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.0 litre engines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Manual, five forward speeds and reverse. Synchromesh on all forward
speeds
R25
R28
Torque wrench settings
Nm
Drain plug . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Engine to transmission support bracket bolts - 2.0 litre engines with one-piece sump:
Bracket-to-engine bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Bracket-to-transmission bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Filler plug . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Gearchange lever retaining bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Gearchange linkage rod clamp bolt:
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Angle-tighten a further 135 to 180º
Propeller shaft flange nut . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150
Reversing light switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Transmission unit mounting bolts:
Transmission-to-cylinder block bolts . . . . . . . . . . . . . . . . . . . . . . . . . 60
Transmission-to-sump flange bolts (engines with a two-piece sump) . 40
Rear upper mounting bracket bolts . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Rear mounting crossmember-to-body bolts . . . . . . . . . . . . . . . . . . . 45
lbf ft
22
30
16
22
7
10
110
15
44
30
16
33
7A
1 General information
1 The transmission is contained in a castaluminium alloy casing bolted to the rear of
the engine. Drive is transmitted from the
crankshaft via the clutch to the transmission
input shaft, which has a splined extension to
accept the clutch friction plate. The
transmission input shaft transfers drive to the
auxiliary shaft which is positioned directly
below the main shaft, both shafts being
parallel to the crankshaft and propeller shaft.
2 Gear selection is via a floor-mounted lever
and selector linkage mechanism. The selector
linkage cause the appropriate selector fork to
move its respective synchro-sleeve along the
shaft, to lock the gear pinion to the synchrohub. Since the synchro-hubs are splined to
the main shaft, this locks the pinion to the
shaft, so that drive can be transmitted. To
ensure that gear-changing can be made
quickly and quietly, a synchro-mesh system is
fitted to all forward gears, consisting of baulk
rings and spring-loaded fingers, as well as the
gear pinions and synchro-hubs. The synchromesh cones are formed on the mating faces
of the baulk rings and gear pinions.
3510 Vauxhall/Opel Omega
2 Transmission oil draining, refilling and checking
3
Note: There have been three different types of
oil used in the manual transmission unit by
Vauxhall (see Lubricants and fluids in Weekly
checks). Bearing in mind that the different types
of oil should never be mixed, it is essential that
the transmission unit is refilled either with the
same type of oil as that which has been drained
or the very latest specification oil (used in
production from 1999 model year onwards). If it
is not known what type of oil has been drained,
7A•2 Manual transmission
Warning: If the oil is hot, take
precautions against scalding.
5 When the oil has finished draining, clean
the drain plug threads and those of the
transmission casing then refit the drain plug
and tighten to the specified torque.
Refilling
2.4 Removing the transmission drain plug
the transmission unit should be flushed before
filling with the latest specification oil. To do this,
using the latest type of oil (part number 19 40
768), refill the transmission unit so that the oil
level is right up to the base of the filler plug
aperture then refit the plug. Take the vehicle on
a journey of approximately 15 miles (20 km)
then, on your return, drain the oil out again and
refill the transmission as normal with the latest
type of oil. If the flushing process has already
been carried out an early (pre 1999 model year)
vehicle, the drain plug will be marked with a dot
of green paint.
6 Refilling the transmission is an extremely
awkward operation. Above all, allow plenty of
time for the oil level to settle properly before
checking it. Note that the car must be parked
on flat level ground when checking the oil
level.
7 Refill the transmission with the exact
amount of the specified type of oil then check
the oil level as described in paragraphs 12
and 13. When the level is correct, refit the filler
plug and tighten it to the specified torque.
8 Take the vehicle on a short journey so that
the new oil is distributed fully around the
transmission components.
9 On your return, park the vehicle on level
ground and recheck the transmission oil level
again to ensure the level is correct.
of a piece of welding rod with a right-angled
bend in it. Insert the rod into the filler hole and
check the oil level; the oil level should be
approximately 9 mm below the lower edge of
the filler plug aperture.
Caution: When checking the oil level, take
great care not to drop the dipstick into the
transmission unit.
13 If topping up is necessary, add the correct
type of oil through the filler hole until the oil
level is correct. Note: Do not overfill the
transmission as this will adversely affect the
gearchange action. Any excess oil must be
either be siphoned or drained from the
transmission unit before the vehicle is used.
14 Once the transmission oil level is correct,
refit the filler plug and tighten it to the
specified torque.
3 Gearchange linkage adjustment
3
1 This operation is much quicker and more
efficient if the car is first taken on a journey of
sufficient length to warm the engine/transmission up to normal operating temperature.
2 Park the car on level ground, switch off the
ignition and apply the handbrake firmly. For
improved access, jack up the front of the car
and support it securely on axle stands. Note
that the car must be lowered to the ground
and level, to ensure accuracy, when refilling
and checking the oil level.
3 Remove all traces of dirt then unscrew the
filler plug from the right-hand side of the
transmission housing.
4 Position a suitable container under the
drain plug situated on the base of the
transmission housing then unscrew the drain
plug and allow the oil to drain completely into
the container (see illustration). Clean both
the filler and the drain plugs, being especially
careful to wipe any metallic particles off the
magnetic inserts.
Note: It is essential that the transmission unit
is topped up with the same type of oil as that
with which it is filled; there are three different
types of oil available and they must never be
mixed. If it is not known which type of oil the
transmission is filled with, it is recommended
that the unit is drained, flushed and then
refilled with the latest type of oil (see Note at
the start of the Section).
10 Position the vehicle over an inspection pit,
on vehicle ramps, or jack it up, but make sure
that it is level. The oil level must be checked
before the car is driven, or at least 5 minutes
after the engine has been switched off. If the
oil is checked immediately after driving the
car, some of the oil will remain distributed
around the transmission components,
resulting in an inaccurate level reading.
11 Wipe clean the area around the filler plug
which is located on the right-hand side of the
transmission housing. Unscrew the plug and
clean it.
12 To check the oil level, it will be necessary
to fabricate a dipstick. This can be made out
Note: Vauxhall service tool KM-631A will be
required to carry out this procedure.
1 Adjustment of the gearchange linkage is not
a routine operation and should only be
needed if the mechanism has been removed.
If the gearchange action is stiff or imprecise,
check that it is correctly adjusted as follows.
2 Position the gearchange lever in the neutral
position, firmly apply the handbrake then jack
up the front of the vehicle and support it on
axle stands.
3 Remove the retaining clips securing the
protective cover to the vehicle underbody
then fold the cover forwards to gain access to
the clamp bolt on the rear end of the
gearchange linkage rod. Slacken the clamp
bolt so that the end fitting is free to move
easily in the rod (see illustrations).
4 From inside the vehicle, unclip the
gearchange lever gaiter from the centre
console and fold it back over the lever. Free
the rubber gaiter from the mounting plate and
fold it back to gain access to the base of the
gearchange lever.
5 Lock the gearchange lever in position by
fitting the service tool (KM-631A) into the
gearchange lever housing whilst holding the
lever over to the right.
3.3a Release the retaining clips
(arrowed) . . .
3.3b . . . and peel back the protective
cover . . .
3.3c . . . to gain access to the gearchange
linkage clamp bolt (arrowed)
Draining
Checking
3510 Vauxhall/Opel Omega
Manual transmission 7A•3
6 From underneath the vehicle, using an openended spanner on the flats provided, turn the
gearchange linkage rod fully clockwise (as
viewed from the rear of the vehicle). Hold the
rod in this position then tighten the rod clamp
bolt first to the specified stage 1 torque and
then through the specified stage 2 angle.
7 Remove the service tool and check the
operation of the gearchange lever before
seating the rubber gaiter onto its mounting
and clipping the gaiter back into the centre
console.
8 Ensure the protective cover is correctly
seated on the base of the gearchange lever,
securing it in position with the retaining clips,
then lower the vehicle to the ground.
4 Gearchange linkage removal and refitting
3
Removal
Gearchange lever
1 Firmly apply the handbrake then jack up the
front of the vehicle and support it on axle
stands.
2 Remove the retaining clips securing the
protective cover to the vehicle underbody
then fold the cover forwards to gain access to
the base of the gearchange lever (see
illustrations 3.3a and 3.3b).
3 Slide off the retaining clip and withdraw the
pivot pin from the lever end of the linkage rod
(see illustration). Free the rod from the base
of the gearchange lever taking care not to lose
the pivot bushes.
4 Slacken and remove the four bolts securing
the lever assembly to the floor.
5 From inside the vehicle, unclip the
gearchange lever gaiter from the centre
console and fold it back over the lever.
6 Free the rubber gaiter from the mounting
plate and remove the lever assembly from the
vehicle, taking care not to lose the threaded
retaining plates. Recover the sealing washer
which is fitted between the lever mounting
and floor.
7 Check the lever assembly for signs of wear
or damage and renew damaged components
as necessary.
4.3 Slide off the retaining clip (arrowed)
then withdraw the pivot pin securing the
linkage rod to the gearchange lever
4.9 Slacken and remove the nut and pivot
bolt (arrowed) securing the linkage rod to
the transmission unit
and the threaded retaining plates with multipurpose grease (Vauxhall recommend the use
of grease 19 48 606 or 19 48 608 - available
from your Vauxhall dealer) and stick the
sealing washer to the base of the mounting.
11 Ensure the retaining plates are correctly
positioned then refit the lever assembly to the
vehicle. Make sure the lever mounting lugs are
correctly seated (the larger lug should be at
the rear) then refit the retaining bolts and
tighten them to the specified torque.
12 Align the linkage rod with the lever then
insert the pivot pin and secure it in position
with the retaining clip. Ensure the protective
cover is correctly seated on the base of the
gearchange lever and secure it in position
with the retaining clips.
13 Seat the gearchange lever rubber gaiter
onto its mounting and clipping the gaiter back
into the centre console.
transmission flange and remove the vibration
damper (where fitted). If necessary, to
improve access to the flange remove the shaft
completely.
2 To prevent the rotation as the shaft nut is
slackened bolt a length of bar with two holes
drilled in it to the flange. Alternatively, a tool
can be fabricated from two lengths of steel
strip (one long, one short) and a nut and bolt;
the nut and bolt forming the pivot of a forked
tool (see illustration).
3 Hold the flange then slacken and remove
the retaining nut from the end of the
transmission main shaft. Remove the holding
tool and slide off the flange (see illustration).
4 Note the correct fitted depth of the seal in
the transmission housing then carefully prise it
out of position using a large flat-bladed
screwdriver.
5 Check the propeller flange sealing surface
for signs of wear or damage. If there is visible
signs of damage, renew the flange.
6 Clean all traces of dirt from the area around
the oil seal aperture and remove all traces of
thread locking compound from the main shaft
and flange nut threads.
7 Apply a smear of grease to the outer lip of
the new oil seal then, making sure its sealing
lip is facing inwards, slide it over the main
shaft end. Tap the seal squarely into position,
using a suitable tubular drift (such as a socket)
which bears only on the hard outer edge of
the seal, until it is positioned at the same
depth in the housing that the original was.
8 Lubricate the seal with a smear of
Linkage rod
14 Refitting is the reverse of removal
lubricating the pivots with multi-purpose
grease.
5 Oil seals renewal
4
Propeller shaft flange oil seal
1 Working as described in Chapter 8, free the
front end of the propeller shaft from the
7A
Linkage rod
8 Carry out the operations described in
paragraphs 1 to 3.
9 Slacken and remove the nut and bolt
securing the front end of the linkage rod to the
transmission selector rod joint and remove the
rod from underneath the vehicle (see
illustration). Recover the spacer from the
joint and inspect the joint pivot bushes for
signs of wear.
Refitting
Gearchange lever
10 Lubricate the lever pivot ball and bushes
5.2 Slacken and remove the retaining nut
whilst retaining the propeller shaft flange
with a home-made tool . . .
3510 Vauxhall/Opel Omega
5.3 . . . then remove the flange from the
output shaft (shown with transmission
removed)
7A•4 Manual transmission
transmission oil then carefully slide the
propeller flange into position, taking care not
to damage the seal lip.
9 Apply a few drops of thread locking
compound (Vauxhall recommend the use of
locking compound 15 10 181 - available from
your Vauxhall dealer) to the threads of the
flange retaining nut. Refit the nut and tighten it
to the specified torque using the method
employed on removal to prevent rotation.
10 Reconnect/refit the propeller shaft as
described in Chapter 8 then check the transmission oil level as described in Section 2.
4 Disconnect the wiring connector, then
unscrew the switch and remove it from the
transmission casing along with its sealing
washer.
Refitting
5 Fit a new sealing washer to the switch, then
screw it back into position in the top of the
transmission housing and tighten it to the
specified torque. Reconnect the wiring
connector and test the operation of the circuit
then lower the vehicle to the ground.
Input shaft oil seal
Note: A leak around the transmission input
shaft can come either from the input shaft seal
or from the clutch release cylinder sealing
ring. Whilst the cylinder is removed renew
both items regardless of their apparent
condition.
11 Remove the clutch release cylinder as
described in Chapter 6.
12 Note the correct fitted depth of the seal in
the release cylinder then carefully prise it out of
position using a large flat-bladed screwdriver.
13 Clean all traces of dirt from the area
around the oil seal aperture and apply a smear
of grease to the outer lip of the new oil seal.
Making sure its sealing lip is facing outward
(towards the transmission unit when the
cylinder is fitted), seat the seal in the rear of
the cylinder and press it squarely into position
until it is positioned at the same depth in the
housing that the original was. If necessary, tap
the seal into position, using a suitable tubular
drift (such as a socket) which bears only on
the hard outer edge of the seal.
14 Fit a new sealing ring and refit the release
cylinder as described in Chapter 6.
6 Reversing light switch testing, removal and refitting
2
Testing
1 The reversing light circuit is controlled by a
plunger-type switch that is screwed into the
rear of the transmission, above and to the left
of the propeller shaft. If a fault develops in the
circuit, first ensure that the circuit fuse has not
blown.
2 To test the switch, disconnect the wiring
connector. Use a multimeter (set to the
resistance function) or a battery-and-bulb test
circuit to check that there is continuity
between the switch terminals only when
reverse gear is selected. If this is not the case,
and there are no obvious breaks or other
damage to the wires, the switch is faulty, and
must be renewed.
Removal
3 Firmly apply the handbrake then jack up the
front of the vehicle and support it on axle
stands.
7 Transmission removal and refitting
4
Removal
1 Disconnect the battery negative terminal.
Note: On models with a Vauxhall anti-theft
warning system (ATWS), the battery negative
terminal must be disconnected within 15
seconds of the ignition being switched off to
prevent the alarm system being triggered.
2 Chock the rear wheels, then firmly apply the
handbrake. Jack up the front of the vehicle,
and securely support it on axle stands. Undo
the retaining bolts and remove the undercover
from beneath the engine/transmission unit.
3 Trace the clutch hydraulic hose/pipe back
from the transmission unit to connector on the
engine compartment bulkhead. Minimise fluid
loss by clamping the fluid supply hose linking
the fluid reservoir to the clutch master cylinder
then release the connector from the bulkhead.
Slide out the retaining clip and separate the
two halves of the pipe, plugging the pipe ends
to minimise fluid loss and prevent the entry of
dirt. Refit the retaining clip to the connector
groove, ensuring its is correctly located, then
check the lower end of the pipe is free to
removed with the transmission unit.
Caution: Do no depress the clutch pedal
whilst the hose is disconnected.
4 Disconnect the wiring connector from the
reversing light switch, which is located at the
rear of the transmission unit.
5 Working as described in Chapter 8, unbolt
the front end of the propeller shaft from the
transmission flange and remove the vibration
damper (where fitted). Position the propeller
shaft to the right of the transmission unit and
tie it to the vehicle underbody.
6 Remove the gearchange linkage rod as
described in Section 4 and proceed as
described under the relevant sub-heading.
2.0 litre engines
7 On SOHC engines, disconnect the wiring
connector from the DIS module. Slacken and
remove the module mounting bracket
retaining bolts, noting the correct fitted
location of the engine lifting bracket, then free
the wiring harness and remove the DIS
module and bracket from the rear of the
3510 Vauxhall/Opel Omega
cylinder head. Free the HT leads from their
retaining clips and position the assembly clear
of the transmission unit.
8 On all models unclip the oxygen sensor
wiring connector from transmission unit and
disconnect it.
9 Slacken and remove the exhaust system
front pipe mounting bracket retaining bolts
and remove the bracket. Also remove the
bolts securing the front pipe to the
intermediate pipe and separate the two
exhaust sections.
10 On models with a one-piece engine sump,
slacken and remove the bolts securing the
support brackets to the transmission housing
and sides of the cylinder block. Remove both
brackets from the engine then remove the
flywheel lower cover plate from the base of
the transmission housing.
11 On all models slacken and remove the
two bolts securing the rear of the transmission
unit to the upper mounting bracket.
12 Place a jack with a block of wood beneath
the transmission, and raise the jack to take
the weight of the transmission.
13 With the transmission securely supported,
slacken and remove the bolts securing the
transmission unit rear mounting crossmember
to the vehicle body.
14 Lower the transmission unit slightly then
slacken and remove all the bolts securing the
transmission housing to the engine unit. Note
the correct fitted positions of each bolt, and
the necessary brackets, as they are removed,
to use as a reference on refitting. Make a final
check that all components have been
disconnected, and are positioned clear of the
transmission so that they will not hinder the
removal procedure.
15 With the bolts removed, move the trolley
jack and transmission to the rear, to free it
from its locating dowels. Once the
transmission is free, lower the jack and
manoeuvre the unit out from under the
vehicle. Remove the locating dowels from the
transmission or engine if they are loose, and
keep them in a safe place.
16 With the transmission removed from the
vehicle, slide off the clutch release bearing
from the release cylinder and check it for
wear. The bearing contact surface should
rotate smoothly and easily, with no sign of
noise or roughness, and that the surface itself
is smooth and unworn, with no signs of
cracks, pitting or scoring. If there is any doubt
about its condition, the bearing should be
renewed.
2.5 and 3.0 litre engines
17 Remove both exhaust system front pipes
as described in Chapter 4A.
18 Remove the transmission unit as
described in paragraphs 11 to 16.
Refitting
19 The transmission is refitted by a reversal
of the removal procedure, bearing in mind the
following points.
Manual transmission 7A•5
a) Remove all traces of dirt and grease from
the input shaft splines and the contact
surfaces of the clutch release bearing and
release cylinder. Lubricate the inner bore
of the release bearing with a smear of
high temperature grease (Vauxhall
recommend the use of lubricating paste
19 42 530 - available from your Vauxhall
dealer) and apply a thin smear of grease
to the input shaft splines; do apply too
much or there is risk of the clutch friction
plate becoming contaminated. Fit the
release bearing to the cylinder making
sure it is the correct way around.
b) Ensure the locating dowels are correctly
positioned prior to refitting the
transmission to the engine. As the
transmission unit is fitted, take great care
not to allow the weight of the unit to hang
on the input shaft.
c) Remove all traces of locking compound
from the transmission unit rear mounting
crossmember to body bolt threads. Apply
a few drops of thread locking compound
(Vauxhall recommend the use of locking
compound 15 10 181 - available from
your Vauxhall dealer) to the threads of
each bolt prior to refitting and tighten
both bolts to the specified torque.
d) Tighten all nuts and bolts to the specified
torque (where given).
e) Ensure the clutch hydraulic pipe
connector sealing ring is in good
condition before clipping the hose/pipe
end fitting into position. Ensure the end
fitting is securely retained by its clip then
remove the clamp from the master
cylinder hose and bleed the hydraulic
system as described in Chapter 6.
f) On completion check and, if necessary,
top up the transmission oil level as
described in Section 2. If necessary, also
adjust the gearchange linkage as
described in Section 3.
8 Transmission overhaul general information
5
1 Overhauling a manual transmission unit is a
difficult and involved job for the DIY home
mechanic. In addition to dismantling and
reassembling many small parts, clearances
must be precisely measured and, if necessary,
changed by selecting shims and spacers.
Internal transmission components are also
often difficult to obtain, and in many instances,
extremely expensive. Because of this, if the
transmission develops a fault or becomes
noisy, the best course of action is to have the
unit overhauled by a specialist repairer, or to
obtain an exchange reconditioned unit.
2 Nevertheless, it is not impossible for the
more experienced mechanic to overhaul the
transmission, provided the special tools are
available, and the job is done in a deliberate
step-by-step manner, so that nothing is
overlooked.
3 The tools necessary for an overhaul include
internal and external circlip pliers, bearing
pullers, a slide hammer, a set of pin punches,
a dial test indicator, and possibly a hydraulic
press. In addition, a large, sturdy workbench
and a vice will be required.
4 During dismantling of the transmission,
make careful notes of how each component is
fitted, to make reassembly easier and more
accurate.
5 Before dismantling the transmission, it will
help if you have some idea what area is
malfunctioning. Certain problems can be
closely related to specific areas in the
transmission, which can make component
examination and replacement easier. Refer to
the Fault finding Section of this manual for
more information.
7A
3510 Vauxhall/Opel Omega
7B•1
Chapter 7 Part B:
Automatic transmission
Contents
Automatic transmission - removal and refitting . . . . . . . . . . . . . . . . . 9
Automatic transmission fluid level check . . . . . . . . . . . .See Chapter 1
Automatic transmission overhaul - general information . . . . . . . . . . 10
Fluid cooler - general information . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
General information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Oil seals - renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Selector lever assembly - removal and refitting . . . . . . . . . . . . . . . .
Selector linkage - adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Selector linkage - removal and refitting . . . . . . . . . . . . . . . . . . . . . . .
Transmission control system electrical components - removal and
refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Transmission fluid - draining and refilling . . . . . . . . . . . . . . . . . . . . .
5
3
4
8
2
Degrees of difficulty
Easy, suitable for
novice with little
experience
1
Fairly easy, suitable
for beginner with
some experience
2
Fairly difficult,
suitable for competent
DIY mechanic
3
Difficult, suitable for
experienced DIY
mechanic
4
Very difficult,
suitable for expert DIY
or professional
5
Specifications
General
Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Four-speed electronically-controlled automatic with three (normal,
sport and winter) driving modes
Identification code*:
2.0 and 2.5 litre models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . AR25
3.0 litre models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . AR35
*The code is marked on the identification plate which is attached to the left-hand side of the transmission unit, behind the selector lever.
Torque wrench settings
Nm
Engine-to-transmission support bracket bolts - 2.0 litre engines with one-piece sump:
Bracket-to-engine bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Bracket-to-transmission bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Fluid cooler pipe unions:
Union bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Union nut . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Fluid filter retaining bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Fluid level plug . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Output speed sensor bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Propeller shaft centre bearing bracket bolts . . . . . . . . . . . . . . . . . . . . . 20
Propeller shaft flange nut . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
Rear mounting crossmember-to-body bolts . . . . . . . . . . . . . . . . . . . . . 45
Selector lever position switch bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Selector linkage fixings:
Linkage rod clamp bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Lever pivot shaft nut . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Lever to transmission selector shaft nut . . . . . . . . . . . . . . . . . . . . . . . 20
Sump retaining bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Torque converter-to-driveplate bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Transmission unit mounting bolts:
Transmission-to-cylinder block bolts . . . . . . . . . . . . . . . . . . . . . . . . . 60
Transmission-to-sump flange bolts
(engines with a two-piece sump) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
1 General information
Note: On later models, if the battery is
disconnected with the selector lever in the P
position, the lever will be locked in position. To
manually release the lever, carefully unclip the
selector lever gaiter from the top of the centre
console then, depress the yellow release lever
on the left-hand side of the selector lever with
a pen or screwdriver (see illustrations). The
selector lever can then be moved as normal.
1 Most models covered in this manual were
offered with the option of a four-speed,
3510 Vauxhall/Opel Omega
Ibf ft
30
16
18
22
15
24
9
15
74
33
10
6
21
15
9
22
44
30
electronically-controlled automatic transmission, consisting of a torque converter, an
epicyclic geartrain, and hydraulically-operated
clutches and brakes. The unit is controlled by
the electronic control unit (ECU) via
electrically-operated solenoid valves. The
transmission unit has three driving modes;
normal (economy), sport and winter modes.
7B
7B•2 Automatic transmission
2 Transmission fluid draining and refilling
3
1.0a On later models, to release the
selector lever from the P position with the
battery disconnected, unclip the selector
lever gaiter . . .
1.0b . . . then depress the yellow release
lever (arrowed) on the selector lever
mounting
2 The normal (economy) mode is the
standard mode for driving in which the
transmission shifts up at relatively low engine
speeds to combine reasonable performance
with economy. If the transmission unit is
switched into sport mode, using the button
on the selector lever, the transmission shifts
up only at high engine speeds, giving
improved acceleration and overtaking
performance. When the transmission is in
sport mode, the indicator light in the
instrument panel is illuminated. If the
transmission is switched into winter mode,
using the button on the centre console, the
transmission will be select third gear as the
vehicle pulls away from a standing start; this
helps to maintain traction on very slippery
surfaces.
3 The torque converter provides a fluid
coupling between engine and transmission,
which acts as an automatic clutch, and also
provides a degree of torque multiplication
when accelerating.
4 The epicyclic geartrain provides either of
the four forward or one reverse gear ratios,
according to which of its component parts are
held stationary or allowed to turn. The
components of the geartrain are held or
released by brakes and clutches which are
activated by the control unit. A fluid pump
within the transmission provides the
necessary hydraulic pressure to operate the
brakes and clutches.
5 Driver control of the transmission is by a
seven-position selector lever. The drive D
position,
allows
automatic
changing
throughout the range of all four gear ratios. An
automatic kickdown facility shifts the
transmission down a gear if the accelerator
pedal is fully depressed. The transmission
also has three hold positions, 1 means only
the first gear ratio can be selected, 2 allows
both the first and second gear ratios position
to be automatically selected and 3 allows
automatic changing between the first three
gear ratios. These hold positions are useful for
providing engine braking when travelling
down steep gradients. Note, however, that the
transmission should never be shifted down a
position at high engine speeds.
6 If the ECU senses a fault in the transmission
operation it will illuminate the warning light on
the instrument panel and the relevant fault
code will be stored in the ECU memory. If the
warning light comes on, the vehicle should be
taken to a Vauxhall dealer at the earliest
opportunity. A complete test of the
transmission unit can then be carried out,
using a special electronic diagnostic test unit
which is simply plugged into the system’s
diagnostic connector. The connector is
located behind the fusebox cover panel on
the drivers’ side of the facia.
7 Due to the complexity of the automatic
transmission, any repair or overhaul work
must be left to a Vauxhall dealer. The contents
of the following Sections are therefore
confined to supplying general information,
and any service information and instructions
that can be used by the owner.
Note: A new main sump gasket will be
required for this operation. If the intermediate
sump is also to be removed, obtain a new
gasket for that as well.
1 Since the transmission fluid is not renewed
as part of the manufacturers maintenance
schedule, no drain plug is fitted to the
transmission. If for any reason the
transmission needs to be drained, the only
way of doing so is to remove the main sump
and, if necessary, the intermediate sump.
2 Park the vehicle on level ground, switch off
the ignition, and apply the handbrake firmly.
For improved access, jack up the front of the
car and support it securely on axle stands but
note that the vehicle must be level when the
transmission is refilled.
3 Position a container under the fluid level
plug on the right-hand side of the transmission main sump. Unscrew the plug and
remove it along with its sealing washer (see
illustration).
4 Allow the fluid to drain out into the container
then refit the level plug (see illustration).
5 Bearing in mind that the sump will still be full
of oil, position a large container underneath
the main sump. Evenly and progressively
slacken and remove the sump retaining bolts,
noting the correct location of the cooler pipe
retaining clip(s) (see illustration). Carefully
remove the sump and empty its contents into
the container. Remove the gasket and discard
it; a new one should be used on refitting.
6 To drain the transmission unit completely,
slacken and remove the retaining bolts, then
remove the intermediate sump from the
transmission unit and empty its contents into
the container. Remove the gasket and discard
it; a new one should be used on refitting.
7 Whilst the main sump is removed, take the
opportunity to check the transmission fluid
filter. Undo the three retaining bolts, then
remove the filter from the underside of the
transmission (see illustrations). Clean the
filter element in a bath of solvent, then
examine the element for signs of clogging or
damage. If the filter element is split or blocked
2.3 Slacken and remove the fluid level
plug from the main sump . . .
2.4 . . . and allow the transmission fluid to
drain into a suitable container
2.5 Unscrew the retaining bolts and
remove the main sump from the
transmission unit
3510 Vauxhall/Opel Omega
Automatic transmission 7B•3
2.7a Undo the retaining bolts (arrowed) . . .
2.7b . . . and remove the fluid filter from
the transmission unit
or its seal is damaged, then the filter must be
renewed (the seal is not available separately).
8 Remove all traces of dirt and fluid from the
sump and transmission mating surfaces and
wipe clean the inside of the sump(s). Remove
the magnet from inside the main sump and
clean all traces of metal filings from it; the
filings should be very fine - any sizeable chips
of metal indicate a worn component in the
transmission (see illustration). Also remove
all traces of locking compound from the
threads of the sump retaining bolts.
9 Ensure that the filter element and
transmission mating surfaces are clean and
dry. Offer up the filter to the transmission then
refit the retaining bolts and tighten them to the
specified torque.
10 Where necessary, ensure the mating
surfaces are clean and dry then refit the
intermediate sump to the transmission unit,
complete with a new gasket (see illustration).
Apply a drop of thread locking compound
(Vauxhall recommend the use of locking
compound 15 10 181 - available from your
Vauxhall dealer) to the each of the retaining
bolts then refit the bolts, tightening them
evenly and progressively to the specified
torque setting.
11 Ensure the mating surfaces of the main
sump and transmission unit are clean and dry.
Fit a new gasket to the sump and apply a drop
of thread locking compound (Vauxhall
recommend the use of locking compound 15
10 181 - available from your Vauxhall dealer)
to the each of the retaining bolts. Offer up the
sump and gasket then refit the bolts,
tightening them evenly and progressively to
the specified torque setting (see illustration).
12 Refilling the transmission is an awkward
operation, adding the specified type and
amount of fluid to the transmission a little at a
time via the level plug hole in the main sump.
Ensure that the vehicle is level then fill the
transmission with new fluid of the specified
type allowing plenty of time for the fluid level
to settle properly. Once the fluid level is up to
the base of the level plug aperture with the
engine stopped, it will be necessary to start
the engine and add the rest of the fluid with
the engine running.
13 Start the engine and allow it to idle then
carefully add the rest of the fluid. Once the
fluid level is up to the base of the level plug
aperture, refit the level plug and sealing
washer and tighten to the specified torque.
14 Take the car on a short run to fully
distribute the new fluid around the
transmission, then recheck the fluid level as
described in Chapter 1 with the transmission
at normal operating temperature. Once the
fluid level is correct fit a new sealing washer to
the level plug then refit the plug and tighten it
to the specified torque.
2.10 Refit the intermediate sump using a
new gasket
2.8 Clean all traces of metal fillings from
magnet which is fitted inside the main
sump
selector lever position indicator. If adjustment
is necessary, continue as follows.
2 Position the selector lever in the P (park)
position. Firmly apply the handbrake then jack
up the front of the vehicle and support it on
axle stands.
3 Locate the selector lever on the left-hand
side of the transmission unit and slacken the
clamp bolt at the transmission end of the
linkage rod (see illustration). Pull the
transmission selector lever fully backwards to
ensure it is located in the P (Park) position
then tighten the linkage rod clamp bolt to the
specified torque.
4 Check the operation of the selector lever
and the position indicator switch. If necessary,
adjust the switch as described in Section 8
then lower the vehicle to the ground.
4 Selector linkage removal and refitting
3
Removal
1 Operate the selector lever throughout its
entire range and check that the transmission
engages the correct gear indicated on the
1 Firmly apply the handbrake then jack up the
front of the vehicle and support it on axle
stands.
2 Slide off the retaining clips then free the
linkage rod from the transmission and selector
lever and manoeuvre it out from underneath
the vehicle (see illustration). Recover the
bushes which are fitted to the lever pivot pins
and renew them if they show signs of wear or
damage.
2.11 Ensure the mating surfaces are clean
and dry then refit the main sump complete
with a new gasket
3.3 Slacken the clamp bolt (arrowed) and
adjust the selector linkage as described in
text
3 Selector linkage adjustment
3510 Vauxhall/Opel Omega
3
7B
7B•4 Automatic transmission
Refitting
4.2 Slide off the retaining clip (arrowed)
and detach the selector linkage rod from
the selector lever
Refitting
3 Apply a smear of multi-purpose grease to
the linkage rod pivot pins. Ensure the bushes
are in position then refit the rod to the
transmission and selector lever and secure it
in position with the retaining clips.
4 Check the operation of the selector linkage
and, if necessary, adjust as described in
Section 3 before lower the vehicle to the
ground.
5 Selector lever assembly removal and refitting
3
Note: Renewal of the lever switches is
covered in Section 8
Removal
Note: A pop rivet gun and new rivets will be
required on refitting.
1 Remove the centre console as described in
Chapter 11 then position the selector lever in
the P (park) position.
2 Firmly apply the handbrake then jack up the
front of the vehicle and support it on axle
stands.
3 Slide off the retaining clip and detach the
selector linkage rod from the base of the lever.
Take care not to lose the lever pivot bush.
4 Slacken and remove the retaining nuts and
bolt then remove the front and rear support
brackets from the rear heater/ventilation duct.
Unclip the duct and remove it from the around
the selector lever.
5 Disconnect the wiring connector from the
selector lever mode switch and unclip the
wiring so that it is free to be removed with the
lever. On later models were the lever is fitted
with a selector lever pawl, remove the pawl
switch and the ignition key release switch as
described in Section 8.
6 Carefully drill off the heads from the rivets
securing the lever mounting plate to the floor
then ease the selector lever out of position.
Recover seal (where fitted) which is fitted
between the housing and floor.
7 Inspect the selector lever mechanism for
signs of wear or damage and renew worn
components as necessary
8 Ensure the mating surfaces of the lever
mounting plate and body are clean and dry.
Where a seal was fitted between the mounting
plate and body ensure the seal is in good
condition then position it on the body. Where
no seal was fitted apply and thin film of
sealant to the mating surface of the mounting
plate to ensure a water-tight seal.
9 Manoeuvre the lever assembly into position
and seat it on the body. Locate all the new
pop rivets in the mounting plate holes to
ensure the lever is correct positioned then
secure all the rivets in position with a pop rivet
gun.
10 Ensure the lever mode switch wiring is
correctly routed then reconnect its connector.
Where necessary, refit the pawl switch and
the ignition key release switch as described in
Section 8.
11 Clip the rear heater/ventilation duct back
into position then refit the support brackets,
tightening their retaining bolt/nuts securely.
12 Refit the centre console as described in
Chapter 11.
13 Ensure the pivot bush is correctly
positioned then reconnect the linkage rod to
the transmission selector lever and secure it in
position with the retaining clip.
14 Check the operation of the selector
linkage and, if necessary, adjust as described
in Section 3 before lower the vehicle to the
ground.
6 Oil seals renewal
4
Propeller shaft flange oil seal
Note: A new flange sealing ring and retaining
nut will be required.
1 Working as described in Chapter 8, free the
front end of the propeller shaft from the
transmission flange and remove the vibration
damper (where fitted). If necessary, to
improve access to the flange remove the shaft
completely.
2 To prevent the rotation as the shaft nut is
slackened bolt a length of bar with two holes
drilled in it to the flange. Alternatively, a tool
can be fabricated from two lengths of steel
strip (one long, one short) and a nut and bolt;
the nut and bolt forming the pivot of a forked
tool.
3 Hold the flange then slacken and remove
the retaining nut from the end of the
transmission main shaft. Remove the holding
tool and slide off the flange complete with its
sealing ring. Discard the nut and sealing ring;
new ones should be used on refitting.
4 Note the correct fitted depth of the seal in
the transmission housing then carefully prise it
out of position using a large flat-bladed
screwdriver.
5 Check the propeller flange sealing surface
3510 Vauxhall/Opel Omega
for signs of wear or damage. If there is visible
signs of damage, renew the flange.
6 Clean all traces of dirt from the area around
the oil seal aperture then apply a smear of
grease to the outer lip of the new oil seal.
7 Making sure its sealing lip is facing inwards,
slide the new seal over the main shaft end and
tap it squarely into position, using a suitable
tubular drift (such as a socket) which bears
only on the hard outer edge of the seal.
Ensure the seal is positioned at the same
depth in the housing that the original was.
8 Fit the new sealing ring to the flange then
lubricate the seal with a smear of transmission
oil. Carefully slide the propeller flange into
position, taking care not to damage the seal
lip. Fit the new nut and tighten it to the
specified torque using the method employed
on removal to prevent rotation.
9 Reconnect/refit the propeller shaft as
described in Chapter 8.
10 Take the vehicle on a short run then check
the transmission fluid level as described in
Chapter 1.
Selector shaft oil seal
11 Remove the selector lever position switch
as described in Section 8.
12 Using a small flat-bladed screwdriver,
carefully lever the oil seal out from the housing
then slide it off of the shaft.
13 Clean all traces of dirt from the area
around the oil seal aperture then apply a
smear of grease to the outer edge and lip of
the new oil seal.
14 Making sure its sealing lip is facing
inwards, slide the new seal along the selector
shaft and tap it squarely into position, using a
suitable tubular drift (such as a socket) which
bears only on the hard outer edge of the seal.
15 Refit the selector lever position switch as
described in Section 8.
7 Fluid cooler general information
1 The transmission fluid cooler is an integral
part of the radiator assembly. Refer to
Chapter 3 for removal and refitting details, if
the cooler is damaged the complete radiator
assembly must be renewed.
8 Transmission control system
electrical components removal and refitting
4
Selector lever position switch
1 The switch is a multi-function switch,
performing the reversing light and starter
inhibitor switch functions as well as operating
the selector lever position indicator panel. If at
any time the indicator panel or reversing light
operation becomes faulty, or it is noted that
the engine can be started with the selector
Automatic transmission 7B•5
lever in any position other than P (park) or N
(neutral), then it is likely that the switch is
faulty. If adjustment fails to correct the fault
then the switch assembly must be renewed.
Removal
2 Position the selector lever in the N (neutral)
position. Firmly apply the handbrake then jack
up the rear of the vehicle and support it on
axle stands.
3 Referring to Chapter 4A, slacken and
remove the bolts securing the front pipe/
catalytic converter to the intermediate pipe and
separate the flange joint; on 2.5 and 3.0 litre
models disconnect both left- and right-hand
sides. Unbolt the heatshield(s) from the vehicle
underbody to gain access to the propeller shaft
centre bearing.
4 Slacken and remove the two bolts securing
the propeller shaft centre bearing bracket to
the vehicle body (see Chapter 8). Recover any
washers (where fitted) which are positioned
between the bracket and vehicle body.
5 Trace the wiring back from the switch and
disconnect it at the wiring connector. Unclip
the wiring connector from the side of the
transmission housing so that it is free to be
removed with the switch. If the connector
retaining clip is broken on removal, obtain a
new one for refitting.
6 Unclip the protective cover from the switch
then unscrew the retaining nut and free the
selector lever from the end of the transmission
shaft (see illustrations).
7 Place a jack with a block of wood beneath
the transmission, and raise the jack to take
the weight of the transmission.
8 With the transmission securely supported,
slacken and remove the bolts securing the
transmission unit rear mounting crossmember
to the vehicle body.
9 Lower the transmission slightly until access
can be gained to the switch retaining bolts. As
the transmission is lowered, take great care to
ensure excess strain is not placed on the
propeller shaft or any of the engine
components and enlist the help of an
assistant to make sure nothing becomes
trapped between the rear of the engine and
bulkhead. Note: On 2.0 litre SOHC engines it
maybe necessary to remove the DIS module
assembly to gain the necessary clearance
required (see Chapter 5B).
10 Slacken and remove the retaining bolts
and slide the switch off of the selector shaft.
Whilst the switch is removed check the shaft
oil seal for signs of leakage and renew if
necessary (see Section 6).
Refitting
11 Prior to refitting, first make sure that the
transmission selector shaft is still in the N
(neutral) position. If there is any doubt, engage
the selector lever with the transmission shaft
and move the lever fully backwards (to the P
position) then move it two notches forwards.
12 If a new switch is being fitted, locate the
switch on the shaft then refit the retaining
8.6a Unclip the protective cover from the
position switch . . .
8.6b . . . then slacken and remove the
retaining nut (arrowed) and free the
selector lever from the shaft
bolts, tightening them to the specified torque.
Note that it is not necessary to adjust the
switch since it is set at the factory and sealed
in position; the seal will be broken the first
time the selector lever is moved.
13 If the original switch is being refitting,
locate the switch on the transmission shaft
then refit the retaining bolts. Adjust the switch
as described in paragraph 21 before tightening
the retaining bolts to the specified torque.
14 Reconnect the selector lever to the
transmission shaft then refit the retaining nut.
Tighten the nut to the specified torque setting
then clip the protective cover back onto the
switch.
15 Securely reconnect the wiring connector
then clip the switch connector back onto the
transmission unit and raise the transmission
unit back up into position.
16 Remove all traces of locking compound
from the transmission unit rear mounting
crossmember to body bolt threads. Apply a few
drops of thread locking compound (Vauxhall
recommend the use of locking compound
15 10 181 - available from your Vauxhall dealer)
to the threads of each bolt then refit the bolts
and tighten to the specified torque.
17 Align the propeller shaft centre bearing
bracket with the body making sure any
necessary washers (where fitted) are
positioned between the bracket and body.
Refit the bracket retaining bolts and tighten to
the specified torque.
18 Referring to Chapter 4A, refit the heatshields and reconnect the exhaust system
flange joint(s) then lower the vehicle to the
ground.
21 With the transmission in neutral, the slot on
the switch body should be correctly aligned
with the slot on the switch inner ring. Check this
by inserting the welding rod (see illustration). If
adjustment is necessary, slacken the switch
retaining bolts and rotate the switch assembly
as necessary before retightening the bolts to
the specified torque setting.
22 Refit the selector lever to the shaft and
tighten its retaining nut to the specified torque.
23 Clip the protective cover back onto the
switch then lower the vehicle to the ground.
Sport mode switch
Note: A soldering iron and solder will be
required to renew the switch.
Removal
24 Unclip the selector lever gaiter from the
centre console.
25 Push the switch out of the top of the
selector lever by inserting a length of welding
rod up through the selector lever bore.
26 Make identification marks between the
switch and wires then carefully unsolder the
wires from the switch terminals and remove
the switch.
Refitting
27 Solder the wires to the terminals of the
switch, using the marks made prior to removal
to ensure they are correctly connected.
7B
Adjustment
Note: Before adjusting the switch first ensure
the selector linkage is correctly adjusted (see
Section 3). A short length of welding rod with
a diameter of 2.0 to 2.3 mm will be required
for adjustment.
19 Position the selector lever in the N
(neutral) position. Firmly apply the handbrake
then jack up the rear of the vehicle and
support it on axle stands.
20 Unclip the protective cover from the
switch then unscrew the retaining nut and free
the selector lever from the end of the
transmission shaft.
3510 Vauxhall/Opel Omega
8.21 Adjusting the selector lever position
switch
1 Switch retaining
bolts
2 Switch grooves
3 Welding rod
7B•6 Automatic transmission
connector then carefully free the ignition key
switch wiring from the rear of the connector.
Disconnect the switch earth lead from the
lever mounting plate.
43 Prise off the retaining clips and remove
the switch from the vehicle (see illustration).
Refitting
44 Refitting is the reverse of removal using
new retaining clips.
Electronic control unit (ECU)
Removal
8.30 Removing the winter mode switch
panel from the centre console
8.35 Selector lever pawl switch later models
28 Push the switch securely into position
then clip the selector lever gaiter back onto
the console.
Winter mode switch
from the around the selector lever.
35 Disconnect the wiring connectors then
prise off the retaining clips and remove the
switch from the selector lever mounting plate
(see illustration).
Removal
Refitting
29 Unclip the selector lever gaiter from the
centre console.
30 Reach in behind the console and push the
switch panel out of position, disconnecting its
wiring connector as it becomes accessible
(see illustration). The switch and panel can
then be separated.
36 Refitting is the reverse of removal
ensuring the switch is securely retained by the
new clips.
Refitting
37 Remove the selector lever as described in
Section 5 (see illustration).
38 Disconnect the solenoid earth lead from
the lever mounting plate and carefully free the
solenoid wiring from the main wiring
connector.
39 Undo the retaining screws and remove
the solenoid from the lever mounting plate.
31 Refitting is the reverse of removal
ensuring the wiring is correctly routed.
Kickdown switch
32 The kickdown switch is an integral part of
the accelerator cable and cannot be renewed
separately. Refer to Chapter 4A for details of
accelerator cable removal and refitting.
Selector lever pawl contact
switch - later models
Note: New switch retaining clips should be
used on refitting.
Removal
Selector lever pawl starter
solenoid - later models
Removal
Refitting
40 Refitting is the reverse of removal making
sure the solenoid is correctly engaged with
the pawl.
Ignition key release contact
switch - later models
45 The ECU is located behind the right-hand
side of the facia. Prior to removal, disconnect
the battery negative terminal.
46 On right-hand drive models, release the
retaining clips (rotate them through 90º) then
remove the undercover panel from the drivers’
side of the facia. Remove the fastener (prise
out the centre pin then pull out the fastener
outer section) then unclip and remove the
heater/ventilation duct.
47 On left-hand drive models remove the
glovebox (see Chapter 11).
48 On all models, unscrew the retaining nuts
securing the ECU to the pillar then carefully
lower the ECU out of position. Release the
retaining clip and disconnect the wiring
connector then remove the ECU from the
vehicle.
Refitting
49 Refitting is the reverse of removal
ensuring that the wiring is securely
reconnected. If a brand new ECU has been
fitted it will be necessary to take the vehicle to
a Vauxhall dealer to have the unit coded to
match the performance of the relevant engine
fitted to your vehicle.
Transmission output shaft speed
sensor
Removal
33 Remove the centre console as described
in Chapter 11 then position the selector lever
in the P (park) position.
34 Slacken and remove the retaining nuts
and bolt then remove the front and rear
support brackets from the rear heater/
ventilation duct. Unclip the duct and remove it
Note: New switch retaining clips should be
used on refitting.
41 Carry out the operations described in
paragraphs 33 and 34.
42 Disconnect the selector lever main wiring
50 The output shaft speed sensor is fitted to
the rear of the transmission unit where it is
located above and to the left off the propeller
shaft flange (see illustration).
51 To gain access to the sensor, firmly apply
the handbrake then jack up the front of the
vehicle and support it on axle stands.
52 Disconnect the wiring connector and wipe
8.37 Selector lever pawl starter solenoid later models
8.43 Ignition key release contact switch later models
8.50 Transmission output shaft speed
sensor location
Removal
3510 Vauxhall/Opel Omega
Automatic transmission 7B•7
9.3 Slide off the retaining clip and detach
the selector linkage rod from the
transmission
clean the area around the sensor.
53 Undo the retaining bolt and remove the
sensor from the transmission. Remove the
sealing ring from the sensor and discard it, a
new one should be used on refitting.
Refitting
54 Fit the new sealing ring to the sensor
groove and lubricate it with a smear of
transmission fluid.
55 Ease the sensor into position then refit the
retaining bolt and tighten it to the specified
torque setting. Reconnect the wiring
connector then lower the vehicle to the
ground.
Transmission solenoid valves
56 Removal and refitting of the various
solenoid valves should be entrusted to a
Vauxhall dealer.
9 Automatic transmission removal and refitting
4
Removal
1 Chock the rear wheels, apply the
handbrake, and place the selector lever in the
N (neutral) position. Jack up the front of the
vehicle, and securely support it on axle
stands. Undo the retaining screws and
remove the undercover from beneath the
engine unit. Disconnect the battery negative
terminal. Note: On models with a Vauxhall
anti-theft warning system (ATWS), the battery
negative terminal must be disconnected within
15 seconds of the ignition being switched off
to prevent the alarm system being triggered.
2 Working as described in Chapter 8, unbolt
the front end of the propeller shaft from the
transmission flange and remove the vibration
damper (where fitted). Position the propeller
shaft to the right of the transmission unit and
tie it to the vehicle underbody.
3 Slide off the retaining clips and detach the
selector linkage rod from the transmission unit
and selector lever and remove it from the
vehicle (see illustration). Take care not to
lose the lever pivot bushes.
4 Trace the fluid cooler pipes back from the
transmission unit to their flexible hoses.
9.4a Release the retaining clips and
disconnect the oil cooler pipes . . .
9.4b . . . then fold them back and connect
them as shown to minimise fluid loss
Remove all traces of dirt then slacken the
retaining clips and disconnect both hoses.
Minimise fluid loss by folding each hose back
on itself and securely connecting it to its
adjacent pipe (see illustrations).
5 Disconnect the wiring connector from the
output shaft speed sensor (see illustration
8.50), which is located at the rear of the
transmission unit, and free the wiring from the
transmission unit.
6 On SOHC engines, disconnect the wiring
connector from the DIS module (see Chapter 5B). Slacken and remove the module
mounting bracket retaining bolts, noting the
correct fitted location of the engine lifting
bracket, then free the wiring harness and
remove the module and bracket from the rear
of the cylinder head. Free the HT leads from
their retaining clips and position the assembly
clear of the transmission unit.
7 On all models unclip the oxygen sensor
wiring connector from transmission unit and
disconnect it.
8 Slacken and remove the exhaust system
front pipe mounting bracket bolt then remove
the bolts securing the front pipe to the
intermediate pipe and separate the two
exhaust sections.
9 On models with a one-piece engine sump,
slacken and remove the bolts securing the
support brackets to the transmission housing
and sides of the cylinder block. Remove both
brackets from the engine then remove the
torque converter lower cover plate from the
base of the transmission housing.
10 On models with a two-piece engine sump,
remove the cover from the sump flange to
gain access to the torque converter to
driveplate bolts.
11 Slacken and remove the visible bolt(s) then,
using a socket and extension bar to rotate the
crankshaft pulley, undo the remaining bolts
securing the torque converter to the driveplate
as they become accessible; there are six bolts
in total. If necessary, to prevent rotation as the
bolts are slackened, remove the cover from the
base of the torque converter housing and retain
the driveplate by inserting a large screwdriver
in through the hole.
12 Place a jack with a block of wood beneath
the transmission, and raise the jack to take the
weight of the transmission (see illustration).
13 With the transmission securely supported,
slacken and remove the bolts securing the
transmission unit rear mounting crossmember
to the vehicle body (see illustration).
14 Lower the transmission unit slightly and
disconnect the vent hose from the top of the
transmission housing.
15 Trace the wiring back from the selector
lever position switch and disconnect it at the
wiring connector. Unclip the wiring connector
and position it clear of the transmission
housing; if the connector retaining clip is
broken on removal, obtain a new one for
refitting.
16 Release the retaining clips and disconnect
the wiring connectors from the side of the
transmission main and intermediate housings
(see illustration). Release all the wiring from
its retaining clips, noting its correct routing,
and position it clear of the transmission unit.
9.12 Securely support the transmission
unit with a suitable jack . . .
9.13 . . . then slacken and remove the
bolts securing the transmission unit
crossmember to the body
2.0 litre engines
3510 Vauxhall/Opel Omega
7B
7B•8 Automatic transmission
9.16 Disconnect the wiring connectors
from the transmission unit and free the
wiring from its retaining clips
17 Slacken and remove all the bolts securing
the transmission housing to the engine. Note
the correct fitted positions of each bolt, and
the necessary brackets, as they are removed,
to use as a reference on refitting. Make a final
check that all components have been
disconnected, and are positioned clear of the
transmission so that they will not hinder the
removal procedure.
18 To ensure that the torque converter does
not fall out as the transmission is removed,
slide the converter along the shaft and fully
into the transmission housing.
19 Move the trolley jack and transmission to
the rear, to free it from its locating dowels.
Once the transmission is free, carefully lower
the jack and manoeuvre the unit out from
under the vehicle. Remove the locating
dowels from the transmission or engine if they
are loose, and keep them in a safe place.
2.5 and 3.0 litre models
20 Remove both the exhaust system front
pipes as described in Chapter 4A.
21 Remove the cover from the sump flange
to gain access to the torque converter
retaining bolts. Slacken and remove the
visible bolt then, using a socket and extension
bar to rotate the crankshaft pulley, undo the
remaining bolts securing the torque converter
to the driveplate as they become accessible;
there are six bolts in total. If necessary, to
prevent rotation as the bolts are slackened,
remove the cover from the base of the torque
converter housing and retain the driveplate by
inserting a large screwdriver in through the
hole (see illustrations).
9.21c If necessary, the driveplate can be
retained by removing the cover and inserting
a large screwdriver in through the hole
9.21a Prise out the cover from the sump
flange . . .
22 Remove the transmission as described in
paragraphs 12 to 19.
Refitting
23 The transmission is refitted by a reversal
of the removal procedure, bearing in mind the
following points.
a) If a new transmission unit is being
installed, drain the fluid cooler and blow
out the cooler lines using low-pressure
compressed air.
b) Check the torque converter centering pin
and the crankshaft bush for signs of wear
or damage. Remove all traces of dirt and
rust then lubricate the bush a pin with a
thin smear of molybdenum disulphide
grease (Vauxhall recommend the use of
lubricating grease 19 48 568 - available
from your Vauxhall dealer).
c) Prior to refitting, ensure that the torque
converter is correctly engaged with the
transmission by measuring the distance
from the converter driveplate bolt lugs to
the transmission mating surface. This
should be 15 mm (see illustration).
d) Ensure the locating dowels are correctly
positioned and take great care not to
allow the weight of the unit to hang on the
torque converter as it is installed. Once
the transmission and engine are correctly
joined, refit the securing bolts, tightening
them to the specified torque setting.
e) Align the torque converter with the
driveplate then refit the retaining bolts
tightening them lightly only to start then
go around and tighten them to the
specified torque setting in a diagonal
sequence.
f) Ensure that the transmission wiring/hoses
are correctly routed and retained by all
the necessary clips.
g) Remove all traces of locking compound
from the transmission unit rear mounting
crossmember to body bolt threads. Apply
a few drops of thread locking compound
(Vauxhall recommend the use of locking
compound 15 10 181 - available from
your Vauxhall dealer) to the threads of
each bolt prior to refitting and tighten
both bolts to the specified torque.
h) Tighten all nuts and bolts to the specified
torque (where given).
3510 Vauxhall/Opel Omega
9.21b . . . then slacken and remove the
torque converter to driveplate bolts as
described in text
i) On completion, refill the transmission with
the specified type and quantity of fluid as
described in Section 2 and adjust the
selector linkage as described in Section 3.
10 Automatic transmission
overhaul general information
5
1 Overhaul of an automatic transmission unit
is beyond the scope of the home mechanic
and should be entrusted to a transmission
specialist.
2 In the event of a fault occurring with the
transmission, the vehicle should be taken to a
suitably-equipped Vauxhall dealer for testing.
A wiring block connector is incorporated in
the electronic control circuit, into which a
special electronic diagnostic tester can be
plugged (see Section 1) and this should locate
the fault.
3 Do not remove the transmission from the
car for possible repair before professional
fault diagnosis has been carried out, since
most tests require the transmission to be in
the vehicle.
9.23 Check the torque converter is fully
engaged by measuring the distance (X)
from the converter bolt lugs to the
transmission surface. This should be 15 mm
8•1
Chapter 8
Final drive, driveshafts and propeller shaft
Contents
Driveshaft - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . .
Driveshaft rubber gaiters and outer constant velocity joint - renewal
Final drive unit - oil level check . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Final drive unit - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . .
Final drive unit damping bracket - renewal . . . . . . . . . . . . . . . . . . . .
Final drive unit differential bearing oil seal - renewal . . . . . . . . . . . . .
8
9
3
2
4
7
Final drive unit pinion oil seal - renewal . . . . . . . . . . . . . . . . . . . . . . . 6
Final drive unit rear cover gasket - renewal . . . . . . . . . . . . . . . . . . . . 5
General description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Propeller shaft - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . 10
Propeller shaft centre bearing - renewal . . . . . . . . . . . . . . . . . . . . . . 11
Propeller shaft disc joints - renewal . . . . . . . . . . . . . . . . . . . . . . . . . 12
Degrees of difficulty
Easy, suitable for
novice with little
experience
1
Fairly easy, suitable
for beginner with
some experience
2
Fairly difficult,
suitable for competent
DIY mechanic
3
Difficult, suitable for
experienced DIY
mechanic
4
Very difficult,
suitable for expert DIY
or professional
5
Specifications
Final drive
Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Final drive ratio:
Up to 1998 model year:
All 2.0 litre 4-cylinder models . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.5 litre 6-cylinder models:
Manual transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Automatic transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.0 litre 6-cylinder models:
Manual transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Automatic transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
From 1998 model year:
All 2.0 litre 4-cylinder models . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.5 litre 6-cylinder models:
Manual transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Automatic transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.0 litre 6-cylinder models:
Manual transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Automatic transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Limited slip differential lock-up value:
Typical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Minimum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Unsprung, attached to rear suspension crossmember and underbody.
Limited slip differential optional.
3.90 : 1
3.70 : 1
3.90 : 1
3.70 : 1
3.70 : 1
3.90 : 1
3.90 : 1
4.22 : 1
3.70 : 1
3.90 : 1
45 %
25 %
Driveshaft
Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Maintenance-free double constant velocity joint
Propeller shaft
Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Two-piece tubular shaft with centre bearing, centre universal joint, and
flexible disc joint connections to transmission and differential
Lubrication
Final drive lubricant capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Final drive lubricant type/specification:
Excluding limited-slip differential:
Renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Top-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Limited-slip differential:
Renewal:
First 0.25 litres . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Remaining 0.75 litres . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Top-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Driveshaft CV joint grease type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1.0 litre
GM special lubricant 19 42 382 (9 293 688)
Hypoid gear oil, viscosity SAE 90
GM special fluid additive 19 70 452 (90 004 033)
GM special lubricant 19 42 382 (9 293 688)
GM special lubricant 19 42 382 (9 293 688)
GM special grease 19 41 522 (90 007 999)
3510 Vauxhall/Opel Omega
8
8•2 Final drive, driveshafts and propeller shaft
Torque wrench settings
Damping bracket to final drive unit*:
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Disc joint to propeller shaft transmission or differential:
Hexagon bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Torx bolt*:
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Driveshaft to hub:
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Final drive oil level check plug:
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Final drive unit damping bracket bush to rear crossmember*:
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Final drive unit rear cover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Final drive unit to crossmember*:
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Propeller shaft centre bearing bracket to underbody . . . . . . . . . . . . . . .
Propeller shaft centre bearing to bracket . . . . . . . . . . . . . . . . . . . . . . . .
Propeller shaft to flexible joint:
Hexagon bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Torx bolt*:
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Speed sensor to bracket (with ABS) . . . . . . . . . . . . . . . . . . . . . . . . . . . .
*Indicates that a new bolt/nut must be used.
1 General description
1 The final drive unit houses the differential
gears and is bolted directly to the rear
suspension crossmember. The unit has a cast
aluminium casing which incorporates external
ribs to improve structural rigidity and fluid
cooling. A bracket with an integral rubber
damping block bolted between the final drive
casing and the suspension crossmember
controls the movement of the final drive
during operation.
2 A limited-slip differential may be fitted as an
option; this incorporates a clutch mechanism
which controls the difference in speed
between the left and right hand driveshafts.
Under normal conditions, the clutch slips
allowing the driveshafts to rotate at different
speeds, such as during cornering. When the
speed differential increases beyond a preset
limit, such as during wheelspin caused by
rapid acceleration or poor road surfaces, the
clutch locks thus preventing the differential
from supplying all available drive to the
spinning wheel, and ensuring equal
distribution of drive to both rear wheels.
Nm
lbf ft
90
Tighten a further 45º
Tighten a further 15º
66
95
70
50
Tighten a further 75º
Tighten a further 15º
37
50
Tighten a further 60º
Tighten a further 15º
37
22
Tighten a further 90º
Tighten a further 180º
16
100
Tighten a further 75º
Tighten a further 15º
60
74
44
90
Tighten a further 30º
Tighten a further 15º
20
22
15
16
95
70
50
Tighten a further 45º
Tighten a further 15º
4
37
3 Two driveshafts, incorporating Rzeppa-type
constant velocity joints, transmit drive from the
final drive differential to the rear wheels. The
inner joints incorporates the Anti-lock Braking
System (ABS) rear wheel sensor reluctor discs
- see Chapter 9 for details. Flexible rubber
gaiters filled with grease encapsulate each
joint, keeping the joint lubricated and
preventing the ingress of dirt and debris.
4 A two-piece, tubular propeller shaft
transmits drive from the transmission from to
the final drive unit. It incorporates a centre
66
3
bearing supported in a rubber insulator. The
rear section of the shaft has a universal joint at
its front end, and the front section has a slider
joint at its rear end. The propeller shaft is
secured to the transmission and differential by
flexible disc joints.
Final drive identification
5 The type of final drive unit fitted can be
determined by examining the identification
plate affixed to the underside of the final drive
unit (see illustration).
2 Final drive unit removal and refitting
3
Removal
1.5 Final drive unit identification plate
1 Limited slip differential
(0 = yes, 1 = no)
2 Final drive ratio
3510 Vauxhall/Opel Omega
1 Chock the front wheels securely. Jack up
the rear of the vehicle, support it on axle
stands and remove both rear wheels.
2 Remove both driveshafts with reference to
Section 8.
3 Unhook the exhaust system mounting
rubbers and lower the rear of the system
approximately 300 mm (12.0 in). Support or
tie the system in this position.
Final drive, driveshafts and propeller shaft 8•3
4 Unbolt the propeller shaft rear flange from
the flexible drive joint and lever the propeller
shaft from the joint. Support the propeller
shaft on an axle stand - do not let it hang by
the universal joint.
5 Position a trolley jack underneath the final
drive unit, and raise it until it just comes into
contact with the underside of the casing.
6 Unplug the wiring from both ABS wheel
sensors at the connectors.
7 Unscrew the bolt securing the damping
bracket at the front of the final drive casing to
the suspension crossmember.
8 Unscrew and withdraw the bolt securing
the rear of the final drive casing to the
suspension crossmember.
9 Lower the trolley jack and remove the final
drive from the underside of the vehicle.
Refitting
10 Refitting is a reversal of removal, noting
the following points:.
a) Check that the distance between the two
final drive bushes on the suspension
crossmember is between 300 and 302
mm. If necessary, adjust this dimension
by altering the position of the bushes in
the crossmember, using a universal puller
or similar tool.
b) Ensure that the wiring for the ABS wheel
sensors is securely reconnected.
c) Use new bolts/nuts where indicated (see
Specifications) and tighten all fixings to
the specified torque.
d) Refit the driveshafts with reference to
Section 8.
e) On completion, check the oil level in the
final drive unit as described in Section 3.
3 Final drive unit oil level check
2
Level check
1 Jack up the front and rear of the vehicle
and support it on axle stands so that the
vehicle is level.
2 Using a hexagon key, unscrew the filler
plug from the right-hand side of the final drive
unit. On models with a limited slip differential,
it will be necessary to prise the bung from the
centre of the plug first (see illustration).
3 Check that the oil level is up to the lower
edge of the filler plug aperture using a (clean)
piece of bent wire as a dipstick.
4 If necessary, top-up with the correct type of
oil as given in the Specifications.
5 Refit and tighten the filler plug to the
specified torque, and wipe clean. Refit the
plastic bung to the centre of the plug on
models with a limited slip differential.
6 Check the pinion final drive unit oil seal and
differential bearing oil seals for leaks. If
evident, renew them.
7 Lower the car to the ground.
3.2 Final drive unit oil filler/level plug (A) and plastic bung (B)
Complete refill
8 Proceed as described for Level check
noting the following points:.
a) On models without a limited slip
differential, GM special differential oil
must be used if the final drive is being
refilled from empty, rather than just
topped-up (see Specifications).
b) On models with a limited slip differential, if
the final drive is being refilled from empty,
rather than just topped-up, the procedure
must be carried out in two stages:
1) Pour 0.25 litres of GM special
differential oil additive into the final
drive
2) Pour approximately 0.75 litres of GM
special differential oil into the final
drive, until the level reaches the
lower edge of the filler plug aperture
(see Specifications).
4 Final drive unit
damping bushes renewal
suspension crossmember. Lower the final
drive unit slightly, using the trolley jack.
6 Slacken and withdraw the three bolts
securing the damping bracket to the final
drive unit casing. Be prepared for some oil
leakage - position a drip tray underneath the
final drive casing to catch the oil.
7 Detach the damping bush bracket from the
final drive casing and remove it from the
vehicle. Withdraw the securing bolt from the
damper bush.
8 Press the old bush from the bracket using a
hydraulic press, or drive it out using a suitable
drift. Drive or press the new bush into
position, ensuring that the recessed section of
the bush is correctly aligned with the bracket
boss (see illustration).
9 Commence refitting by inserting the
securing bolt through the centre of the
damper bush.
3
8
Front bush
1 Chock the front wheels. Jack up the rear of
the vehicle and support it on axle stands.
2 Support the final drive unit on a trolley jack.
3 Unplug the wiring from both ABS wheel
sensors at the connectors.
4 Slacken and withdraw the bolts securing
the rear of the final drive unit to the
suspension crossmember.
5 Fully unscrew the bolt securing the
damping bush bracket to the front of the
3510 Vauxhall/Opel Omega
4.8 Ensuring that the recessed section of
the bush is aligned with the bracket boss
as shown
8•4 Final drive, driveshafts and propeller shaft
4.19 Press the new bushes into the crossmember, ensuring that the distance measured
between their inner edges (I) is between 300 and 302 mm
10 Offer the bracket, bush and securing bolt
up to the final drive casing. Insert the three
bracket securing bolts and tighten them to the
specified torque.
11 Raise the final drive casing up into
position using the trolley jack, then tighten the
damper bush-to-suspension crossmember
bolt and tighten it to the specified torque.
12 Refit the two rear final drive casing-tosuspension crossmember bolts and tighten
them to the specified torque.
13 Reconnect the wiring for the ABS wheel
sensors.
14 On completion, top-up the differential oil
with reference to Section 3, then lower the
vehicle to the ground.
Rear bushes
15 Remove the final drive unit as described in
Section 2.
16 Unbolt the fuel filter from its mountings
and move to one side, with reference to
Chapter 1. There should be no need to
disconnect the fuel lines from it.
17 With reference to Chapter 4A, unhook the
exhaust system intermediate silencer from its
mountings and support it on axle stand.
18 Extract the bushes from the suspension
crossmember using a universal puller or
similar tool. The bushes are removed from the
outside of the crossmember.
19 Press the new bushes into the
crossmember, ensuring that the distance
measured between their inner edges is
between 300 and 302 mm (see illustration).
20 Refit the final drive unit as described in
Section 2.
21 Refit the fuel filter and exhaust system
silencer as described in Chapters 1 and 4A
respectively.
5 Final drive unit
rear cover gasket renewal
3
1 Remove the final drive unit as described in
Section 2.
2 Place the final drive unit in a suitable drip
tray, then unbolt and remove the rear cover
from the casing. Remove the gasket and allow
the oil to drain.
3 Thoroughly clean the joint faces of the final
drive casing and cover.
4 Apply a coat of the recommended sealant
to the mating surface of the final drive casing.
5 Refit the cover, then insert and tighten the
bolts progressively to the specified torque. It
is recommended that new bolts are used.
6 Refit the final drive unit to the vehicle as
described in Section 2.
7 Lower the vehicle to the ground. On
completion, refill the final drive unit with the
specified quantity and grade(s) of oil, as
described in Section 3.
6 Final drive unit pinion oil seal
- renewal
7 Final drive unit
differential bearing oil seal renewal
3
1 Chock the front wheels. Jack up the rear of
the vehicle and support it on axle stands.
Remove the appropriate rear wheel.
2 Remove the appropriate driveshaft with
reference to Section 8.
3 Note the fitted depth of the oil seal in the
final drive casing.
4 Using a screwdriver or hooked instrument,
lever out the oil seal (see illustration), taking
3
Caution: The pinion bearing pre-load will
be affected by the renewal of the pinion oil
seal and must be reset accurately
following repair work. The following
procedure describes how to reset the
bearing pre-load approximately, using
rudimentary tools, but we recommend that
the pre-load is set accurately by a Vauxhall
dealer, or an engineering workshop.
1 Remove the final drive unit as described in
Section 2.
3510 Vauxhall/Opel Omega
2 Mount the unit in a vice.
3 Measure the pinion bearing pre-load as
follows: fit a socket on the pinion nut, and
using an adjustable low-torque wrench,
measure the torque which must be applied to
cause pinion to just start to rotate - the figure
should be approximately 90 to 120 Ncm.
Record this figure for later reference.
4 Mark the drive flange nut in relation to the
drive flange and pinion.
5 Hold the drive flange stationary by bolting a
length of metal bar to it, then unscrew the nut
noting the exact number of turns necessary to
remove it.
6 Using a suitable puller, draw the drive
flange from the pinion.
7 Lever the oil seal from the final drive casing
with a screwdriver. Wipe clean the oil seal
seating.
8 Smear a little differential oil (see
Specifications) on the sealing lip of the new oil
seal, then drive it squarely into the casing until
flush with the outer face. Ideally use metal
tubing to fit the oil seal, but alternatively a
block of wood may be used on each side of
the pinion.
9 Locate the drive flange on the pinion in its
original position, then refit the nut to its
original position, using the markings and
notes made during removal.
10 The pinion drive bearing pre-load must
now be reset to its original value. Measure the
torque required to turn the pinion, as
described in paragraph 3. Adjust the position
of the pinion nut until the measured value is
the same as that recorded earlier.
11 Refit the final drive unit with reference to
Section 2.
7.4 Differential bearing oil seal
Final drive, driveshafts and propeller shaft 8•5
great care avoid damaging the surface of the
seal housing. Wipe the oil from the oil seal
housing.
5 Smear a little oil on the sealing lip of the
new oil seal. Using suitable metal tubing drive
the oil seal squarely into the casing to the
previously noted position.
6 Refit the driveshaft with reference to
Section 8.
7 Refit the wheel and lower the vehicle to the
ground.
8 Driveshaft removal and refitting
3
Removal
1 Chock the front wheels, then jack up the
rear of the vehicle and support it on axle
stands.
2 Unscrew the socket-head bolts securing
the driveshaft to the rear hub while holding the
rear wheel stationary. Recover the lockwashers.
3 Lever the driveshaft from the rear hub and
support it above the disc brake assembly.
4 Remove the rear wheel.
5 Position a container under the final drive
unit to catch any spilled oil.
6 Carefully lever the driveshaft from the final
drive unit differential. On models with
anti-lock braking take care not to damage the
wheel speed sensor and reluctor wheel.
7 Withdraw the driveshaft from the side of the
vehicle.
8 Check the circlip on the inner end of the
driveshaft and if necessary renew it.
Refitting
9 Refitting is a reversal of removal, but make
sure that the driveshaft is fully entered in the
differential side gear with the circlip engaged
in its groove. Tighten the mounting bolts in
three stages, as detailed in the Specifications
(see illustrations). Check and if necessary
top up the oil level in the final drive unit, as
described in Section 3.
8.9a Tighten the driveshaft mounting bolts
to the specified first stage torque . . .
9 Driveshaft rubber gaiters
and outer constant velocity
joint - renewal
3
1 Remove the driveshaft as described in
Section 8 and mount it in a vice.
2 Using a small drift, tap the metal cover from
the outer joint.
3 Loosen and remove both clips from the
rubber bellows.
4 Using a sharp knife slice through the rubber
bellows and remove them from the driveshaft.
5 Scoop out the grease from the joint and
wipe the driveshaft clean.
6 Using circlip pliers, extract the circlip from
the outer end of the driveshaft.
7 Support the outer joint on a vice, then tap
the driveshaft down through it.
8 Fill the inner joint with the specified type of
grease using a wooden spatula.
9 Fit the new inner bellows, check that it is
not twisted then fit and tighten the clips.
10 Locate the outer bellows on the driveshaft.
11 Fit the outer joint, using a tubular metal
drift, with the driveshaft mounted in a vice.
Make sure that the joint abuts the shoulder.
12 Fit the circlip making sure that it fully
enters the groove.
13 Using the wooden spatula fill the outer
joint with grease.
14 Locate the outer bellows on the plate,
check that it is not twisted then fit and tighten
the clips.
8.9b . . . then angle tighten to the specified
second and third stages
15 Locate the cover on the joint using two
driveshaft bolts to ensure correct alignment.
Tap the cover on the joint with a soft-faced
mallet.
16 Extract the retaining circlip from the inner
end of the driveshaft and fit a new one.
17 Refit the driveshaft with reference to
Section 8.
10 Propeller shaft removal and refitting
3
Removal
1 Chock the front wheels. Jack up the rear of
the vehicle and support it on axle stands.
2 On models equipped with a catalytic
converter, from underneath the vehicle, undo
the retaining bolts and remove both the large
and small catalytic converter heatshields from
the vehicle underbody (see illustration).
3 At the sliding joint, mark the relationship
between the front and rear sections of the
propeller shaft. If the two halves of the shaft
become separated during removal, reconnect
them using the alignment markings, to
preserve the balance characteristics.
4 Using a conventional, or Torx, socket as
applicable, unscrew the bolts securing the
front flexible disc joint to the transmission
output flange (see illustration).
5 At the rear of the propeller shaft, unscrew
the bolts securing the rear disc joint to the
differential flange (see illustration).
8
10.2 Remove the exhaust heat shields
from the vehicle underbody
10.4 Unscrew the bolts (arrowed) securing
the front flexible disc joint to the
transmission output flange
3510 Vauxhall/Opel Omega
10.5 Unscrew the bolts (arrowed) securing
the rear disc joint to the differential flange
8•6 Final drive, driveshafts and propeller shaft
3
11 Propeller shaft
centre bearing renewal
10.6 Centre bearing support bracket bolts
(arrowed)
6 Support the centre of the propeller shaft on
an axle stand, then unbolt the centre bearing
support bracket from the underbody, noting
the location of any alignment shims (see
illustration).
7 Push the front section rearwards along the
slider joint splines until clear of the
transmission output flange.
8 Withdraw the propeller shaft forwards,
making sure that the front section remains on
the slider joint splines (see paragraph 3).
9 Unbolt the centre support bracket from the
centre bearing, noting the location of any
alignment shims.
10 Unbolt the front and rear disc joints from
the propeller shaft. Note that on some models
a vibration damper is fitted at the front of the
propeller shaft.
Refitting
11 Refitting is a reversal of removal, noting
the following points:.
a) Coat the inboard splines of the driveshaft
with differential oil before inserting them
into the final drive.
b) Tighten all nuts and bolts to the specified
torque.
1 Remove the propeller shaft as described in
Section 10.
2 Mount the rear propeller shaft section in a
vice, using shaped blocks of wood to prevent
damage.
3 Mark the front and rear sections in relation
to each other, then pull the front section from
the splines.
4 Slide off the rubber sleeve, then using
circlip pliers, extract the circlip from the
groove in front of the centre bearing (see
illustration). Extract the dust seal washer.
5 Unbolt the centre bearing from its mounting
bracket.
6 Support the centre bearing on a vice, and
press or drive the rear propeller shaft section
down through the bearing. Recover the dust
seal washer.
7 Similarly, press or drive the ball bearing
from the centre bearing housing, and remove
the dust cover.
8 Clean the removed components and the
end of the propeller shaft. Lightly grease the
splines.
9 Press or drive the new ball bearing into the
housing, and align the dust washer.
10 Support the rear section universal joint on
a vice, and press or drive the centre bearing
over the splines using a metal tube on the
inner track. Make sure that the bearing makes
contact with its seating shoulder.
11 Bolt the mounting bracket to the centre
bearing and tighten the bolts to the specified
torque.
12 Mount the rear section in a vice, and fit
the front dust washer and the circlip, making
sure that it is correctly located in the groove.
13 Locate the rubber sleeve over the splines.
14 Fit the front section on the rear section
11.4 Extract the circlip from the groove in front of the
centre bearing
splines, making sure that the previously-made
marks are aligned, to preserve the balance
characteristics. Note that a master spline is
provided to ensure correct assembly (see
illustration).
15 Refit the propeller shaft as described in
Section 10.
12 Propeller shaft disc joints renewal
3
1 Chock the front wheels. Jack up the rear of
the vehicle and support it on axle stands.
2 Apply the handbrake, then where
applicable, unbolt and remove the heatshields
from the vehicle underbody to gain access to
the disc joints.
3 If removing the rear disc joint, unbolt the
propeller shaft centre bearing mounting
bracket from the underside of the vehicle and
support the propeller shaft on an axle stand.
4 Unbolt the propeller shaft flange(s) from the
flexible disc joint(s).
5 Unbolt the flexible disc joint from the
transmission and/or differential drive flange(s).
6 Push the appropriate propeller shaft section
towards the centre bearing and remove the
disc joint(s). If necessary, use a lever to prise
the propeller shaft clear of the drive flange(s).
7 Fit the new flexible disc joint(s) using a
reversal of the removal procedure, noting the
following points:.
a) Bolt the disc joint to the propeller first, then
to the transmission/final drive flange.
b) Tighten all nuts and bolts to the specified
torque (see Specifications).
c) Where applicable, refit the propeller shaft
centre bearing mounting bracket to the
underside of the vehicle as described in
Section 11.
d) Securely refit all heatshield panels
removed for access.
11.14 Note that a master spline (arrowed) is provided to ensure
correct assembly
3510 Vauxhall/Opel Omega
9•1
Chapter 9
Braking system
Contents
Anti-lock Braking System/Traction Control system (ABS/TC) component removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Anti-lock Braking System/Traction Control system (ABS/TC) information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Brake disc - inspection, removal and refitting . . . . . . . . . . . . . . . . . . 6
Brake fluid reservoir and level sensor - removal and refitting . . . . . . 11
Brake pedal - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Front brake caliper - removal, overhaul and refitting . . . . . . . . . . . . . 4
Front brake pads - inspection, removal and refitting . . . . . . . . . . . . 2
General description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Handbrake cable - removal and refitting . . . . . . . . . . . . . . . . . . . . . . 8
Handbrake lever - removal and refitting . . . . . . . . . . . . . . . . . . . . . . 9
Handbrake shoes - inspection and renewal . . . . . . . . . . . . . . . . . . . 7
Hydraulic brake lines and hoses - removal and refitting . . . . . . . . . . 13
Hydraulic system - bleeding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Master cylinder - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . 10
Rear brake caliper - removal, overhaul and refitting . . . . . . . . . . . . . 5
Rear brake pads - inspection, removal and refitting . . . . . . . . . . . . . 3
Vacuum servo hose and non-return valve - renewal . . . . . . . . . . . . . 14
Vacuum servo unit - testing, removal and refitting . . . . . . . . . . . . . . 15
Degrees of difficulty
Easy, suitable for
novice with little
experience
1
Fairly easy, suitable
for beginner with
some experience
2
Fairly difficult,
suitable for competent
DIY mechanic
3
Difficult, suitable for
experienced DIY
mechanic
4
Very difficult,
suitable for expert DIY
or professional
5
Specifications
General
System type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Servo diameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Servo piston rod, adjustment length . . . . . . . . . . . . . . . . . . . . . . . . . . .
Brake fluid capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Brake pedal travel to illuminate brake lights . . . . . . . . . . . . . . . . . . . . . .
Master cylinder, nominal diameter:
Up to 1998 model year:
4 cylinder engine models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6 cylinder engine models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
From 1998 model year:
All models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Front and rear discs, floating front caliper, fixed rear caliper, tandem
master cylinder with hydraulic system split front/rear, vacuum servo
unit, rear brake proportioning valve on certain models. Electronic
anti-lock braking system (ABS) on all models. Cable-operated
handbrake to shoes bearing on drums incorporated into rear discs.
200/225 mm
106 + 0.5 mm
0.5 litre (approx.)
15 ± 5 mm
23.81/20.64 mm
25.40/20.64 mm
25.40 mm
Front brakes
Disc diameter:
Up to 1998 model year:
4 cylinder engine models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6 cylinder engine models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
From 1998 model year:
All models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Disc thickness (new):
Up to 1998 model year:
4 cylinder engine models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6 cylinder engine models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
From 1998 model year:
All models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Disc thickness (minimum, after machining*):
Up to 1998 model year:
4 cylinder engine models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6 cylinder engine models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
From 1998 model year:
All models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
286 mm
296 mm
296 mm
24 mm
28 mm
28 mm
22.5 mm
26.5 mm
26.5 mm
3510 Vauxhall/Opel Omega
9
9•2 Braking system
Front brakes (continued)
Disc thickness (minimum, wear limit):
Up to 1998 model year:
4 cylinder engine models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6 cylinder engine models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
From 1998 model year:
All models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Disc maximum thickness variation . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Disc maximum run-out . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Disc maximum score depth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Brake pad thickness (including backplate):
New . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Minimum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Caliper piston diameter:
Up to 1998 model year:
4 cylinder engine models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6 cylinder engine models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
From 1998 model year:
All models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
*After machining the disc surface, new brake pads must be fitted. Once
new discs must then be fitted.
21 mm
25 mm
25 mm
0.01 mm
0.12 mm
0.4 mm
17.5 ± 0.6 mm
8.0 mm
54 mm
54 mm
57 mm
these are worn, no more new pads may be used with the same discs -
Rear brakes
Discs diameter (new) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 286 mm
Disc thickness:
New . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12.0 mm
Minimum (after machining*) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.0 mm
Minimum (wear limit) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.0 mm
Variation (maximum) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.01 mm
Run-out (maximum) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.12 mm
Caliper piston diameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40.0 mm
Brake pad thickness (including backplate):
New . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17.0 mm
Minimum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.0 mm
Handbrake shoe minimum thickness (lining only) . . . . . . . . . . . . . . . . . 1.0 mm
Handbrake drum diameter:
New . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160.0 mm
Maximum (wear limit**) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161.0 mm
*After machining the disc surface, new brake pads must be fitted. Once these are worn, no more new pads may be used with the same discs new discs must then be fitted.
**After machining the drum surface, new brake shoes must be fitted. Once these are worn, no more new shoes may be used with the same drums
- new drums must then be fitted.
Torque wrench settings
Nm
lbf ft
ABS control unit bracket to modulator . . . . . . . . . . . . . . . . . . . . . . . . . . 8
6
ABS modulator to bodywork . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
7
ABS modulator-to-bracket nuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
6
ABS wheel sensor securing screws . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
6
Brake disc locking screw . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3
Brake line union nuts/bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
12
Brake pedal bracket to bulkhead . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
15
Brake pedal shaft to bracket . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
13
Caliper bleed screw . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
7
Caliper brake hose union bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
30
Caliper guide bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
22
Front caliper mounting bracket-to-steering knuckle bolts (all calipers)*:
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
70
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Angle-tighten through 30º to 45º
Handbrake lever . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
15
Master cylinder front mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
16
Master cylinder to vacuum servo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
16
Rear caliper mounting bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
59
Road wheel bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
81
Vacuum servo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
15
*Use new bolts.
Note: The threads of all fasteners secured with locking compound must be thoroughly cleaned and, if necessary, re-cut to remove all traces of the
old locking compound. Fresh locking compound should then be reapplied at reassembly.
3510 Vauxhall/Opel Omega
Braking system 9•3
1 General description
1 The braking system is of dual hydraulic
circuit type with front and rear discs. The front
and rear hydraulic circuits are operated
independently, so that in the event of a failure
in one circuit the remaining circuit still
functions. The floor-mounted handbrake lever
operates brake shoes by means of a cable.
The handbrake shoes are mounted inside the
rear brake discs; the inner surface of each rear
brake disc incorporates a brake drum. The
disc brakes are self-adjusting in use, however
the handbrake is adjusted manually.
2 An Anti-lock Braking System (ABS) is fitted
as standard equipment on all models. Pre1998 models have 3-channnel ABS, with
independent hydraulic circuits for each front
brake, and a shared hydraulic circuit for the
rear brakes. Later models have 4-channel ABS,
with independent circuits for all four brakes.
3 During braking, the ABS system adjusts the
braking system hydraulic pressure, to prevent
the road wheels from locking, thereby
reducing the likelihood of skidding in slippery
conditions and/or during heavy braking. The
system incorporates an electronic control unit
which is supplied with signals from the wheel
speed sensors. The signals are compared with
each other and, if one wheel is found to be
decelerating more rapidly than the others, the
hydraulic pressure to that wheel is reduced
until its speed matches the other wheels. The
ABS unit is fitted in the hydraulic lines leading
from the master cylinder to the brakes, the
vacuum servo unit and master cylinder being
of similar type for both non-ABS and ABS
models. The ABS control system also
manages the operation of the Traction Control
(TC) system fitted to models with 6-cylinder
engines. For more details of the ABS/TC
systems, refer to Sections 17 and 18.
4 Should the ABS develop a fault, it is
recommended that a complete system check
is carried out by a GM dealer or ABS specialist,
who will have access to the specialist
equipment necessary to make an accurate
diagnosis of the problem.
2.5 Unclip the pad wear sensor from the
caliper aperture
2 Front brake pads inspection, removal
and refitting
3
Warning: Renew both sets of front
brake pads at the same time never renew the pads on only one
wheel, as uneven braking may result. Note
that the dust created by wear of the pads
may contain asbestos, which is a health
hazard. Never blow it out with compressed
air, and don’t inhale any of it. An approved
filtering mask should be worn when
working on the brakes. DO NOT use
petroleum-based solvents to clean brake
parts - use brake cleaner or methylated
spirit only.
Removal
1 Apply the handbrake. Jack up the front of
the vehicle and support it on axle stands.
Remove the front wheels.
2 Turn the steering to full right-hand lock and
check the wear of the linings on the
right-hand brake pads through the inspection
aperture at the front of the caliper body.
Check that the thickness of the lining
including the backing plate is as shown in the
Specifications using a steel rule or vernier
calipers.
3 Turn the steering to full left-hand lock and
check the left-hand brake pads in the same
way.
2.6 Slide out the metal retaining clip and
release the brake hose from the
suspension strut
4 If any brake pad is worn below the
minimum thickness, renew all the front pads
as a set together with new anti-rattle springs,
as described in the following paragraphs.
5 Using a small flat bladed screwdriver,
unclip the pad wear sensor from the caliper
aperture, and position it clear of the work area
(see illustration).
6 Slide out the metal retaining clip and
release the brake hose from its support
bracket at the side of the suspension strut
(see illustration).
4-cylinder engined models up to 1998
7 Remove the large spring clip from the side
of the brake caliper (see illustration). The clip
is under relatively high tension and may fly off
with some force when released; to prevent
injury, cover the spring with a large rag before
prising it from the caliper with a stout
screwdriver.
8 Remove the dust caps from the caliper
guide pin bolt holes, then slacken and remove
the two guide pin bolts (see illustrations),
and withdraw them from the caliper.
9 Withdraw the caliper from its mounting
bracket, then tie the caliper to the suspension
strut, using a suitable piece of wire (see
illustration).
Warning: Take great care to avoid
kinking or placing any strain on
the flexible brake hose.
10 Remove the outer pad from the caliper
mounting bracket.
9
2.7 Remove the large spring clip from the
side of the brake caliper
2.8a Remove the dust caps . . .
3510 Vauxhall/Opel Omega
2.8b . . . then slacken and remove the two
guide pin bolts
9•4 Braking system
15 First measure the thickness of each brake
pad (friction material and backing plate) (see
illustration). If either pad is worn at any point
to the specified minimum thickness (see
Specifications), all four front brake pads must
be renewed, so that even braking balance is
maintained. The pads should also be renewed
if any are fouled with oil or grease; there is no
satisfactory way of degreasing friction
material, once it is contaminated. If any of the
brake pads are worn unevenly or fouled with
oil or grease, trace and rectify the cause
before reassembly. If the pad wear sensor has
been in contact with the brake disc (causing
the brake pad warning light to illuminate), that
must also be renewed.
16 Inspect the brake disc with reference to
the information given in Section 6.
17 If the brake pads are still serviceable,
carefully clean them using a clean, fine wire
brush or similar, paying particular attention to
the sides and back of the metal backing.
Clean out the grooves in the friction material
(where applicable), and pick out any large
embedded particles of dirt or debris. Carefully
clean the pad locations in the caliper body
and mounting bracket. Check that the guide
pins are free to slide easily in the caliper
mounting bushes. Brush the dust and dirt
from the caliper and piston, but do not inhale
it, as it is injurious to health. Inspect the dust
seal around the piston for damage, and the
piston for evidence of fluid leaks, corrosion or
damage. If attention to any of these
components is necessary, refer to the
information given in the following sub-section.
18 If new brake pads are being fitted, the
caliper piston must be pushed back into the
cylinder to make room for the greater depth of
friction material. Either use a G-clamp or
similar tool, or use suitable pieces of wood as
levers (see illustration). Provided that the
master cylinder reservoir has not been
overfilled with hydraulic fluid, there should be
no spillage, but keep a careful watch on the
fluid level while retracting the piston. If the
fluid level rises above the maximum level
mark, the surplus should be siphoned off
using a syringe, or ejected via a plastic tube
connected to the bleed screw, to avoid
overflow, before retracting the piston any
further.
19 Prior to fitting the pads, check that the
guide bolts are a snug fit in the caliper
bushes. Remove any remaining dust and dirt
2.12a Slacken the lower guide pin bolt,
counterholding the guide pin with a
second spanner . . .
2.12b . . . and withdraw the guide pin bolt
from the caliper
2.13 Pivot the caliper upwards to expose
the brake pads
2.14a Remove the outer . . .
2.14b . . . and inner brake pads from the
caliper bracket
2.15 Measuring the thickness of a
brake pad
2.9 Remove the caliper from its mounting
brackets
11 Carefully prise the inner pad from the
caliper piston, which is retained by metal
spring clip attached to the rear of the pad
backing plate (see illustration).
4-cylinder engined models from 1998
and all 6-cylinder engined models
12 Remove the dust caps from the caliper
lower guide pin bolt hole, then slacken the
lower guide pin bolt, and withdraw it from the
caliper. Counterhold the guide pin with a
second spanner (see illustrations).
13 Pivot the caliper upwards (see
illustration), to expose the brake disc and
pads. Suspend the caliper in the vertical
position, using a suitable piece of wire.
Warning: Take great care to avoid
kinking or placing any strain on
the flexible brake hose.
14 Remove both brake pads from the caliper
bracket (see illustrations).
2.11 Carefully prise the inner pad from the
caliper piston
Inspection
3510 Vauxhall/Opel Omega
Braking system 9•5
2.18 Using a retraction tool to push the
piston back into the brake caliper
2.19a Apply a little high-melting-point
copper brake grease to the brake pad
backing plates . . .
2.19b . . . and the brake pad contact
points on the caliper mounting bracket
from the caliper, piston and caliper mounting
bracket using a stiff brush and proprietary
brake component cleaning fluid - the use of
other solvents or cleaning agents may cause
damage to the caliper rubber seals. Apply a
little high-melting-point copper brake grease
to the areas on the pad backing plates and
caliper mounting bracket which contact the
caliper and piston (see illustrations).
Caution: Take great care to avoid
contaminating the pad friction material
and brake disc surface.
Inspect the dust seal around the piston for
damage, and the piston for evidence of fluid
leaks, corrosion or damage. If attention to any
of these components is necessary, refer to
front brake caliper overhaul information in
Section 4.
brake disc. Check that the pads slide easily
along their guides towards the brake disc.
26 Pivot the caliper body down over the
pads, ensuring that caliper piston bears
against the rear of the inner pad’s backing
plate and that the outer edge of the caliper
bears against the rear of the outer pad’s
backing plate. Check that the butterfly springs
at the edge of the pad bear on the inside of
the caliper and are not jammed in the caliper
inspection aperture.
27 Thoroughly clean the threads of the
caliper lower guide pin bolt, fit it to the caliper
and then tighten it to the specified torque.
Refit the dust cover.
31 Refit the roadwheels, then lower the car to
the ground and tighten the roadwheel bolts to
the specified torque setting.
32 Check the hydraulic fluid level and top up
if necessary.
Refitting
4-cylinder engined models up to 1998
20 Fit the inner brake pad to the caliper by
pressing the spring clip on the pad backing
plate into the piston. Check that the butterfly
spring at the edge of the pad bears on the
inside of the caliper and is not jammed in the
caliper inspection aperture.
21 Place the outer pad in the caliper
mounting bracket, with the friction material
facing the disc, and check that it slides freely
along its guides towards the brake disc.
22 Fit the brake caliper and outer pad over
the disc, ensuring that the outer edge of the
caliper bears squarely on the rear of the outer
brake pad’s backing plate. Check that the
butterfly spring at the edge of the pad bears
on the inside of the caliper and is not jammed
in the caliper inspection aperture.
23 Thoroughly clean the threads of the
caliper guide pin bolts, fit them to the caliper
and then tighten them to the specified torque.
Refit the dust covers.
24 Refit the caliper spring, ensuring that its
ends are firmly pressed into the holes in the
side of the caliper body (see illustration).
3 Rear brake pads inspection and renewal
3
Note: Before starting work, refer to the note at
the beginning of Section 2 concerning the
dangers of hydraulic fluid, and asbestos dust.
Inspection
All models
28 Clip the pad wear sensor into position on
the inner brake pad. If a new sensor is being
installed, trace the wiring of the original
sensor back to the connector, then
disconnect it and remove the old sensor from
the vehicle. Connect the wiring connector of
the new sensor, ensuring that the wiring is
correctly routed and retained by all the
necessary clips.
29 Check that the caliper body slides
smoothly on its guide pins, then depress the
brake pedal repeatedly until the pads are
pressed into firm contact with the brake disc,
and normal (non-assisted) pedal pressure is
restored.
30 Repeat the above procedure on the
remaining front brake caliper.
1 Chock the front wheels then jack up the
rear of the vehicle and support it on axle
stands. Release the handbrake. Remove the
rear wheels.
2 Inspect the brake pad linings for wear.
Using a steel rule or vernier calipers, check
that the thickness of the lining including the
backing plate is as shown in the
Specifications.
3 If any brake pad is worn below the
minimum thickness, renew all the rear pads as
a set together with new anti-rattle springs.
Removal
4 Note how the anti-rattle spring is located,
then drive out the upper pad securing pin
using a thin punch from the outside (see
illustration).
9
4-cylinder engined models from 1998
and all 6-cylinder engined models
25 Fit the inner and outer brake pads to the
caliper mounting bracket ensuring that the
friction material is facing the surface of the
2.24 Refit the caliper spring, ensuring that
its ends are firmly pressed into the holes in
the side of the caliper body
3510 Vauxhall/Opel Omega
3.4 Driving out the upper rear brake pad
pins using a thin punch
9•6 Braking system
3.5a Remove the anti-rattle spring . . .
3.5b . . . then drive out the lower pad
securing pin
3.6a Use a pair of grips . . .
3.6b . . . or a pad extraction tool . . .
3.6c . . . to remove the brake pads from
the caliper
3.8 Using a retraction tool to press the
pistons back into the caliper body
5 Remove the anti-rattle spring, then drive out
the lower pad securing pin (see illustrations).
6 Push the brake pads apart slightly to give a
small amount of clearance then pull them from
the caliper (see illustrations). If they are tight,
use pliers or a pad extraction tool to remove
them.
15 Refit the rear wheels and lower the vehicle
to the ground. Check the brake fluid level with
reference to Weekly checks.
7 Brush the dust and dirt from the caliper and
intermediate plates, but take care not inhale it.
Clean any rust from the edge of the brake
disc.
8 Press both pistons fully into their cylinders
using a length of wood or piston retraction
tool (see illustration).
9 Check that the cut-away recesses on the
pistons are positioned downwards at
approximately 23º to the horizontal. A
template made of card may be used to check
the setting (see illustration). If necessary,
turn the pistons to their correct positions.
10 Apply a little high-melting point grease to
the top and bottom edges of the backplates
on the new brake pads (see illustration).
Take great care to avoid contaminating the
brake pad friction material with grease.
11 Insert the new brake pads in the caliper
and check that they are free to move.
12 Locate the anti-rattle spring on the pads,
then insert the pins from the inside while
depressing the spring. Tap the pins firmly into
the caliper (see illustration).
13 Renew the brake pads on the remaining
rear wheel in the same manner.
14 Depress the footbrake pedal several times
in order to reset the brake pads to their
normal position.
3.9 Check that the cut-away recesses on
the pistons are positioned downwards at
approximately 23º to the horizontal
3.10 Apply a little high-melting point
grease to the top and bottom edges of the
backplates on the brake pads
3.12 Drive the brake pad securing pins in
from the inner surface of the caliper
Refitting
3510 Vauxhall/Opel Omega
4 Front brake caliper removal, overhaul and refitting
4
Removal
Note: Before starting work, refer to the note at
the beginning of Section 2 concerning the
dangers of hydraulic fluid, and asbestos dust.
1 Apply the handbrake then jack up the front
of the vehicle and support it on axle stands.
Remove the relevant road wheel.
2 On pre-1998 models with 4-cylinder
engines, locate the large spring clip at the
Braking system 9•7
4.3a Slacken the upper guide pin bolt,
counterholding the guide pin with a
second spanner . . .
4.3b . . . withdraw the guide pin bolt from
the caliper . . .
4.3c . . . and remove the caliper from its
mounting bracket
side of the brake caliper. The clip is under
relatively high tension and may fly off with
some force when released; to prevent injury,
cover the spring with a large rag before
prising it from the caliper with a stout
screwdriver.
3 Remove the dust caps from the caliper
guide pin bolt holes, then slacken both guide
pin bolts, and withdraw them from the caliper
(see illustrations).
4 Withdraw the caliper from its mounting
bracket, then tie the caliper to the suspension
strut, using a suitable piece of wire.
Warning: Take great care to avoid
kinking or placing any strain on
the flexible brake hose.
5 On post-1998 models with 4-cylinder
engines and all models with 6-cylinder engines,
remove both brake pads from the caliper
mounting bracket.
6 On pre-1998 models with 4-cyliner engines,
remove the outer pad from the caliper
mounting bracket, then carefully prise the
inner pad from the caliper piston, which is
retained by metal spring attached to the rear
of the pad backing plate.
7 Fit a brake hose clamp to the flexible hose
leading to the brake caliper. Alternatively
remove the cap from the hydraulic fluid
reservoir and refit it with a piece of polythene
sheeting covering the opening to help
minimise the loss of brake fluid when the
caliper hose is disconnected.
8 Clean the area around the union, then undo
the brake hose union bolt, and disconnect the
hose from the caliper - be prepared for some
brake fluid leakage. Plug the end of the hose
and the caliper orifice, to prevent dirt entering
the hydraulic system. Discard the sealing
washers; they must be renewed whenever
disturbed.
9 Slacken and remove the two securing bolts,
then detach the caliper mounting bracket
from the hub carrier (see illustrations).
Warning: Use eye protection
during this procedure, as droplets
of brake fluid may be ejected as
the piston leaves the cylinder under
pressure. Keep your hands away from the
end of the piston as it will leave the
cylinder with considerable force.
13 Using a blunt, non-metallic instrument
(such as an old plastic knife), extract the
piston hydraulic seal, taking great care not to
damage the caliper bore.
14 Press the rubber guide sleeves out of the
caliper body using a suitable socket (see
illustration).
15 Thoroughly clean all components, using
only clean brake fluid as a cleaning medium.
Never use mineral-based solvents such as
petrol or paraffin, as they will attack the
hydraulic system’s rubber components. Dry the
components immediately, using compressed
air or a clean, lint-free cloth. Use compressed
air to blow clear the fluid passages.
Overhaul
10 With the caliper on the bench, wipe away
all traces of dust and dirt using copious
quantities of brake cleaning fluid.
Warning: Avoid inhaling the brake
dust, as it may contain asbestos
which is injurious to health.
11 On post-1998 models with 4-cylinder
engines and all models with 6-cylinder engines,
prise open the three tangs and remove the
protective plate from the contact face of the
piston.
12 Withdraw the piston from the caliper
body, and remove the dust seal. The piston
can be withdrawn by hand, or can if
necessary be pushed out by applying
compressed air to the brake pipe union bolt
hole. Only low pressure should be required,
such as that generated by a foot pump - place
a block of hardwood between the end of the
piston and the caliper body to prevent
damage to the piston as it exits from the
cylinder.
Warning: Wear eye protection
when using compressed air!
16 Check all components, and renew any that
are worn or damaged. Pay particular attention
to the cylinder bore and piston; these must be
renewed if they are scratched, worn or
corroded in any way (see illustration).
9
4.9a Slacken and remove the two securing
bolts . . .
4.9b . . . then detach the caliper mounting
bracket from the hub carrier
3510 Vauxhall/Opel Omega
4.14 Prise open the three tangs and
remove the protective plate from the
contact face of the piston
9•8 Braking system
4.16 Extract the piston hydraulic seal
using a blunt, non-metallic instrument
Warning: Do not use abrasives or
tools to remove any material from
the piston or cylinder in an attempt
to effect a repair or remove corrosion - the
piston and caliper body must be renewed as
a complete assembly.
17 Where applicable, check the condition of
the guide bolts/pins and their sleeves; both
guide bolts/pins should be undamaged and
(when cleaned) a reasonably-tight sliding fit in
the sleeves. If there is any doubt about the
condition of any component, renew it.
18 If the assembly is fit for further use, obtain
new piston and dust seals, and a tube of
brake cylinder paste from a Vauxhall dealer.
19 Smear a little brake cylinder paste onto
the surfaces of the caliper bore, piston and
piston seal.
20 Install the piston seal in the caliper bore,
using only your fingers to manipulate it into its
groove - do not use tools that may damage
the new seal.
21 Fit the new dust seal to the caliper
cylinder, ensuring that the inner edge seats
correctly in the cylinder groove.
22 Offer up the piston to the cylinder and
ease the lip at the outer edge of the dust seal
over the end of the piston.
23 Carefully press the piston to the caliper
bore, using a twisting motion, ensuring that it
enters the bore squarely.
24 Press the piston fully into the bore, until
the outer edge of the dust seal drops into the
groove at the outer edge of the piston. On
pre-1998 models with 4-cyliner engines,
rotate the piston so that the raised section of
the piston contact surface is positioned
horizontally in relation to the caliper body (see
illustration).
25 On post-1998 models with 4-cylinder
engines and all models with 6-cylinder
engines, fit the protective plate in position on
the piston contact surface and press the three
tangs into their corresponding recesses.
26 Lubricate the rubber caliper guide sleeves
with a little soapy water, then press them into
position in the caliper body.
27 Finally, clean the caliper mounting bracket
to remove all traces of dust and corrosion,
using a wire brush if necessary. Pay particular
attention to the machined surfaces which
come into contact with the brake pads.
Refitting
28 Refit the caliper mounting bracket to the
hub carrier, then fit new securing bolts and
tighten them to the specified torque.
29 Apply a little high-melting-point brake
grease to the areas on the pad backing plates
and caliper mounting bracket which contact
the caliper and piston.
Caution: Take great care to avoid
contaminating the pad friction material
and brake disc surface.
4-cylinder engined models up to 1998
30 Fit the inner brake pad to the caliper by
pressing the spring clip on the pad backing
plate into the piston. Check that the butterfly
spring at the edge of the pad bears on the
inside of the caliper and is not jammed in the
caliper inspection aperture.
31 Place the outer pad in the caliper
mounting bracket, with the friction material
facing the disc, and check that it slides freely
along its guides towards the brake disc.
32 Fit the brake caliper and outer pad over
the disc, ensuring that the outer edge of the
caliper bears squarely on the rear of the outer
brake pad’s backing plate. Check that the
butterfly spring at the edge of the pad bears
on the inside of the caliper and is not jammed
in the caliper inspection aperture.
33 Thoroughly clean the threads of the
caliper guide pin bolts, fit them to the caliper
and then tighten them to the specified torque.
Refit the dust covers.
34 Refit the caliper spring, ensuring that its
ends are firmly pressed into the holes in the
side of the caliper body.
plate and that the outer edge of the caliper
bears against the rear of the outer pad’s
backing plate. Check that the butterfly springs
at the edge of the pad bear on the inside of
the caliper and are not jammed in the caliper
inspection aperture.
37 Thoroughly clean the threads of the
caliper guide pin bolts, fit them to the caliper
and then tighten them to the specified torque.
Refit the dust covers.
All models
38 Position a new sealing washer on each
side of the brake hose union, then pass the
bolt through the union and thread it into the
caliper. Ensure that the brake hose union is
correctly positioned against the lug on the
caliper, and tighten the union bolt to the
specified torque setting. Remove the brake
hose clamp (where applicable).
39 Clip the pad wear sensor into position on
the inner brake pad. If a new sensor is being
installed, trace the wiring of the original
sensor back to the connector, then
disconnect it and remove the old sensor from
the vehicle. Connect the wiring plug of the
new sensor, ensuring that the wiring is
correctly routed and retained by all the
necessary clips.
40 Bleed the hydraulic system as described
in Section 12. Note that, providing the precautions described were taken to minimise brake
fluid loss, it should only be necessary to bleed
the relevant caliper.
41 Refit the roadwheel, then lower the car to
the ground and tighten the roadwheel bolts to
the specified torque.
42 Thoroughly check the operation of the
braking system before bringing the vehicle
back into service on the public highway.
5 Rear brake caliper removal, overhaul and refitting
4
Removal
1 Chock the front wheels then jack up the
rear of the vehicle and support it on axle
stands. Remove the wheel.
2 Fit a brake hose clamp to the flexible hose
leading to the brake caliper (see illustration).
4-cylinder engined models from 1998
and all 6-cylinder engined models
4.24 Rotate the piston so that the raised
section of the piston contact surface is
positioned horizontally in relation to the
caliper body
35 Fit the inner and outer brake pads to the
caliper mounting bracket ensuring that the
friction material is facing the surface of the
brake disc. Check that the pads slide easily
along their guides towards the brake disc.
36 Place the caliper body in position over the
brake pads, ensuring that caliper piston bears
against the rear of the inner pad’s backing
3510 Vauxhall/Opel Omega
5.2 Fit a brake hose clamp to the flexible
hose leading to the brake caliper
Braking system 9•9
5.4a Unscrew the union nut . . .
5.4b . . . and disconnect the rigid brake
line from the caliper
Alternatively remove the cap from the
hydraulic fluid reservoir and refit it with a piece
of polythene sheeting covering the opening to
help prevent loss of brake fluid when the
caliper hose is disconnected.
3 Remove the brake pads as described in
Section 3.
4 Unscrew the union nut securing the rigid
brake line to the caliper, and remove the
brake line (see illustrations).
5 Unscrew the hexagon mounting bolts and
withdraw the caliper from the semi-trailing
arm (see illustration).
rotate them so that the cut-away recesses are
positioned downwards at an angle of approximately 23º; this ensures that only the
raised section of the piston contact face bears
on the rear of the pad.
Overhaul
6 Clean the outer surfaces of the caliper.
7 Note that no attempt must be made to
separate the two halves of the caliper.
8 Prise the rings and dust covers from each
side of the caliper and pull the covers from the
piston grooves (see illustration).
9 Position a thin piece of wood between the
pistons, then using air pressure from an air
line or foot pump through the fluid inlet,
carefully force the pistons from the cylinders.
If one piston exits before the other, remove
the piston and then seal off the open cylinder
to allow the remaining piston to be ejected.
10 Prise the piston seals from the cylinders,
taking care not to scratch the bore surfaces.
11 Clean the pistons and cylinders with new
brake fluid and allow to dry. Examine the
surfaces of the pistons and cylinder bores for
wear, damage and corrosion. If evident, renew
the caliper complete, however if the surfaces
are good obtain a repair kit which includes
piston seals and dust covers. Also obtain a
tube of brake cylinder paste.
12 Apply a little brake cylinder paste to the
pistons, cylinder bores and piston seals.
13 Locate the piston seals in the cylinder
grooves, then insert the pistons carefully until
they enter the seals. It may be necessary to
rotate the pistons to prevent them jamming in
the seals. Do not press the pistons fully into
the cylinders at this stage as it will be difficult
to fit the dust covers.
14 Ease the dust covers into the piston
grooves then locate them on the caliper
housing. Press the retaining rings over the
dust covers.
15 Press the pistons into their cylinders, then
5.5a Unscrew the hexagon mounting
bolts . . .
Make up a card template to
check the setting.
Refitting
16 To refit the caliper locate it on the
semi-trailing arm, insert the mounting bolts
and tighten them to the specified torque (see
illustration).
17 Locate the rigid brake line on the caliper
and tighten the union nut to the specified
torque.
18 Refit the brake pads with reference to
Section 3.
19 Remove the brake hose clamp or
polythene sheeting and bleed the hydraulic
system as described in Section 12. Provided
that there has been no loss of brake fluid, it
should only be necessary to bleed the caliper
which was removed, however if brake fluid
has been lost, then bleed the complete
system.
20 Refit the wheel and lower the vehicle to
the ground. Check the operation of the
braking system before using the vehicle.
5.5b . . . and withdraw the caliper from the
semi-trailing arm
6 Brake disc inspection, removal
and refitting
3
Inspection
1 Jack up the front or rear of the vehicle as
applicable and support it on axle stands.
Release the handbrake and chock the front
wheels if checking a rear disc. Remove the
appropriate wheel.
2 Check that the brake disc securing screw is
tight, then refit and tighten a wheel bolt
opposite the screw using a spacer washer approximately 10.0 mm (0.4 in) thick.
3 Rotate the brake disc and examine it for
deep scoring or grooving. Light scoring is
normal, but if excessive, the disc should be
removed and either renewed or machined
within limits by a suitable engineering works.
9
5.8 Removing the dust cover ring from the
rear brake caliper
3510 Vauxhall/Opel Omega
5.16 Tighten the caliper mounting bolts to
the specified torque
9•10 Braking system
6.4 Checking the front brake disc runout
6.6 Checking the thickness of the front
brake disc using a micrometer
6.8a Remove the securing screw . . .
6.8b . . . then withdraw the front brake
disc from the hub
6.9a Remove the securing screw . . .
6.9b . . . and withdraw the rear brake disc
from the hub
It is worth mentioning that some garages may
be able to regrind the discs in situ, using a
specially adapted electric grinder.
4 Using a dial gauge, or metal block and
feeler gauges, check that the disc run-out
does not exceed the amount given in
Specifications, measured at a radius of
approximately 10.0 mm from the outer edge
of the disc (see illustration). Check the
run-out at several positions around the disc.
5 If the run-out is excessive, remove the disc
and check that the disc-to-hub surfaces are
perfectly clean. Refit the disc and check the
run-out again.
6 Check the thickness of the disc using a
micrometer at several points across the area
swept by the brake pads (see illustration).
Compare your measurement with the figures
listed in the Specifications. If either of the
discs has worn beyond its minimum
permissible thickness at any point, both discs
must be renewed as pair.
caliper mounting bracket from the hub carrier,
as described in Section 4.
9 To remove a rear disc, unbolt the brake
caliper from the semi-trailing arm as
described in Section 5, and support it away
from the disc, taking care not to damage the
rigid brake line. Slacken the handbrake
adjustment screw via the access hole in brake
disc, as described in Chapter 1, Section 9 this will retract the handbrake shoes from the
inside of the disc. Remove the securing screw
and withdraw the brake disc from the hub
(see illustrations).
Section 2 or 3 (as applicable). After refitting a
rear brake disc, adjust the handbrake as
described in Chapter 1, Section 9.
Refitting
10 Refitting is a reversal of removal, but make
sure that the mating faces of the disc and hub
are perfectly clean, and before inserting the
securing screw apply a little locking fluid to its
threads. Refit the brake pads with reference to
Removal
7 To remove the brake disc, first remove the
brake pads as described in Section 2 (front
brake pads) or Section 3 (rear brake pads). On
models with 6-cylinder engines and post1998 models with 4-cylinder engines, unbolt
the caliper body from its mounting bracket, as
described in Section 4.
8 To remove a front disc, remove the
securing screw then withdraw the disc from
the hub, tilting it as necessary to clear the
brake caliper (see illustrations). On later
models it may be necessary to unbolt the
7 Handbrake shoes inspection, removal
and refitting
4
Note: Before starting work, refer to the note at
the beginning of Section 2 concerning the
dangers of hydraulic fluid, and asbestos dust.
Inspection
1 Remove the rear brake discs as described
in Section 6.
2 Brush the dust and dirt from the shoes,
backplate and from inside the disc drum.
3 Check the thickness of the linings on the
shoes and if less than shown in the
Specifications, renew the shoes at both rear
brakes as a complete axle set.
4 Also check the surface inside the drums.
These should not normally be worn unless the
handbrake has been binding; check the
diameter of the inner surface and compare it
with the figure listed in Specifications.
Removal
7.6 Handbrake shoe anti-rattle spring
(arrowed) - early model
3510 Vauxhall/Opel Omega
5 Unhook the return spring from the lever on
the rear of the brake backplate then unhook
the handbrake cable from it.
6 Using a screwdriver through a hole in the
hub flange, twist and remove the brake shoe
anti-rattle springs and retaining pins (see
illustration).
Braking system 9•11
7.7 On later models, where the retaining
pins are not cross-headed, depress the
spring cups and turn them through 90°
using two pairs of pliers
7.9a Handbrake shoe adjuster (A) and
spring (B)
7.9b Handbrake shoe lower lever
assembly
7 On later models, where the retaining pins
are not cross-headed, depress the spring
cups and turn them through 90° using two
pairs of pliers (see illustration). This is a
difficult task due to the strong spring tension
and limited access - an alternative method is
to use a small socket, inserted on a the end of
an extension bar through the holes in the hub
flange, to depress the springs. To remove the
pins from the backplate, first remove the
backplate heatshield securing screws via the
holes in the hub flange, then move the
heatshield to one side to allow the withdrawal
of the shoe retaining pins.
8 Mark the brake shoes for location. Also
note the fitted positions of the return springs.
9 Prise the brake shoes from the adjuster and
lever. Disconnect the upper and lower return
springs from the brake shoes (see
illustrations), then remove the brake shoes
from the backplate.
10 Remove the adjuster and handbrake
cable shoe actuator lever.
11 Clean the backplate, springs, adjuster and
lever.
12 Apply a little brake grease to the threads
of the adjuster then screw it together to its
minimum length.
temporarily holding the backplate in position
on the trailing arm using two bolts. After
reassembly the rear hub can then be refitted.
14 Reassemble the lever assembly and apply
a little copper grease to the contact surfaces,
then refit to the backplate and insert through
the rubber grommet (see illustrations).
15 Refit the handbrake cable to the shoe
actuator lever, then refit the return spring (see
illustration).
16 Apply a thin smear of high-temperature
copper-based brake grease or anti-seize
compound to the shoe contact surfaces on
the backplate.
17 With the pins already fitted to the
backplate, refit the front (trailing) shoe and
secure with the hold-down spring and cup
(see illustrations).
7.14a The lever assembly dismantled
7.14b The lever assembled
Refitting
13 Prior to installation, clean the backplate
thoroughly. The handbrake shoes can be
reassembled using a reversal of the
dismantling procedure, however improved
access is possible by removing the rear hub
assembly as described in Chapter 10 and
7.14c Refitting the lever assembly to the
backplate
9
7.15 Refitting the return spring
7.17a Locate the front (trailing) shoe on
the backplate . . .
3510 Vauxhall/Opel Omega
7.17b . . . then refit the spring and cup . . .
9•12 Braking system
7.17c . . . and use a pair of pliers to
depress and turn the cup
7.18a Refit the rear (leading) shoe and the
lower return spring
7.18b Engage the bottom of the shoe on
the lever . . .
7.19 . . . then refit the hold-down spring
and cup
7.20 Refit the adjuster between the upper
ends of the shoes
7.21 Hook the upper return spring on the
shoes
18 Locate the rear (leading) shoe on the lever
assembly and refit the lower return spring
(see illustrations).
19 Refit the hold-down spring and cup to
secure the leading shoe to the backplate (see
illustration).
20 Refit the adjuster between the upper ends
of the shoes (see illustration).
21 Hook the upper return spring on the shoes
(see illustration).
22 Where removed the rear hub can now be
refitted (see illustration).
23 Temporarily refit the disc over the shoes
to determine the adjustment, then if
necessary use a screwdriver to turn the
serrated adjuster nut until it is just possible to
refit the disc over the shoes without them
binding (see illustration).
24 Refit the brake disc with reference to
Section 6.
25 Adjust the handbrake as described in
Chapter 1.
26 Refit the roadwheels and lower the vehicle
to the ground.
1 Chock the front wheel, then jack up the rear
of the vehicle and support it on axle stands.
Remove the rear wheels and release the
handbrake.
2 On models with 4-cylinder engines, unhook
the rear and intermediate silencer rubber
mountings from their floorpan mountings.
Suspend the rear section of the exhaust
system on axle stands, or using lengths of
wire, so that access to the heat shields can be
gained. See Chapter 4A for details.
3 On models with 6-cylinder engines, unbolt
the rear section of the exhaust system at the
joints downstream of both catalytic converters.
Remove the tailpipe and intermediate silencers
from underneath the vehicle as a complete
assembly. See Chapter 4A for details.
4 Unscrew the securing bolts and lower the
exhaust system heatshields away from the
underside of the vehicle (see illustration).
5 Unscrew and remove the propeller shaft
centre bearing retaining bolts, with reference
to Chapter 8, Section 11. Support the centre
bearing on an axle stand.
6 Locate the compensator bar at the front
end of the handbrake cable (see illustration).
Unscrew the adjustment nut from the
threaded handbrake lever rod, counting the
7.22 The handbrake shoes assembled
ready for refitting of the rear hub
7.23 Using a screwdriver through the hole
in the drive flange to turn the serrated nut
on the adjuster
8.4 Unscrew the securing bolts and lower
the exhaust system heatshields away from
the underside of the vehicle
8 Handbrake cable removal and refitting
3
Removal
3510 Vauxhall/Opel Omega
Braking system 9•13
number of turns required to remove it; record
the number for use later.
7 Slide the compensator bar from the
threaded handbrake lever rod.
8 Working at each rear brake caliper in turn,
unhook the return spring from the lever on the
rear of the brake backplate, then unhook the
handbrake cable.
9 Pull the rear of the outer cable from the
guide on the semi-trailing arm on both sides.
10 Pull the front ends of the outer cables
from the guides, and unhook the inner cables.
Release the remainder of each cable from its
respective retaining clips, then withdraw the
cable assembly from under the vehicle.
Refitting
11 Refitting is a reversal of removal, noting
the following points:.
a) Use a new compensator bar adjustment
nut and screw it onto the threaded
handbrake lever rod by the number of
turns noted during removal.
b) Apply some molybdenum disulphide
paste to the plastic guides at the front of
the inner cables.
c) Refit the exhaust system with reference to
Chapter 4A.
d) Refit the propeller shaft centre bearing
with reference to Chapter 8.
e) Finally, adjust the handbrake as described
in Chapter 1.
9 Handbrake lever removal and refitting
3
Removal
1 Chock the front wheels then jack up the
rear of the vehicle and support it on axle
stands.
2 Remove the screws and lower the metal
heat shield away from the propeller shaft
centre bearing. Unbolt and withdraw the
propeller shaft centre bearing bolts as
described in Chapter 8. Support the centre
bearing on an axle stand.
3 At the front of the handbrake cable unscrew
the adjustment nut from the threaded
handbrake lever rod, and slide off the
compensator bar; see Section 8 for details.
4 Prise the rubber gaiter from the underbody
and remove it from the handbrake lever rod.
5 Remove the rear section of the centre
console; see Chapter 11 Section 30 for
details.
6 Unclip and remove the handbrake lever
folding cover. Remove the securing nuts and
detach the air ducting from its support
bracket. Move the ducting to the left, away
from the work area.
7 Unscrew the handbrake lever mountings
bolts, then disconnect the wiring from the
warning switch.
8 Remove the handbrake lever from the
vehicle.
Refitting
8.6 Handbrake cable compensator bar
adjuster nut (arrowed)
Refitting
9 Refitting is a reversal of removal, but on
completion adjust the handbrake cable as
described in Chapter 1.
10 Master cylinder removal and refitting
4
Removal
1 Depress the footbrake pedal several times
to dissipate the vacuum in the servo unit.
2 Remove the fluid reservoir from the master
cylinder, as described in Section 11.
3 Locate a container beneath the master
cylinder to catch spilled brake fluid.
4 Identify the brake lines for position, then
unscrew the union nuts and pull the lines from
the master cylinder. Plug the open ports and
brake pipes to minimise fluid leakage and
prevent the ingress of foreign material.
5 Unscrew the mounting nuts and withdraw
the master cylinder from the studs on the
vacuum servo unit (see illustration). Take
care not to drop any brake fluid on the body
paintwork. If accidentally spilt, wash off
immediately with copious amounts of cold
water.
6 Extract the O-ring seal from the master
cylinder sealing surface, and the rubber
grommets from the fluid reservoir ports, then
discard them as new items must be fitted.
7 Fit a new O-ring seal to the master cylinder
mating surface, and new rubber grommets to
the fluid reservoir ports.
8 Refit the master cylinder to the brake servo,
then fit and tighten the mounting nuts to the
specified torque.
9 Reconnect the brake pipes to the master
cylinder ports and tighten the unions to the
specified torque. A crow’s-foot adapter may
be required to apply torque to the union nuts.
10 Refit the brake fluid reservoir as described
in Section 11.
11 On completion, bleed the entire brake
hydraulic system as described in Section 12.
12 Check the master cylinder unions for
signs of leakage and test the operation of the
braking system thoroughly before using the
vehicle on the road.
11 Brake fluid reservoir
and level sensor removal and refitting
2
Reservoir
Removal
1 Ensure that ignition key is turn to the Off
position, then unplug the wiring from the fluid
reservoir level sensor at the connector.
2 Unscrew the cap from the fluid reservoir,
then remove as much of the brake fluid as is
possible; use an old poultry baster or similar
tool - do not siphon the fluid out as it is
poisonous. Discard the fluid as it will not be fit
for re-use.
3 Slacken and separate the union, then
disconnect the clutch master cylinder supply
pipe from the side of the fluid reservoir.
4 Carefully prise the fluid reservoir from the
brake master cylinder ports. Extract the
rubber grommets from the brake master
cylinder and discard them. Clean the ports at
the base of the fluid reservoir.
Refitting
5 Fit new rubber grommets to the brake
master cylinder ports.
6 Press the fluid reservoir into the brake
master cylinder ensuring that the rubber
grommets do not become dislodged.
7 Reconnect the clutch master cylinder
supply pipe, then tighten the union securely.
8 Fill the reservoir up the MAX marking with
new brake fluid of the specified grade.
9 On completion, bleed the brake hydraulic
system as described in Section 12. Check the
operation of the braking system before using
the vehicle on the road.
Level sensor
Removal
10.5 Master cylinder mounting nuts
(arrowed)
3510 Vauxhall/Opel Omega
10 The sensor is integral with the brake fluid
reservoir filler cap. Ensure that ignition key is
turn to the Off position, then unplug the wiring
from the sensor at the connector.
9
9•14 Braking system
11 Unscrew the cap from the reservoir and
allow the excess fluid to drain off.
Refitting
12 Refitting is a reversal of removal. After
reconnecting the wiring, the operation of the
sensor can be tested by suspending the
reservoir cap above the reservoir, so that the
float slides down to the end of its travel. The
facia tell-tale warning lamp should illuminate.
12 Hydraulic system bleeding
3
Warning: Hydraulic fluid is
poisonous; thoroughly wash off
spills from bare skin without
delay. Seek immediate medical advice if
any fluid is swallowed or gets into the eyes.
Certain types of hydraulic fluid are
flammable and may ignite when brought
into contact with hot components; when
servicing any hydraulic system, it is safest
to assume that the fluid is inflammable and
to take precautions against the risk of fire
as though it were petrol that was being
handled. Hydraulic fluid is an effective
paint stripper and will also attack many
plastics. If spillage occurs onto painted
bodywork or fittings, it should be washed
off immediately, using copious quantities
of fresh water. It is also hygroscopic i.e. it
can absorb moisture from the air, which
then renders it useless. Old fluid may have
suffered contamination and should never
be re-used. When topping-up or renewing
the fluid, always use the recommended
grade, and ensure that it comes from a
new, sealed container.
General information
1 The correct operation of any hydraulic
braking system relies on the fact that the fluid
used in it is incompressible, otherwise the
effort exerted at the brake pedal and master
cylinder will not be fully transmitted to the
brake calipers or wheel cylinders. The
presence of contaminants (such as air) in the
hydraulic system will result in a spongy feel to
the brakes and unpredictable performance, in
12.14a Remove the dust cap from the
caliper bleed screw
the form of brake fade or at worst brake
failure. In addition, brake fluid deteriorates
with age through oxidation and water
absorption. This lowers its boiling point and
may cause vaporisation under hard braking,
again affecting brake performance. For this
reason, old or contaminated brake fluid must
be renewed regularly (see Chapter 1 for the
service interval) - this is achieved by bleeding
the entire system. Similarly, if you have
disturbed any part of the hydraulic system
during repair or servicing, the system must be
bled to remove the air that will have been
admitted.
2 When refilling the system, use only clean,
new hydraulic fluid of the recommended type
and grade; never re-use fluid that has already
been bled from the system. Ensure that
sufficient fluid is available before starting work.
3 If there is any possibility of there being
incorrect fluid in the system already, the brake
components and circuits must be flushed
completely with new fluid of the correct type
and grade and new seals should be fitted
throughout the system.
4 If hydraulic fluid has been lost from the
system, or air has entered because of a leak,
ensure that the fault is corrected before
proceeding further.
5 Park the vehicle on level ground, switch off
the engine and select first or reverse gear
(manual transmission) or Park (automatic
transmission), then chock the wheels and
release the handbrake.
6 Check that all pipes and hoses are secure,
unions tight and bleed screws closed.
Remove the dust caps and clean off all dirt
from around the bleed screws.
7 Unscrew the master cylinder reservoir cap,
and top the master cylinder reservoir up to the
MAX level line; refit the cap loosely, and
remember to maintain the fluid level at least
above the MIN level line throughout the
procedure, otherwise there is a risk of further
air entering the system, as the level drops.
8 There are a number of one-man, do-ityourself brake bleeding kits currently available
from motor accessory shops. It is
recommended that one of these kits is used
whenever possible, as they greatly simplify
the bleeding operation, and also reduce the
risk of expelled air and fluid being drawn back
12.14b Fit the spanner over the bleed
screw and push the tube onto the bleed
screw nipple
3510 Vauxhall/Opel Omega
into the system. If such a kit is not available,
the basic (two-man) method must be used,
which is described in detail below.
9 If a kit is to be used, prepare the vehicle as
described previously, and follow the kit
manufacturer’s instructions, as the procedure
may vary slightly according to the type being
used. Generally, they are as outlined below in
the relevant sub-section.
10 Whichever method is used, the same
sequence must be followed to ensure the
removal of all air from the system.
Bleeding sequence
Note: It is possible to partially bleed the
system, i.e. just one brake line and caliper at a
time. Providing fluid loss is kept to a minimum
and air is not drawn into the system, it will not
be necessary to bleed the other brake lines as
well.
Pre-1998 models with 3-channel ABS
11 Bleed the system in the following
sequence:.
1
Front left hand brake
2
Front right hand brake
3
Rear left hand brake
4
Rear right hand brake
Post-1998 models with 4-channel ABS
12 Bleed the system in the following
sequence:.
1
Left-hand rear brake.
2
Right-hand front brake.
3
Right-hand rear brake.
4
Left-hand front brake.
Bleeding basic (two-man) method
13 Obtain a clean glass jar, a suitable length
of plastic or rubber tubing which is a tight fit
over the bleed screw, and a ring spanner to fit
the screw. Alternatively, a proprietary brake
bleeding kit can be obtained. Note: The help
of an assistant will also be required.
14 Remove the dust cap from the first
caliper’s bleed screw. Fit the spanner over the
bleed screw and push the tube onto the bleed
screw nipple (see illustrations). Place the
other end of the tube in the jar and pour in
sufficient fluid to cover the end of the tube.
15 Throughout the procedure, keep an eye
on the reservoir fluid level and ensure that it is
maintained above the MIN level line as the
brakes are bled; top it up before starting if
necessary.
16 Have the assistant fully depress the brake
pedal several times to build up pressure - then
on the final downstroke, keep it depressed.
17 While pedal pressure is maintained,
slacken the bleed screw (approximately one
turn) and allow the brake fluid to flow into the
jar. Pedal pressure should be maintained
throughout; follow the pedal down to the end
of its travel if necessary, but do not release it.
When the flow stops, tighten the bleed screw
again, then have your assistant release the
pedal slowly. Re-check the reservoir fluid level
and top it up if necessary.
Braking system 9•15
18 If air is present in the brake lines, it will
appear as bubbles in the expelled fluid.
Repeat the steps given in the two previous
paragraphs until the fluid emerging from the
bleed screw is free from air bubbles. If the
master cylinder has been drained and refilled
and air is being bled from the first brake line in
the sequence, allow several seconds between
cycles for the master cylinder passages to
refill.
19 When no more air bubbles appear, tighten
the bleed screw securely, remove the tube
and spanner then refit the dust cap.
Caution: Do not overtighten the bleed
screw.
20 Repeat the procedure on the remaining
brake lines to be bled, until all air is removed
from the system and the brake pedal feels
firm again.
Bleeding using a one-way valve kit
21 As their name implies, these kits consist
of a length of tubing with a one-way valve
fitted, to prevent expelled air and fluid being
drawn back into the system; some kits include
a translucent container, which can be
positioned so that the air bubbles can be
more easily seen flowing from the end of the
tube.
22 The kit is connected to the bleed screw,
which is then opened. The user returns to the
driver’s seat, depresses the brake pedal with
a smooth, steady stroke and slowly releases
it; this process is repeated until the expelled
fluid is free of air bubbles .
23 Note that the use of these kits can
simplify the bleed operation so much, that it is
easy to forget the reservoir fluid level. Ensure
that it is maintained at least above the MIN
level line at all times, or air may be drawn into
the system.
Bleeding using a pressure-bleeding kit
24 These kits are usually powered by
pressurised air, such as that provided by the
vehicle’s spare tyre. However, note that it will
probably be necessary to reduce the tyre
pressure to a lower level than normal before
connecting to the bleeding kit; refer to the
manufacturer’s instructions supplied with the
kit.
25 The method involves connecting a
pressurised, fluid-filled container to the
master cylinder reservoir. Bleeding can then
be carried out simply by opening each bleed
screw in turn, and allowing the fluid to flow
out under moderate pressure until no more air
bubbles can be seen in the expelled fluid.
26 This method has the advantage that the
large reservoir of fluid provides an additional
safeguard against air being drawn into the
system during bleeding.
27 Pressure-bleeding is particularly effective
when bleeding difficult systems, or when
bleeding the complete system at the time of
routine fluid renewal.
All methods
28 When bleeding is complete, and firm
pedal feel is restored, wash off any spilt fluid,
tighten the bleed screws securely, and refit
their dust caps (where applicable).
29 Check the hydraulic fluid level in the
master cylinder reservoir; top it up if
necessary (see Weekly checks).
30 Dispose of any hydraulic fluid that has
been bled from the system; it must not be reused.
31 Check the feel of the brake pedal. If it
feels at all spongy, or has greater travel than
expected, it is probable that air is still present
in the system; further bleeding will therefore
be required. If the bleeding procedure has
been repeated several times and brake feel
has still not been restored, the problem may
be caused by air trapped in ABS hydraulic
modulator. This can be dislodged by
actuating the ABS return pump during the
bleeding process, but note that this operation
can only be carried out by a Vauxhall dealer
with the necessary ABS diagnostic
equipment.
13 Hydraulic brake lines
and hoses removal and refitting
3
1 Remove the cap from the brake fluid
reservoir and refit it with a piece of polythene
sheeting covering the opening to help prevent
subsequent loss of brake fluid.
2 Jack up the front or rear of the vehicle, as
applicable, and support it on axle stands.
Front flexible hose
3 Remove the front wheel.
4 Turn the steering on full lock. Unscrew the
bolt securing the hose to the caliper and
recover the copper washers.
5 Pull the locking plates from the mountings
and disconnect the hose from the retaining
clips.
6 Unscrew the rigid brake line union, and
remove the hose.
7 Refitting is a reversal of removal, but make
sure that the hose is not twisted or kinked.
Bleed the hydraulic system as described in
Section 12 .
the brake lines can be obtained from motor
accessory shops.
12 To remove a brake line, unscrew the
unions at each end and release it from the
clips.
13 Refitting is a reversal of removal. Bleed the
hydraulic system as described in Section 12.
14 Vacuum servo hose
and non-return valve renewal
3
1 When new, the vacuum hose is shrunk onto
the non-return valve using a heat process,
therefore when the valve is first renewed it is
necessary to fit a conventional vacuum hose,
using hose clips to secure the valve.
Thereafter the hose and valve may be
renewed separately.
2 Unscrew the hose union nut at the inlet
manifold.
3 Pull or prise the elbow connector out of the
servo. Note that some models may be
equipped with a quick-release fitting. To
disconnect the fitting, depress the catch at
the side of the fitting and separate the two
halves of the fitting.
4 Release the hose from the plastic straps.
Where applicable, unplug the narrow-bore
vacuum hose from the T-piece.
5 Cut the hose off the non-return valve, the
elbow and the inlet manifold union.
6 Cut the new braided vacuum hoses to
length (it is sold in 5.0 metre lengths) and
secure to the non-return valve, elbow and
union using proprietary clips. Make sure that
the arrows on the valve point towards the inlet
manifold end.
7 Press the elbow into the servo rubber
grommet (or reconnect the quick-release
union, as applicable) and tighten the union nut
on the inlet manifold. Fit new plastic straps to
secure the hose in position. Reconnect the
narrow-bore vacuum hoses to the T-pieces.
8 Check the operation of the vacuum servo
(see Section 15), then entire braking system,
before using the vehicle on the road.
15 Vacuum servo unit testing, removal and refitting
3
Rear flexible hose
8 Pull the locking plates from the mountings.
9 Unscrew the rigid brake line unions, and
remove the hose.
10 Refitting is a reversal of removal, but
make sure that the hose is not twisted or
kinked. Bleed the hydraulic system as
described in Section12 .
Brake lines
11 Some commonly-used brake lines can be
obtained from GM parts stores already
formed complete with unions, however other
brake lines must be prepared from brake
pipes of the required diameter. Kits for making
3510 Vauxhall/Opel Omega
Testing
1 To establish whether or not the servo is
operating, proceed as follows.
2 With the engine stopped, apply the brake
pedal several times in order to dissipate the
vacuum from the servo unit.
3 Hold the brake pedal depressed, then start
the engine. The pedal should move a small
distance towards the floor with the additional
assistance of the servo unit. If not, check the
vacuum hose and non-return valve. If these
prove to be satisfactory, the servo unit itself is
faulty and should be renewed.
9
9•16 Braking system
Removal
4 Depress the footbrake pedal several times
to dissipate the vacuum in the servo unit.
5 Disconnect the wiring for the brake fluid
level warning lamp from the reservoir filler
cap.
6 With reference to Chapter 12, remove both
windscreen wiper arms from their respective
shafts.
7 Carefully peel the rubber sealing strips from
the rear edge of the engine compartment
bulkhead, then remove the securing screws
and withdraw the cowl panel from the lower
edge of the windscreen.
8 Unscrew the master cylinder mounting nuts
and pull the unit from the studs on the
vacuum servo unit sufficiently to allow room
for removal of the servo unit. Leave the brake
lines connected to the master cylinder, but do
not exert excessive force on the brake lines as
this may cause them to fracture.
9 Pull or prise out the vacuum hose elbow
connector, or unplug the quick-release
connector, as applicable. Move the bulkhead
wiring harness to one side.
10 Working inside the vehicle, in the driver’s
footwell, remove the screws and lower the
cover panel away from the underside of the
facia. Unscrew the fixings and remove the
footwell air ducting.
11 Unhook the return spring from the brake
pedal. Remove the brake light switch from its
mounting bracket (see Chapter 12, Section 4).
12 Extract the spring clip and pull out the
clevis pin, to disconnect the servo pushrod
from the brake pedal.
13 Unscrew the mounting nuts, then tilt the
servo unit and remove it from the bulkhead
into the engine compartment. Recover the
gasket. Note that the nuts double up as the
brake pedal bracket mounting nuts (see
Section 16).
14 Loosen the locknut and unscrew the
clevis fork from the pushrod. Unscrew the
locknut.
15 Unscrew the nuts and remove the support
bracket and gaskets from the servo unit.
Refitting
16 Commence refitting by placing the
support bracket together with a new gasket in
position on the servo and tightening the
securing nuts to the specified torque.
17 Screw the locknut and clevis fork onto the
pushrod. With the pushrod in its rest position
adjust the fork so that the distance between
the servo support bracket face and the clevis
pin centre line is 106.0 + 0.5 mm. Tighten the
locknut to secure the fork in this position.
18 Refit the servo unit to the bulkhead using
a new gasket. Fit the mounting nuts and
tighten them to the specified torque.
19 Connect the pushrod to the brake pedal
with the clevis pin and spring clip.
20 Reconnect the brake pedal return springs,
then refit the brake light switch with reference
to Chapter 12, Section 4.
21 Refit the footwell ventilation ducting and
facia lower cover panelling.
22 Press the vacuum hose elbow connector
in the servo rubber grommet, or reconnect the
quick release fitting, as applicable.
23 If necessary, renew the O-ring seal on the
master cylinder flange then locate the unit on
the servo studs and tighten the mounting nuts
(see Section 10 for details).
24 Press the brake pipes firmly into their
retaining clips on the engine compartment
bulkhead.
25 Reconnect the level sensor wiring to the
brake fluid reservoir filler cap.
26 Refit the cowl panel to the lower edge of
the windscreen, and secure it in position with
the screws.
27 Press the rubber sealing strips into
position at the rear of the engine
compartment, then refit the windscreen wiper
arms with reference to Chapter 12.
28 Test the operation of the vacuum servo as
described at the beginning of this Section.
Test the operation of the entire braking
system before using the vehicle on the road.
16 Brake pedal removal and refitting
3
Removal
1 Working inside the vehicle, in the driver’s
footwell, remove the screws and lower the
cover panel away from the underside of the
facia. Unscrew the fixings and remove the
footwell air ducting.
2 Disconnect the wiring from the brake
stop-lamp switch, then unclip the switch from
the pedal bracket, noting its fitted position.
3 Unhook both the brake pedal return
springs.
4 Extract the spring clip and pull out the
clevis pin securing the servo pushrod to the
brake pedal.
5 Slacken and withdraw the uppermost pedal
bracket securing bolt.
6 Unscrew the nuts holding the pedal bracket
to the bulkhead; note that these nuts double
up as the servo mounting nuts (see Section
15). Pull the servo away from the bulkhead
slightly, to withdraw the servo studs from
pedal bracket.
7 Pivot the bracket downwards to release it
from the upper servo studs then remove the
bracket and pedal assembly from the vehicle.
8 Remove the spring clip, the unscrew the
nut from the end of the pedal shaft, and
remove the washer.
9 Remove the pedal location clips and
carefully drive the shaft from the bracket, until
the brake pedal can be removed. Recover the
thrust washers (where fitted) and the centre
spring (see illustration).
Refitting
16.9 Brake pedal and associated components
1 Pedal bracket
2 Spring clip
3 Nut
4 Washer
5 Return spring
6 Pedal shaft
7 Pedal
3510 Vauxhall/Opel Omega
10 Refitting is a reversal of removal, but
lubricate the pedal shaft with grease. Tighten
all fixings to the specified torque where
applicable. Refer to the information given in
Chapter 12, Section 4 when refitting the brake
light switch.
Braking system 9•17
17 Anti-lock Braking System/
Traction Control system
(ABS/TC) - information
4
Information
1 ABS is fitted as standard to all models.
Traction control is fitted as standard to
models with 6-cylinder engines.
2 The ABS system comprises a hydraulic
modulator and electronic control unit together
with four roadwheel sensors. The hydraulic
modulator contains the electronic control unit
(ECU), the hydraulic solenoid valves and the
electrically-driven return pump. The purpose
of the system is to prevent the road wheel(s)
locking during braking. This is achieved by
automatic adjustment of the hydraulic
pressure applied to the brake on the wheel(s)
that is/are about to skid. During normal
operation, the system functions in the same
way as a non-ABS braking system. In the
event of ABS failure, the braking system
reverts to conventional, non-ABS operation.
3 The solenoid valves are controlled by the
ECU, which receives wheel rotation speed
information from each of the four wheel speed
sensors. By comparing these signals, the ECU
can determine the speed at which the vehicle
is travelling. It can then use this speed to
determine when a wheel is decelerating at an
abnormal rate, compared to the speed of the
vehicle, and therefore predicts when a wheel
is about to lock.
4 If the ECU senses that a wheel is about to
lock, it operates the relevant solenoid valve(s)
in the hydraulic unit, which then isolates from
the master cylinder the relevant brake(s) on
the wheel(s) which is/are about to lock,
effectively sealing-in the hydraulic pressure.
On models built before 1998 model year, the
two front brakes are modulated separately,
but the two rear brakes are modulated
together via a shared hydraulic circuit. On
later models, the hydraulic pressure to each
caliper is modulated individually.
5 If the speed of rotation of the wheel
continues to decrease at an abnormal rate,
the ECU operates the electrically-driven pump
which pumps the hydraulic fluid back into the
master cylinder, releasing the brake. Once the
speed of rotation of the wheel returns to an
acceptable rate, the pump stops, and the
solenoid valves switch again, allowing the
hydraulic master cylinder pressure to return to
the caliper/wheel cylinder (as applicable),
which then re-applies the brake. This cycle
can be carried out many times per second.
6 The action of the solenoid valves and return
pump creates pulses in the hydraulic circuit.
When the ABS system is functioning, these
pulses can be felt through the brake pedal and
the return pump can also be heard to operate.
7 On models with 6-cylinder models, the
hydraulic unit incorporates an additional set of
solenoid valves which operate the Traction
Control (TC) system. The system operates at
speeds up to approximately 30 mph (60 km/h)
using the signals supplied by the wheel sensors.
If the ECU senses that a driving wheel is about to
lose traction, it prevents this by momentarily
applying the relevant rear brake.
8 The operation of the ABS and the traction
control system is entirely dependent on
electrical signals. To prevent the system
responding to any inaccurate signals, a builtin safety circuit monitors all signals received
by the ECU. If an inaccurate signal or low
battery voltage is detected, the system is
automatically shut down, and the warning
light on the instrument panel is illuminated, to
inform the driver that the system is not
operational. Normal braking is still available,
however.
Precautions
a) Do not disconnect the ABS/TC control
unit multiway harness plug with the
ignition switched on.
b) Do not use a battery booster to start the
engine.
c) Unplug the multi-way wiring connector
from the ABS/TC control unit before
carrying out any electrical welding on the
car.
d) Do not expose the unit to temperatures
exceeding 80ºC (e.g. during paint-oven
work).
18 Anti-lock Braking System/
Traction Control system component removal and refitting
4
Hydraulic modulator early models with (3-channel)
ABS 2-SH or 2-SH/TC
Removal
1 Disconnect the battery negative cable and
position it away from the terminal.
2 Remove the cap from the brake fluid
reservoir and refit it with a piece of polythene
sheeting covering the opening to help prevent
subsequent loss of brake fluid.
3 Unplug the wiring from the alarm system
bonnet switch, then unscrew the bolt from the
power steering reservoir clamp and tie the
reservoir to one side.
4 Remove the ABS control unit as described
later in this Section. Undo the securing
screws and remove the ABS control unit
mounting bracket from the modulator.
4-cylinder engined models
5 Identify all five brake lines on the modulator
for location, then unscrew the union nuts and
pull the brake lines just clear of the modulator.
Be prepared for brake fluid leakage - place a
suitable container underneath the unions
before disconnection. If possible, plug the
ends of the brake lines, or at least cover them
to prevent excessive fluid brake fluid loss the
ingress of dust and dirt. Also cover the
hydraulic modulator ports.
3510 Vauxhall/Opel Omega
6 Slacken and remove the securing screws,
then remove the heat shield from the
modulator.
6-cylinder engined models
7 Identify the three uppermost brake lines on
the modulator for location, then unscrew the
union nuts and pull the brake lines just clear
of the modulator. Be prepared for brake fluid
leakage - place a suitable container
underneath the unions before disconnection.
If possible, plug the ends of the brake lines,
or at least cover them to prevent excessive
fluid brake fluid loss the ingress of dust and
dirt. Also cover the hydraulic modulator
ports.
8 Apply the handbrake, raise the front of the
vehicle and rest it securely on axle stands.
9 Remove the engine compartment lower
cover panel to allow access to the underside
of the hydraulic modulator.
10 Slacken and remove the securing screws,
then remove the heat shield from the
modulator.
11 Identify the two lowermost brake lines on
the modulator for location, then unscrew the
union nuts and pull the brake lines just clear of
the modulator. Again, be prepared for brake
fluid leakage.
All models
12 Unscrew the nut and disconnect the earth
cable from the rear of the hydraulic modulator.
13 Unscrew the securing nuts from the
hydraulic modulator guide pins, then move
the brake lines carefully to one side and slide
the modulator from the guide pins.
14 Remove the modulator from the engine
compartment taking care to prevent brake
fluid from running out of the modulator ports.
15 Check that the guide pin rubber
mountings on the modulator are in good
condition. No further dismantling of the
hydraulic modulator is possible.
Refitting
16 Refitting is a reversal of removal but
tighten all nuts and bolts to the correct torque
(where specified), and finally bleed the
hydraulic system as described in Section 12.
Check that the ABS warning light extinguishes
at the first application of the brake pedal after
starting the engine. On completion take the
vehicle to a GM dealer and have the system’s
operation verified with ABS test equipment.
Hydraulic modulator and
ABS/TC control unit later models with (4-channel)
ABS 5.3 or 5.3/TC
Removal
17 Disconnect the battery negative cable and
position it away from the terminal.
18 Apply the handbrake, raise the front of the
vehicle and support it securely on axle stands.
19 Undo the screws and lower the cover
panel away from the underside of the engine
compartment.
9
9•18 Braking system
18.46a Unscrew the mounting bolt . . .
18.46b . . . and withdraw the ABS sensor
18.51 ABS rear wheel speed sensors
(arrowed)
20 Unscrew the fixings and remove the heat
shield from the side of the hydraulic
modulator.
21 With reference to Chapter 10 Section 26
disconnect the high pressure hydraulic fluid
delivery pipe from the power steering pump.
Position a container underneath the
disconnected union to catch escaping
hydraulic fluid.
22 Unclip the cover from the engine
compartment auxiliary fusebox and detach
the fuseholder from the base of the fusebox.
23 Unclip the cover from the engine
compartment relay box. Withdraw the engine
management system electronic control unit,
then unplug the multiway connector from it;
refer to Chapter 4A for details.
24 Release the engine management system
relay from the relay box, together with its
mounting bracket.
25 Disconnect the three main wiring harness
plugs located at the rear of the main engine
compartment fusebox.
26 Remove as much hydraulic fluid as
possible from the power steering fluid
reservoir, using an old (but clean) poultry
baster or similar.
27 Slacken the hose clips and disconnect the
two fluid hoses from the base of the power
steering fluid reservoir. Place a suitable
container underneath the reservoir to catch
the hydraulic fluid that will run out.
28 Remove the power steering fluid reservoir
from its mounting bracket then unbolt the
bracket from the bodywork and remove it.
29 Undo the securing screw and unplug the
multiway wiring harness connector from the
ABS/TC control unit.
30 Remove as much hydraulic fluid as
possible from the brake fluid reservoir, using
an old (but clean) poultry baster or similar.
31 With reference to Section 10, undo the
unions and disconnect the brake pipes from
the side of the master cylinder. Place a
suitable container underneath the reservoir to
catch the brake fluid that will run out. Plug the
ends of the brake lines.
32 Carefully label all six brake lines at the
hydraulic modulator (to ensure that they are
reconnected in correct order later) then
unscrew the union nuts and pull the brake
lines just clear of the modulator. Be prepared
for brake fluid leakage - place a suitable
container underneath the unions before
disconnection. If possible, plug the ends of
the brake lines, or at least cover them to
prevent excessive fluid brake fluid loss, and
the ingress of dust and dirt. Also cover the
hydraulic modulator ports.
33 Detach the hydraulic modulator from its
mounting bracket and remove it from the
engine compartment, taking care to prevent
brake fluid from running out of the modulator
ports.
Off position, then carefully prise the switch
from the facia panel, using a small
screwdriver. Use card or cloth to prevent
damage to the facia.
41 Unplug the wiring connector from the rear
of the switch.
Refitting
43 Disconnect the battery negative lead.
44 Apply the handbrake, then jack up the
front of the vehicle and support it on axle
stands (see Jacking and Vehicle Support).
Remove the relevant front roadwheel.
45 Disconnect the sensor wiring and release
it from the clips on the front suspension strut
and wheel arch. Do not confuse it with the
brake pad wear sensor wiring connector.
46 Unscrew the mounting bolt using a Torx
key and withdraw the sensor from the
mounting bracket (see illustrations).
34 Refitting is a reversal of removal, noting
the following points:.
a) Tighten all nuts and bolts to the correct
torque (where specified)
b) Top up the power steering system with
the correct grade of fluid as described in
Weekly checks.
c) Bleed the hydraulic system as described
in Section 12.
d) Check that the ABS warning light
extinguishes at the first application of the
brake pedal after starting the engine.
e) On completion take the vehicle to a GM
dealer and have the system’s operation
verified with ABS test equipment.
ABS/TC control unit early models with (3-channel)
ABS 2-SH or 2-SH/TC
Removal
35 Disconnect the battery negative cable and
position it away from the terminal.
36 Unscrew the securing bolt and remove
the cover panel from the ABS/TC control unit.
37 Unplug the three multiway wiring harness
connectors from the ABS/TC control unit.
38 Slacken and remove the securing bolts
and then lift the ABS/TC control unit away
from the engine compartment.
Refitting.
39 Refitting is a reversal of removal. On
completion take the vehicle to a GM dealer
and have the system’s operation verified with
ABS test equipment.
Traction Control switch
Removal
40 Ensure that ignition key is turned to the
3510 Vauxhall/Opel Omega
Refitting
42 Refitting is a reversal of removal.
Front wheel speed sensors
Removal
Refitting
47 Refitting is a reversal of removal but
smear a little anti-seize grease on the sides of
the sensor casing before inserting it. On
completion take the vehicle to a GM dealer
and have the system’s operation verified with
ABS test equipment.
ABS rear wheel speed sensors
Removal
48 Disconnect the battery negative lead.
49 Chock the front wheels, then jack up the
rear of the vehicle and support it on axle
stands (see Jacking and Vehicle Support).
Remove the relevant rear roadwheel.
50 Disconnect the sensor wiring and release
it from the clips on the underbody.
51 Unscrew the mounting bolt using a Torx
key and withdraw the sensor from the final
drive unit (see illustration).
Refitting
52 Refitting is a reversal of removal but
smear a little anti-seize grease on the sides of
the sensor casing before inserting it into the
final drive unit. On completion take the vehicle
to a GM dealer and have the system’s
operation verified with ABS test equipment.
10•1
Chapter 10
Suspension and steering
Contents
Front anti-roll bar - removal and refitting . . . . . . . . . . . . . . . . . . . . . . 6
Front anti-roll bar drop link - removal and refitting . . . . . . . . . . . . . . 7
Front hub and bearings - removal and refitting . . . . . . . . . . . . . . . . . 9
Front lower suspension arm - removal and refitting . . . . . . . . . . . . . 4
Front suspension subframe - removal and refitting . . . . . . . . . . . . . . 10
Front suspension lower balljoint - renewal . . . . . . . . . . . . . . . . . . . . 5
Front suspension strut - camber adjustment . . . . . . . . . . . . . . . . . . 3
Front suspension strut - removal. overhaul and refitting . . . . . . . . . . 2
General description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Power steering pump - removal and refitting . . . . . . . . . . . . . . . . . . 27
Rear anti-roll bar - removal and refitting . . . . . . . . . . . . . . . . . . . . . . 14
Rear axle (complete assembly) - removal and refitting . . . . . . . . . . . 17
Rear coil spring - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . 13
Rear hub and bearing - removal and refitting . . . . . . . . . . . . . . . . . . 20
Rear semi-trailing arm - removal and refitting . . . . . . . . . . . . . . . . . . 12
Rear shock absorber - removal and refitting . . . . . . . . . . . . . . . . . . . 11
Rear suspension level control system - component removal and
refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Rear suspension subframe - removal and refitting . . . . . . . . . . . . . . 18
Rear suspension subframe mountings - renewal . . . . . . . . . . . . . . . 19
Rear suspension track control arm - removal and refitting . . . . . . . . 15
Steering column - removal and refitting . . . . . . . . . . . . . . . . . . . . . . 22
Steering column lock/ignition switch - removal and refitting . . . . . . 23
Steering gear - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . 24
Steering idler - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . 26
Steering knuckle - removal and refitting . . . . . . . . . . . . . . . . . . . . . . 8
Steering tie-rods - removal and refitting . . . . . . . . . . . . . . . . . . . . . . 25
Steering wheel - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . 21
Wheel alignment - checking and adjustment . . . . . . . . . . . . . . . . . . 28
Degrees of difficulty
Easy, suitable for
novice with little
experience
1
Fairly easy, suitable
for beginner with
some experience
2
Fairly difficult,
suitable for competent
DIY mechanic
3
Difficult, suitable for
experienced DIY
mechanic
4
Very difficult,
suitable for expert DIY
or professional
5
Specifications
Front suspension
Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Independent MacPherson struts, coil springs and anti-roll bar,
double-acting telescopic shock absorbers. Adjustable camber.
Rear suspension
Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Independent, semi-trailing arms and coil springs, anti-roll bar, doubleacting telescopic shock absorbers. Adjustable track control arms.
Steering
Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Overall steering ratio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Lubricant quantity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Hydraulic fluid pressure:
At full lock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
At rest in centre position . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Recirculating ball, worm shaft and nut with sector shaft and drop arm,
adjustable track control rods. Hydraulic power-assistance on all models,
Servotronic speed-sensitive power assistance on 6-cylinder models.
14.8:1
1.3 litres
100 to 110 bar
2 to bar
10
Front suspension
Coil springs (typical):
SOHC 4-cylinder engines up to 1998 . . . . . . . . . . . . . . . . . . . . . . . . .
DOHC 4-cylinder engines, with air conditioning from 1998 . . . . . . . .
6-cylinder engines, without air conditioning, up to 1998 . . . . . . . . . .
6-cylinder engines, with air conditioning, from 1998 . . . . . . . . . . . . .
Colour code
Blue/Brown
Blue/Orange
Yellow/Lilac
Brown/Brown
3510 Vauxhall/Opel Omega
Spring length
368 mm
390 mm
362 mm
373 mm
Compression rate
21 N/mm
21 N/mm
24 N/mm
24 N/mm
10•2 Suspension and steering
Front wheel alignment*
Camber:
Saloon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Estate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Maximum deviation, left to right wheel . . . . . . . . . . . . . . . . . . . . . . . .
Castor:
Saloon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Estate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Maximum deviation, left to right wheel . . . . . . . . . . . . . . . . . . . . . . . .
Toe-in:
Saloon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Estate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Variation with inner wheel turned in at 20‡ . . . . . . . . . . . . . . . . . . . . .
-1º40’ ± 45’
-1º40’ ± 45’
1º
5º40’ ± 1º
5º ± 1º
1º
0º10’ ± 10’
0º10’ ± 10’
1º40’ ± 45’
Rear wheel alignment*
Camber:
Saloon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -1º50’ ± 40’
Estate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -1º40’ ± 40’
Maximum deviation, left to right wheel . . . . . . . . . . . . . . . . . . . . . . . . 45’
Toe-in:
Saloon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0º20’ ± 10’
Estate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0º20’ ± 10’
Maximum deviation, left to right wheel . . . . . . . . . . . . . . . . . . . . . . . . 25’
*Note: Measurements taken and adjustments made with all tyres inflated to their fully laden pressures and the vehicle laden, i.e. a 70kg load in
each front seat and a full tank of fuel.
Wheels
Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pressed steel or alloy
6 1/2 J x 15, 7J x 15 or 7J x 16, depending on model and specification.
Tyres
Sizes
Saloon and estate models with 4-cylinder engines . . . . . . . . . . . . . . . .
Saloon and estate models with 6-cylinder engines . . . . . . . . . . . . . . . .
* Refer to vehicle handbook or Vauxhall dealer for tyre speed ratings.
195/65 R 15, 205/65 R 15 or 225/55 R 16
205/65 R 15 or 225/55 R 16
Pressures
Refer to end of Weekly checks on page 0•17
Torque wrench settings
Nm
lbf ft
20
angle tighten through 30º
angle tighten through 15º
65
65
15
Front suspension
Anti-roll bar bearing bracket bolts:
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Anti-roll bar link rod to anti-roll bar . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Anti-roll bar link rod to strut . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Front subframe*:
Front mounting bolts:
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Centre mounting bolts:
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rear mounting bolts:
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Hub nut* . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Lower balljoint to arm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Lower balljoint to knuckle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Lower suspension arm pivot bolt:*
Front:
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
48
48
65
angle tighten through 30º
angle tighten through 15º
48
150
angle tighten through 30º
angle tighten through 15º
112
130
angle tighten through 30º
angle tighten through 15º
320
35
100
96
120
angle tighten through 30º
angle tighten through 15º
3510 Vauxhall/Opel Omega
236
26
74
89
Suspension and steering 10•3
Torque wrench settings (continued)
Front suspension (continued)
Lower suspension arm pivot bolt (continued):*
Rear:
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Strut damper rod nut . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Strut mounting nuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Strut to steering knuckle:*
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rear suspension
Anti-roll bar drop link to semi-trailing arm . . . . . . . . . . . . . . . . . . . . . . .
Anti-roll bar to subframe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Damping blocks to body . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Damping blocks to subframe:
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Driveshaft to rear hub:
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stage 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rear hub nut* . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Semi-trailing arm pivot bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Shock absorber lower mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Shock absorber upper mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Subframe to body . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Subframe to differential damping bush . . . . . . . . . . . . . . . . . . . . . . . . .
Track control arm to semi-trailing arm . . . . . . . . . . . . . . . . . . . . . . . . . .
Track control arm to subframe* . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Steering
Airbag unit to steering wheel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Centre tie rod to drop arm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Centre tie rod to idler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Drop arm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel supply and return union nuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Idler mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Outer tie-rod clamp bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Outer tie rods to centre tie rod . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Power steering pump:
4-cylinder engines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6-cylinder engines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Power steering pump hydraulic fluid union . . . . . . . . . . . . . . . . . . . . . .
Power steering pump pulley . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Steering column . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Steering column support bracket nut . . . . . . . . . . . . . . . . . . . . . . . . . . .
Steering gear clamp bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Steering gear heat shields . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Steering gear mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Steering pump support brackets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Steering shaft clamp bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Steering wheel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tie-rod balljoint nut* . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Nm
lbf ft
120
angle tighten through 30º
angle tighten through 15º
70
55
89
52
41
90
angle tighten through 45º
angle tighten through 15º
66
20
22
65
15
16
48
90
angle tighten through 30º
angle tighten through 15º
66
50
angle tighten through 60º
angle tighten through 15º
300
100
110
20
65
125
45
90
37
221
74
81
15
48
92
33
66
8
60
60
160
28
60
15
60
6
44
44
118
21
44
11
44
25
20
28
20
22
22
22
15
55
20
22
20
60
18
15
21
15
16
16
16
11
41
15
16
15
44
Wheels
Wheel bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
81
*Use a new nut/bolt
Note 1: As a general rule, any fastener which has been angle-tightened should be renewed.
Note 2: The threads of all fasteners secured with locking compound must be thoroughly cleaned and, if necessary, re-cut to remove all traces of
the old locking compound. Fresh locking compound should then be reapplied at reassembly.
3510 Vauxhall/Opel Omega
10
10•4 Suspension and steering
2.4a Pull out the retaining clip . . .
1 General description
1 The front suspension is of independent
MacPherson strut type incorporating coil
springs and double-acting telescopic shock
absorbers. An anti-roll bar, connected to the
suspension struts via drop links is mounted
forward of the suspension arms.
2 The rear suspension is of independent type
with coil springs, double-acting gas-filled
telescopic shock absorbers, semi-trailing
arms, anti-roll bar and adjustable track control
arms. All components are mounted on a
single subframe, which also houses the final
drive unit (see Chapter 8 for general
information relating to the final drive unit).
3 Power-assisted steering is fitted to all
models, consisting of a recirculating ball and
worm-type steering box with drop arm, a
2.7b . . . then unscrew . . .
2.8b . . . unscrew the upper mounting
nut . . .
2.4b . . . and disconnect the hydraulic
hose from the bracket on the strut
2.7a Mark the top of the steering knuckle
in relation to the strut, to retain the camber
setting . . .
1 Apply the handbrake, then jack up the front
of the vehicle and support it on axle stands.
2 Remove the relevant front road wheel.
3 Remove the brake caliper from the steering
knuckle, as described in Chapter 9. Support
the caliper to avoid straining the brake hose.
4 Pull out the retaining clip and disconnect
the hydraulic hose from the bracket on the
strut (see illustrations).
5 Remove the ABS wheel speed sensor from
the steering knuckle and disconnect the
wiring with reference to Chapter 9.
6 Unscrew the nut and separate the bottom
of the anti-roll bar link from the end of the
anti-roll bar (see Section 7). To prevent the
ball-pin from turning, hold it stationary with a
spanner on the two flats provided.
7 Mark the top of the steering knuckle in
relation to the strut, to retain the camber
setting then unscrew and withdraw the strut
lower securing bolts (see illustrations). Pull
down on the lower suspension arm, to release
the strut from the top of the steering knuckle.
8 Support the suspension strut by hand, then
remove the cap, unscrew the upper mounting
nut and remove the upper plate. Counterhold
the damper rod with a second spanner to
prevent it from rotating (see illustrations).
2.7c . . . and withdraw the strut lower
securing bolts
2.8a Remove the cap . . .
centre tie rod, idler arm and adjustable outer
tie rods. 6-cylinder models are fitted with
Servotronic speed sensitive power steering.
2 Front suspension strut removal and refitting
3
Warning: If you are renewing the
strut as part of the overhaul procedure, both the left and right
hand struts should be renewed as a pair, to
preserve the handling characteristics of the
vehicle.
Removal
2.8c . . . and remove the upper plate
3510 Vauxhall/Opel Omega
2.8d Counterhold the damper rod with a
second spanner to prevent it from rotating
Suspension and steering 10•5
2.9 Withdrawing the front suspension strut
from the wheel arch
2.11 Fitting the spring compressor to the
strut coil spring
2.12a Hold the piston rod stationary with
an Allen key . . .
2.12b . . . then unscrew the damper rod
nut . . .
2.12c . . . and withdraw the washer
renewed (in which case, the spring, upper
mounting
components,
bushes,
and
associated components can be transferred to
the new strut).
16 With the strut assembly now dismantled,
examine all the components for wear, damage
or
deformation.
Check
the
rubber
components for deterioration. Renew any of
the components as necessary.
17 Examine the shock absorber for signs of
fluid leakage. Check the damper rod for signs of
wear or corrosion along its entire length, and
check the strut body for signs of damage or
corrosion. While holding it in an upright position,
test the operation of the strut by moving the
damper rod through a full stroke, and then
through short strokes of 50 to 100 mm. In both
cases, the resistance felt should be smooth and
continuous. If the resistance is jerky, or uneven,
or if there is any visible sign of wear or damage
to the strut, renewal is necessary.
18 If any doubt exists about the condition of
the coil spring, carefully release the spring
compressors, and check the spring for
distortion and signs of cracking. Measure the
unloaded height of the spring and compare it
with the figure listed in the Specifications.
19 If a new shock absorber is being fitted,
before reassembly push the damper rod fully
into the shock absorber body, and then
extend the rod to end of its travel. Do this
three or four times to ensure that the shock
absorber is fully primed.
20 Refit the rubber damper to the lower
spring seat. Ensure that the coil spring is
compressed sufficiently to enable the upper
mounting components to be fitted, then lower
the coil spring (together with the spring
compressors) onto the lower spring seat,
ensuring that the lower end of the coil spring
abuts the stepped section of the rubber
damper (see illustrations).
Warning: Do not unscrew the
damper rod nut (exposed by the
removal of the upper mounting
nut and plate) until spring compressors
have been fitted to the suspension strut.
9 Pivot the lower end of the strut away from
the wheel arch, then lower it away from the
upper mounting and withdraw it from under
the vehicle (see illustration).
Overhaul
Note: A purpose-made spring compressor is
essential for this work. Use of makeshift or
unsuitable tools may result in injury.
10 Remove the strut as described in the
previous sub-Section. If required, mount it in a
vice with padded jaws.
11 Fit the spring compressor and tighten it
compress the coil spring, unloading the
pressure on the upper seat and mounting (see
illustration).
12 Hold the piston rod stationary with an
Allen key, then unscrew the damper rod nut
and withdraw the washer (see illustrations).
13 Remove the bearing and washer (noting
its orientation), then slide off the upper spring
seat, upper rubber damper, bump stop rubber
and dust cover from the damper rod and from
the top of the coil spring. Extract the rubber
damper from the lower spring seat (see
illustrations).
14 Lift off the coil spring together with the
spring compressors.
15 It is not possible to separate the shock
absorber from the strut body, so if the shock
absorber is faulty the strut assembly must be
10
2.13a Remove the bearing . . .
2.13b . . . and washer . . .
3510 Vauxhall/Opel Omega
2.13c . . . then slide off the upper spring
seat, upper rubber damper, bump stop
rubber and dust cover
10•6 Suspension and steering
2.20a Refit the rubber damper to the lower
spring seat
2.20b Lower the coil spring, together with
the spring compressors, onto the lower
spring seat
21 Locate the rubber damper in the upper
spring seat, then slide the upper spring seat,
bump stop rubber and dust cover over the
damper rod (see illustration).
22 Ensure that the upper end of the coil
spring abuts the stepped section of the
rubber damper.
23 Fit the washer and strut bearing to the
strut damper rod and secure them in position
with the washer and a new damper rod nut.
Hold the damper rod stationary using an Allen
key and then tighten the nut to specified
torque. A crow’s foot adapter may be required
to allow the damper rod to be held still as the
nut is tightened.
24 Slowly release the spring compressor and
make sure that the coil spring locates
correctly on the damping rings.
25 Refit the front suspension strut, as
described in the following sub-Section.
to the markings made on the steering knuckle
during removal, to preserve the camber
setting, then fit the new nuts, and tighten
them to the specified torque.
Note: If the original front wheel camber setting
has been lost, or if new struts are being fitted,
the camber setting must be checked and
adjusted, using a camber gauge, before the
strut lower nuts are tightened to their final
torque setting; see Section 3 for details.
28 Reconnect the drop link to the end of the
anti-roll bar and tighten the nut to the
specified torque; see Section 7 for details.
29 Refit the ABS wheel speed sensor and
reconnect the cable, with reference to
Chapter 9.
30 Press the brake hydraulic hose into the
bracket on the strut and secure with the metal
retaining clip. Refit the brake caliper with
reference to Chapter 9.
31 Refit the front wheel, then lower the
vehicle to the ground and tighten the wheel
bolts to the specified torque.
32 Finally, have the front wheel toe-in adjustment checked and if necessary adjusted.
Refitting
26 Commence refitting by inserting the strut
up into the upper mounting. Refit the upper
plate, then fit a new securing nut. Tighten the
nut to the specified torque whilst holding the
piston rod stationary with an Allen key. A
crow’s foot adapter may be required to allow
the damper rod to be held still as the nut is
tightened.
27 Fit the lower end of the strut to the
steering knuckle and insert a pair of new
securing bolts, noting that the bolts are
inserted from the front of the strut, so that the
heads face front of the car. Ensure that the
lower end of the strut is positioned according
2.21 Locate the rubber damper in the
upper spring seat
3 Front suspension camber adjustment
5
1 After disturbing the front suspension strut or
any of the front suspension components that
have an effect on wheel camber, the front
wheel camber setting must be checked, and if
necessary adjusted, to preserve the vehicle’s
handling characteristics and to prevent uneven
tyre wear. It is recommended that this
operation is carried out by a Vauxhall dealer,
who will have access to the necessary
measuring equipment. However, the procedure
is given here for reference.
2 Apply the handbrake, select first gear or
Park (as applicable) then jack up the front of
the vehicle and support it on axle stands.
3 Remove both front road wheels.
4 Remove both brake calipers from the
steering knuckles, as described in Chapter 9.
Support the calipers to avoid straining the
brake hoses.
5 Working on one side of the vehicle, slacken
and withdraw the front suspension strut lower
3510 Vauxhall/Opel Omega
securing bolts. Fit two new securing bolts and
nuts, noting that the bolts are fitted from the
front of the strut so that their heads face the
front of the car.
6 Set the wheel to maximum positive camber
by pressing the top of the brake disc inwards,
towards the engine compartment. The strut
lower mountings bolts will pivot on their
slotted mounting holes. Tighten the nuts to
approximately 20 Nm only, then refit the brake
caliper (see Chapter 9) and the road wheel.
7 Repeat the operations in paragraphs 5 and
6 on the opposite front wheel.
8 Carefully lower the vehicle to the ground
and tighten the road wheel bolts to the
specified torque.
9 Load the vehicle to its specified adjustment
weight, as described in Specifications, Front
wheel alignment.
10 Using a proprietary camber gauge, set the
front wheels to the specified camber angle.
Adjustments are made by grasping the top of
the road wheel and pivoting the steering
knuckle inwards or outwards to achieve the
correct camber angle.
11 When the correct camber angles are
obtained, tighten the strut lower mounting nuts
progressively in two stages; first to 50 Nm,
then to 90 Nm.
12 Release the handbrake and select neutral,
then rock the vehicle on its road wheels to
settle the suspension.
13 Recheck the camber setting; if further
adjustment is required, repeat the operations
described in paragraphs 2 to 12 inclusive. If
no further adjustment is required, tighten the
strut lower mounting nuts to their specified
Stage 1 and Stage 2 torque settings.
4 Front lower suspension arm
- removal and refitting
3
Removal
1 Apply the handbrake, then jack up the front
of the vehicle and support it on axle stands.
2 Remove the relevant front road wheel.
3 Unscrew and remove the pinch-bolt, and
pull down the lower suspension arm to
release the balljoint from the steering knuckle.
4 Unscrew the vertical front mounting bolt
and the horizontal rear mounting bolt, discard
them, and withdraw the lower suspension arm
from under the vehicle. Note the horizontal
bolt head faces towards the rear of the car.
Note also that access to the front mounting
bolt is via the top of the suspension subframe
and access is very limited due to the proximity
of the engine mounting bracket.
5 Refer to Section 5 if renewing the
suspension balljoint. Examine the rubber
bushes in the arm and if necessary renew
them using a hydraulic press. Note the
orientation of the existing bushes in the lower
arm before pressing them out, and ensure that
the new bushes are fitted in the same way.
Suspension and steering 10•7
10 Refit the front wheel and lower the vehicle
to the ground.
11 Finally, have the front wheel alignment
checked and if necessary adjusted.
5 Front suspension
lower balljoint renewal
5.2 Drilling out the front suspension lower
balljoint rivets
Refitting
6 Commence refitting by locating the arm on
the underbody and inserting the new mounting
bolts. Do not re-use the old mounting bolts.
Insert the front mounting bolt from back to
front, and insert the (shorter) rear mounting
bolt from top to bottom.
7 Hold the arm horizontally and tighten the
securing nuts and bolts to the specified
torque.
8 Insert the balljoint in the steering knuckle
and fit a pinch-bolt, with its head facing the
rear of the vehicle. Fit a new nut and tighten to
the specified torque.
9 Reconnect the links to the anti-roll bar and
tighten the nuts.
7.2a Unscrew the upper nut . . .
3
1 Remove the front lower suspension arm as
described in Section 4.
2 The balljoint is riveted to the suspension
arm when new, with subsequent balljoints
bolted on. Where necessary drill out the rivets
using a 12.0 mm drill. One side of each rivet
has a centre punch to facilitate accurate
drilling in order to prevent enlarging the holes
in the arm (see illustration).
3 Coat the newly-drilled holes with a suitable
rust-preventing agent.
4 Using only the special bolts supplied the
new balljoint, fit the balljoint and tighten the
nuts to the specified torque. The nuts must
face downwards.
5 Refit the front lower suspension arm with
reference to Section 4.
6 Front anti-roll bar removal and refitting
3
6.4 Unscrew the anti-roll bar mounting
clamp bolts (arrowed)
Refitting
6 Examine the mounting rubbers for wear and
deterioration and, if necessary, prise them
from the bar. Coat the new rubbers with a
silicone-based spray and fit them on the bar
with their slits facing towards the rear of the
vehicle.
7 Insert the anti-roll bar from under the front
of the vehicle, and refit the clamps. Insert the
bolts loosely.
8 Reconnect the drop links to the ends of the
anti-roll bar; use new securing nuts and
tighten them to the specified torque.
9 Tighten the anti-roll bar mounting clamp
bolts to the specified torque.
10 Refit the front wheels and lower the
vehicle to the ground.
Removal
1 Apply the handbrake, then jack up the front
of the vehicle and support it on axle stands.
Remove the front wheels.
2 Unscrew the nuts and separate the lower
ends of the drop links from the ends of the
anti-roll bar (see Section 7). Prevent the link
ball-pins from turning by holding them with a
spanner on the two flats provided.
3 Refer to Section 10 and remove the front
suspension subframe.
4 From inside the engine compartment
unscrew the anti-roll bar mounting clamp
bolts, and unclip the clamps (see
illustration).
5 Withdraw the anti-roll bar from under the
vehicle.
7 Front anti-roll bar drop link removal and refitting
2
Removal
1 Apply the handbrake, then jack up the front
of the vehicle and support it on axle stands.
Remove the appropriate front wheel.
2 Note which way round the link is fitted then
unscrew the nuts while holding the ball-pins
with a spanner on the two flats provided (see
illustrations).
3 Remove the link from the strut and anti-roll
bar.
10
7.2b . . . and detach the drop link from the
suspension strut
7.2c Detach the drop link from the anti-roll
bar
3510 Vauxhall/Opel Omega
7.2d Counterhold the drop link stud using
the flats provided
10•8 Suspension and steering
7.4 Tighten the anti-roll bar drop link
securing nuts to the specified torque
Refitting
4 Refitting is a reversal of removal but fit new
securing nuts and tighten them to the
specified torque (see illustration).
8 Steering knuckle removal and refitting
3
Removal
1 Remove the front hub as described in
Section 9.
2 Unbolt the brake disc shield from the
steering knuckle.
3 With reference to Section 24, unscrew the
nut from the steering tie-rod balljoint, and use
a proprietary balljoint separator to release the
ball joint pin from the steering knuckle lug.
8.6a Unscrew and remove the
pinch-bolt . . .
8.6b . . . and then lift the knuckle from the
lower arm
4 Remove the ABS wheel speed sensor and
disconnect the cable with reference to
Chapter 9, Section 18.
5 Mark the top of the steering knuckle in
relation to the strut in order to retain the
camber setting, then unscrew and discard the
bolts and separate the strut from the knuckle.
Note that the bolt heads face forwards.
6 Unscrew and remove the pinch-bolt, and
then lift the knuckle from the lower arm (see
illustrations).
the road wheel and lower the vehicle to the
ground; with the road wheel in contact with
the ground, it will be much easier to slacken
the hub nut.
3 Chock the roadwheels securely, then using
a socket, sturdy T-bar and a long extension
bar for leverage, slacken the hub nut by about
half a turn. Note that the nut is tightened to a
very high torque setting, and considerable
effort will be required to slacken it.
4 Jack up the front of the vehicle again and
support it on axle stands. Remove the
appropriate road wheel.
5 Remove the brake caliper and brake disc
with reference to Chapter 9.
6 Fully unscrew and remove the hub nut, and
pull the hub from the stub axle (see
illustrations). If the inner bearing track
remains on the stub axle, remove it with a
universal bearing puller and recover the oil
seal which will have been pulled out of the
hub.
Refitting
7 Refitting is a reversal of removal, but be
sure to use new bolts and nuts. On no
account should the old bolts be re-used.
Tighten to the specified torque wrench
settings and if necessary have the camber
and wheel alignment checked by a Vauxhall
dealer.
9
Front hub and bearings removal and refitting
4
1 Apply the handbrake, then jack up the front
of the vehicle and support it on axle stands.
Remove the appropriate front road wheel.
2 Lever the dust cap from the hub, then refit
7 The bearings cannot be renewed separately
to the hub, so if the bearings are worn or the
oil seal leaking the complete hub must be
renewed. The new hub includes a plastic
sleeve which holds the bearing inner tracks
together while fitting the hub.
8 Locate the hub and plastic sleeve on the
stub axle, then carefully drive the inner tracks
onto the stub axle using a suitable size socket
or metal tube (see illustration). Remove the
plastic sleeve.
9.6c . . . and pull the hub from the stub
axle
9.8 Carefully drive the hub onto the stub
axle using a suitable socket
Note: A torque wrench capable of measuring
the high torque of the front hub nut should be
obtained before commencing work.
Removal
9.6a Fully unscrew . . .
9.6b . . . and remove the hub nut . . .
Refitting
3510 Vauxhall/Opel Omega
Suspension and steering 10•9
Refitting
9 Refit the components in the reverse order
to removal, noting the following points (see
illustration):
a) Tighten all nuts and bolts to the specified
torque.
b) Use a new hub nut and ensure that it
tightened to the specified torque
c) Refit the brake disc and caliper as
described in Chapter 9.
d) Fit a new hub dust cap.
10 Front suspension subframe removal and refitting
3
9.9 Fitting a new hub dust cap
lengths and diameters, then lower the
subframe to the ground using the trolley jack.
Removal
Refitting
1 Apply the handbrake, then jack up the front
of the vehicle and support it securely on axle
stands. Unscrew the fixings and lower the
cover panel away from the underside of the
engine compartment.
2 On models with Xenon headlamps, unplug
the wiring from the front vehicle level sensor;
refer to Chapter 12, Section 13 for details.
3 Unbolt both lower suspension arm balljoints
from the base of each steering knuckle, as
described in Section 4.
4 Unbolt the anti-roll bar drop links from the
ends of the anti-roll bar, as described in
Section 7.
5 Unscrew the nuts securing both engine
mountings to the subframe and engine
brackets, with reference to Chapter 2A. Where
applicable, also unbolt the engine vibration
damper strut from the subframe.
6 Position an engine hoist or lifting beam over
the engine compartment. Attach the lifting jib
to the engine lifting eyelets at the side of the
cylinder head(s) and raise it to take the weight
of the engine.
7 Mark the relationship between the
subframe and underbody using a marker pen
to ensure correct alignment on refitting.
8 Support the weight of the subframe using a
trolley jack and a stout length of wood.
9 Identify the six subframe mounting bolts for
position. Progressively slacken and remove
the bolts, noting that they are of different
10 Refitting is a reversal of removal, noting
the following points:
a) Refit the subframe according to the
alignment markings made during removal.
b) Fit new subframe securing bolts..
c) Tighten all nuts and bolts to the correct
torque, where specified.
d) On completion have the front wheel
alignment (see Section 27) and camber
setting (see Section 3) checked and if
necessary corrected.
11 Rear shock absorber removal and refitting
3
Note: Shock absorbers should always be
renewed as a pair, to preserve the handling
characteristics of the vehicle.
Removal
1 Chock the front wheels, then jack up the
rear of vehicle and support it securely on axle
stands.
2 Raise the relevant semi-trailing arm using a
trolley jack to relieve the load on the shock
absorber.
3 On Saloon models, remove the trim panel
from the side of the boot space, then prise the
rubber cap from the top of the shock absorber
upper mounting.
4 On Estate models, fold back the load space
carpet, then remove the screws and lift off the
cover to expose the shock absorber upper
mountings.
5 Unscrew the upper mounting nuts and
remove the washer and rubber buffers (see
illustration).
6 On models fitted with rear suspension
level control, reach in through the rear wheel
arch and release the air pressure from the
valve on the side of the shock absorber
body. Release the clip and disconnect the
pressure line from the shock absorber.
7 Lower the semi-trailing arm using the trolley
jack, then unscrew the lower mounting bolt
and washer, then remove the shock absorber
(see illustrations).
8 With the shock absorber removed, examine
it for wear, damage or deformation. Check the
rubber
mounting
components
for
deterioration. Renew any of the components
as necessary.
9 Examine the shock absorber for signs of
fluid leakage. Check the damper rod for signs
of wear or corrosion along its entire length,
and check the strut body for signs of damage
or corrosion. While holding it in an upright
position, test the operation of the shock
absorber by moving the damper rod through
one or two full strokes, and then through short
strokes of about 50 to 100 mm. In both cases,
the resistance felt should be smooth and
continuous. If the resistance is jerky, or
uneven, or if there is any visible sign of wear
or damage to the strut, renewal is necessary.
10 If a new shock absorber is being fitted,
before reassembly push the damper rod fully
into the shock absorber body, and then pull
the rod out to end of its travel. Do this three or
four times to ensure that the shock absorber
is fully primed.
Refitting
11 Commence refitting by locating the shock
absorber on the semi trailing arm and
inserting the bottom mounting bolt loosely.
Ensure that the bush engages with the recess
in the lower mounting.
12 Raise the semi-trailing arm using a trolley
jack and guide the top of the shock absorber
through its upper wheel arch mountings.
10
11.5 Unscrew the rear shock absorber
upper mounting nut
11.7a Unscrew the rear shock absorber
lower mounting bolt and washer . . .
3510 Vauxhall/Opel Omega
11.7b . . . then remove the shock absorber
from the wheel arch
10•10 Suspension and steering
13 On models with rear suspension level
control, charge the shock absorber slightly with
compressed air. An exact initial pressure is not
specified by the manufacturer but carefully
inflate the shock absorber until it protrudes
through the upper mountings. Refit the pressure
line to the shock absorber valve and secure it in
position with the retaining clip. Ensure that the
pressure line is positioned so that it does not
foul any suspension components.
14 Refit the upper mounting rubber buffers
and washer. Fit a new securing nut and
tighten it to the specified torque.
15 Tighten the lower shock absorber
mounting bolt to the specified torque.
16 On estate models, refit the cover panel
and secure it position with the screws.
17 On Saloon models, press the rubber cap
onto the top of the shock absorber.
18 Refit the road wheels and lower the
vehicle to the ground.
19 Carry out a check of the rear suspension
level control system’s operation, where
applicable.
12 Rear semi-trailing arm removal and refitting
3
Removal
1 Chock the front wheels, then jack up the
rear of the vehicle and support on axle stands
positioned under the subframe mountings.
2 With reference to Chapter 8, Section 8,
unbolt the relevant driveshaft from the rear
hub and support it to one side.
3 Disconnect the hydraulic brake hose from
the bracket on the semi-trailing arm.
4 Remove the rear brake caliper and brake
disc as described in Chapter 9.
5 Unhook the return spring and disconnect
the handbrake cable from the lever on the
semi-trailing arm. Disconnect the cable from
the bracket.
6 On models with rear suspension level
control, unplug the wiring from the rear
vehicle level sensor. Mark the relationship
between the level sensor actuator arm and the
anti-roll bar drop link, to ensure correct
alignment on refitting, then prise the link rod
from the balljoint on the sensor actuator arm.
7 Using a socket through the unthreaded
holes in the hub unscrew the brake anchor
plate bolts and remove the locking plate.
8 Remove the rear hub with reference to
Section 20, then withdraw the brake anchor
plate and brake shoes as an assembly.
9 Unbolt the track control arm from the semitrailing arm, with reference to Section 15.
10 With reference to Chapter 4A, disconnect
the mounting rubbers from the exhaust
system intermediate and rear silencers, then
lower the exhaust system away from the
floorpan by approximately 30 cm. Support the
exhaust in this position with wire or nylon
cable ties.
11 Unbolt the rear anti-roll bar drop link from
the semi-trailing arm. Pivot the link upwards
to keep it clear of the work area.
12 Raise the semi-trailing arm slightly using a
trolley jack, to relieve the load on the shock
absorber.
13 On models fitted with rear suspension
level control, release the air pressure via the
shock absorber valve by disconnecting the
pressure line from the shock absorber (see
Section 11).
14 Unscrew and withdraw the shock
absorber lower mounting bolt with reference
to Section 11.
15 Lower the semi-trailing arm using the
trolley jack until the rear coil spring and
damping rubbers can be removed (see
Section 13).
16 Position a trolley jack underneath the final
drive unit, the raise the jack head until it is just
support the weight of the unit.
17 Remove the heat shield panels, then with
reference to Chapter 8, unbolt the propeller
shaft centre bearing support bracket from the
underbody. Support the propeller shaft on an
axle stand.
18 Slacken and remove the bolts securing
the leading edge of the rear subframe to the
floorpan. Lower the final drive unit and
subframe slightly, using the trolley jack, until
the semi-trailing arm bolts are accessible.
19 Slacken and withdraw the pivot bolts and
remove the semi-trailing arm from the subframe.
20 If the pivot bushes are worn, they may be
renewed. Cut the shoulders from the old
bushes and press them from the semi-trailing
arm using a hydraulic press. Fit the new
bushes in a similar way, but dip them in soapy
water first to assist fitting. Note that the plasticcoated bush, nearest the final drive unit, is
fitted with its collar facing the final drive unit.
Refitting
21 Refitting is a reversal of removal, noting
the following points.
a) Tighten all nuts and bolts to the specified
torque.
b) The semi-trailing arm pivot bolt must be
inserted such that their heads face away
from final drive unit.
c) On vehicles with rear suspension level
control, refit the level sensor connecting
rod with respect to the alignment
markings made during removal.
d) When reconnecting the pressure line to
the shock absorber on models with rear
suspension level control, ensure that the
line cannot be fouled by any of the
suspension components.
e) On models with Xenon headlamps, reconnect the wiring to the vehicle level sensor.
22 On completion adjust the handbrake with
reference to Chapter 1, then have the rear
wheel alignment checked and if necessary
adjusted by a Vauxhall dealer. On models with
Xenon headlamps, it is also recommended
that the headlight beam alignment is checked
by a Vauxhall dealer.
3510 Vauxhall/Opel Omega
13 Rear coil spring removal and refitting
3
Note: Suspension coil springs should always
be renewed as a matched pair, to preserve the
handling characteristics of the vehicle.
Removal
1 Chock the front wheels, then jack up the
rear of the vehicle and support on axle stands.
Remove the relevant rear wheel.
2 Disconnect the hydraulic brake hose from
the bracket on the semi-trailing arm by pulling
out the locking plate.
3 With reference to Chapter 4A, disconnect
the mounting rubbers from the exhaust
system intermediate and rear silencers, then
lower the exhaust system away from the
floorpan by approximately 30 cm. Support the
exhaust in this position with wire or nylon
cable ties.
4 On models with rear suspension level
control, unplug the wiring from the rear
vehicle level sensor. Mark the relationship
between the level sensor actuator arm and the
anti-roll bar drop link, to ensure correct
alignment on refitting, then prise the link rod
from the balljoint on the sensor actuator arm.
5 Using a trolley jack, slightly raise the
semi-trailing arm to relieve the load on the
shock absorber.
6 On models fitted with rear suspension level
control, release the air pressure via the shock
absorber valve by disconnecting the pressure
line from the shock absorber (see Section 11).
7 Unbolt the lower end of the shock absorber
with reference to Section 11.
8 Unclip the ABS rear wheel speed sensor
cables from the underbody, then unplug the
cables from the sensor at the connectors; see
Chapter 9 for details.
9 Using a trolley jack, support the final drive
unit then unbolt the subframe rear damping
brackets from the underbody (see Section 19).
10 Lower the final drive unit, subframe and
semi-trailing arm until the rear coil spring and
damping rubbers can be removed. Note that
the upper damping rubber incorporates a
buffer.
Refitting
11 Refitting is a reversal of removal, noting
the following points.
a) When refitting the coil spring, ensure that
the end face of the top of the coil is facing
the rear of the vehicle.
b) Tighten all nuts and bolts to the specified
torques.
c) On vehicles with rear suspension level
control, refit the level sensor connecting
rod with respect to the alignment
markings made during removal.
d) Refit the ABS wheel speed sensors with
reference to Chapter 9.
Suspension and steering 10•11
14 Rear anti-roll bar removal and refitting
Pressure line
3
Removal
Removal
1 Chock the front wheels, then jack up the
rear of the vehicle and support securely on
axle stands.
2 On models with rear suspension level
control, mark the relationship between the
level sensor actuator arm and the anti-roll bar
drop link, to ensure correct alignment on
refitting, then prise the link rod from the
balljoint on the sensor actuator arm.
3 Disconnect the wiring from the ABS wheel
speed sensors, then release the wiring from
the clips on the rear subframe.
4 Unbolt the two anti-roll bar drop links from
the ends semi-trailing arms, and remove the
rubber mountings (see illustration).
5 Support the final drive unit on a trolley jack.
Unbolt the subframe rear damping brackets
from the underbody, then lower the final drive
unit slightly, until access to the anti-roll bar
mounting clamp bolts can be gained.
6 Unscrew the clamp bolts from the top of
the subframe and release the clamps from the
anti-roll bar. Pass the anti-roll bar over the
rear of the subframe and withdraw it together
with its drop links from under the vehicle.
7 Unbolt the drop links from the anti-roll bar.
If necessary, the clamp mounting rubbers
may be pressed from the links and renewed,
using a hydraulic press. Dip the new rubbers
in soapy water to assist fitting them.
Refitting
8 Refitting is a reversal of removal, but tighten
all nuts and bolts to their correct torques,
where specified.
15 Rear track control arm removal and refitting
3
14.4 Rear anti-roll bar-to-drop link bolt
nuts/bolts where indicated in the Specifications.
Tighten all fixings to the specified torque. On
completion, have the rear wheel alignment
checked and if necessary adjusted by a
Vauxhall dealer.
16 Rear suspension level
control system - component
removal and refitting
3
Compressor
Removal
1 The compressor is located in the right hand
front wheel arch. To gain access, raise the
front of the vehicle and rest it securely on axle
stands. Remove the right hand roadwheel, the
unscrew the fixings and detach the liner from
the right hand wheel arch.
2 Unplug the wiring connector from the
compressor.
3 Disconnect the air intake hose from the
cavity behind the right hand headlight unit.
4 Release the securing clip and detach the air
pressure pipe from the top of the compressor.
5 Slacken and withdraw the securing screws
then remove the compressor together with its
mounting bracket from the bodywork.
Refitting
Removal
1 Chock the front wheels, then jack up the
rear of the vehicle and support securely on
axle stands.
2 Unscrew the nut securing the track control
arm to the semi-trailing arm (see illustration).
Disconnect the rod from the arm using a
proprietary ball joint separator.
3 Unbolt the track control arm from the
subframe (see illustration), and remove the
arm from the vehicle.
4 If the track control arm is to be dismantled,
first measure its overall length to obtain an
approximate rear wheel alignment setting
after refitting.
6 Refitting is a reversal of removal. On
completion, check the operation of the level
control system as described in the last subSection.
7 Disconnect the pressure line from the
compressor as described in the previous subSection.
8 Raise the rear of the vehicle and rest it
securely on axle stands.
9 Release the metal spring clip and
disconnect the pressure line from the valve on
the side of the first rear shock absorber.
Disconnect the pressure pipe from the
opposite shock absorber in a similar manner.
10 Locate the pressure T-piece which is
mounted on vehicle underbody. Release the
clips and disconnect the pressure pipe from
the T-piece.
11 Work along the underside of the vehicle,
releasing the pressure pipe from its securing
clips, then remove the pipe from the vehicle.
Refitting
12 Refitting is a reversal of removal. When
refitting the pressure pipes to the rear shock
absorbers, ensure that they are positioned
such that they cannot be fouled by the rear
suspension components. On completion,
check the operation of the level control
system as described in the last sub-Section.
Level sensor
Removal
13 Disconnect the battery negative cable and
position it away from the terminal.
14 Chock the front wheels, then raise the rear
of the vehicle and support it securely on axle
stands. Remove the rear road wheels.
15 Unplug the wiring from the level sensor at
the multiway connector.
16 Prise the connecting rod from the balljoint
on the sensor’s actuator arm.
17 Undo the securing screws and remove the
sensor together with its bracket from the
subframe.
Refitting
18 Refitting is a reversal of removal. On
completion, check the operation of the level
control system as described in the next subSection.
System operation check
19 Park the vehicle (unloaded) on level
10
Refitting
5 Refit the track control arm by following the
removal procedure in reverse, using new
15.2 Track control arm-to-semi-trailing
arm bolt
3510 Vauxhall/Opel Omega
15.3 Track control arm-to-subframe bolt
10•12 Suspension and steering
ground. Release the handbrake and let the
engine idle for while, to allow the rear
suspension ride height to stabilise. Re-apply
the handbrake.
20 Measure the vertical distance from the
ground to a convenient point on the rear
bumper.
21 Place a heavy load in the boot/load
space. Release the handbrake and let the
engine idle for while, to allow the rear
suspension ride height to stabilise. Re-apply
the handbrake.
22 Repeat the measure carried out in
paragraph 20. If operating correctly, the rear
suspension control system should control the
loaded ride height to a value 3 to 5 cm less
than the unloaded ride height within 20
seconds.
23 Remove the load and allow the rear ride
height to stabilise again. The system should
return the ride height to the original unloaded
ride height within 20 seconds.
17 Rear axle
(complete assembly) removal and refitting
4
Removal
1 Chock the front wheels, then jack up the
rear of the vehicle and support it on axle
stands. Position the axle stands such access
can still be gained to all the rear subframe
mounting bolts. Remove both rear road
wheels.
2 Remove the intermediate and rear sections
of the exhaust system with reference to
Chapter 4A.
3 Note the position of the adjustment nut on
the handbrake rod, then unscrew it and slide
off the compensator bar; see Chapter 9,
Section 8.
4 With reference to Chapter 9, unbolt both
rear brake calipers from the semi-trailing arms
and support them away from the disc, taking
care not to damage the rigid brake lines.
5 Release the handbrake cables and
hydraulic brake hoses from the brackets on
both semi-trailing arms.
6 On models with Xenon headlamps, unplug
the wiring from the rear vehicle level sensor;
see Chapter 12 Section 13.
7 Unbolt the ABS wheel speed sensors from
the final drive unit, with reference to Chapter 9,
Section 18.
8 At the rear of the propeller shaft unscrew
the bolts securing the rear disc joint to the
differential flange.
9 Position a length of wood beneath the
semi-trailing arms and support in the middle
with a trolley jack.
10 Unbolt the final drive unit rear damping
brackets from the underbody and lower the
unit onto the length of wood.
11 Unscrew the shock absorber bottom
mounting bolts on each side.
12 Lower the trolley jack until both rear coil
springs and damping rubbers can be
removed. Note that the upper damping
rubbers incorporate buffers.
13 Raise the trolley jack until the rear
damping bracket touches the underbody,
then unscrew the three bracket bolts and
centre bolt from the subframe front mountings
(see illustration). As a precaution, have an
assistant steady the assembly to prevent it
falling from the trolley jack.
14 Lower the rear axle assembly to the
ground and withdraw from under the vehicle.
Be prepared to support the propeller shaft as
it releases from the final drive unit.
Refitting
15 Refitting is a reversal of removal, noting
the following points.
a) Tighten all nuts and bolts to the correct
torque settings, where specified.
b) Adjust the handbrake with reference to
Chapter 1.
c) On completion it is recommended that
the rear wheel alignment is checked and if
necessary corrected by a Vauxhall dealer.
17.13 Unscrew the three bracket bolts (A) and centre bolt (B)
from the subframe front mountings
3510 Vauxhall/Opel Omega
18 Rear suspension subframe removal and refitting
3
Removal
1 Remove the rear axle assembly as
described in Section 17.
2 Unscrew the anti-roll bar clamp bolts from
the top of the subframe and release the clamps.
3 Unscrew the final drive unit mounting bolts
and lower the unit from the subframe.
4 Unscrew and remove the semi-trailing arm
pivot bolts, noting that the bolt heads are
facing each other on each arm. Remove the
subframe.
5 If necessary renew the mountings with
reference to Section 19.
Refitting
6 Refitting is a reversal of removal, but tighten
all nuts and bolts to the specified torques. The
semi-trailing arms should be positioned
horizontally before tightening the pivot bolts.
19 Rear suspension
subframe mountings renewal
2
Removal
1 Chock the front wheels, then jack up the
rear of the vehicle and support on axle stands
positioned under the rear underbody channel
sections. Remove both rear wheels.
2 Disconnect the exhaust rear mounting
rubbers and lower the exhaust approximately
30 cm. Temporarily support the exhaust in
this position with wire or nylon cable ties.
3 Disconnect the hydraulic brake hoses from
the brackets on the semi-trailing arms by
pulling out the locking plates.
4 Support the final drive unit on a trolley jack.
5 Unscrew the three bracket bolts and one
centre bolt from the subframe mountings on
each side and remove the brackets.
19.6 Withdrawing the subframe mountings
Suspension and steering 10•13
6 The mountings must now be pulled from the
subframe. The Vauxhall tool for this task is
shown in (see illustration). The subframe is
lowered slightly and the mounting bolt inserted
from the top, then the puller is assembled as
shown and the nut tightened to withdraw the
mounting. If a similar arrangement using a
conventional puller is not possible, use metal
tubing, a long bolt, and large washers or a
metal plate to remove the mounting.
7 The Vauxhall tool for inserting the
mountings is shown in (see illustration), and
here again a similar tool may be fabricated
from metal plate and a long bolt.
21 Steering wheel removal and refitting
Models without driver’s airbag
Removal
Refitting
8 Refitting is a reversal of removal.
19.7 Pressing in the subframe mountings
20 Rear hub and bearing removal and refitting
12 Extract the circlip from the semi-trailing
arm then press out the bearing, again using a
bearing puller bolted to the arm.
13 If the inner bearing track has remained on
the hub remove it with a bearing puller.
14 Clean all the components and examine
them for wear and damage. Obtain a new
bearing.
4
Note: A torque wrench capable of measuring
the high torque of the rear hub nut should be
obtained before commencing work. If such a
torque wrench is not available, it is
recommended that the work is entrusted to a
Vauxhall dealer.
Removal
1 Chock the front wheels, then jack up the rear
of the vehicle and support it on axle stands.
2 Unscrew the socket-head bolts securing
the driveshaft to the rear hub while holding the
rear wheel stationary. Recover the lockwashers.
3 Lever the driveshaft from the rear hub and
support it to one side.
4 Remove the rear wheel.
5 Disconnect the hydraulic brake hose from
the bracket on the semi-trailing arm by pulling
out the locking plate.
6 Unbolt and remove the brake caliper and
support it to one side without straining the
hydraulic brake hose Unscrew the retaining
screw and remove the brake disc. Refer to
Chapter 9 for details of both operations.
7 Refer to Chapter 10 and unbolt the shock
absorber lower mounting bolt from the
semi-trailing arm. Support the semi-trailing
arm on the head of a trolley jack.
8 Using an Allen key through an unthreaded
hole in the hub drive flange, unscrew the
brake backplate mounting bolts. Note that the
upper bolts are shorter and are fitted with a
locking plate.
9 Insert the wheel bolts and use a long bar to
hold the hub stationary, then remove the
locking plate and unscrew the central hubsecuring nut (exposed by the removal of
driveshaft) from the rearward-facing surface
of the hub (see illustration).
10 Pull off the driveshaft flange using a
suitable puller.
11 Press the rear hub outwards from the
bearing using a suitable puller bolted to the
semi-trailing arm.
3
Refitting
15 Press the new bearing into the
semi-trailing arm using pressure on the outer
track. If necessary, a long bolt and a selection
of flat washers may be used to do this.
16 Fit the bearing retaining circlip.
17 Support the wheel bearing inner track on
the inside with a metal tube, then carefully
drive in the rear hub from the outside.
18 Fit the driveshaft flange on the inside of
the hub. If necessary, support the outside of
the hub and drive the flange fully on from the
inside.
19 Refit the hub nut and tighten to the
specified torque while holding the hub
stationary. Drive in the special locking plate to
secure the nut in position.
20 The remainder of the refitting procedure is
a reversal of removal, but note the following
points.
a) Tighten all nuts and bolts to the specified
torque wrench settings
b) Adjust the handbrake with reference to
Chapter 1.
20.9 Driveshaft flange and rear hub nut
3510 Vauxhall/Opel Omega
1 Disconnect the battery negative lead.
2 Set the front wheels in the straight-ahead
position.
3 Prise the horn pad from the centre of the
steering wheel and disconnect the two wires.
4 With the ignition key inserted check that the
steering lock is disengaged.
5 Bend back the locktab and unscrew the
retaining nut. Remove the locktab.
6 Mark the inner column and steering wheel
in relation to each other then remove the
steering wheel by carefully rocking it from side
to side. Do not use a hammer or mallet to
remove it.
7 If necessary, unclip the horn contact ring
from the steering wheel, noting that the
direction indicator return segment points to
the left.
8 Check that the spring is located on the
inner column, and lightly lubricate the horn
contact finger with a copper-based grease.
Refitting
9 Refitting is a reversal of removal, but tighten
the nut to the specified torque and bend up
the locktab to lock the nut in position.
Models with driver’s airbag
Warning:
Refer
to
the
Supplementary Restraint System
(SRS) precautions given in
Chapter 12 before disturbing the
driver’s airbag.
Removal
10 Before removing the driver’s airbag, carry
out the following operations: disconnect the
negative cable from the battery and position it
clear of the terminal. Wait at least one minute
before proceeding, to allow the SRS control
unit capacitor to discharge. Failure to observe
these steps may result in accidental
detonation of the airbag.
11 Remove the driver’s airbag from the
steering wheel, as described in Chapter 12,
Section 24: Supplementary Restraint System
(SRS) components - removal and refitting.
12 Set the steering wheel in the straight
ahead position, then remove the ignition key
and allow the steering column lock to engage.
Ensure that the steering column remains in
this position throughout the entire procedure.
13 Mark the relationship between the
steering wheel and column to ensure correct
alignment on refitting.
14 Unplug the horn button wiring at the
multiway connector. Where applicable, also
unplug the audio remote control button wiring
(see illustration).
10
10•14 Suspension and steering
21.14 Unplug the horn button/audio
control wiring at the multiway connector(s)
21.15a Bend back the locktab . . .
21.15b . . . and then slacken . . .
21.15c . . . and remove the steering wheel
retaining nut . . .
21.15d . . . and remove the locktab
21.16a Remove the steering wheel from
the steering column
15 Bend back the locktab and then unscrew
the steering wheel retaining nut. Remove the
locktab (see illustrations).
16 Remove the steering wheel from the
steering column by carefully rocking it from
side to side. Do not use a hammer or mallet to
remove it. Guide the horn and audio control
wiring through the aperture at the centre of
the steering wheel (see illustrations).
to the flexible joint, then unscrew and remove
the upper clamp bolt, to separate the end of
the inner section of the steering column from
the flexible joint (see illustration).
3 Remove the steering wheel as described in
Section 21. On models fitted with a driver’s
airbag, remove the airbag contact unit, with
reference to Chapter 12, Section 24.
Warning: Refer to the precautions
given in Chapter 12 before
disturbing the any of Supplementary Restraint System (SRS) components.
Refitting
21.16b If necessary, use a proprietary
steering wheel puller to assist removal
17 Refitting is a reversal of removal, but
tighten the nut to the specified torque and
bend up the locktab to lock the nut in
position. Refit the driver’s airbag with
reference to Chapter 12, Section 24:
Supplementary Restraint System (SRS)
components - removal and refitting.
22 Steering column removal and refitting
4
Removal
22.2 Unscrew and remove the upper
clamp bolt (arrowed) to separate the inner
section of the steering column from the
flexible joint
1 Park the vehicle on level ground with the
steering wheel turned to the straight-ahead
position. Disconnect the battery negative
lead.
2 Working in the driver’s footwell, release the
clip and screws and detach the lower trim
panel from underside of the facia. Mark the
inner section of the steering column in relation
3510 Vauxhall/Opel Omega
4 Where applicable, unscrew the shaft from
steering column height adjustment lever.
5 Remove the screws and withdraw the
upper and lower shroud panels from the
steering column.
6 Remove the steering column lock cylinder
with reference to Section 23.
7 Remove the ignition switch contact unit
with reference to Section 23.
8 Depress the locking clips and remove the
stalk switch units from the steering column;
refer to Chapter 12, Section 4.
9 At the lower edge of the facia, below the
steering column, release the securing clip and
hinge the access panel downwards away from
the fuse box and relay box. Remove the
screws, unhook the check strap and remove
the lid from the facia.
10 Slacken and withdraw the securing
screws, then release the fuse box and relay
box from the facia, leaving the wiring
harnesses connected.
Suspension and steering 10•15
22.11 Steering column upper mounting nut (A) and shear bolt (B)
11 The upper column mounting consists of a
nut and a shear bolt (see illustration). Ideally
a bolt extractor should be used to remove the
shear bolt by first drilling a 3.2 mm hole then
using the extractor to unscrew the bolt.
Alternatively, drill off the head and use grips to
unscrew the remainder of the bolt later.
12 Unscrew the upper mounting nut and
withdraw the steering column rearwards from
the flexible coupling. The column should be
handled carefully to avoid damage to the
latticed safety outer column and special inner
column.
Refitting
13 Refitting is a reversal of removal but
tighten all nuts and bolts to the specified
torque. Before tightening the shear bolt,
check that the column is correctly aligned
then tighten the bolt until the head shears off.
Check that, with the front wheels in the
straight-ahead position, the steering wheel
spokes are centred. Before tightening the
clamp bolt, check that the steering column is
not stressed, then tighten the bolt to the
specified torque. Make sure that the switch
rubber grommets are correctly located in the
upper shroud.
23.3 Slide the immobiliser receiver from the lock cylinder housing
23 Steering column
lock/ignition switch removal and refitting
3
Lock cylinder
Removal
1 Remove the steering wheel as described in
Section 21.
2 Slacken and withdraw the screws, then
detach the upper lower sections of the shroud
panelling from the steering column.
3 Unplug the wiring and slide the immobiliser
receiver from the lock cylinder housing (see
illustration).
4 Insert the ignition key into the lock cylinder
and turn it to position I.
5 Depress the recessed locking button with a
suitable tool and withdraw the lock cylinder,
together with the key from, from the housing
(see illustrations).
Refitting
6 Before inserting the lock cylinder into its
housing, check that the steering lock bolt has
not engaged; if this is the case, it will not be
possible to fully insert the lock cylinder into the
housing. Correct this condition by inserting a
flat bladed screwdriver into the housing and
pressing the locking button latch downwards,
until the bolt disengages (see illustration).
7 Slide the lock cylinder into its housing, until
the locking bolt engages.
8 Where applicable, slide the immobiliser
receiver into position over the lock cylinder
housing and reconnect the wiring.
9 Refit the steering column shroud panelling
and tighten the screws securely.
10 Reconnect the battery negative cable.
Ignition switch contact unit
Removal
11 Remove the lock cylinder as described in
the previous sub-Section.
12 Unplug the multiway connector from the
rear of the switch contact unit. To release the
connector, depress the locking tab at the
centre of the connector body using a thin flat
bladed screwdriver (see illustration).
Carefully prise the connector from the contact
unit by gently levering between them with a
screwdriver - take care to avoid damaging the
connector terminals.
10
23.5a Depress the recessed locking
button with a suitable tool . . .
23.5b . . . and withdraw the lock cylinder,
together with the key from, from the
housing
3510 Vauxhall/Opel Omega
23.6 If necessary, press the locking button
latch (arrowed) downwards, until the
steering lock bolt disengages
10•16 Suspension and steering
23.12 Depress the connector body locking
tab and unplug connector from the rear of
the ignition switch contact unit
13 Depress the locking button using a
suitable tool and withdraw the contact unit
from the rear of the lock cylinder housing (see
illustrations).
Refitting
14 Refitting is a reversal of removal.
24 Steering gear removal and refitting
4
Models with 4-cylinder engines
Removal
1 Park the vehicle on a level surface and set
the steering wheel in the straight ahead
position. On models with a driver’s airbag,
remove the ignition key and engage the
steering column lock, to prevent rotation of
the steering wheel.
2 Disconnect the battery negative cable and
position it away from the terminal.
3 Apply the handbrake, select first gear (or
Park, as applicable), then jack up the front of
the vehicle and support it securely on axle
stands.
4 Where applicable, remove the fixings and
lower the undertray away from the engine bay.
5 Mark the position of the steering drop arm
in relation to the steering gear arm. Unscrew
the nut securing the steering drop arm to the
bottom of the steering gear, then use a
suitable puller to pull the arm from the splines
on the sector shaft.
6 Working in the driver’s footwell, remove the
securing clips/screws and detach the trim
panel from the lower side of the facia.
7 Unscrew and remove the upper clamp bolt
from the steering column flexible coupling;
refer to Section 22. Slacken and remove the
lower clamp bolt, that secures the flexible
joint to the top of the steering gear. Prise the
flexible joint apart, to release it from the
steering gear, then slide it upwards onto the
steering column as far as it will go.
8 Position a container beneath the steering
gear to catch any spilt hydraulic fluid.
9 Identify the pressure and return lines for
location then unscrew the union nuts and pull
the lines from the steering gear. Plug the line
23.13a Depress the locking button . . .
23.13b . . . and withdraw the contact unit
from the rear of the lock cylinder housing
ends and steering gear ports to reduce
leakage and to prevent the ingress of debris.
10 Unscrew the securing bolts and remove
the metal heat shield from the steering gear
casing.
11 Unscrew the mounting bolts and nuts and
withdraw the steering gear via the underside
of the vehicle. Recover any shims fitted and
make a note of their locations to aid correct
refitting.
union nuts to the specified torque.
19 Refit the engine compartment undertray
and tighten the screws securely.
20 Lower the vehicle to the ground, then
reconnect the battery negative cable.
21 Check the fluid level in the power steering
fluid reservoir. Top up if necessary and refit
the cap.
22 With the engine idling, turn the steering
from lock to lock several times in order to bleed
trapped air from the system, then recheck and
top-up the power steering fluid level.
Refitting
Note: If you are fitting a new steering gear
assembly to a pre- 1996 vehicle, it will be
necessary to fit a modified steering gear-tobulkhead rubber seal.
12 Where applicable (see Note above), slide
the new rubber seal over the steering gear,
such that the OBEN marking is aligned with
the identification plate on the steering gear.
13 With the steering wheel centralised, lift the
steering gear into position and insert each of
the securing bolts, together with any shims
recovered during removal. Tighten the bolts
progressively to the specified torque, in a
clockwise sequence, starting with the upper
left hand bolt, as viewed from the right hand
wheel arch.
14 Ensure that the steering wheel and road
wheels are still in the straight ahead position,
then reconnect the steering drop arm to the
steering gear sector shaft and tighten the nut
to the specified torque. On models equipped
with a driver’s airbag, insert the ignition key to
release the steering column lock and observe
the alignment markings made during removal
when reconnecting the drop arm to the
steering gear.
15 Fit the heat shield to the steering gear
casing, then insert and tighten the securing
bolts to the specified torque.
16 Working inside the vehicle, slide the
flexible coupling down the inner section of the
steering column and engage it with the top of
the steering gear. Insert the flexible coupling
upper and lower clamp bolts and tighten them
to the specified torque.
17 Refit the lower trim panel to the underside
of the facia.
18 Fit new O-ring seals to the hydraulic
pressure and return lines. Remove the plugs,
then reconnect the pressure and return lines
to the steering gear ports and tighten the
3510 Vauxhall/Opel Omega
Models with 6- cylinder engines
Removal
23 Park the vehicle on a level surface and set
the steering wheel in the straight ahead
position.
24 Disconnect the battery negative cable and
position it away from the terminal.
25 Apply the handbrake, select first gear (or
Park, as applicable), then jack up the front of
the vehicle and support it securely on axle
stands.
26 Remove the fixings and lower the
undertray away from the engine bay.
27 Mark the position of the steering drop arm
in relation to the steering gear arm. Unscrew
the nut securing the steering drop arm to the
bottom of the steering gear, then use a
suitable puller to pull the arm from the splines
on the sector shaft.
28 Unscrew the securing bolts and remove
the metal heat shield from the steering gear
casing.
29 Unplug the wiring harness from the steering
gear transducer at the multiway connector.
30 Unbolt the engine movement damping
strut from the right hand side of the engine,
then remove the nut securing the right hand
engine mounting block to the chassis bracket;
see Chapter 2C, Section 17, for details.
31 On models with a driver’s airbag, remove
the ignition key and engage the steering
column lock, to prevent rotation of the
steering wheel.
32 Disconnect the vacuum hose from the brake
servo, with reference to Chapter 9, Section 15.
33 Depressurise the fuel system as
described in Chapter 4A, then unscrew the
union nuts and disconnect the fuel supply and
return lines from the manifold.
Suspension and steering 10•17
34 Unbolt the coolant reservoir from the
bodywork and position it to one side, leaving
the coolant hoses connected.
35 Disconnect the fuel vapour hoses from the
charcoal canister ports, as described in
Chapter 4B, Section 4.
36 Position a container beneath the steering
gear to catch any spilt hydraulic fluid.
37 Identify the pressure and return lines for
location then unscrew the union nuts and pull
the lines from the steering gear (see
illustration). Plug the line ends and steering
gear ports to reduce leakage and to prevent
the ingress of debris.
38 Working in the driver’s footwell, remove
the securing clips/screws and detach the trim
panel from the lower side of the facia.
Remove the securing screws and detach the
ventilation duct from the rear of the vent grille
assembly and the side of the air distributor.
39 Unscrew and remove the upper clamp
bolt from the steering column flexible
coupling; refer to Section 22. Slacken and
remove the lower clamp bolt, that secures the
flexible joint to the top of the steering gear.
Prise the flexible joint apart, to release it from
the steering gear, then slide it upwards onto
the steering column as far as it will go.
40 Attach an engine lifting hoist or beam to
the engine lifting eyelets and raise the right
hand side of the engine slightly - refer to the
information given in Chapter 2C, Section 17.
Raise the engine by about 3 cm to allow
access to the steering gear.
41 Remove the starter motor as described in
Chapter 5A.
42 Unscrew the mounting bolts and nuts and
withdraw the steering gear via the underside
of the vehicle (see illustration). Recover any
shims fitted and make a note of their locations
to aid correct refitting.
Refitting
Note: If you are fitting a new steering gear
assembly to a pre- 1996 vehicle, it will be
necessary to fit a modified steering gear-tobulkhead rubber seal.
43 Where applicable (see Note above), slide
the new rubber seal over the steering gear,
such that the OBEN marking is aligned with
the identification plate on the steering gear.
44 With the steering wheel centralised, lift the
steering gear into position and push the upper
24.37 Power steering gear fluid pressure
and return lines (arrowed)
24.42 Steering gear mounting bolts viewed
via right hand wheel arch
shaft as far as possible into the flexible joint.
Insert each of the steering gear securing bolts,
together with any shims/spacers recovered
during removal. Tighten the bolts progressively
to the specified torque, in a clockwise
sequence, starting with the upper left hand
bolt, as viewed from the right hand wheel arch.
45 Reconnect the wiring to the steering gear
transducer.
46 Refit the starter motor as described in
Chapter 5A.
47 Working inside the vehicle, slide the
flexible coupling down the inner section of the
steering column and engage it with the top of
the steering gear. Insert the flexible coupling
upper and lower clamp bolts and tighten them
to the specified torque.
48 Refit the ventilation duct, then refit the
lower trim panel to the underside of the facia.
49 Lower the engine and remove the engine
lifting equipment. Refit the engine mounting
block securing nuts and the engine movement
damper strut, as described in Chapter 2C,
Section 17.
50 Reconnect the vacuum hose to the brake
servo, with reference to Chapter 9, Section 15.
51 Refit the coolant reservoir to the
bodywork and tighten the bolts securely.
52 Fit new O-ring seals to the hydraulic
pressure and return lines. Remove the plugs,
then reconnect the pressure and return lines
to the steering gear ports and tighten the
union nuts to the specified torque.
53 Reconnect the fuel supply and return lines
to the manifold and tighten the union nuts to
the specified torque.
54 Reconnect the fuel vapour hoses to the
charcoal canister ports, with reference to
Chapter 4B, Section 4.
55 Ensure that the steering wheel and road
wheels are still in the straight ahead position,
then reconnect the steering drop arm to the
steering gear sector shaft and tighten the nut
to the specified torque. Observe the alignment
markings made during removal when reconnecting the drop arm to the steering gear.
56 Fit the heat shield to the steering gear
casing, then insert and tighten the securing
bolts to the specified torque.
57 Refit the engine compartment undertray
and tighten the screws securely.
58 Lower the vehicle to the ground, then
reconnect the battery negative cable.
59 Check the fluid level in the power steering
fluid reservoir. Top up if necessary and refit
the cap.
60 With the engine idling, turn the steering
from lock to lock several times in order to bleed
trapped air from the system, then recheck and
top-up the power steering fluid level.
25 Steering tie-rods removal and refitting
3
Removal
1 Apply the handbrake, jack up the front of
the vehicle and support it on axle stands.
Remove the front wheels.
2 To remove a side tie-rod unscrew the nuts
and use a proprietary balljoint removal tool
to press out the ball-pins (see illustrations).
10
25.2a Unscrew the securing nut . . .
25.2b . . . and use a proprietary balljoint
removal tool . . .
3510 Vauxhall/Opel Omega
25.2c . . . to separate the tie rod from the
steering knuckle
10•18 Suspension and steering
25.5a Centre tie rod - engine and
transmission removed for clarity
25.5b Centre tie-rod-to-idler balljoint nut
(arrowed)
If it is required to renew just one tie-rod end,
disconnect the appropriate end only.
3 Loosen the clamp bolts and unscrew the
tie-rod ends from the tie-rod tube, counting the
exact number of turns required to remove them.
4 To remove the centre tie-rod, the side
tie-rods must first be disconnected at their
inner ends as described in paragraph 2. Note
the fitted position of the centre tie-rod, to
ensure correct refitting: the light-coloured
rubber cover is nearest the idler arm, the
darker-coloured rubber cover is nearest the
steering arm.
5 Unscrew the nuts and disconnect the centre
tie-rod from the drop arm and idler arm using
the balljoint removal tool (see illustration).
Refitting
6 Refitting is a reversal of removal; screw the
tie-rod ends into the tie rod tube by the same
number of turns counted during removal. Use
new self-locking nuts and tighten all nuts and
bolts to the specified torques (see
illustration). On completion check and if
necessary adjust the front wheel toe-in setting
as described in Section 27.
26 Steering idler removal and refitting
3
Removal
1 Apply the handbrake, jack up the front of
the vehicle and support on axle stands.
Remove the left-hand wheel.
2 Disconnect the centre tie-rod by
unscrewing the nut and using a balljoint
removal tool to press out the ball-pin.
3 Unscrew the nut from the bottom of the
idler bracket, and remove the heat shield
followed by the idler arm. It is not possible to
renew the bush separately from the arm.
4 If necessary, unbolt the idler bracket from
the underbody.
27 Power steering pump removal and refitting
on the temperature of the engine (see Weekly
checks). Refit the cap on completion.
Models with 6-cylinder engines
Removal
Models with 4-cylinder engines
Removal
1 Remove the auxiliary drive belt as
described in Chapter 1.
2 Position a container beneath the power
steering pump, then unscrew the union nut
and disconnect the pressure pipe. Loosen the
clip and disconnect the supply hose - allow
the excess hydraulic fluid to drain into the
container.
3 Support the pump and remove the three
mounting bolts. Withdraw the pump from the
engine compartment.
Refitting
4 Refit the power steering pump using a
reversal of the removal pro