Chapter 2 Part A: In-car engine repair procedures

Chapter 2 Part A: In-car engine repair procedures
2A•1
Chapter 2 Part A:
In-car engine repair procedures
Contents
Camshaft - removal, inspection and refitting . . . . . . See Chapter 2B
Compression check . . . . . . . . . . . . . . . . . . . . . . . . . See Chapter 2B
Crankshaft rear oil seal - renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Cylinder head - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . 12
Cylinder head - dismantling and inspection . . . . . . . See Chapter 2B
Drivebelt check, adjustment and renewal . . . . . . . .
See Chapter 1
Engine - removal and refitting . . . . . . . . . . . . . . . . . See Chapter 2B
Engine mountings - check and renewal . . . . . . . . . . . . . . . . . . . . . . 17
Engine oil and filter change . . . . . . . . . . . . . . . . . . .
See Chapter 1
Engine overhaul - general information . . . . . . . . . . . See Chapter 2B
Exhaust manifold - removal and refitting . . . . . . . . . . . . . . . . . . . . . 6
Flywheel/driveplate - removal and refitting . . . . . . . . . . . . . . . . . . . 15
Front oil seals - renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
General information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Intake manifold - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . 5
Oil pump - removal, inspection and refitting . . . . . . . . . . . . . . . . . . 14
Repair operations possible with the engine in the vehicle . . . . . . . . 2
Rocker arm and shaft assembly - dismantling, inspection
and reassembly . . . . . . . . . . . . . . . . . . . . . . . . . . . See Chapter 2B
Spark plug renewal . . . . . . . . . . . . . . . . . . . . . . . . . .
See Chapter 1
Sump - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Timing belt and sprockets - removal, inspection and refitting . . . . . 10
Timing belt covers - removal and refitting . . . . . . . . . . . . . . . . . . . . . 9
Timing chain and sprockets - removal, inspection and refitting . . . . 8
Timing chain covers - removal and refitting . . . . . . . . . . . . . . . . . . . 7
Top Dead Centre (TDC) for No 1 piston - locating . . . . . . . . . . . . . . 3
Valve clearance check and adjustment . . . . . . . . . . .
See Chapter 1
Valve cover - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Valves - servicing . . . . . . . . . . . . . . . . . . . . . . . . . . . See Chapter 2B
Degrees of difficulty
Easy, suitable for
novice with little
experience
Fairly easy, suitable
for beginner with
some experience
2A
Fairly difficult,
suitable for competent
DIY mechanic
Difficult, suitable for
experienced DIY
mechanic
Specifications
General
Displacement
3-series, E30 body style
316i (1988 to 1991) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
316 (1983 to 1988) and 318i (1983 to 1987) . . . . . . . . . . . . . . . .
318i (1987 1991) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
320i (1987 to 1991) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
325i (1987 to 1991) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5-series, E28 body style (“old-shape”)
518 (1981 to 1985) and 518i (1985 to 1988) . . . . . . . . . . . . . . . .
525i (1981 to 1988) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
528i (1981 to 1988) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
535i (1985 to 1988) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
M535i (1985 to 1988) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5-series, E34 body style (“new-shape”)
518i (1990 to 1993) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
520i (1988 to 1991) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
525i (1988 to 1991) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
530i (1988 to 1991) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
535i (1988 to 1993) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Firing order
Four-cylinder engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Six-cylinder engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1596 cc (M40/4-cylinder engine)
1766 cc (M10/4-cylinder engine)
1796 cc (M40/4-cylinder engine)
1990 cc (M20/6-cylinder engine)
2494 cc (M20/6-cylinder engine)
1766 cc (M10/4-cylinder engine)
2494 cc (M30/6-cylinder engine)
2788 cc (M30/6-cylinder engine)
3430 cc (M30/6-cylinder engine)
3430 cc (M30/6-cylinder engine)
1796 cc (M40/4-cylinder engine)
1990 cc (M20/6-cylinder engine)
2494 cc (M20/6-cylinder engine)
2986 cc (M30/6-cylinder engine)
3430 cc (M30/6-cylinder engine)
1-3-4-2
1-5-3-6-2-4
Lubrication system
Oil pressure (all engines)
At idle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Running (for example, at 4000 rpm) . . . . . . . . . . . . . . . . . . . . . . . . . .
Oil pump rotor clearance - M40 engine
(body-to-outer rotor/outer rotor-to-inner rotor) . . . . . . . . . . . . . . . . . . .
Oil pump pressure relief valve spring length - M40 engine . . . . . . . . . .
0.5 to 2.0 bars
4 bars or above (typically)
0.12 mm to 0.20 mm
84.1 mm
Very difficult,
suitable for expert
DIY or professional
2A•2 In-car engine repair procedures
Torque wrench settings
Nm
Timing chain tensioner plug . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Timing belt tensioner bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Camshaft sprocket-to-camshaft bolt
M10 and M30 engines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
M20 and M40 engines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
Flange to camshaft (M30 engine) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
Timing chain or belt covers-to-engine
M6 bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
M8 bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
M10 (bolt size) bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Crankshaft pulley bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Crankshaft hub bolt or nut
M10 engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190
M20 engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 410
M30 engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 440
M40 engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 310
Cylinder head bolts*
M10 four-cylinder engine
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Stage 2 (wait 15 minutes) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Angle-tighten an additional 33°
Stage 3 (engine at normal operating temperature) . . . . . . . . . . . . . Angle-tighten an additional 25°
M20 six-cylinder engine with hex-head bolts
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Stage 2 (wait 15 minutes) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Stage 3 (engine at normal operating temperature) . . . . . . . . . . . . . Angle-tighten an additional 25°
M20 six-cylinder engine with Torx-head bolts
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Angle-tighten an additional 90°
Stage 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Angle-tighten an additional 90°
M30 six-cylinder engine (up to and including 1987 model year)
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Stage 2 (wait 15 minutes) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Angle-tighten an additional 33°
Stage 3 (engine at normal operating temperature) . . . . . . . . . . . . . Angle-tighten an additional 33°
M30 six-cylinder engine (from 1988 model year)
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Stage 2 (wait 20 minutes) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
Stage 3 (engine at normal operating temperature) . . . . . . . . . . . . . Angle-tighten an additional 35°
M40 four-cylinder engine
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Angle-tighten an additional 90°
Stage 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Angle-tighten an additional 90°
Intake manifold-to-cylinder head bolts
M8 bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
M7 bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
M6 bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Exhaust manifold-to-cylinder head nuts
M6 nut . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
M7 nut . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Flywheel/driveplate bolts
Manual transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
Automatic transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
Intermediate shaft sprocket bolt (M20 engines) . . . . . . . . . . . . . . . . . . . 60
Sump-to-block bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 to 11
Oil pump bolts (except M40 engines) . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Oil pump sprocket bolts (M10 and M30 engines) . . . . . . . . . . . . . . . . . 10
Oil pump cover plate-to-engine front end cover (M40 engines) . . . . . . . 9
Front end cover-to-engine bolts (M20 and M40 engines)
M6 bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
M8 bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Crankshaft rear oil seal retainer-to-block bolts
M6 bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
M8 bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
* BMW recommend that the cylinder head bolts are renewed as a matter of course.
In-car engine repair procedures 2A•3
1 General information
This Part of Chapter 2 is devoted to invehicle engine repair procedures. All
information concerning engine removal and
refitting and engine block and cylinder head
overhaul can be found in Chapter 2B.
The following repair procedures are based
on the assumption that the engine is still fitted
in the vehicle. If the engine has been removed
from the vehicle and mounted on a stand,
many of the steps outlined in this Part of
Chapter 2 will not apply.
The Specifications included in this Part of
Chapter 2 apply only to the procedures
contained in this Part. Chapter 2B contains
the Specifications necessary for cylinder head
and engine block rebuilding.
The single overhead camshaft four- and
six-cylinder engines covered in this manual
are very similar in design. Where there are
differences, they will be pointed out.
The means by which the overhead
camshaft is driven varies according to engine
type; M10 and M30 engines use a timing
chain, while M20 and M40 engines have a
timing belt.
2 Repair operations possible
with the engine in the vehicle
Many major repair operations can be
accomplished without removing the engine
from the vehicle.
Clean the engine compartment and the
exterior of the engine with some type of
degreaser before any work is done. It will
make the job easier, and help keep dirt out of
the internal areas of the engine.
Depending on the components involved, it
may be helpful to remove the bonnet to
improve access to the engine as repairs are
performed (see Chapter 11 if necessary).
Cover the wings to prevent damage to the
paint. Special pads are available, but an old
bedspread or blanket will also work.
If vacuum, exhaust, oil or coolant leaks
develop, indicating a need for gasket or seal
renewal, the repairs can generally be made
with the engine in the vehicle. The intake and
exhaust manifold gaskets, sump gasket,
crankshaft oil seals and cylinder head gasket
are all accessible with the engine in place.
Exterior components, such as the intake
and exhaust manifolds, the sump, the oil
pump, the water pump, the starter motor, the
alternator, the distributor and the fuel system
components, can be removed for repair with
the engine in place.
The cylinder head can be removed without
removing the engine, so this procedure is
covered in this Part of Chapter 2. Camshaft,
rocker arm and valve component servicing is
most easily accomplished with the cylinder
head removed; these procedures are covered
in Part B of this Chapter. Note, however, that
the camshaft on the M40 engine may be
removed with the engine in the vehicle since it
is retained by bearing caps.
In extreme cases caused by a lack of
necessary equipment, repair or renewal of
piston rings, pistons, connecting rods and
big-end bearings is possible with the engine in
the vehicle. However, this practice is not
recommended, because of the cleaning and
preparation work that must be done to the
components involved.
3 Top Dead Centre (TDC) for
No 1 piston - locating
2
Note 1: The following procedure is based on
the assumption that the distributor (if
applicable) is correctly fitted. If you are trying
to locate TDC to refit the distributor correctly,
piston position must be determined by feeling
for compression at the No 1 spark plug hole,
then aligning the ignition timing marks or
inserting the timing tool in the flywheel, as
applicable.
Note 2: The No 1 cylinder is the one closest to
the radiator.
1 Top Dead Centre (TDC) is the highest point
in the cylinder that each piston reaches as it
travels up and down when the crankshaft
turns. Each piston reaches TDC on the
compression stroke and again on the exhaust
stroke, but TDC generally refers to piston
position on the compression stroke.
2 Positioning the piston at TDC is an essential
part of many procedures, such as timing belt
or chain removal and distributor removal.
3 Before beginning this procedure, be sure to
place the transmission in Neutral, and apply
the handbrake or chock the rear wheels. Also,
disable the ignition system by detaching the
coil wire from the centre terminal of the
distributor cap, and earthing it on the engine
block with a jumper wire. Remove the spark
plugs (see Chapter 1).
4 In order to bring any piston to TDC, the
crankshaft must be turned using one of the
methods outlined below. When looking at the
front of the engine, normal crankshaft rotation
is clockwise.
(a) The preferred method is to turn the
crankshaft with a socket and ratchet
attached to the bolt threaded into the
front of the crankshaft.
(b) A remote starter switch, which may save
some time, can also be used. Follow the
instructions included with the switch.
Once the piston is close to TDC, use a
socket and ratchet as described in the
previous paragraph.
(c) If an assistant is available to turn the
ignition switch to the Start position in
short bursts, you can get the piston close
to TDC without a remote starter switch.
3.8 Align the notch in the pulley with the
notch on the timing plate, then check to
see if the distributor rotor is pointing to the
No 1 cylinder (if not, the camshaft is 180
degrees out - the crankshaft will have to
be rotated 360 degrees)
Make sure your assistant is out of the
vehicle, away from the ignition switch,
then use a socket and ratchet as
described in (a) to complete the
procedure.
5 Note the position of the terminal for the
No 1 spark plug lead on the distributor cap. If
the terminal isn’t marked, follow the plug lead
from the No 1 cylinder spark plug to the cap
(No 1 cylinder is nearest the radiator).
6 Use a felt-tip pen or chalk to make a mark
directly below the No 1 terminal on the
distributor body or timing cover.
7 Detach the distributor cap, and set it aside
(see Chapter 1 if necessary).
8 Turn the crankshaft (see paragraph 4
above) until the timing marks (located at the
front of the engine) are aligned (see
illustration). The M40 engine does not have
any timing marks at the front of the engine,
but instead has a timing hole in the flywheel
which must be aligned with a hole in the rear
flange of the cylinder block. On this engine,
turn the crankshaft until the distributor rotor is
approaching the No 1 TDC position, then
continue to turn the crankshaft until a suitable
close-fitting drill can be inserted through the
hole in the cylinder block and into the
flywheel.
9 Look at the distributor rotor - it should be
pointing directly at the mark you made on the
distributor body or timing cover.
10 If the rotor is 180 degrees out, the No 1
piston is at TDC on the exhaust stroke.
11 To get the piston to TDC on the
compression stroke, turn the crankshaft one
complete turn (360°) clockwise. The rotor
should now be pointing at the mark on the
distributor or timing cover. When the rotor is
pointing at the No 1 spark plug lead terminal
in the distributor cap and the ignition timing
marks are aligned, the No 1 piston is at TDC
on the compression stroke. Note: If it’s
impossible to align the ignition timing marks
when the rotor is pointing at the mark, the
timing belt or chain may have jumped the
teeth on the sprockets, or may have been
fitted incorrectly.
2A
2A•4 In-car engine repair procedures
12 After the No 1 piston has been positioned
at TDC on the compression stroke, TDC for
any of the remaining pistons can be located
by turning the crankshaft and following the
firing order. Mark the remaining spark plug
lead terminal locations just like you did for the
No 1 terminal, then number the marks to
correspond with the cylinder numbers. As you
turn the crankshaft, the rotor will also turn.
When it’s pointing directly at one of the marks
on the distributor, the piston for that particular
cylinder is at TDC on the compression stroke.
4 Valve cover removal and refitting
1
Caution: If the radio in your
vehicle is equipped with an antitheft system, make sure you
have the correct activation code
before disconnecting the battery.
Note: If, after connecting the battery, the
wrong language appears on the instrument
panel display, refer to page 0-7 for the
language resetting procedure.
4.6a Valve cover bolt locations (arrowed)
on M10 four-cylinder engines
4.6b Valve cover bolt locations (arrowed)
on M20 six-cylinder engines
from the stud(s), and set it aside. It will usually
not be necessary to disconnect the leads from
the spark plugs.
7 Remove the valve cover and gasket.
Discard the old gasket. On the M40 engine,
also remove the camshaft cover (see
illustrations). If applicable, remove the semicircular rubber seal from the cut-out at the
front of the cylinder head.
should be tight enough to prevent oil from
leaking past the gasket, but not so tight that
they warp the valve cover.
11 The remainder of refitting is the reverse of
removal.
2
Refitting
1 Disconnect the battery negative cable.
2 Detach the breather hose from the valve
cover.
3 On M20 engines, unbolt and remove the
intake manifold support bracket and, if
applicable, the bracket for the engine sensors
or idle air stabiliser (it will probably be
necessary to disconnect the electrical
connectors from the sensors and stabiliser).
4 On M30 engines, disconnect the electrical
connector for the airflow sensor. Unclip the
electrical harness, moving it out of the way.
5 Where necessary on M30 engines, remove
the hoses and fittings from the intake air hose,
then loosen the clamp and separate the hose
from the throttle body. Unscrew the mounting
nuts for the air cleaner housing, and remove
the housing together with the air hose and
airflow sensor.
6 Remove the valve cover retaining nuts and
washers (see illustrations). Where necessary,
disconnect the spark plug lead clip or cover
8 Using a scraper, remove all traces of old
gasket material from the sealing surfaces of
the valve cover and cylinder head.
Caution: Be very careful not to
scratch or gouge the delicate
aluminium surfaces. Gasket
removal solvents are available at
motor factors, and may prove helpful.
After all gasket material has been
removed, the gasket surfaces can be
degreased by wiping them with a rag
dampened with a suitable solvent.
9 If applicable, place a new semi-circular
rubber seal in the cut-out at the front of the
cylinder head, then apply RTV-type gasket
sealant to the joints between the seal and the
mating surface for the valve cover gasket.
Note: After the sealant is applied, you should
refit the valve cover and tighten the nuts within
ten minutes.
10 Refit the camshaft cover (M40 engine), the
valve cover and a new gasket. Refit the
washers and nuts; tighten the nuts evenly and
securely. Don’t overtighten these nuts - they
4.7a Removing the valve cover on the
M40 engine
4.7b Removing the camshaft cover on the
M40 engine
Removal
5 Intake manifold removal and refitting
Removal
1 Allow the engine to cool completely, then
relieve the fuel pressure on fuel-injection
engines (see Chapter 4).
2 Disconnect the battery negative cable.
Caution: If the radio in your
vehicle is equipped with an antitheft system, make sure you
have the correct activation code
before disconnecting the battery.
Note: If, after connecting the battery, the
wrong language appears on the instrument
panel display, refer to page 0-7 for the
language resetting procedure.
3 Drain the engine coolant (see Chapter 1)
below the level of the intake manifold. If the
coolant is in good condition, it can be saved
and reused.
4 On fuel injection engines, loosen the hose
clamp and disconnect the large air inlet hose
from the throttle body. It may also be
necessary to remove the entire air
cleaner/inlet hose assembly to provide
enough working room (see Chapter 4).
4.7c Removing the valve cover gasket on
the M40 engine
In-car engine repair procedures 2A•5
5.9a On the M40 engine, remove the nuts
and special bolts . . .
5.9b . . . and remove the upper part of the
intake manifold . . .
5.9c . . . and gaskets
5 On carburettor engines, remove the
complete air cleaner assembly (see Chapter 4).
6 Disconnect the coolant hoses from the
throttle body/intake manifold as applicable.
7 Disconnect the throttle cable and, if
applicable, cruise control cable (see Chapter 4).
8 Remove the EGR valve and line where
applicable (see Chapter 6).
9 At this stage on the M40 engine, the upper
part of the intake manifold should be removed
by unscrewing the bolts and nuts. Remove
the gaskets (see illustrations).
10 On fuel injection engines, disconnect the
vacuum hose from the fuel pressure regulator,
and disconnect the electrical connectors from
the fuel injectors (see Chapter 4).
11 Disconnect the fuel lines from the fuel rail
or carburettor, as applicable (see Chapter 4).
12 On the M40 engine, unbolt and remove
the support bracket from the bottom of the
intake manifold (see illustration).
13 Disconnect all remaining hoses and wires
attached between the intake manifold/throttle
body assembly and the engine or chassis.
14 Remove the bolts and/or nuts that attach
the manifold to the cylinder head (see
illustrations). Start at the ends and work
toward the middle, loosening each one a little
at a time until they can be removed by hand.
Support the manifold while removing the
fasteners so it doesn’t fall. Note: You can
remove the manifold without removing the
throttle body, injectors, vacuum/thermo
valves, fuel pressure regulator or carburettor.
If you’re fitting a new manifold, transfer the
components (see Chapter 4) and lines to the
new manifold before it is fitted on the cylinder
head.
15 Move the manifold up and down to break
the gasket seal, then lift it away from the head
and remove the gasket (see illustrations).
16 Remove the old gasket, then carefully
scrape all traces of sealant off the head and
the manifold mating surfaces. Be very careful
not to nick or scratch the delicate aluminium
mating surfaces. Gasket removal solvents are
available at motor factors, and may prove
helpful. Make sure the surfaces are perfectly
clean and free of dirt and oil.
17 Check the manifold for corrosion (at the
coolant passages), cracks, warping and other
damage. Cracks and warping normally show
up near the gasket surface, around the stud
holes. If defects are found, have the manifold
repaired (or renew it, as necessary).
18 When refitting the manifold, always use a
new gasket. Where one side of the gasket has
a graphite surface, this must face the cylinder
head.
19 Refit the nuts and bolts and tighten them
gradually, working from the centre out to the
ends, to the torque listed in this Chapter’s
Specifications.
20 The remainder of refitting is the reverse of
removal. On the M40 engine, renew the
gaskets between the upper and lower parts of
the manifold.
5.12 Removing the support bracket from
the bottom of the intake manifold
(M40 engine)
5.14a Remove the intake manifold nuts
with a socket, ratchet and long extension
(M20 engine)
5.15a Removing the lower intake manifold
(M40 engine)
5.15b Removing the lower intake manifold
gasket (M40 engine)
5.14b Removing the lower intake manifold
nuts (M40 engine)
Refitting
2A
2A•6 In-car engine repair procedures
6 Exhaust manifold removal and refitting
1
Warning: Make sure the engine is
completely cool before beginning
work on the exhaust system.
Caution: If the radio in your
vehicle is equipped with an antitheft system, make sure you
have the correct activation code
before disconnecting the battery.
Note: If, after connecting the battery, the
wrong language appears on the instrument
panel display, refer to page 0-7 for the
language resetting procedure.
1 Disconnect the battery negative cable.
2 On models where the air cleaner is on the
exhaust manifold side of the engine, remove
the air cleaner housing assembly and/or
airflow sensor to provide sufficient working
area (see Chapter 4, if necessary).
Remove the windscreen
washer reservoir from the
right-hand side of the engine
compartment to give more
working room.
3 Unplug the HT leads and set the spark plug
lead harness aside (see Chapter 1).
4 Clearly label, then disconnect or remove, all
wires, hoses, fittings, etc. that are in the way.
Be sure to disconnect the oxygen sensor,
where fitted.
5 Raise the vehicle, and support it securely
on axle stands. Working from under the
vehicle, separate the exhaust downpipe from
the manifold. Use penetrating oil on the
fasteners to ease removal (see illustrations).
6 Remove the axle stands, and lower the
vehicle. Working from the ends of the
manifold toward the centre, loosen the
retaining nuts gradually until they can be
removed. Again, penetrating oil may prove
helpful.
7 Pull the manifold off the head, then remove
the old gaskets (see illustrations). Note: Be
very careful not to damage the oxygen sensor,
where fitted.
6.7a Removing the exhaust manifold
(M40 engine)
6.5a Remove the exhaust manifold nuts
(arrowed) from the exhaust pipe (M20
engine) - soaking the nuts with penetrating
oil should make them easier to remove
6.5b Exhaust manifold-to-downpipe flange
(M40 engine)
8 Clean the gasket mating surfaces of the
head and manifold, and make sure the
threads on the exhaust manifold studs are in
good condition.
9 Check for corrosion, warping, cracks, and
other damage. Repair or renew the manifold
as necessary.
10 When refitting the manifold, use new
gaskets. Tighten the manifold-to-head
retaining nuts gradually, starting at the centre
and working out to the ends, to the torque
listed in this Chapter’s Specifications. Also
tighten the downpipe-to-manifold nuts.
11 The remaining steps are simply a reversal
of the removal procedure.
Caution: If the radio in your
vehicle is equipped with an antitheft system, make sure you
have the correct activation code before
disconnecting the battery.
Note: If, after connecting the battery, the
wrong language appears on the instrument
panel display, refer to page 0-7 for the
language resetting procedure.
7 Timing chain covers removal and refitting
5
Note 1: This procedure applies to M10 and
M30 engines.
Note 2: The upper timing chain cover can be
removed separately. If you need to remove
both the upper and lower covers, special tools
are required. Read paragraphs 8 and 9 before
beginning work.
Removal
1 Disconnect the battery negative cable.
6.7b Removing the exhaust manifold
gasket (M40 engine)
2 If you’re removing the lower timing chain
cover (the upper cover can be removed
separately), remove the cooling fan and fan
shroud, the radiator and the fan drivebelt
pulley (see Chapter 3).
3 On the M10 engine only, remove the water
pump (see Chapter 3).
4 On engines where the distributor cap is
mounted directly to the timing chain cover,
remove the cap, rotor and the black plastic
cover beneath the rotor (see Chapter 1).
5 On the M30 engine fitted with the
L-Jetronic fuel system, remove the
distributor from the upper timing cover (see
Chapter 5).
6 Remove the valve cover (see Section 4).
7 If you’ll be removing the lower timing chain
cover on the M30 engine, remove the crankshaft
pulley from the vibration damper/hub. Hold the
pulley stationary with a socket on the centre
bolt, and remove the pulley bolts with another
socket (see illustration).
8 If you’ll be removing the lower timing chain
6.7c Removing the exhaust manifold-todownpipe gasket (M40 engine)
In-car engine repair procedures 2A•7
7.7 Place a socket and ratchet on the
centre bolt to keep the pulley stationary,
and use another socket and ratchet to
remove the smaller bolts attaching the
pulley to the vibration damper
cover, remove the vibration damper/hub by
locking the crankshaft in position and
loosening the large centre bolt. Since the bolt
is on very tight, you’ll need to use an
extension bar and socket to break it loose. On
M30 engines, BMW recommends using a
3/4-inch drive socket and extension bar, since
the bolt is extremely tight on these engines.
To lock the crankshaft in place while the bolt
is being loosened, use BMW special tool
No. 11 2 100 (or equivalent).
9 On the M10 engine, if the special tool listed
in the previous paragraph is not available, you
may try locking the crankshaft by removing
the flywheel/driveplate inspection cover and
jamming a wide-bladed screwdriver into the
ring gear teeth. On the M30 engine, since the
bolt is so extremely tight, we don’t
recommend substitute methods. Use the
correct tool. On the M10 engine, after the
centre bolt is removed, it will probably be
necessary to use a jaw-type puller to pull the
vibration damper off the crankshaft. Position
the jaws behind the inner pulley groove, and
tighten the puller centre bolt very slowly,
checking the pulley to make sure it does not
get bent or otherwise damaged by the puller.
If the pulley seems to be
sticking on the crankshaft, it
may help to spray the hub
area with some penetrating
oil, and to gently tap on the hub area
with a hammer.
10 Unscrew the plug and remove the timing
chain tensioner spring (see illustration). The
tensioner plunger may come out with the
spring. If not, reach down into the hole where
the tensioner spring was, and remove the
plunger. To check the plunger for proper
operation, see Section 8.
Caution: The spring is under
tension, and this could cause the
plug to be ejected from its hole with
considerable force. Hold the
tensioner plug securely as it’s being
7.10 Unscrew the plug from the timing
chain cover, and remove the tensioner
spring and plunger
unscrewed, and release the spring tension
slowly.
11 On the M30 engine, if you’re removing the
upper timing cover, unbolt the thermostat cover
and remove the thermostat (see Chapter 3).
12 On the M30 engine, if you’re removing the
lower timing cover, loosen the alternator
mounting bolts, and swing the alternator to
one side. Remove the front lower mounting
bracket bolt, and loosen the other bolts. Also
unbolt the power steering pump mounting
bracket, and move it to one side.
13 Remove the bolts and nuts securing the
upper timing chain cover to the engine block,
and remove the cover. Draw a simple diagram
showing the location of the bolts, so they can
be returned to the same holes from which
they’re removed. Remove the upper timing
chain cover. If it sticks to the engine block, tap
it gently with a rubber mallet, or place a piece
of wood against the cover and hit the wood
with a hammer. On the M30 engine fitted with
the L-Jetronic fuel system, remove the
distributor driveshaft.
14 Remove the bolts and nuts attaching the
lower timing chain cover to the engine block.
Be sure to remove the three bolts from
underneath that connect the front of the sump
to the bottom of the front cover (see
illustration). Loosen the remaining sump bolts.
15 Run a sharp, thin knife between the sump
gasket and lower timing chain cover, cutting
the cover free from the gasket. Be very careful
not to damage or dirty the gasket, so you can
re-use it.
16 Break the lower timing chain cover-toblock gasket seal by tapping the cover with a
rubber mallet, or with a hammer and block of
wood. Do not prise between the cover and the
engine block, as damage to the gasket sealing
surfaces will result.
17 Using a scraper, remove all traces of old
gasket material from the sealing surfaces of
the covers and engine block.
Caution: Be very careful not to
scratch or gouge the delicate
aluminium surfaces. Also, do not
damage the sump gasket, and
keep it clean. Gasket removal solvents are
available at motor factors, and may prove
helpful. After all gasket material has been
7.14 From underneath the vehicle, remove
the three bolts (arrowed) that connect the
cover and the sump
removed, the gasket surfaces can be
degreased by wiping them with a rag
dampened with a suitable solvent.
Refitting
18 Renew the front oil seals (see Section 11).
It’s not wise to take a chance on an old seal,
since renewal with the covers removed is very
easy. Be sure to apply a little oil to the front oil
seal lips.
19 Apply a film of RTV-type gasket sealant to
the surface of the sump gasket that mates
with the lower timing chain cover. Apply extra
beads of RTV sealant to the edges where the
gasket meets the engine block. Note: If the
sump gasket is damaged, instead of fitting a
whole new gasket, you might try trimming the
front portion of the gasket off at the point
where it meets the engine block, then trim off
the front portion of a new sump gasket so it’s
exactly the same size. Cover the exposed
inside area of the sump with a rag, then clean
all traces of old gasket material off the area
where the gasket was removed. Attach the
new gasket piece to the sump with contactcement-type gasket adhesive, then apply
RTV-type sealant as described at the
beginning of this paragraph.
20 Coat both sides of the new gasket with
RTV-type gasket sealant, then attach the
lower timing chain cover to the front of the
engine. Refit the bolts, and tighten them
evenly to the torque listed in this Chapter’s
Specifications. Work from bolt-to-bolt in a
criss-cross pattern to be sure they’re
tightened evenly. Note 1: Tighten the lower
cover-to-block bolts first, then tighten the
sump-to-cover bolts. If the gasket protrudes
above the cover-to-block joint, or bunches up
at the cover-to-sump joint, trim the gasket so
it fits correctly. Note 2: After applying RTVtype sealant, reassembly must be completed
in about 10 minutes so the RTV won’t
prematurely harden.
21 Refit the upper timing chain cover in the
same way as the lower cover. If the gasket
protrudes beyond the top of the cover and the
engine block, trim off the excess with a razor
blade.
22 Refitting is otherwise the reverse of
removal.
2A
2A•8 In-car engine repair procedures
8 Timing chain and
sprockets - removal,
inspection and refitting
5
Note: This procedure applies to M10 and M30
engines.
Caution: Once the engine is set
at TDC, do not rotate the
camshaft or crankshaft until the
timing chain is reinstalled. If the
crankshaft or camshaft is rotated with the
timing chain removed, the valves could hit
the pistons, causing expensive internal
engine damage.
Removal
1 Position the No 1 cylinder at Top Dead
Centre (TDC) on the compression stroke (see
Section 3).
2 Remove the valve cover (see Section 4).
Double-check that the No 1 cylinder is at TDC
on the compression stroke by making sure the
No 1 cylinder rocker arms are loose (not
compressing their valve springs).
3 Remove the upper timing chain cover (see
Section 7). Note the location of the camshaft
timing marks, which should now be aligned.
On four-cylinder (M10) engines, there’s
usually a stamped line on the camshaft flange
that aligns with a cast mark on the top of the
cylinder head; also, the camshaft sprocket
dowel pin hole will be at its lowest point. On
six-cylinder (M30) engines, a line drawn
through two of the camshaft sprocket bolts
opposite each other would be exactly vertical,
while a line drawn through the other two bolts
would be horizontal. Additionally, the locating
pin should be in the lower left corner (between
the 7 and 8 o’clock positions). Be sure you’ve
identified the correct camshaft TDC position
before dismantling, because correct valve
timing depends on you aligning them exactly
on reassembly. Note: As the engine is
mounted in the engine compartment at an
angle, all references to horizontal and vertical
whilst timing the camshafts are in relation to
the crankshaft, and not the ground.
4 Hold the crankshaft stationary with a socket
and ratchet on the vibration damper centre bolt,
then loosen (but don’t unscrew completely) the
four bolts attaching the camshaft sprocket to
the camshaft. Be very careful not to rotate the
camshaft or crankshaft. Note: Some earlier
models may have locking tabs for the camshaft
sprocket bolts. Bend the tabs down before
loosening the bolts. The tabs are no longer
available from the manufacturer, and do not
have to be used on refitting.
5 Remove the lower timing chain cover (see
Section 7).
6 Unscrew and remove the four camshaft
sprocket bolts, then disengage the chain from
the crankshaft sprocket and carefully remove
the chain and camshaft sprocket from the
engine. It may be necessary to gently prise
the camshaft sprocket loose from the
camshaft with a screwdriver.
Inspection
Timing sprockets
7 Examine the teeth on both the crankshaft
sprocket and the camshaft sprocket for wear.
Each tooth forms an inverted V. If worn, the
side of each tooth under tension will be
slightly concave in shape when compared
with the other side of the tooth (i.e. one side of
the inverted V will be concave when
compared with the other, giving the teeth a
hooked appearance). If the teeth appear to be
worn, the sprockets must be renewed. Note:
The crankshaft sprocket is a press fit on the
crankshaft, and can be removed with a jawtype puller after the Woodruff key and oil
pump are removed (see Section 14). However,
BMW recommends the new sprocket be
pressed onto the crankshaft after being
heated to 80° C (175° F) on the M10 engine, or
to 200° C (390° F) on the M30 engine. For this
reason, if the crankshaft sprocket requires
renewal, we recommend removing the
crankshaft (see Part B of this Chapter) and
taking it to an engineering works to have the
old sprocket pressed off and a new one
pressed on.
Timing chain
8 The chain should be renewed if the
sprockets are worn or if the chain is loose
(indicated by excessive noise in operation).
It’s a good idea to renew the chain anyway if
the engine is stripped down for overhaul. The
rollers on a very badly worn chain may be
slightly grooved. To avoid future problems, if
there’s any doubt at all about the chain’s
condition, renew it.
10 Shake the tensioner plunger, and listen for
a rattling sound from the check ball. If you
can’t hear the ball rattling, renew the plunger.
11 To further check the tensioner plunger,
blow through it first from the closed end, then
from the slotted (guide) end. No air should
flow through the plunger when you blow
through the closed end, and air should flow
through it freely when you blow through the
slotted end. If the tensioner fails either test,
renew it.
Refitting
12 Refit the tensioner rail and chain guide
rail, if removed.
13 Temporarily refit the lower timing chain
cover and vibration damper, so you can check
the crankshaft timing marks. Once you’ve
verified the TDC marks are aligned, remove
the damper and cover.
14 Loop the timing chain over the crankshaft
sprocket, then loop it over the camshaft
sprocket and, guiding the chain between the
chain guide and tensioner rail, refit the
camshaft sprocket on the camshaft. Make
sure the camshaft timing marks are aligned.
15 The remainder of refitting is the reverse of
removal. Be sure to tighten the fasteners to
the correct torques (see this Chapter’s Specifications).
9 Timing belt covers removal and refitting
Note: This procedure applies to M20 and M40
engines.
Caution: If the radio in your
vehicle is equipped with an antitheft system, make sure you
have the correct activation code
before disconnecting the battery.
Note: If, after connecting the battery, the
wrong language appears on the instrument
panel display, refer to page 0-7 for the
language resetting procedure.
1 Disconnect the battery negative cable.
2 Remove the fan clutch and fan shroud (see
Chapter 3).
3 On the M20 engine, remove the radiator
(see Chapter 3).
4 Remove the fan drivebelt pulley.
Chain rail and tensioner
8.9 To remove the tensioner or chain guide
rail, remove the circlips with a pointed tool
or needle-nose pliers - the circlips tend to
fly off when they’re released, so make sure
you catch them or they’ll get lost (or,
worse, wind up in the engine!)
9 Inspect the chain guide rail and tensioner
rail for deep grooves caused by chain contact.
Renew them if they are excessively worn. The
rails can be renewed after removing the
circlips with a pointed tool or needle-nose
pliers (see illustration).
2
9.6a Unbolt the distributor cap
(M40 engine) . . .
In-car engine repair procedures 2A•9
9.6b . . . then unbolt the rotor . . .
9.6c . . . and remove the black plastic
cover
9.8 Remove all the nuts/ bolts (arrowed)
that attach the upper and lower covers
(M20 engine - removed for clarity)
2A
9.9a Remove the upper timing belt cover
first, then the lower cover (M20 engine)
1 Upper timing belt cover
2 Lower timing belt cover
5 If applicable, disconnect the reference
sensor wiring harness which runs across the
front of the timing belt cover, and set it aside.
6 If the distributor cap is mounted directly to
the upper timing belt cover, remove the cap,
rotor and the black plastic cover beneath the
rotor (see illustrations).
7 Remove the lower fan drivebelt pulley and
vibration damper. Secure the crankshaft
pulley centre bolt while you loosen the outer
pulley/damper bolts (see illustration 7.7).
8 Remove the bolts/nuts attaching the timing
belt covers to the engine (see illustration).
9 Remove the upper cover first, then the
lower cover (see illustrations). Note: The
upper cover has two alignment sleeves in the
top bolt positions. Be sure these are in place
upon reassembly.
10 Refitting is the reverse of the removal
procedure. Tighten the cover bolts securely.
10 Timing belt and sprockets removal, inspection and
refitting
9.9b Removing the upper timing belt cover
on the M40 engine
9.9c Removing the lower timing belt cover
on the M40 engine
Caution: If the radio in your
vehicle is equipped with an antitheft system, make sure you
have the correct activation code
before disconnecting the battery.
Note: If, after connecting the battery, the
wrong language appears on the instrument
panel display, refer to page 0-7 for the
language resetting procedure.
hose, unbolt the thermostat housing and
remove the thermostat (see Chapter 3).
4 Set the No 1 piston at TDC (see Section 3).
Caution: Once the engine is set at
TDC, do not rotate the camshaft
or crankshaft until the timing belt
is refitted. If the crankshaft or
camshaft is rotated with the timing belt
removed, the valves could hit the pistons,
causing expensive internal engine damage.
5 On the M20 engine, the crankshaft mark
should be aligned with the mark on the inner
cover (see illustration). The mark on the
camshaft sprocket should be aligned with the
stamped line on the cylinder head (see
illustration). On the M40 engine, make an
Removal
1 Disconnect the negative cable from the
battery.
2 Remove the timing belt covers (see Section 9).
3 On the M40 engine, drain the cooling
system (see Chapter 1), then disconnect the
5
Note 1: This procedure applies to M20 and
M40 engines.
Note 2: Before removing the camshaft
sprocket on the M40 engine, it is necessary to
obtain a tool to hold the camshaft for the
refitting procedure (see paragraph 10).
10.5a Align the groove in the hub on the
end of the crankshaft with the notch in the
front inner cover (arrowed) and mark them
for assembly reference later on
10.5b Align the mark on the camshaft
sprocket with the mark on the cylinder
head (arrowed)
2A•10 In-car engine repair procedures
10.6 Loosen the idler pulley bolts
(arrowed) to relieve the tension on the
timing belt so it can be removed
10.9b Removing the timing belt from the
camshaft sprocket on the M40 engine
10.10 Removing the camshaft sprocket on
the M40 engine
10.11a The BMW tool for holding the
camshaft in the TDC position on
M40 engines
10.9a When removing the timing belt on
models with a two-piece crankshaft hub,
it’s a tight fit to remove it around the hub,
but it’s a lot easier than removing the
crankshaft hub assembly, which is secured
by a very tight bolt
alignment mark on the camshaft sprocket and
rear timing cover to ensure correct refitting.
6 On the M20 engine, loosen the two
tensioner roller retaining bolts a little, and
push the tensioner towards the water pump
(see illustration). With the timing belt tension
relieved, re-tighten the retaining bolt.
7 On the M40 engine, loosen the tensioner
retaining nut, and use an Allen key to rotate
the tensioner clockwise. This will relieve the
tension of the timing belt. Tighten the
retaining nut to hold the tensioner in its free
position.
8 If the same belt is to be refitted, mark it with
an arrow indicating direction of rotation.
Caution: It is not advisable to
refit a timing belt which has been
removed unless it is virtually
new. On the M40 engine, BMW
recommend that the timing belt is
renewed every time the tensioner roller is
released.
9 Remove the timing belt by slipping it off the
roller(s) and the other sprockets (see
illustrations).
10 If it’s necessary to remove the camshaft
or the intermediate shaft sprocket, remove the
sprocket bolt while holding the sprocket to
prevent it from moving. To hold the sprocket,
wrap it with a piece of an old timing belt
(toothed side engaging the sprocket teeth) or
10.11b The BMW camshaft-holding tool in
position on the M40 engine
a piece of leather, then hold the sprocket
using a strap spanner. If a strap spanner is not
available, clamp the ends of the piece of belt
or leather tightly together with a pair of grips.
Before loosening the bolt, make sure you have
the necessary tool for positioning the
camshaft as described in the following
paragraph (see illustration).
Caution: Do not use the timing
belt you’re planning to refit to
hold the sprocket. Also, be sure
to hold the camshaft sprocket
very steady, because if it moves more than
a few degrees, the valves could hit the
pistons.
Note: On the M40 engine, the sprocket is not
directly located on the camshaft with a key, as
the groove in the end of the camshaft allows
the sprocket to move several degrees in either
direction. The retaining bolt locks the sprocket
onto a taper after positioning the camshaft
with a special tool.
11 The BMW tool for positioning the camshaft
on the M40 engine consists of a metal plate
which locates over the square lug near the No
1 cylinder lobes on the camshaft - the valve
cover must be removed first (see
illustrations). If the BMW tool cannot be
obtained, a home-made tool should be
fabricated out of metal plate. The tool must be
made to hold the square lug on the camshaft
at right-angles to the upper face of the cylinder
head (ie the contact face of the valve cover).
12 If it’s necessary to remove the crankshaft
sprocket, remove the crankshaft hub centre
bolt while holding the crankshaft steady.
Note: The removal of the crankshaft hub
mounting bolt requires a heavy-duty holding
device because of the high torque used to
tighten the bolt. BMW has a special tool,
numbered 112150 (M20 engines) or 112170
(M40 engines), for this purpose. If this tool
cannot be bought or borrowed, check with a
tool dealer or motor factors for a tool capable
of doing the job. Note that the tool number
112170 bolts on the rear of the cylinder head
and engages with the flywheel ring gear, so it
will only be possible to use this tool if the
gearbox has been removed, or if the engine is
out of the vehicle (see illustrations). On
10.12a Home-made tool for holding the
crankshaft stationary while the crankshaft
pulley bolt is being loosened (engine
removed for clarity)
In-car engine repair procedures 2A•11
models with a two-piece hub, after removing
the outer hub piece, you’ll then need to
remove the sprocket with a bolt-type puller
(available at most motor factors). When using
the puller, thread the crankshaft centre bolt in
approximately three turns, and use this as a
bearing point for the puller’s centre bolt.
Inspection
13 Check for a cracked, worn or damaged
belt. Renew it if any of these conditions are
found (see illustrations). Also look at the
sprockets for any signs of irregular wear or
damage, indicating the need for renewal.
Note: If any parts are to be renewed, check
with your local BMW dealer parts department
to be sure compatible parts are used. On M20
engines, later sprockets, tensioner rollers and
timing belts are marked “Z 127”. Renewal of
the timing belt on M20 engines will mean that
the later belt tensioner should also be fitted, if
not already done.
14 Inspect the idler roller and, on M20
engines, the tension spring. Rotate the
tensioner roller to be sure it rotates freely, with
no noise or play. Note: When fitting a new
timing belt, it is recommended that a new
tensioner be fitted also.
Refitting
15 On the M20 engine, refit the idler/
tensioner/spring so that the timing belt can be
fitted loosely.
16 Refit the sprockets using a reversal of the
removal procedure; tighten the retaining bolts
to the specified torque. On the M40 engine,
turn the camshaft sprocket clockwise as far
as possible within the location groove, then
tighten the retaining bolt to an initial torque of
1 to 3 Nm at this stage.
17 If you are refitting the old belt, make sure
the mark made to indicate belt direction of
rotation is pointing the right way (the belt
should rotate in a clockwise direction as you
face the front of the engine).
18 Refit the timing belt, placing the belt
under the crankshaft sprocket first to get by
10.21 On the M20 engine, after the belt
has been installed correctly around all
sprockets and the tensioner pulley, lightly
apply pressure to the tensioner, to be sure
the tensioner isn’t stuck and has full
movement against the timing belt
10.12b Removing the crankshaft pulley
bolt (M40 engine)
the housing. Guide the belt around the other
sprocket(s).
19 Finally, place the belt over the
idler/tensioner rollers.
20 On the M20 engine, loosen the tensioner
bolts and allow the spring tension to be
applied to the belt.
21 On the M20 engine, lightly apply pressure
behind the tensioner to be sure spring
pressure is being applied to the belt (see
illustration). Don’t tighten the bolts while
applying pressure; lightly tighten the bolts
only after releasing the tensioner.
22 On the M40 engine, unbolt and remove
the valve cover, then use the special tool to
hold the camshaft in the TDC position (see
paragraph 11).
23 On the M40 engine, loosen the tensioner
roller retaining nut, and use an Allen key to
rotate the roller anti-clockwise until the timing
belt is tensioned correctly. The 90°-twist
method of checking the tension of the timing
belt is not accurate enough for this engine,
and it is strongly recommended that the
special BMW tensioning tool is obtained if at
all possible (apply 32 ±2 graduations on the
tool) (see illustration). A reasonably accurate
alternative can be made using an Allen key
and a spring balance (see illustration). Make
sure that the spring balance is positioned as
shown, since the tensioner roller is on an
eccentric, and different readings will be
obtained otherwise. The spring balance
should be connected 85 mm along the Allen
key, and a force of 2.0 kg (4.4 lb) should be
10.23a Using the special BMW tool to
check the tension of the timing belt on the
M40 engine
10.12c Removing the crankshaft sprocket
from the front of the crankshaft
2A
10.13a Inspect the timing belt carefully for
cracking, as shown here. . .
10.13b . . . and any other damage
10.23b Using a spring balance and Allen
key to adjust the tension of the timing belt
on the M40 engine
Dimension A = 85 mm
2A•12 In-car engine repair procedures
applied. Tighten the retaining nut to the
specified torque to hold the tensioner in its
correct position. Note: It is important that the
timing belt is tensioned correctly. If the belt is
over-tightened, it will howl, and there is the
possibility of it being damaged. If the belt is
too slack, it may jump on the sprockets.
24 Check to make sure the camshaft and
crankshaft timing marks are still aligned (see
illustrations 10.5a and 10.5b).
25 Turn the crankshaft clockwise through
two complete revolutions. (Remove the
camshaft positioning tool from the M40
engine first.)
Caution: This is necessary to
stretch the new belt. If not done,
the belt tensioner will be too
loose, and damage could result.
26 On the M20 engine, loosen the tensioner
roller bolts, then tighten them to the torque
listed in this Chapter’s Specifications.
27 On the M40 engine, loosen the tensioner
roller retaining nut, and re-adjust the tension
of the timing belt as described in paragraph
23. On completion, tighten the tensioner roller
retaining nut, then fully tighten the camshaft
sprocket bolt if previously loosened (see
illustration).
28 Verify that the timing marks are still
perfectly aligned. If not, remove and refit the
timing belt.
29 The remainder of refitting is the reverse of
removal.
11 Front oil seals - renewal
5
Note: Oil seals are fitted with their sealing lips
facing inwards (towards the engine).
M10 and M30 (timing chain)
engines
Camshaft front seal (M30 engines
only)
1 Remove the upper timing chain cover only
(see Section 7).
10.27 Tightening the camshaft sprocket
retaining bolt on the M40 engine
2 Support the cover on two blocks of wood,
and drive out the seal from behind with a
hammer and screwdriver. Be very careful not
to damage the seal bore in the process.
3 Coat the outside diameter and lip of the
new seal with multi-purpose grease, and drive
the seal into the cover with a hammer and a
socket slightly smaller in diameter than the
outside diameter of the seal.
4 The remainder of refitting is the reverse of
removal.
Crankshaft front seal (M10 and
M30 engines)
5 Remove the crankshaft pulley and vibration
damper (see Section 7).
6 Carefully prise the old seal out of the cover
with a large screwdriver. Be very careful not to
damage the seal bore or the crankshaft with
the tool. Wrap the tip of the screwdriver with a
piece of tape to prevent damage.
7 Clean the bore in the cover, and coat the
outer edge of the new seal with engine oil or
multi-purpose grease. Also lubricate the lips
of the seal with multi-purpose grease. Using a
socket with an outside diameter slightly
smaller than the outside diameter of the seal,
carefully drive the new seal into place with a
hammer (see illustration). If a socket isn’t
available, a short section of large-diameter
pipe will work. Check the seal after refitting to
be sure the spring around the inside of the
seal lip didn’t pop out of place.
8 The remainder of refitting is the reverse of
removal.
hammer and screwdriver. Be very careful not
to damage the seal housing.
12 On the M40 engine, prise the seal out
from the cylinder head using a screwdriver,
being careful not to damage the camshaft
surface or the seal bore.
13 Coat the lip and outside diameter of the
new seal with multi-purpose grease.
14 On the M40 engine, wrap some adhesive
tape around the end of the camshaft to
protect the new seal from the location groove
as it is being fitted (see illustration).
15 Carefully locate the new seal in position,
and press it in by hand initially so that it enters
the bore. Drive the new seal into the housing
or cylinder head (as applicable) using a
hammer and a socket with a diameter slightly
smaller than the outside diameter of the seal.
On the M40 engine, remove the adhesive tape
from the end of the camshaft.
16 On the M20 engine, renew the O-ring on
the back of the seal housing, and work the lip
of the seal over the end of the camshaft. Refit
the screws and tighten them securely.
17 The remainder of refitting is the reverse of
removal.
Crankshaft and intermediate shaft
front seals (M20 engines)
9 Remove the timing belt and camshaft
sprocket (see Section 10).
10 On the M20 engine only, remove the two
screws, and separate the camshaft seal
housing from the cylinder head by pulling it as
you rotate it back and forth.
11 On the M20 engine only, support the
housing on two blocks of wood, and drive the
seal out of the housing from behind using a
18 Remove the timing belt and crankshaft
and intermediate shaft pulleys as applicable
(see Section 10). Note: We recommend the
timing belt be renewed any time it is removed.
19 Remove the bolts and nuts securing the
front cover to the engine block. Be sure to
remove the three bolts from underneath that
connect the front of the sump to the bottom of
the front cover (see illustration 7.14).
20 Run a sharp, thin knife between the sump
gasket and the front cover, cutting the cover
free from the gasket. Be very careful not to
damage the gasket, and keep it clean so you
can re-use it.
21 Break the front cover-to-block gasket seal
by tapping the cover with a rubber mallet or
block of wood and hammer. Do not prise
between the cover and the engine block, as
damage to the gasket sealing surfaces will
result.
11.7 The crankshaft front oil seal is
pressed into the front of the lower timing
chain cover (cover removed from the
engine for clarity)
11.14 Fitting a new camshaft oil seal on
the M40 engine (note the adhesive tape
around the end of the camshaft to protect
the seal)
M20 and M40 (timing belt)
engines
Camshaft front seal (M20 and
M40 engines)
In-car engine repair procedures 2A•13
22 Using a scraper, remove all traces of old
gasket material from the sealing surfaces of
the covers and engine block.
Caution: Be very careful not to
scratch or gouge the delicate
aluminium surfaces. Also, do not
damage the sump gasket, and
keep it clean. Gasket removal solvents are
available at motor factors, and may
prove helpful. After all gasket material has
been removed, the gasket surfaces
can be degreased by wiping them
with a rag dampened with a suitable
solvent.
23 Support the cover on two blocks of wood,
and drive out the seals from behind with a
hammer and screwdriver. Be very careful not
to damage the seal bores in the process.
24 Coat the outside diameters and lips of the
new seals with multi-purpose grease, and
drive the seals into the cover with a hammer
and a socket slightly smaller in diameter than
the outside diameter of the seal.
25 Apply a film of RTV-type gasket sealant to
the surface of the sump gasket that mates
with the front cover. Apply extra beads of RTV
sealant to the edges where the gasket meets
the engine block. Note: If the sump gasket is
damaged, instead of fitting a whole new
gasket, you might try trimming the front
portion of the gasket off at the point where it
meets the engine block, then trim off the front
portion of a new sump gasket so it’s exactly
the same size. Cover the exposed inside area
of the sump with a rag, then clean all traces of
old gasket material off the area where the
gasket was removed. Attach the new gasket
piece to the sump with contact-cement-type
gasket adhesive, then apply RTV-type sealant
as described at the beginning of this
paragraph.
26 Coat both sides of the new gasket with
RTV-type gasket sealant, then attach the front
cover to the front of the engine, carefully
working the seals over the crankshaft and
intermediate shaft. Refit the bolts and tighten
them evenly to the torque listed in this
Chapter’s Specifications. Work from bolt-tobolt in a criss-cross pattern, to be sure they’re
tightened evenly. Note 1: Tighten the front
cover-to-block bolts first, then tighten the
sump-to-cover bolts. Note 2: After applying
RTV-type sealant, reassembly must be
completed in about 10 minutes so the RTV
won’t prematurely harden.
27 The remainder of refitting is the reverse of
removal.
Crankshaft front seal (M40 engines)
28 Remove the timing belt and crankshaft
sprocket (see Section 10).
29 Remove the Woodruff key from the
groove in the end of the crankshaft.
30 Note the fitted position of the oil seal, then
prise it out from the front cover using a
screwdriver, but take care not to damage the
bore of the cover or the surface of the
crankshaft. If the seal is tight, drill two small
holes in the metal end of the seal, and use two
self-tapping screws to pull out the seal. Make
sure all remains of swarf are removed.
31 Coat the outside diameter and lip of the
new seal with multi-purpose grease, then
drive it into the cover with a hammer and a
socket slightly smaller in diameter than the
outside diameter of the seal. Make sure the
seal enters squarely.
32 The remainder of refitting is the reverse of
removal. Note that it is recommended that the
timing belt be renewed - see Section 10.
12 Cylinder head removal and refitting
5
Removal
1 Relieve the fuel pressure on all fuel injection
engines (see Chapter 4).
2 Disconnect the negative cable from the
battery. Where the battery is located in the
engine compartment, the battery may be
removed completely (see Chapter 5).
Caution: If the radio in your
vehicle is equipped with an antitheft system, make sure you
have the correct activation code
before disconnecting the battery.
Note: If, after connecting the battery, the
wrong language appears on the instrument
panel display, refer to page 0-7 for the
language resetting procedure.
3 Remove the air cleaner assembly (see
Chapter 4).
4 Disconnect the wiring from the distributor
(mark all wiring for position first, if necessary),
and the HT lead from the coil (see Chapter 5).
5 Disconnect the lead from the coolant
temperature sender unit (see Chapter 3).
6 Disconnect the fuel lines from the fuel rail or
carburettor as applicable (see Chapter 4).
7 Drain the cooling system (see Chapter 3).
8 Clearly label then disconnect all other
hoses from the throttle body, intake manifold,
carburettor and cylinder head, as applicable.
9 Disconnect the throttle cable from the
throttle linkage or carburettor (see Chapter 4).
10 Disconnect the exhaust manifold from the
cylinder head (see Section 6). Depending on
the engine type, It may not be necessary to
disconnect the manifold from the exhaust
pipe; however, on right-hand-drive models,
the steering column intermediate shaft may
not allow the manifold to clear the studs on
the cylinder head.
11 Remove or disconnect any remaining
hoses or lines from the intake manifold,
including the ignition advance vacuum line(s),
and the coolant and heater hoses.
12 On early carburettor models, disconnect
the wiring from the alternator and starter
motor.
13 Remove the intake manifold (see Section 5). Do not dismantle or remove any fuel
injection system components unless it is
absolutely necessary.
14 Remove the fan drivebelt and fan (see
Chapter 3).
15 Remove the valve cover and gasket (see
Section 4). Remove the semi-circular rubber
seal from the front of the cylinder head, where
this is not incorporated in the valve cover
gasket.
16 Set No 1 piston at Top Dead Centre on
the compression stroke (see Section 3).
17 Remove the timing chain or belt (see
Section 8 or 10). Note: If you want to save
time by not removing and refitting the timing
belt or chain and re-timing the engine, you can
unfasten the camshaft sprocket and suspend
it out of the way - with the belt or chain still
attached - by a piece of rope. Be sure the
rope keeps firm tension on the belt or chain,
so it won’t become disengaged from any of
the sprockets.
18 Loosen the cylinder head bolts a quarterturn at a time each, in the reverse of the
tightening sequence shown (see illustrations
12.30a, 12.30b, 12.30c or 12.30d). Do
not dismantle or remove the rocker arm
assembly at this time on M10, M20 and M30
engines.
19 Remove the cylinder head by lifting it
straight up and off the engine block. Do not
prise between the cylinder head and the
engine block, as damage to the gasket sealing
surfaces may result. Instead, use a blunt bar
positioned in an intake port to gently prise the
head loose.
20 Remove
any
remaining
external
components from the head to allow for
thorough cleaning and inspection. See
Chapter 2B for cylinder head servicing
procedures. On the M40 engine, remove the
rubber O-ring from the groove in the top of the
oil pump/front end cover housing.
Refitting
21 The mating surfaces of the cylinder head
and block must be perfectly clean when the
head is refitted.
22 Use a gasket scraper to remove all traces
of carbon and old gasket material, then clean
the mating surfaces with a suitable solvent. If
there’s oil on the mating surfaces when the
head is refitted, the gasket may not seal
correctly, and leaks could develop. When
working on the block, stuff the cylinders with
clean rags to keep out debris. Use a vacuum
cleaner to remove material that falls into the
cylinders.
23 Check the block and head mating
surfaces for nicks, deep scratches and other
damage. If the damage is slight, it can be
removed with a file; if it’s excessive,
machining may be the only alternative.
24 Use a tap of the correct size to chase the
threads in the head bolt holes, then clean the
holes with compressed air - make sure that
2A
2A•14 In-car engine repair procedures
12.24 The cylinder head bolt holes should
be cleaned and restored with a tap (be
sure to remove debris from the holes after
this is done)
12.25 A die should be used to remove
sealant and corrosion from the head bolt
threads prior to installation
12.26 Fitting a new rubber O-ring in the
groove in the top of the oil pump/front end
cover on the M40 engine
nothing (including oil, water, etc) remains in
the holes (see illustration).
25 BMW recommend head bolts are renewed,
but if the old ones are re-used, mount each bolt
in a vice, and run a die down the threads to
remove corrosion and restore the threads. Dirt,
corrosion, sealant and damaged threads will
affect torque readings (see illustration). If the
bolts or their threads are damaged, do not reuse the bolts - fit a new set.
26 Refit any components removed from the
head prior to cleaning and inspection. On the
M40 engine, locate a new rubber O-ring in the
groove in the top of the oil pump/front end
cover housing (see illustration).
27 Make sure the gasket sealing surfaces of
the engine block and cylinder head are clean
and oil-free. Lay the head gasket in place on
the block, with the manufacturer’s stamped
mark facing up (it usually says “UP,” “OBEN”
or something similar). Use the dowel pins in the
top of the block to properly locate the gasket.
28 Carefully set the cylinder head in place
on the block. Use the dowel pins to properly
align it. Where the engine is tilted slightly (ie
M40 engine) you may find it helpful to fit
guide studs to ensure correct positioning of
the cylinder head on the block. Use two old
head bolts, one screwed into each end of
the block. Cut the heads off the bolts, and
use a hacksaw to cut slots in the tops
of the bolts so they can be removed once
the cylinder head is in position (see
illustration).
29 Fit the cylinder head bolts (see
illustration).
30 Tighten the cylinder head bolts, in the
sequence shown, to the torque listed in this
Chapter’s Specifications (see illustrations).
Note that on some engines the final stage of
tightening takes place after the engine has
been run.
31 The remainder of refitting is the reverse of
removal. Set the valve clearances on M10,
M20 and M30 engines (see Chapter 1) before
refitting the valve cover (check them again
after the engine is warmed-up). Run the
engine and check for leaks.
12.28 Lowering the cylinder head onto the
block (M40 engine)
12.29 Inserting a cylinder head bolt
(M40 engine)
12.30a Cylinder head bolt TIGHTENING
sequence for M10 (four-cylinder) engines
12.30b Cylinder head bolt TIGHTENING
sequence for M20 (six-cylinder) engines
12.30c Cylinder head bolt TIGHTENING
sequence for M30 (six-cylinder) engines
12.30d Cylinder head bolt TIGHTENING
sequence for M40 (four-cylinder) engines
In-car engine repair procedures 2A•15
12.30e Angle-tightening the cylinder head
bolts (M40 engine)
13 Sump - removal and refitting
1
1 Drain the engine oil (see Chapter 1).
2 Raise the front of the vehicle and place it
securely on axle stands.
3 Remove the splash shields from under the
engine.
4 Where applicable, disconnect the hoses
attached to the sump, and move them to one
side (see illustration).
5 Where applicable, disconnect the oil level
sensor electrical connector (see illustration).
6 Where applicable, remove the castaluminium inspection cover that covers the
rear of the sump (see illustrations).
7 On models with the M40 engine, unbolt and
remove the lower sump section and remove
the gasket (this is necessary for access to the
front mounting bolts). Unscrew the mounting
bolt, and pull the oil dipstick tube from the
sump (see illustrations). Check the condition
of the O-ring, and renew it if necessary.
8 On models with the M40 engine, unscrew
the engine mounting nuts on both sides, then
attach a suitable hoist and lift the engine
sufficiently to allow the sump to be removed.
As a safety precaution, position axle stands or
blocks of wood beneath the engine.
9 Remove the bolts securing the sump to the
13.7a Main sump retaining bolts accessed
after removal of the lower sump section on
the M40 engine (engine on bench for clarity)
13.4 If applicable, remove the nut securing
the power steering lines to the sump, and
move the lines to one side to allow you to
get at the sump bolts
13.5 If applicable, disconnect the oil level
sensor connector at the left side of the
engine, down near the power steering
pump mounting bracket
engine block and front/rear covers (see
illustration).
10 Tap on the sump with a soft-faced
hammer to break the gasket seal, and lower
the sump from the engine.
11 Using a gasket scraper, scrape off all
traces of the old gasket from the engine
block, the timing chain cover, the rear main oil
seal housing, and the sump. Be especially
careful not to nick or gouge the gasket sealing
surfaces of the timing chain cover and the oil
seal housing (they are made of aluminium,
and are quite soft).
12 Clean the sump with solvent, and dry it
thoroughly. Check the gasket sealing surfaces
for distortion. Clean any residue from the
gasket sealing surfaces on the sump and
engine with a rag dampened with a suitable
solvent.
13 Before refitting the sump, apply a little
RTV-type gasket sealant to the area where the
front and rear covers join the cylinder block..
Lay a new sump gasket in place on the block.
If necessary, apply more sealant to hold the
gasket in place.
14 Carefully position the sump in place (do
not disturb the gasket) and refit the bolts.
Start with the bolts closest to the centre of the
sump, and tighten them to the torque listed in
this Chapter’s Specifications, using a crisscross pattern. Do not overtighten them, or
leakage may occur.
13.6a Remove the four inspection cover
bolts (arrowed) and . . .
13.6b . . . remove the cover to get to all
the sump bolts
13.7b Removing the oil dipstick tube
bracket mounting bolt
13.9 Remove the bolts holding the sump
to the engine block and front cover, as
shown here on a six-cylinder engine
2A
2A•16 In-car engine repair procedures
15 The remainder of refitting is the reverse of
removal. Fit a new gasket to the lower sump
section on models with the M40 engine.
16 On completion refill the engine with oil
(Chapter 1). Run the engine and check that
there are no oil leaks from the sump gasket or
other disturbed components.
14 Oil pump - removal,
inspection and refitting
5
Removal
1 Remove the sump (see Section 13).
M10, M20 and M30 engines
2 On M10 and M30 engines, remove the
three bolts that attach the gear to the front of
the pump (see illustration). Note: Some
models have a single centre nut attaching the
gear to the oil pump.
3 Unbolt the oil pump from the engine block
(see illustrations) and remove it.
4 On the M20 engine, the intermediate shaft
drives the oil pump driveshaft, which drives
the oil pump. To remove the driveshaft,
remove the hold-down plate from the block,
and lift out the plug. Check the condition of
the O-ring, and renew it if necessary. Lift the
driveshaft out and check both gears for wear,
renewing them if worn or damaged (see
illustration).
5 If the gear on the intermediate shaft is worn,
or the intermediate shaft bearing is worn or
damaged, the intermediate shaft must be
removed. Remove the engine (see Chapter 2B), then remove the timing belt,
crankshaft and intermediate shaft sprockets
(see Section 10) and the engine front cover
(see Section 11). The intermediate shaft can
be slid out the front of the engine.
14.2 On M10 and M30 engines, remove the
three bolts that hold the driven gear to the
oil pump, and remove the gear
14.3a On M20 engines, the oil pump is
bolted across the engine block from side
to side, towards the front of the engine
14.3b On M10 and M30 engines, the oil
pump is bolted to the front and centre of
the engine block
14.4 If necessary on the M20 engine,
remove the plug and oil pump driveshaft
from the engine. Inspect the driveshaft
gear, as well as this intermediate shaft
gear in the engine block (arrowed)
6 Remove the timing belt as described in
Section 10.
7 Remove the cylinder head as described in
Section 12.
8 Unscrew the nut and remove the timing belt
tensioner from the front end cover (see
illustration). If necessary, unscrew the stud
from the cylinder block.
9 Unscrew and remove the crankshaft hub
bolt while holding the crankshaft stationary.
The bolt is tightened to a very high torque,
and it will be necessary to prevent the
crankshaft turning. Ideally, a metal bar should
be bolted to the sprocket, or the starter motor
may be removed and the flywheel held using a
wide-bladed screwdriver. Beware of possible
damage to surrounding components if it is
necessary to improvise some method of
immobilising the crankshaft.
10 Remove the sprocket and spacer, noting
that the shoulder on the spacer faces inwards.
11 Unscrew the bolts and remove the
stabilising and guide rollers from the front end
cover (see illustrations).
12 Using a small screwdriver or similar
instrument, remove the key from the groove in
the nose of the crankshaft (see illustration).
13 Pull the spacer ring off the crankshaft (see
illustration).
14 Unscrew the remaining bolts, and remove
the front end cover and oil pump from the
cylinder block. Note the locations of the front
cover bolts, as they are of different sizes. With
the cover removed, extract the rubber O-ring
from the groove in the nose of the crankshaft
(see illustrations).
15 Note the fitted location of the oil seal, then
prise it out of the housing.
14.8 Removing the timing belt tensioner
(M40 engine)
14.11a Removing the stabilising roller
from the front end cover (M40 engine)
14.11b Removing the guide roller from the
front end cover (M40 engine)
M40 engines
In-car engine repair procedures 2A•17
14.12 Removing the key from the groove
in the nose of the crankshaft (M40 engine)
14.13 Removing the spacer ring from the
front of the crankshaft
14.14a Front end cover and oil pump in
position on the front of the M40 engine
2A
14.14b Extract the rubber O-ring from the
groove in the nose of the crankshaft
(M40 engine)
Inspection
Note: Considering that a malfunctioning oil
pump can easily cause major engine damage,
we recommend that the oil pump should
always be renewed during engine overhaul,
unless it’s in as-new condition.
M10, M20 and M30 engines
16 Remove the cover and check the pump
body, gears or rotors and cover for cracks
and wear (especially in the gear or rotor
contact areas).
17 Check the strainer to make sure it is not
clogged or damaged.
18 Lubricate the gears with clean engine oil,
then attach the pump cover to the body and
tighten the bolts evenly and securely.
14.22a Removing the inner rotor . . .
14.21a Unscrew the bolts . . .
14.21b . . . and remove the oil pump cover
(M40 engine)
19 Before refitting the pump - new, rebuilt or
original - on the engine, check it for proper
operation. Fill a clean container to a depth of
one inch with fresh engine oil of the
recommended viscosity.
20 Immerse the oil pump inlet in the oil, and
turn the driveshaft anti-clockwise by hand. As
the shaft is turned, oil should be discharged
from the pump outlet.
23 Clean the housing and the rotors
thoroughly, then refit the rotors, making sure
that they are in their previously-noted
positions. The inner rotor must be fitted with
the guide facing the body.
24 Using feeler blades, measure the
clearance between the oil pump body and the
outer rotor, then check the clearance
between the outer and inner rotors (see
illustrations).
25 If the clearance is not as given in the
Specifications, the complete oil pump and
front end cover should be renewed. If the
clearance is within tolerance, remove the
rotors, then pour a little engine oil into the
housing. Refit the rotors and turn them to
spread the oil around.
M40 engines
21 With the front end cover on the bench,
unscrew the bolts and remove the cover plate
to expose the oil pump rotors (see
illustrations).
22 Identify the rotors for position, then
remove them from the housing (see
illustrations).
14.22b . . . and outer rotor from the oil
pump (M40 engine)
14.24a Measuring the clearance between
the oil pump body and the outer rotor
(M40 engine)
2A•18 In-car engine repair procedures
14.24b Measuring the clearance between
the oil pump outer and inner rotors
(M40 engine)
26 Refit the cover plate and tighten the bolts
to the specified torque.
27 To check the pressure relief valve, extract
the circlip and remove the sleeve, spring and
piston. Check that the length of the spring is
as given in the Specifications (see
illustrations). Reassemble the pressure relief
valve using a reversal of the dismantling
procedure.
Refitting
M10, M20 and M30 engines
28 Make sure the mounting surfaces are
clean, then insert the pump into the engine
block recess. Refit the bolts and tighten them
to the torque specified at the beginning of this
Chapter.
29 Refitting is the reverse of removal.
14.27a Extract the circlip from the oil
pump (M40 engine) . . .
M40 engines
30 Clean the mating surfaces, then refit the
front end cover and oil pump to the cylinder
block, together with a new gasket (see
illustration). Tighten the bolts to the
specified torque. Note that there are two sizes
of bolts, and they have different torque
settings.
31 Fit the spacer ring on the front of the
crankshaft.
32 Apply engine oil to the lips of the new oil
seal, then press it into the housing to its
previously-noted position. To ensure the oil
seal enters the housing squarely, use a large
socket and the crankshaft pulley bolt to pull it
into position (see illustration).
33 Refit the key to the groove in the nose of
the crankshaft.
14.27b . . . and remove the sleeve . . .
34 Refit the stabilising roller to the front end
cover, and tighten the bolt.
35 Refit the sprocket, spacer and crankshaft
pulley bolt. Tighten the bolt to the specified
torque while holding the crankshaft stationary
using one of the methods previously
described.
36 Refit the timing belt tensioning roller, but
do not tighten the bolt at this stage.
37 Refit the cylinder head as described in
Section 12.
38 Refit the timing belt as described in
Section 10.
39 Refit the sump (see Section 13).
15 Flywheel/driveplate removal and refitting
3
14.27c . . . spring . . .
14.27d . . . and piston
1 Remove the transmission (on vehicles with
manual transmission, see Chapter 7A; on
vehicles with automatic transmission, see
Chapter 7B).
2 On vehicles with manual transmission,
remove the clutch (see Chapter 8).
3 Where necessary, mark the relationship of
the flywheel/driveplate to the crankshaft, so it
can be refitted the same way.
4 The flywheel/driveplate is attached to the
rear of the crankshaft with eight bolts. Loosen
and remove the bolts, then separate it from
14.27e Checking the length of the
pressure relief valve spring (M40 engine)
14.30 Locating a new gasket on the front
of the cylinder block (M40 engine)
14.32 Using a large socket and the
crankshaft pulley bolt to pull the oil seal
into the housing (M40 engine)
In-car engine repair procedures 2A•19
15.4 Using a socket and ratchet, remove
the eight bolts that hold the flywheel/
driveplate to the crankshaft flange - prevent
the flywheel/driveplate from turning by
locking the ring gear with a lever
the crankshaft flange (see illustration). Be
careful - the flywheel is heavy.
5 To refit the flywheel/driveplate on the
crankshaft, use a liquid thread-locking
compound on the bolts, and tighten them
gradually, using a criss-cross pattern, to the
torque listed in this Chapter’s Specifications.
6 The remainder of refitting is the reverse of
removal.
16 Crankshaft rear oil seal renewal
3
1 Remove the flywheel or driveplate (see
Section 15).
2 Remove the bolts and/or nuts attaching the
seal retainer to the engine block. Be sure to
remove the two bolts (from underneath)
connecting the rear of the sump to the bottom
of the seal retainer (see illustration).
3 Run a sharp, thin knife between the sump
gasket and the seal retainer, cutting the
retainer free from the gasket. Be very careful
not to damage the gasket, and keep it clean
so you can re-use it.
4 Break the seal retainer-to-block gasket seal
by tapping the retainer with a plastic mallet or
block of wood and hammer. Do not prise
between the retainer and the engine block, as
damage to the gasket sealing surfaces will
result.
5 Using a scraper, remove all traces of old
gasket material from the sealing surfaces of
the retainer and engine block. Gasket removal
solvents are available at car accessory shops,
and may prove helpful. After all gasket
material has been removed, the gasket
surfaces can be degreased by wiping them
with a rag dampened with a suitable solvent.
Caution: Be very careful not to
scratch or gouge the delicate
aluminium surfaces. Also, do not
damage the sump gasket, and
keep it clean.
6 Support the retainer on two blocks of
wood, and drive out the seal from behind with
a hammer and screwdriver (see illustration).
16.2 Remove the six bolts from the rear of
the block and the two from underneath at
the sump
Be very careful not to damage the seal bore in
the process.
7 Coat the outside diameter and lip of the
new seal with multi-purpose grease, and drive
the seal into the retainer with a hammer and a
block of wood (see illustration).
8 Apply a film of RTV-type gasket sealant to
the surface of the sump gasket that mates with
the seal retainer. Apply extra beads of RTV
sealant to the edges where the gasket meets
the engine block. Note: If the sump gasket is
damaged, instead of fitting a whole new
gasket, you might try trimming the rear portion
of the gasket off at the point where it meets the
engine block, then trim off the rear portion of a
new sump gasket so it’s exactly the same size.
Cover the exposed inside area of the sump
with a rag, then clean all traces of old gasket
material off the area where the gasket was
removed. Attach the new gasket piece to the
sump with contact-cement-type gasket
adhesive, then apply RTV-type sealant as
described at the beginning of this paragraph.
9 Coat both sides of the new retainer gasket
with RTV-type gasket sealant, then attach the
gasket to the seal retainer. Fit the seal retainer
to the rear of the engine, then refit the bolts
and tighten them evenly to the torque listed in
this Chapter’s Specifications. Work from boltto-bolt in a criss-cross pattern to be sure
they’re tightened evenly. Note 1: Tighten the
retainer-to-block bolts first, then tighten the
sump-to-retainer bolts. Note 2: After applying
RTV-type sealant, reassembly must be
16.7 Drive the new seal into the retainer
with a block of wood, or a section of pipe,
if you have one large enough - make sure
the seal enters the retainer bore squarely
16.6 After removing the retainer from the
block, support it on two wood blocks, and
drive out the old seal with a punch and
hammer
completed in about 10 minutes so the RTV
won’t prematurely harden.
10 Refit the flywheel/driveplate (see Section 15).
11 Refit the transmission (on vehicles with
manual transmission, see Chapter 7A; on
vehicles with automatic transmission, see
Chapter 7B).
17 Engine mountings check and renewal
1
1 Engine mountings seldom require attention,
but broken or deteriorated mountings should
be renewed immediately, or the added strain
placed on the driveline components may
cause damage or wear.
Check
2 During the check, the engine must be
raised slightly to remove its weight from the
mounts.
3 Raise the vehicle and support it securely on
axle stands, then position a jack under the
engine sump. Place a large block of wood
between the jack head and the sump, then
carefully raise the engine just enough to take
its weight off the mounts.
Warning: DO NOT place any part
of your body under the engine
when it’s supported only by a
jack!
17.4 As engine mountings wear or age,
they should be inspected for cracking or
separation from their metal plates
2A
2A•20 In-car engine repair procedures
17.5 Lever gently between the block and
the engine mounting attachment point
(arrowed) - if there is movement, tighten
the bolts
17.6 Engine mounting and damper on the
M40 engine
17.10 To remove an engine mounting, first
remove the stud nut (arrowed) M30 engine shown, others similar
4 Check the mountings to see if the rubber is
cracked (see illustration), hardened or
separated from the metal plates. Sometimes
the rubber will split right down the centre.
5 Check for relative movement between the
mounting plates and the engine or frame (use
a large screwdriver or lever to attempt to
move the mountings). If movement is noted,
lower the engine and tighten the mounting
nuts or bolts (see illustration). Rubber
preservative should be applied to the
mountings, to slow deterioration.
6 On models with the M40 engine, check the
condition of the dampers on each mounting
by disconnecting them and attempting to
compress and expand them (see illustration).
If there is very little resistance to movement,
the dampers should be renewed.
before disconnecting the battery.
Note: If, after connecting the battery, the
wrong language appears on the instrument
panel display, refer to page 0-7 for the
language resetting procedure.
9 Support the engine as described in
paragraph 3.
10 Remove the large bracket-to-mounting
nut (see illustration). Raise the engine
slightly, then remove the lower mounting-toframe bolts/nuts and detach the mounting
11 Refitting of the mountings is the reverse of
removal. Use thread-locking compound on
the mounting bolts/nuts, and be sure to
tighten them securely.
Renewal
7 If the dampers on the M40 engine are to be
renewed, simply unscrew the bolts, then fit
the new dampers and tighten the bolts.
8 To renew the mountings, disconnect the
battery negative cable, then raise the vehicle
and support it securely on axle stands if you
haven’t already done so.
Caution: If the radio in your
vehicle is equipped with an antitheft system, make sure you
have the correct activation code
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