1990 BMW 5 SERIES wheel

1 General information
This Part of Chapter 2 is devoted to in-
vehicle 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 ismost 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.
1Top 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.
2Positioning the piston at TDC is an essential
part of many procedures, such as timing belt
or chain removal and distributor removal.
3Before 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).
4In 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.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.
5Note 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).
6Use a felt-tip pen or chalk to make a mark
directly below the No 1 terminal on the
distributor body or timing cover.
7Detach the distributor cap, and set it aside
(see Chapter 1 if necessary).
8Turn 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.
9Look at the distributor rotor - it should be
pointing directly at the mark you made on the
distributor body or timing cover.
10If the rotor is 180 degrees out, the No 1
piston is at TDC on the exhaust stroke.
11To 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.
In-car engine repair procedures 2A•3
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)
2A

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).
9On 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.
10Unscrew 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 beingunscrewed, and release the spring tension
slowly.
11On the M30 engine, if you’re removing the
upper timing cover, unbolt the thermostat cover
and remove the thermostat (see Chapter 3).
12On 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.
13Remove 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.
14Remove 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.
15Run 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.
16Break the lower timing chain cover-to-
block 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.
17Using 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 beenremoved, the gasket surfaces can be
degreased by wiping them with a rag
dampened with a suitable solvent.Refitting
18Renew 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.
19Apply 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 contact-
cement-type gasket adhesive, then apply
RTV-type sealant as described at the
beginning of this paragraph.
20Coat 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 RTV-
type sealant, reassembly must be completed
in about 10 minutes so the RTV won’t
prematurely harden.
21Refit 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.
22Refitting is otherwise the reverse of
removal.
In-car engine repair procedures 2A•7
7.14 From underneath the vehicle, remove
the three bolts (arrowed) that connect the
cover and the sump7.10 Unscrew the plug from the timing
chain cover, and remove the tensioner
spring and plunger7.7 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
2A
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.

alignment mark on the camshaft sprocket and
rear timing cover to ensure correct refitting.
6On 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.
7On 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.
8If 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.
9Remove the timing belt by slipping it off the
roller(s) and the other sprockets (see
illustrations).
10If 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) ora 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.
11The 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).
12If 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
2A•10 In-car engine repair procedures
10.12a Home-made tool for holding the
crankshaft stationary while the crankshaft
pulley bolt is being loosened (engine
removed for clarity)
10.11b The BMW camshaft-holding tool in
position on the M40 engine10.11a The BMW tool for holding the
camshaft in the TDC position on
M40 engines
10.10 Removing the camshaft sprocket on
the M40 engine
10.9b Removing the timing belt from the
camshaft sprocket on the M40 engine
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 bolt10.6 Loosen the idler pulley bolts
(arrowed) to relieve the tension on the
timing belt so it can be removed

15The remainder of refitting is the reverse of
removal. Fit a new gasket to the lower sump
section on models with the M40 engine.
16On 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
1Remove the sump (see Section 13).
M10, M20 and M30 engines
2On 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.
3Unbolt the oil pump from the engine block
(see illustrations)and remove it.
4On 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).
5If 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 Chap-
ter 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.
M40 engines
6Remove the timing belt as described in
Section 10.
7Remove the cylinder head as described in
Section 12.
8Unscrew the nut and remove the timing belt
tensioner from the front end cover (see
illustration). If necessary, unscrew the stud
from the cylinder block.9Unscrew 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.
10Remove the sprocket and spacer, noting
that the shoulder on the spacer faces inwards.
11Unscrew the bolts and remove the
stabilising and guide rollers from the front end
cover (see illustrations).12Using a small screwdriver or similar
instrument, remove the key from the groove in
the nose of the crankshaft (see illustration).
13Pull the spacer ring off the crankshaft (see
illustration).
14Unscrew 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).
15Note the fitted location of the oil seal, then
prise it out of the housing.
2A•16 In-car engine repair procedures
14.11b Removing the guide roller from the
front end cover (M40 engine)14.11a Removing the stabilising roller
from the front end cover (M40 engine)14.8 Removing the timing belt tensioner
(M40 engine)
14.3b On M10 and M30 engines, the oil
pump is bolted to the front and centre of
the engine block14.4 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)
14.3a On M20 engines, the oil pump is
bolted across the engine block from side
to side, towards the front of the engine14.2 On M10 and M30 engines, remove the
three bolts that hold the driven gear to the
oil pump, and remove the gear

26Refit the cover plate and tighten the bolts
to the specified torque.
27To 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
28Make 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.
29Refitting is the reverse of removal.
M40 engines
30Clean 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.
31Fit the spacer ring on the front of the
crankshaft.
32Apply 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).
33Refit the key to the groove in the nose of
the crankshaft.34Refit the stabilising roller to the front end
cover, and tighten the bolt.
35Refit 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.
36Refit the timing belt tensioning roller, but
do not tighten the bolt at this stage.
37Refit the cylinder head as described in
Section 12.
38Refit the timing belt as described in
Section 10.
39Refit the sump (see Section 13).
15 Flywheel/driveplate-
removal and refitting
3
1Remove the transmission (on vehicles with
manual transmission, see Chapter 7A; on
vehicles with automatic transmission, see
Chapter 7B).
2On vehicles with manual transmission,
remove the clutch (see Chapter 8).
3Where necessary, mark the relationship of
the flywheel/driveplate to the crankshaft, so it
can be refitted the same way.
4The flywheel/driveplate is attached to the
rear of the crankshaft with eight bolts. Loosen
and remove the bolts, then separate it from
2A•18 In-car engine repair procedures
14.32 Using a large socket and the
crankshaft pulley bolt to pull the oil seal
into the housing (M40 engine)14.30 Locating a new gasket on the front
of the cylinder block (M40 engine)14.27e Checking the length of the
pressure relief valve spring (M40 engine)
14.27d . . . and piston14.27c . . . spring . . .
14.27b . . . and remove the sleeve . . .14.27a Extract the circlip from the oil
pump (M40 engine) . . .14.24b Measuring the clearance between
the oil pump outer and inner rotors
(M40 engine)

the crankshaft flange (see illustration). Be
careful - the flywheel is heavy.
5To 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.
6The remainder of refitting is the reverse of
removal.
16 Crankshaft rear oil seal-
renewal
3
1Remove the flywheel or driveplate (see
Section 15).
2Remove 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).
3Run 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.
4Break 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.
5Using 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.
6Support the retainer on two blocks of
wood, and drive out the seal from behind with
a hammer and screwdriver (see illustration).Be very careful not to damage the seal bore in
the process.
7Coat 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).
8Apply 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.
9Coat 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 bolt-
to-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 becompleted in about 10 minutes so the RTV
won’t prematurely harden.
10Refit the flywheel/driveplate (see Sec-
tion 15).
11Refit 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
1Engine 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
2During the check, the engine must be
raised slightly to remove its weight from the
mounts.
3Raise 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!
In-car engine repair procedures 2A•19
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
hammer16.2 Remove the six bolts from the rear of
the block and the two from underneath at
the sump15.4 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
17.4 As engine mountings wear or age,
they should be inspected for cracking or
separation from their metal plates
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
2A

detach them. Pieces of masking tape with
numbers or letters written on them work well
(see illustration).
6Label and detach all coolant hoses from the
engine (see Chapter 3).
7Remove the cooling fan, shroud and
radiator (see Chapter 3). Note:On the M40
engine, it is only necessary to remove the
cooling fan and shroud; however, prevent
damage to the radiator by covering it with a
piece of wood or cardboard.
8Remove the drivebelts (see Chapter 1).
9Disconnect the fuel lines from the fuel rail
(see Chapter 4).
Warning: Fuel is extremely
flammable, so take extra
precautions when you work on
any part of the fuel system. Don’t
smoke, or allow open flames or bare light
bulbs, near the work area, and don’t work
in a garage where a natural gas-type
appliance (such as a water heater or
clothes dryer) with a pilot light is present.
If you spill any fuel on your skin, rinse it off
immediately with soap and water. When
you perform any kind of work on the fuel
system, wear safety glasses, and have a
fire extinguisher on hand.
10Disconnect the accelerator cable (see
Chapter 4) and kickdown linkage/speed
control cable (see Chapter 7B), if applicable,
from the engine.
11Where fitted, unbolt the power steering
pump (see Chapter 10). Leave the lines/hoses
attached, and make sure the pump is kept in
an upright position in the engine compartment
(use wire or rope to restrain it out of the way).
12On air-conditioned models, unbolt the
compressor (see Chapter 3) and set it aside,
or tie it up out of the way. Do not disconnect
the hoses.
13Drain the engine oil (see Chapter 1) and
remove the filter. Remove the engine splash
guard from under the engine.
14Remove the starter motor (see Chapter 5).15Remove the alternator (see Chapter 5).
This is not essential on all models, but it is a
good idea in any case to avoid accidental
damage.
16Unbolt the exhaust system from the
engine (see Chapter 4).
17If you’re working on a vehicle with an
automatic transmission, remove the torque
converter-to-driveplate fasteners (see
Chapter 7B). On the M40 engine, unbolt the
automatic transmission fluid coolant pipes
from the sump.
18Support the transmission with a jack.
Position a block of wood between them, to
prevent damage to the transmission. Special
transmission jacks with safety chains are
available - use one if possible.
19Attach an engine sling or a length of chain
to the lifting brackets on the engine. If the
brackets have been removed, the chain can
be bolted directly to the intake manifold studs,
but place a flat washer between the chain and
the nut, and tighten the nut all the way up to
the chain, to avoid the possibility of the studs
bending.
20Roll the hoist into position and connect
the sling to it. Take up the slack in the sling or
chain, but don’t lift the engine.
Warning: DO NOT place any part
of your body under the engine
when it’s supported only by a
hoist or other lifting device.
21On M10, M20 and M30 engines, remove
the transmission rear crossmember, and
slightly lower the rear of the transmission.
22Remove the transmission-to-engine block
bolts using a Torx socket. Note:The bolts
holding the bellhousing to the engine block
will require a swivel at the socket, and a very
long extension going back towards the
transmission.
23Remove the engine mounting-to-frame
bracket nuts. On the M40 engine, unbolt the
dampers from the mountings.
24Recheck to be sure nothing is still
connecting the engine to the transmission or
vehicle. Disconnect anything still remaining.
25Raise the engine slightly. Carefully work it
forwards to separate it from the transmission.
If you’re working on a vehicle with an
automatic transmission, you may find the
torque converter comes forward with theengine. If it stays with the transmission, leave
it, but you may find it easier to let it come
forward until it can be grasped easier and be
pulled from the crankshaft. Note:When
refitting the torque converter to the
transmission before the engine is refitted, be
sure to renew the transmission front pump
seal, which will probably be damaged when
the converter comes out with the engine.
Either method is acceptable, but be prepared
for some fluid to leak from the torque
converter if it comes out of the transmission. If
you’re working on a vehicle with a manual
transmission, draw the engine forwards until
the input shaft is completely disengaged from
the clutch. Slowly raise the engine out of the
engine compartment. Check carefully to make
sure everything is disconnected.
26Remove the flywheel/driveplate (and
where applicable, the engine rear plate), and
mount the engine on an engine stand (see
illustration). Do not turn the M40 engine
upside-down (see Cautionin Section 4).
Refitting
27Check the engine and transmission
mountings. If they’re worn or damaged, renew
them.
28Refit the flywheel or driveplate (see
Chapter 2A). If you’re working on a manual
transmission vehicle, refit the clutch and
pressure plate (see Chapter 7A). Now is a
good time to fit a new clutch.
29If the torque converter came out with the
engine during removal, carefully refit the
converter into the transmission before the
engine is lowered into the vehicle.
30Carefully lower the engine into the engine
compartment - make sure the engine
mountings line up.
31If you’re working on an automatic
transmission vehicle, guide the torque
converter onto the crankshaft following the
procedure outlined in Chapter 7B.
32If you’re working on a manual
transmission vehicle, apply a dab of high-
melting-point grease to the input shaft, and
guide it into the clutch and crankshaft pilot
bearing until the bellhousing is flush with the
engine block.. Do not allow the weight of the
engine to hang on the input shaft.
33Refit the transmission-to-engine bolts,
and tighten them securely.
Caution: DO NOT use the bolts to
force the transmission and
engine together.
34Refit the remaining components in the
reverse order of removal.
35Add coolant, oil, power steering and
transmission fluid as needed.
2B•6 General engine overhaul procedures
5.26 Removing the engine rear plate -
M40 engine5.5 Label each wire before unplugging the
connector
If there’s any possibility of
confusion, make a sketch of
the engine compartment and
clearly label the lines, hoses
and wires.
It may be necessary to rock
the engine slightly, or to turn
the crankshaft, to allow the
input shaft splines to mate
with the clutch plate

36Run the engine and check for leaks and
proper operation of all accessories, then refit
the bonnet and test drive the vehicle.
37Where necessary, have the air
conditioning system recharged and leak-
tested.
6 Engine overhaul- alternatives
The do-it-yourselfer is faced with a number
of options when performing an engine
overhaul. The decision to renew the engine
block, piston/connecting rod assemblies and
crankshaft depends on a number of factors,
with the number one consideration being the
condition of the block. Other considerations
are cost, access to machine shop facilities,
parts availability, time required to complete
the project, and the extent of prior mechanical
experience on the part of the do-it-yourselfer.
Some of the alternatives include:
Individual parts - If the inspection
procedures reveal that the engine block and
most engine components are in re-usable
condition, purchasing individual parts may be
the most economical alternative. The block,
crankshaft and piston/connecting rod
assemblies should all be inspected carefully.
Even if the block shows little wear, the
cylinder bores should be surface-honed.
Crankshaft kit- A crankshaft kit (where
available) consists of a reground crankshaft
with matched undersize new main and
connecting big-end bearings. Sometimes,
reconditioned connecting rods and new
pistons and rings are included with the kit
(such a kit is sometimes called an “engine
kit”). If the block is in good condition, but the
crankshaft journals are scored or worn, a
crankshaft kit and other individual parts may
be the most economical alternative.
Short block- A short block consists of an
engine block with a crankshaft and
piston/connecting rod assemblies already
fitted. New bearings are fitted, and all
clearances will be correct. The existing
camshaft, valve train components, cylinder
head and external parts can be bolted to the
short block with little or no machine shop
work necessary.
Full block - A “full” or “complete” block
consists of a short block plus an oil pump,
sump, cylinder head, valve cover, camshaft
and valve train components, timing sprockets
and chain (or belt) and timing cover. All
components are fitted with new bearings,
seals and gaskets used throughout. The
refitting of manifolds and external parts is all
that’s necessary.
Give careful thought to which alternative is
best for you, and discuss the situation with
local machine shops, parts dealers and
experienced rebuilders before ordering or
purchasing new parts.
7 Engine overhaul-
dismantling sequence
1It’s much easier to dismantle and work on
the engine if it’s mounted on a portable
engine stand. A stand can often be hired quite
cheaply from a tool hire shop. Before the
engine is mounted on a stand, the
flywheel/driveplate should be removed from
the engine.
2If a stand isn’t available, it’s possible to
dismantle the engine with it blocked up on the
floor. Be extra-careful not to tip or drop the
engine when working without a stand.
3If you’re going to obtain a rebuilt engine, all
the external components listed below must
come off first, to be transferred to the new
engine if applicable. This is also the case if
you’re doing a complete engine overhaul
yourself. 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,
brackets, washers, bolts and other small items.
Alternator and brackets
Emissions control components
Distributor, HT leads and spark plugs
Thermostat and housing cover
Water pump
Fuel injection/carburettor and fuel system
components
Intake and exhaust manifolds
Oil filter and oil pressure sending unit
Engine mounting brackets (see illustration)
Clutch and flywheel/driveplate
Engine rear plate (where applicable)
4If you’re obtaining a short block, which
consists of the engine block, crankshaft,
pistons and connecting rods all assembled,
then the cylinder head, sump and oil pump
will have to be removed as well. See Section 6
for additional information regarding the
different possibilities to be considered.
5If you’re planning a complete overhaul, the
engine must be dismantled and the internal
components removed in the following general
order:
Valve cover
Intake and exhaust manifolds
Timing belt or chain covers
Timing chain/belt
Water pump
Cylinder head
Sump
Oil pump
Piston/connecting rod assemblies
Crankshaft and main bearings
Camshaft
Rocker shafts and rocker arms (M10, M20
and M30 engines)
Cam followers and hydraulic tappets
(M40 engine)
Valve spring retainers and springs
Valves
6Before beginning the dismantling andoverhaul procedures, make sure the following
items are available. Also, refer to Section 21
for a list of tools and materials needed for
engine reassembly.
Common hand tools
Small cardboard boxes or plastic bags for
storing parts
Compartment-type metal box for storing
the hydraulic tappets (M40 engine)
Gasket scraper
Ridge reamer
Vibration damper puller
Micrometers
Telescoping gauges
Dial indicator set
Valve spring compressor
Cylinder surfacing hone
Piston ring groove cleaning tool
Electric drill motor
Tap and die set
Wire brushes
Oil gallery brushes
Cleaning solvent
8 Cylinder head- dismantling
4
1Remove the cylinder head (see Chapter 2A).
2Remove the oil supply tube from its
mounting on top of the cylinder head (see
illustrations). Note:It’s important to renew
the seals under the tube mounting bolts.
General engine overhaul procedures 2B•7
7.3 Engine left-hand mounting bracket -
M40 engine
8.2a Remove the oil tube from the top of
the cylinder head (M10 engine). Be sure to
note the location of all gaskets and
washers for reassembly
2B