driveshaft BMW 3 SERIES 1990 E30 Workshop Manual

0•4Introduction
The E30 3-Series range first became
available in the UK in March 1983, and
continued in production until April 1991, when
the revised E36 3-Series range (not covered
by this manual) was introduced. Convertible
and Touring (Estate) models were introduced
for 1988, and these models have continued in
E30 form to date.
The E28 5-Series models were introduced
in October 1981, and were superseded in
June 1988 by the revised E34 5-Series range,
Touring versions of which became available
from March 1992. Throughout this manual,
E28 models are also referred to as “old-
shape”, while E34 models are designated
“new-shape”.
The models covered by this manual are
equipped with single overhead cam in-line
four- and six-cylinder engines. Early 316 and
518 models are fitted with carburettors, but all
other models are fitted with fuel injection
systems. Transmissions are a five-speed
manual, or three- or four-speed automatic.
The transmission is mounted to the back of
the engine, and power is transmitted to the
fully-independent rear axle through a two-
piece propeller shaft. The final drive unit is
bolted solidly to a frame crossmember, and
drives the rear wheels through driveshaftsequipped with inner and outer constant
velocity joints.
The front suspension is of MacPherson
strut type, with the coil spring/shock absorber
unit making up the upper suspension link. The
rear suspension is made up of coil spring-
over-shock absorber struts, or coil springs
and conventional shock absorbers,
depending on model.
The brakes are disc type at the front, with
either drums or discs at the rear, depending
on model. Servo assistance is standard on all
models. Some later models are equipped with
an Anti-lock Braking System (ABS).
All models are manufactured to fine limits,
and live up to the BMW reputation of quality
workmanship. Although many of the models
covered by this manual appear complex at
first sight, they should present no problems to
the home mechanic.
Note for UK readers
The greater part of this manual was
originally written in the USA. Some of the
photographs used are of American-market
models, but the procedures given are fully
applicable to right-hand-drive models (or have
been amended where necessary).
Acknowledgements
Thanks are due to Champion Spark Plug,
who supplied the illustrations showing spark
plug conditions. Thanks are also due to
Sykes-Pickavant Limited, who provided some
of the workshop tools, and to all those people
at Sparkford who helped in the production of
this manual. Technical writers who
contributed to this project include Robert
Maddox, Mark Ryan and Mike Stubblefield.
We take great pride in the accuracy of
information given in this manual, but
vehicle manufacturers make alterations
and design changes during the production
run of a particular vehicle of which they do
not inform us. No liability can be accepted
by the authors or publishers for loss,
damage or injury caused by any
errors in, or omissions from, the
information given.
Project vehicles
The main project vehicle used in the
preparation of this manual for the UK market
was a 1988 BMW 318i with an M40/B18
engine.
Introduction to the BMW 3- and 5-Series
BMW 320i Saloon (E30)

0•10Roadside Repairs
Puddles on the garage floor or drive, or
obvious wetness under the bonnet or
underneath the car, suggest a leak that needs
investigating. It can sometimes be difficult to
decide where the leak is coming from,
especially if the engine bay is very dirty
already. Leaking oil or fluid can also be blown
rearwards by the passage of air under the car,
giving a false impression of where the
problem lies.Warning: Most automotive oils
and fluids are poisonous. Wash
them off skin, and change out of
contaminated clothing, without
delay.
Identifying leaks
The smell of a fluid leaking
from the car may provide a
clue to what’s leaking. Some
fluids are distinctively
coloured. It may help to clean the car
carefully and to park it over some clean
paper overnight as an aid to locating the
source of the leak.
Remember that some leaks may only
occur while the engine is running.
Sump oil Gearbox oil
Brake fluid Power steering fluidOil from filter
Antifreeze
Engine oil may leak from the drain plug......or from the base of the oil filter.
Leaking antifreeze often leaves a crystalline
deposit like this.Gearbox oil can leak from the seals at the
inboard ends of the driveshafts.
A leak occurring at a wheel is almost
certainly brake fluid.Power steering fluid may leak from the pipe
connectors on the steering rack.

1
Engine
Oil filter
M10 engines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Champion C121
M20 engines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Champion C160
M30 engines
3-Series . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Champion C160
5-Series . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Champion X115
M40 engines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Champion X120
Valve clearances (intake and exhaust)
M10 engines
Cold . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.20 mm
Hot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.25 mm
M20 engines
Cold . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.25 mm
Hot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.30 mm
M30 engines
Cold . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.30 mm
Hot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.35 mm
M40 engines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Hydraulic adjusters
Cooling system
Antifreeze mixture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40% antifreeze/60% water
Chapter 1
Routine maintenance and servicing
Air filter renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Automatic transmission fluid and filter change . . . . . . . . . . . . . . . . . 28
Automatic transmission fluid level check . . . . . . . . . . . . . . . . . . . . . 8
Battery check, maintenance and charging . . . . . . . . . . . . . . . . . . . . 13
Brake system check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Cooling system - draining, flushing and refilling . . . . . . . . . . . . . . . . 29
Cooling system check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Differential lubricant change . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Differential lubricant level check . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Driveshaft gaiter check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Drivebelt check, adjustment and renewal . . . . . . . . . . . . . . . . . . . . . 11
Engine idle speed and CO level check and adjustment . . . . . . . . . . 12
Engine oil and filter change . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Engine timing belt renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Exhaust system check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Evaporative Emissions Control (EVAP) system check . . . . . . . . . . . 33
Fluid level checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Fuel filter renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Fuel system check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Manual transmission lubricant change . . . . . . . . . . . . . . . . . . . . . . . 31
Manual transmission lubricant level check . . . . . . . . . . . . . . . . . . . . 16
Power steering fluid level check . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Routine maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Service light resetting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Spark plug check and renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Spark plug HT leads, distributor cap and rotor - check
and renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Steering and suspension check . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Throttle linkage - check and lubrication . . . . . . . . . . . . . . . . . . . . . . 19
Tyre and tyre pressure checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Tyre rotation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Tune-up general information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Underbonnet hoses - check and renewal . . . . . . . . . . . . . . . . . . . . . 10
Valve clearances - check and adjustment . . . . . . . . . . . . . . . . . . . . 18
Wiper blades - check and renewal . . . . . . . . . . . . . . . . . . . . . . . . . . 27
1•1
Easy,suitable for
novice with little
experienceFairly easy,suitable
for beginner with
some experienceFairly difficult,
suitable for competent
DIY mechanic
Difficult,suitable for
experienced DIY
mechanicVery difficult,
suitable for expert
DIY or professional
Degrees of difficulty
Specifications Contents

Maintenance schedule
The following maintenance intervals are based on the assumption
that the vehicle owner will be doing the maintenance or service work,
as opposed to having a dealer service department do the work.
Although the time/mileage intervals are loosely based on factory rec-
ommendations, most have been shortened to ensure, for example, that
such items as lubricants and fluids are checked/changed at intervals
that promote maximum engine/driveline service life. Also, subject to
the preference of the individual owner interested in keeping his or her
vehicle in peak condition at all times, and with the vehicle’s ultimate
resale in mind, many of the maintenance procedures may be
performed more often than recommended in the following schedule.
We encourage such owner initiative.
When the vehicle is new, it should be serviced initially by a factory-
authorised dealer service department, to protect the factory warranty.
In many cases, the initial maintenance check is done at no cost to the
owner (check with your dealer service department for more
information).
1•4Maintenance and servicing
Every 250 miles or weekly, whichever
comes first
m mCheck the engine oil level (Section 4)
m mCheck the engine coolant level (Section 4)
m mCheck the brake fluid level (Section 4)
m mCheck the clutch fluid level (Section 4)
m mCheck the washer fluid level (Section 4)
m mCheck the tyres and tyre pressures (Section 5)
Every 6000 miles or 6 months,
whichever comes first
All items listed above, plus:
m mChange the engine oil and oil filter (Section 6)
m mCheck the power steering fluid level (Section 7)
m mCheck the tyres, and rotate if necessary (Section 9)
m mCheck the automatic transmission fluid level
(Section 8)
m mCheck the underbonnet hoses (Section 10)
m mCheck/adjust the drivebelts (Section 11)
m mCheck engine idle speed and CO (Section 12)
Every 12 000 miles or 12 months,
whichever comes first
All items listed above, plus:
m mCheck/service the battery (Section 13)
m mCheck the spark plugs (Section 14)
m mCheck/renew the HT leads, distributor cap and
rotor (Section 15)
m mCheck/top-up the manual transmission lubricant
(Section 16)
m mCheck the differential oil level (Section 17)
m mCheck the valve clearances, and adjust if
necessary - does not apply to M40 engines
(Section 18)
m mCheck and lubricate the throttle linkage (Section 19)
m mRenew the air filter (Section 20)
m mCheck the fuel system (Section 21)
m mInspect the cooling system (Section 22)
m mInspect the exhaust system (Section 23)
m mInspect the steering and suspension components
(Section 24)
m mCheck the driveshaft gaiter(s) (Section 25)
m mInspect the brakes (Section 26)
m mInspect/renew the windscreen wiper blades
(Section 27)
Every 24 000 miles or 2 years,
whichever comes first
All items listed above plus:
m mChange the automatic transmission fluid and filter
(Section 28)
m mDrain, flush and refill the cooling system (Section 29)
m mRenew the spark plugs (Section 14)
m mCheck/renew the spark plug HT leads (Section 15)
m mRenew the fuel filter (Section 30)
m mChange the manual transmission lubricant (Section 31)
m mChange the differential oil (Section 32)
m mCheck the evaporative emissions system, where
applicable (Section 33)
m mReset the service indicator lights (Section 34)
m mRenew brake fluid by bleeding (see Chapter 9)
m mCheck the handbrake operation (see Chapter 9)
Every 60 000 miles
m
mRenew the timing belt (Section 35)

1•6Maintenance and Servicing
Front underbody view of a UK model 318i
(1988)
1 Radiator
2 Engine oil drain plug
3 Front suspension control arm (left-hand
side)
4 Front anti-roll bar
5 Clutch slave cylinder
6 Transmission
7 Exhaust downpipe
8 Front suspension control arm (right-hand
side)
Typical rear underside components
1 Exhaust system
2 Differential fill/check plug
3 Driveshaft boot
4 Fuel tank filler tube
5 Differential drain plug
6 Rear brake
7 Rear shock absorber

no cause for concern. Make sure that any fluid
noted is from the struts/shocks, and not from
any other source. If leakage is noted, renew
the struts or shock absorbers in axle pairs (or
as a full set).
7Check the struts/shock absorbers to be
sure that they are securely mounted and
undamaged. Check the upper mountings for
damage and wear. If damage or wear is
noted, renew the struts or shock absorbers.
8If the struts or shock absorbers must be
renewed, refer to Chapter 10 for the
procedure. Always renew both units on the
same axle, or the safety of the vehicle may be
compromised. If possible, renew all four as a
set.
Steering and suspension check
9Inspect the steering system components
for damage and distortion. Look for leaks and
damaged seals, boots and fittings.
10Clean the lower end of the steering
knuckle. Have an assistant grasp the lower
edge of the tyre and move the wheel in and
out, while you look for movement at the
steering knuckle-to-axle arm balljoints.
Inspect the balljoint boots for tears (see
illustration). If there is any movement, or the
boots are torn or leaking, the balljoint(s) must
be renewed.
11Grasp each front tyre at the front and rear
edges, push in at the front, pull out at the rear
and feel for play in the steering linkage. If any
free play is noted, check the steering gear
mountings and the track rod balljoints for
looseness. If the steering gear mountings are
loose, tighten them. If the track rods are
loose, the balljoints may be worn (check to
make sure the nuts are tight). Additional
steering and suspension system information
can be found in Chapter 10.
25 Driveshaft gaiter check
1
1The driveshaft gaiters are very important
because they prevent dirt, water and foreign
material from entering and damaging the
constant velocity (CV) joints. External oil and
grease contamination can cause the gaitermaterial to deteriorate prematurely, so it’s a
good idea to wash the gaiters with soap and
water.
2Inspect the gaiters for tears and cracks, as
well as for loose clamps (see illustration). If
there is any evidence of cracks or leaking
lubricant, the gaiter must be renewed (see
Chapter 8).
26 Brake system check
2
Warning: Dust produced by lining
wear and deposited on brake
components may contain
asbestos, which is hazardous to
your health. Do not blow it out with
compressed air, and don’t inhale it! Do not
use petroleum-based solvents to remove
the dust. Brake system cleaner or
methylated spirit should be used to flush
the dust into a drain pan. After the brake
components are wiped with a damp rag,
dispose of the contaminated rag(s) and the
drain pan contents into a covered and
labelled container. Try to use asbestos-
free new parts whenever possible.
Note:In addition to the specified intervals, the
brake system should be inspected each time
the wheels are removed or a malfunction is
indicated. Because of the obvious safety con-
siderations, the following brake system checks
are some of the most important maintenance
procedures you can perform on your vehicle.
Symptoms of brake system
problems
1The disc brakes have built-in electrical wear
indicators which cause a warning light on the
dash to come on when they’re worn to the
renewal point. When the light comes on,
renew the pads immediately, or expensive
damage to the brake discs could result.
2Any of the following symptoms could
indicate a potential brake system defect:
a) Vehicle pulls to one side when the brake
pedal is depressed
b) Brakes make squealing or dragging noises
when applied
c) Brake pedal travel excessived) Brake pedal pulsates (normal if ABS is
working)
e) Brake fluid leaks (usually on the inner side
of the tyre or wheel)
3If any of these conditions are noted, inspect
the brake system immediately.
Brake lines and hoses
Note: Steel brake pipes are used throughout
the brake system, with the exception of
flexible, reinforced hoses at the front wheels
and as connectors at the rear axle. Periodic
inspection of all these lines is very important.
4Park the vehicle on level ground, and
switch off the engine. Remove the wheel
covers. Loosen, but do not remove, the bolts
on all four wheels.
5Raise the vehicle and support it securely on
axle stands.
6Remove the wheels (see “Jacking and
towing” at the front of this book, or refer to
your owner’s handbook, if necessary).
7Check all brake lines and hoses for cracks,
chafing of the outer cover, leaks, blisters, and
distortion. Check the brake hoses at front and
rear of the vehicle for softening, cracks,
bulging, or wear from rubbing on other
components. Check all threaded fittings for
leaks, and make sure the brake hose
mounting bolts and clips are secure.
8If leaks or damage are discovered, they
must be repaired immediately. Refer to
Chapter 9 for detailed brake system repair
procedures.
Disc brakes
9If it hasn’t already been done, raise the
vehicle and support it securely on axle stands.
Remove the front wheels.
10The disc brake calipers, containing the
pads, are now visible. Each caliper has an
outer and an inner pad - all pads should be
checked.
11Note the pad thickness by looking
through the inspection hole in the caliper (see
illustration). If the lining material is 2.0 mm
thick or less, or if it is tapered from end to
end, the pads should be renewed (see
Chapter 9). Keep in mind that the lining
1•22
26.11 Look through the caliper inspection
window to inspect the brake pads - the
pad lining which rubs against the disc can
also be inspected by looking through each
end of the caliper25.2 Gently probe the driveshaft boots to
check for cracks24.10 Inspect the balljoint boots for tears
(arrowed)
Every 12 000 miles

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.

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

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
16Remove the cover and check the pump
body, gears or rotors and cover for cracks
and wear (especially in the gear or rotor
contact areas).
17Check the strainer to make sure it is not
clogged or damaged.
18Lubricate the gears with clean engine oil,
then attach the pump cover to the body and
tighten the bolts evenly and securely.19Before 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.
20Immerse 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.M40 engines
21With the front end cover on the bench,
unscrew the bolts and remove the cover plate
to expose the oil pump rotors (see
illustrations).
22Identify the rotors for position, then
remove them from the housing (see
illustrations).23Clean 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.
24Using 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).
25If 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.
In-car engine repair procedures 2A•17
14.14a Front end cover and oil pump in
position on the front of the M40 engine14.13 Removing the spacer ring from the
front of the crankshaft14.12 Removing the key from the groove
in the nose of the crankshaft (M40 engine)
14.24a Measuring the clearance between
the oil pump body and the outer rotor
(M40 engine)14.22b . . . and outer rotor from the oil
pump (M40 engine)14.22a Removing the inner rotor . . .
14.21b . . . and remove the oil pump cover
(M40 engine)14.21a Unscrew the bolts . . .14.14b Extract the rubber O-ring from the
groove in the nose of the crankshaft
(M40 engine)
2A

5Gently tap the caps with a soft-faced
hammer, then separate them from the engine
block. If necessary, use the bolts as levers to
remove the caps. Try not to drop the bearing
shells if they come out with the caps.
6Carefully lift the crankshaft out of the
engine. It may be a good idea to have an
assistant available, since the crankshaft is
quite heavy (see illustration). With the
bearing shells in place in the engine block and
main bearing caps, return the caps to their
respective locations on the engine block, and
tighten the bolts finger-tight.
14 Intermediate shaft-
removal and inspection
5
Note:The intermediate shaft is used on the
M20 engine only. The shaft rotates in the
engine block parallel to the crankshaft. It is
driven by the timing belt, and its only purpose
is to drive the oil pump.
1Remove the timing belt (see Chapter 2A).
2With the belt removed, unbolt the gear from
the intermediate shaft and unbolt the front
cover.
3Remove the oil pump driveshaft (see
Chapter 2A).
4The shaft is held in the cylinder block by a
retaining plate with two bolts. Remove the
bolts, and pull the shaft forwards and out of
the block.
5Look for any signs of abnormal wear on the
bearing surfaces or the gear at the back end
of the shaft, which drives the oil pump shaft. If
the bearing surfaces in the engine block show
wear, they’ll have to be attended to by a
machine shop.
15 Engine block- cleaning
2
Caution: The core plugs may be
difficult or impossible to retrieve
if they’re driven into the block
coolant passages.
1Remove the core plugs from the engine
block. To do this, knock one side of each plug
into the block with a hammer and punch,
grasp the other side by its edge with large
pliers, and pull it out.
2Using a gasket scraper, remove all traces of
gasket material from the engine block. Be very
careful not to nick or gouge the gasket sealing
surfaces.
3Remove the main bearing caps, and
separate the bearing shells from the caps and
the engine block. Tag the bearings, indicating
which cylinder they were removed from and
whether they were in the cap or the block,
then set them aside.
4Remove all of the threaded oil gallery plugs
from the block. The plugs are usually very
tight - they may have to be drilled out and theholes retapped. Use new plugs when the
engine is reassembled.
5If the engine is extremely dirty, it should be
taken to a machine shop to be steam-
cleaned.
6After the block is returned, clean all oil
holes and oil galleries one more time. Brushes
specifically designed for this purpose are
available at most motor factors. Flush the
passages with warm water until the water runs
clear, dry the block thoroughly, and wipe all
machined surfaces with a light, rust-
preventive oil. If you have access to
compressed air, use it to speed the drying
process and to blow out all the oil holes and
galleries.
Warning: Wear eye protection
when using compressed air!
7If the block isn’t extremely dirty or sludged
up, you can do an adequate cleaning job with
hot soapy water and a stiff brush. Take plenty
of time, and do a thorough job. Regardless of
the cleaning method used, be sure to clean all
oil holes and galleries very thoroughly, dry the
block completely, and coat all machined
surfaces with light oil.
8The threaded holes in the block must be
clean to ensure accurate torque readingsduring reassembly. Run the proper-size tap
into each of the holes to remove rust,
corrosion, thread sealant or sludge, and to
restore damaged threads (see illustration). If
possible, use compressed air to clear the
holes of debris produced by this operation. Be
sure also that the holes are dry- any oil or
other fluid present could cause the block to
be cracked by hydraulic pressure when the
bolts are tightened. Now is a good time to
clean the threads on all bolts. Note that BMW
recommend that the cylinder head bolts and
main bearing bolts are renewed as a matter of
course.
9Refit the main bearing caps, and tighten the
bolts finger-tight.
10After coating the sealing surfaces of the
new core plugs with a suitable sealant, refit
them in the engine block (see illustration).
Make sure they’re driven in straight and
seated properly, or leakage could result.
Special tools are available for this purpose,
but a large socket, with an outside diameter
that will just slip into the core plug, a 1/2-inch
drive extension, and a hammer, will work just
as well.
11Apply non-hardening sealant to the new
oil gallery plugs, and thread them into the
holes in the block. Make sure they’re
tightened securely.
12If the engine isn’t going to be
reassembled right away, cover it with a large
plastic bag to keep it clean.
2B•14 General engine overhaul procedures
15.10 A large socket on an extension can
be used to drive the new core plugs into
the block
15.8 All bolt holes in the block -
particularly the main bearing cap and head
bolt holes - should be cleaned and
restored with a tap (be sure to remove
debris from the holes after this is done)
13.6 Remove the crankshaft by lifting
straight up. Be very careful when removing
the crankshaft - it is very heavy13.4 Use a centre-punch or number-
stamping dies to mark the main bearing
caps to ensure refitting in their original
locations on the block (make the punch
marks near one of the bolt heads)