torque BMW 3 SERIES 1988 E30 Workshop Manual

0•6Safety First!
Working on your car can be dangerous.
This page shows just some of the potential
risks and hazards, with the aim of creating a
safety-conscious attitude.
General hazards
Scalding
• Don’t remove the radiator or expansion
tank cap while the engine is hot.
• Engine oil, automatic transmission fluid or
power steering fluid may also be dangerously
hot if the engine has recently been running.
Burning
• Beware of burns from the exhaust system
and from any part of the engine. Brake discs
and drums can also be extremely hot
immediately after use.
Crushing
• When working under or near
a raised vehicle,
always
supplement the
jack with axle
stands, or use
drive-on
ramps.
Never
venture
under a car which
is only supported by a jack.
• Take care if loosening or tightening high-
torque nuts when the vehicle is on stands.
Initial loosening and final tightening should
be done with the wheels on the ground.
Fire
• Fuel is highly flammable; fuel vapour is
explosive.
• Don’t let fuel spill onto a hot engine.
• Do not smoke or allow naked lights
(including pilot lights) anywhere near a
vehicle being worked on. Also beware of
creating sparks
(electrically or by use of tools).
• Fuel vapour is heavier than air, so don’t
work on the fuel system with the vehicle over
an inspection pit.
• Another cause of fire is an electrical
overload or short-circuit. Take care when
repairing or modifying the vehicle wiring.
• Keep a fire extinguisher handy, of a type
suitable for use on fuel and electrical fires.
Electric shock
• Ignition HT
voltage can be
dangerous,
especially to
people with heart
problems or a
pacemaker. Don’t
work on or near the
ignition system with
the engine running or
the ignition switched on.• Mains voltage is also dangerous. Make
sure that any mains-operated equipment is
correctly earthed. Mains power points should
be protected by a residual current device
(RCD) circuit breaker.
Fume or gas intoxication
• Exhaust fumes are
poisonous; they often
contain carbon
monoxide, which is
rapidly fatal if inhaled.
Never run the
engine in a
confined space
such as a garage
with the doors shut.
• Fuel vapour is also
poisonous, as are the vapours from some
cleaning solvents and paint thinners.
Poisonous or irritant substances
• Avoid skin contact with battery acid and
with any fuel, fluid or lubricant, especially
antifreeze, brake hydraulic fluid and Diesel
fuel. Don’t syphon them by mouth. If such a
substance is swallowed or gets into the eyes,
seek medical advice.
• Prolonged contact with used engine oil can
cause skin cancer. Wear gloves or use a
barrier cream if necessary. Change out of oil-
soaked clothes and do not keep oily rags in
your pocket.
• Air conditioning refrigerant forms a
poisonous gas if exposed to a naked flame
(including a cigarette). It can also cause skin
burns on contact.
Asbestos
• Asbestos dust can cause cancer if inhaled
or swallowed. Asbestos may be found in
gaskets and in brake and clutch linings.
When dealing with such components it is
safest to assume that they contain asbestos.
Special hazards
Hydrofluoric acid
• This extremely corrosive acid is formed
when certain types of synthetic rubber, found
in some O-rings, oil seals, fuel hoses etc, are
exposed to temperatures above 400
0C. The
rubber changes into a charred or sticky
substance containing the acid. Once formed,
the acid remains dangerous for years. If it
gets onto the skin, it may be necessary to
amputate the limb concerned.
• When dealing with a vehicle which has
suffered a fire, or with components salvaged
from such a vehicle, wear protective gloves
and discard them after use.
The battery
• Batteries contain sulphuric acid, which
attacks clothing, eyes and skin. Take care
when topping-up or carrying the battery.
• The hydrogen gas given off by the battery
is highly explosive. Never cause a spark or
allow a naked light nearby. Be careful when
connecting and disconnecting battery
chargers or jump leads.
Air bags
• Air bags can cause injury if they go off
accidentally. Take care when removing the
steering wheel and/or facia. Special storage
instructions may apply.
Diesel injection equipment
• Diesel injection pumps supply fuel at very
high pressure. Take care when working on
the fuel injectors and fuel pipes.
Warning: Never expose the hands,
face or any other part of the body
to injector spray; the fuel can
penetrate the skin with potentially fatal
results.
Remember...
DO
• Do use eye protection when using power
tools, and when working under the vehicle.
• Do wear gloves or use barrier cream to
protect your hands when necessary.
• Do get someone to check periodically
that all is well when working alone on the
vehicle.
• Do keep loose clothing and long hair well
out of the way of moving mechanical parts.
• Do remove rings, wristwatch etc, before
working on the vehicle – especially the
electrical system.
• Do ensure that any lifting or jacking
equipment has a safe working load rating
adequate for the job.
A few tips
DON’T
• Don’t attempt to lift a heavy component
which may be beyond your capability – get
assistance.
• Don’t rush to finish a job, or take
unverified short cuts.
• Don’t use ill-fitting tools which may slip
and cause injury.
• Don’t leave tools or parts lying around
where someone can trip over them. Mop
up oil and fuel spills at once.
• Don’t allow children or pets to play in or
near a vehicle being worked on.

0•8Roadside Repairs
Jacking and wheel
changing
The jack supplied with the vehicle should
be used only for raising the vehicle when
changing a tyre or placing axle stands under
the frame.
Warning:Never crawl under the
vehicle or start the engine when
this jack is being used as the
only means of support.
When changing a wheel, the vehicle should
be on level ground, with the handbrake firmly
applied, and the wheels chocked. Select
reverse gear (manual transmission) or Park
(automatic transmission). Prise off the hub
cap (if equipped) using the tapered end of the
wheel brace. Loosen the wheel bolts half a
turn, leaving them in place until the wheel is
raised off the ground.
Position the head of the jack under the side
of the vehicle, making sure it engages with thepocket made for this purpose (just behind the
front wheel, or forward of the rear wheel).
Engage the wheel brace handle and turn it
clockwise until the wheel is raised off the
ground. Unscrew the bolts, remove the wheel
and fit the spare.
Refit the wheel bolts and tighten them
finger-tight. Lower the vehicle by turning the
wheel brace anti-clockwise. Remove the jack
and tighten the bolts in a diagonal pattern to
the torque listed in the Chapter 1
Specifications. If a torque wrench is not
available, have the torque checked by a BMW
dealer or tyre fitting specialist as soon as
possible. Refit the hubcap.
Towing
Vehicles with manual transmission can be
towed with all four wheels on the ground, if
necessary. Automatic transmission-equipped
vehicles can only be towed with all fourwheels on the ground providing that the
speed does not exceed 35 mph and the
distance is not over 50 miles, otherwise
transmission damage can result. For
preference, regardless of transmission type,
the vehicle should be towed with the driven
(rear) wheels off the ground.
Proper towing equipment, specifically
designed for the purpose, should be used,
and should be attached to the main structural
members of the vehicle, not to the bumpers or
bumper brackets. Sling-type towing
equipment must notbe used on these
vehicles.
Safety is a major consideration while
towing. The handbrake should be released,
and the transmission should be in neutral. The
steering must be unlocked (ignition switch
turned to position “1”). Remember that
power-assisted steering (where fitted) and the
brake servo will not work with the engine
switched off.
Jacking, towing and wheel changing

Tyre pressures (cold) - bars (psi)Front Rear
3-Series, E30
316 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.9 (28) 2.1 (30)
316i
Saloon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.0 (29) 2.1 (30)
Estate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.0 (29) 2.2 (32)
318i . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.8 (26) 1.9 (28)
320i . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.9 (28) 2.0 (29)
325i . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2 (32) 2.3 (33)
5-Series, E28 (“old-shape”)
518 and 518i . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.0 (29) 2.0 (29)
525i and 528i . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2 (32) 2.2 (32)
535i and M535i . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3 (33) 2.5 (36)
5-Series, E34 (“new-shape”)
518i . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.0 (29) 2.0 (29)
520i . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2 (32) 2.1 (30)
525i, 530i and 535i . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.0 (29) 2.3 (33)
Torque wrench settingsNm
Automatic transmission sump bolts
Three-speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 to 9
Four-speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 to 7
Spark plugs
M10 engines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 to 30
Except M10 engines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 to 33
Oxygen sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 to 33
Wheel bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
Lubricants and fluids
Component or system Lubricant type/specification
Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Multigrade engine oil, viscositySAE 10W/40 to 20W/50, to API SG
Cooling system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ethylene glycol-based antifreeze with corrosion inhibitors
Manual transmission* . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Gear oil, viscosity SAE 80 to API-GL4, or single-grade mineral-based
engine oil, viscosity SAE 20, 30 or 40 to API-SG
Automatic transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Dexron ll type ATF
Final drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BMW-approved hypoid gear oil, viscosity SAE 90**
Brake and clutch hydraulic systems . . . . . . . . . . . . . . . . . . . . . . . . . . Hydraulic brake fluid to SAE J 1703 or DOT 4
Power steering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Dexron ll type ATF
* E34 520i & 525i with air conditioning, E34 530i & 535i - Dexron II type ATF)
** Only available in bulk; refer to your BMW dealer
Capacities*
1•3
1
Engine oil
M10 engines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.0 litres
M20 engines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.3 litres
M30 engines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.8 litres
M40 engines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.0 litres
Cooling system
M10 engines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.0 litres
M20 engines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.5 litres
M30 engines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12.0 litres
M40 engines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.0 litres
Fuel tank
3-Series, E30
Saloon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 litres (early),
64 litres (later)
Estate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 litres (early),
70 litres (later)
5-Series
E28 (“old-shape”) . . . . . . . . . . . . . . . . . . . . . . . . 70 litres
E34 (“new-shape”) . . . . . . . . . . . . . . . . . . . . . . . 81 litresManual transmission
ZF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.2 litres
Getrag . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.0 to 1.5 litres
Automatic transmission (refill)
3-speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.0 litres
4-speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.0 litres
Final drive capacity (drain and refill)
3-Series, E30 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.9 litres
5-Series, E28 (“old-shape”) . . . . . . . . . . . . . . . . . . 0.9 litres
5-Series, E34 (“new-shape”) . . . . . . . . . . . . . . . . . 1.7 litres
*All capacities approximate
Servicing Specifications

1 Introduction
This Chapter is designed to help the home
mechanic maintain his or her vehicle with the
goals of maximum performance, economy,
safety and reliability in mind. Included is a
master maintenance schedule, followed by
procedures dealing specifically with each item
on the schedule. Visual checks, adjustments,
component renewal and other helpful items
are included. Refer to the accompanying
illustrations of the engine compartment and
the underside of the vehicle for the locations
of various components. Servicing the vehicle,
in accordance with the mileage/time
maintenance schedule and the step-by-step
procedures, will result in a planned
maintenance programme that should produce
a long and reliable service life. Keep in mind
that it is a comprehensive plan, so maintaining
some items but not others at specified
intervals, will not produce the same results.
2 Routine maintenance
As you service the vehicle, you will discover
that many of the procedures can - and should
- be grouped together, because of the nature
of the particular procedure you’re performing,
or because of the close proximity of two
otherwise-unrelated components to one
another. For example, if the vehicle is raised
for chassis lubrication, you should inspect the
exhaust, suspension, steering and fuelsystems while you’re under the vehicle. When
the wheels are removed for other work, it
makes good sense to check the brakes, since
the wheels are already removed. Finally, let’s
suppose you have to borrow a torque wrench.
Even if you only need it to tighten the spark
plugs, you might as well check the torque of
as many critical nuts and bolts as time allows.
The first step in this maintenance
programme is to prepare yourself before the
actual work begins. Read through all the
procedures you’re planning to do, then gather
up all the parts and tools needed. If it looks
like you might run into problems during a
particular job, seek advice from a mechanic or
an experienced do-it-yourselfer.
3 Engine “tune-up”-
general information
The term “tune-up” is used in this manual to
represent a combination of individual
operations rather than one specific procedure.
If, from the time the vehicle is new, the
routine maintenance schedule is followed
closely, and frequent checks are made of fluid
levels and high-wear items, as suggested
throughout this manual, the engine will be
kept in relatively good running condition, and
the need for additional work will be minimised.
More likely than not, however, there will be
times when the engine is running poorly due
to a lack of regular maintenance. This is even
more likely if a used vehicle, which has not
received regular and frequent maintenance
checks, is purchased. In such cases, an
engine tune-up will be needed outside of the
regular maintenance intervals. The first step in any tune-up or diagnostic
procedure to help correct a poor-running
engine is a cylinder compression check. A
compression check (see Chapter 2B) will help
determine the condition of internal engine
components, and should be used as a guide
for tune-up and repair procedures. If, for
instance, a compression check indicates
serious internal engine wear, a conventional
tune-up will not improve the performance of
the engine, and would be a waste of time and
money. Because of its importance, the
compression check should be done by
someone with the right equipment, and the
knowledge to use it properly.
The following procedures are those most
often needed to bring a generally poor-
running engine back into a proper state of
tune.
Minor tune-up
Check all engine-related fluids (Section 4)
Check all underbonnet hoses (Section 10)
Check and adjust the drivebelts (Sec-
tion 11)
Clean, inspect and test the battery (Sec-
tion 13)
Renew the spark plugs (Section 14)
Inspect the spark plug HT leads, distributor
cap and rotor (Section 15)
Check the air filter (Section 20)
Check the cooling system (Section 22)
Major tune-up
All items listed under minor tune-up, plus . . .
Check the ignition system (see Chapter 5)
Check the charging system (see Chapter 5)
Check the fuel system (see Chapter 4)
Renew the spark plug HT leads, distributor
cap and rotor (Section 15)
1•7
1
Routine Maintenance
Weekly checks
4 Fluid level checks
1
Note:The following are fluid level checks to
be done on a 250-mile or weekly basis.
Additional fluid level checks can be found in
specific maintenance procedures which
follow. Regardless of intervals, be alert to fluid
leaks under the vehicle, which would indicate
a fault to be corrected immediately.
1Fluids are an essential part of the
lubrication, cooling, brake and windscreen
washer systems. Because the fluids gradually
become depleted and/or contaminated during
normal operation of the vehicle, they must be
periodically replenished. See “Lubricants and
fluids”at the beginning of this Chapter before
adding fluid to any of the following
components. Note:The vehicle must be on
level ground when any fluid levels are
checked.
Engine oil
2Engine oil is checked with a dipstick, which
is located on the side of the engine (refer to
the underbonnet illustrations in this Chapter
for dipstick location). The dipstick extends
through a metal tube down into the sump.
3The engine oil should be checked before
the vehicle has been driven, or at least
15 minutes after the engine has been shut off.
4Pull the dipstick out of the tube, and wipe
all of the oil away from the end with a clean
rag or paper towel. Insert the clean dipstick all
the way back into the tube, and pull it out
again. Note the oil at the end of the dipstick.
At its highest point, the oil should be betweenthe two notches or marks (see illustration).
5It takes one litre of oil to raise the level from
the lower mark to the upper mark on the
dipstick. Do not allow the level to drop below
the lower mark, or oil starvation may cause
4.4 The oil level should be kept between
the two marks, preferably at or near the
upper one - if it isn’t, add enough oil to
bring the level to the upper mark
If the oil is checked
immediately after driving the
vehicle, some of the oil will
remain in the upper part of
the engine, resulting in an inaccurate
reading on the dipstick.

terminals and cable clamps after they are
assembled.
9Make sure that the battery carrier is in good
condition, and that the hold-down clamp bolt
is tight. If the battery is removed (see Chap-
ter 5 for the removal and refitting procedure),
make sure that no parts remain in the bottom
of the carrier when it’s refitted. When refitting
the hold-down clamp, don’t overtighten the
bolt.
10Corrosion on the carrier, battery case and
surrounding areas can be removed with a
solution of water and baking soda. Apply the
mixture with a small brush, let it work, then
rinse it off with plenty of clean water.
11Any metal parts of the vehicle damaged
by corrosion should be coated with a zinc-
based primer, then painted.
12Additional information on the battery and
jump starting can be found in Chapter 5 and
the front of this manual.
Charging
Note: The manufacturer recommends the
battery be removed from the vehicle for
charging, because the gas which escapes
during this procedure can damage the paint or
interior, depending on the location of the
battery. Fast charging with the battery cables
connected can result in damage to the
electrical system.
13Remove all of the cell caps (if applicable),
and cover the holes with a clean cloth to
prevent spattering electrolyte. Disconnect thebattery negative cable, and connect the
battery charger leads to the battery posts
(positive to positive, negative to negative),
then plug in the charger. Make sure it is set at
12 volts if it has a selector switch.
Caution: If the radio in your
vehicle is equipped with an anti-
theft 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.
14If you’re using a charger with a rate higher
than two amps, check the battery regularly
during charging to make sure it doesn’t
overheat. If you’re using a trickle charger, you
can safely let the battery charge overnight
after you’ve checked it regularly for the first
couple of hours. Where a maintenance-free
battery is fitted, special precautions may be
necessary when charging it (for example, the
charge rate is normally very low). There may
be a warning label on the battery, but if not,
consult a BMW dealer or auto-electrician.
15If the battery has removable cell caps,
measure the specific gravity with a
hydrometer every hour during the last few
hours of the charging cycle. Hydrometers are
available inexpensively from car accessory
shops - follow the instructions that come with
the hydrometer. Consider the battery charged
when there’s no change in the specific gravity
reading for two hours, and the electrolyte in
the cells is gassing (bubbling) freely. The
specific gravity reading from each cell should
be very close to the others. If not, the battery
probably has a bad cell(s), and a new one
should be fitted.
16Some maintenance-free (sealed) batteries
have built-in hydrometers on the top,
indicating the state of charge by the colour
displayed in the hydrometer window.
Normally, a bright-coloured hydrometer
indicates a full charge, and a dark hydrometer
indicates the battery still needs charging.
Check the battery manufacturer’s instructions
to be sure you know what the colours mean.17If the battery is sealed and has no built-in
hydrometer, you can connect a digital
voltmeter across the battery terminals to
check the charge. A fully-charged battery
should read 12.6 volts or higher.
18Further information on the battery and
jump starting can be found in Chapter 5 and
at the front of this manual.
14 Spark plug check and
renewal
1
1Before beginning, obtain the necessary
tools, which will include a spark plug socket
and a set of feeler blades. Special spark plug
gap gauges can be obtained from certain
spark plug manufacturers (see illustration).
2The best procedure to follow when
renewing the spark plugs is to purchase the
new spark plugs beforehand, adjust them to
the proper gap, and then renew each plug one
at a time. When buying the new spark plugs, it
is important to obtain the correct plugs for
your specific engine. This information can be
found in the Specifications section in the front
of this Chapter.
3With the new spark plugs at hand, allow the
engine to cool completely before attempting
plug removal. During this time, each of the
new spark plugs can be inspected for defects
and the gaps can be checked.
4The gap is checked by inserting the proper
thickness gauge between the electrodes at the
tip of the plug (see illustration). The gap
between the electrodes should be the same as
that given in the Specifications. The wire
should just touch each of the electrodes. If the
gap is incorrect, use the notched adjuster to
bend the curved side of the electrode slightly
until the proper gap is achieved (see
illustration). Note: When adjusting the gap of a
new plug, bend only the base of the earth
electrode, do not touch the tip. If the earth
electrode is not exactly over the centre
electrode, use the notched adjuster to align the
two. Check for cracks in the porcelain insulator,
indicating the spark plug should not be used.
1•17
14.4b To change the gap, bend the earth
electrode only, as indicated by the arrows,
and be very careful not to crack or chip the
porcelain insulator surrounding the centre
electrode14.4a Spark plug manufacturers
recommend using a wire-type gauge when
checking the gap - if the wire does not
slide between the electrodes with a slight
drag, adjustment is required
14.1 Tools required for changing spark
plugs
1 Spark plug socket- This will have special
padding inside to protect the spark plug’s
porcelain insulator
2 Torque wrench - Although not mandatory,
using this tool is the best way to ensure the
plugs are tightened properly
3 Ratchet - Standard hand tool to fit the
spark plug socket
4 Extension - Depending on model and
accessories, you may need special
extensions and universal joints to reach one
or more of the plugs
5 Spark plug gap gauge- This gauge for
checking the gap comes in a variety of
styles. Make sure the gap for your engine is
included. Feeler blades may be used
instead
1
Every 12 000 miles

5With the engine cool, remove the HT lead
from one spark plug. Do this by grabbing the
connector at the end of the wire, not the lead
itself (see illustration). Sometimes it is
necessary to use a twisting motion while the
connector and HT lead are pulled free.
6If compressed air is available, use it to blow
any dirt or foreign material away from the
spark plug area. A common bicycle pump will
also work. The idea here is to eliminate the
possibility of debris falling into the cylinder as
the spark plug is removed.
7Place the spark plug socket over the plug,
and remove it from the engine by turning it
anti-clockwise (see illustration).
8Compare the spark plug with those shown
in the accompanying photos to get an
indication of the overall running condition of
the engine.
9Apply a little copper-based anti-seize
compound to the threads of the new spark
plug. Locate the plug into the head, screwing
it in with your fingers until it no longer turns,
then tighten it with the socket. If available, use
a torque wrench to tighten the plug to ensure
that it is seated correctly. The correct torque
figure is included in this Chapter’s Specifi-
cations.10Before pushing the HT lead onto the end of
the plug, inspect it as outlined in Section 15.
11Attach the HT lead to the new spark plug,
again using a twisting motion on the
connector until it is firmly seated on the spark
plug.
12Follow the above procedure for the
remaining spark plugs, renewing them one at
a time to prevent mixing up the spark plug HT
leads.
15 Spark plug HT leads,
distributor cap and rotor -
check and renewal
1
1The spark plug HT leads should be checked
at the recommended intervals, and whenever
new spark plugs are fitted in the engine.
2Begin this procedure by making a visual
check of the spark plug HT leads while the
engine is running. In a darkened garage (make
sure there is ventilation) start the engine and
observe each HT lead. Be careful not to come
into contact with any moving engine parts. If
there is a break in the wire, you will see arcing
or a small spark at the damaged area. If arcing
is noticed, make a note to obtain new HT
leads, then allow the engine to cool.
3Disconnect the battery negative cable.
Caution: If the radio in your
vehicle is equipped with an anti-
theft 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.
4The HT leads should be inspected one at a
time to prevent mixing up the firing order,
which is essential for proper engine operation.
5Disconnect the HT lead from the spark
plug. Do not pull on the lead itself, only on the
connector.
6Inspect inside the connector for corrosion,
which will look like a white crusty powder.
Push the HT lead and connector back onto
the end of the spark plug. It should be a tight
fit on the plug end. If it is not, remove the lead
and use pliers to carefully crimp the metal
terminal inside the connector until it fits
securely on the end of the spark plug.
7Using a clean rag, wipe the entire length of
the HT lead to remove any built-up dirt and
grease. Once the lead is clean, check for
burns, cracks and other damage. Do not bend
the lead excessively, since the conductor
might break.
8Disconnect the HT lead from the distributor.
Again, pull only on the connector. Check for
corrosion and a tight fit in the same manner as
the spark plug end. Renew the HT lead in the
distributor if necessary.
9Check the remaining spark plug HT leads,
making sure they are securely fastened at the
distributor and spark plug when the check is
complete.
10If new spark plug HT leads are required,
purchase a set for your specific engine model.
Lead sets are available pre-cut, with the
connectors already fitted. Remove and renew
the HT leads one at a time, to avoid mix-ups
in the firing order.
11Loosen the screws or detach the clips and
remove the distributor cap (see illustration).
Remove the screws (if applicable) and pull the
rotor off the shaft (see illustration). Check the
distributor cap and rotor for wear. Look for
cracks, carbon tracks and worn, burned or
loose contacts (see illustrations). Renew the
cap and rotor if defects are found. It is
common practice to fit a new cap and rotor
whenever new spark plug HT leads are fitted.
When fitting a new cap, remove the HT leads
from the old cap one at a time, and attach
1•18
15.11b Use an Allen key to remove the
screws, then lift the rotor off the shaft
(later models)15.11a On later models, loosen the screws
and detach the distributor cap up so you
can inspect the inside
14.7 Use a socket spanner with an
extension to unscrew the spark plugs14.5 When removing the spark plug HT
leads, pull only on the connector
Every 12 000 miles
Where there might be difficulty in
inserting the spark plugs into the spark
plug holes, or the possibility of cross-
threading them into the head, a short
piece of rubber or plastic tubing can be
fitted over the end of the spark plug.
The flexible tubing will act as a universal
joint to help align the plug with the plug
hole, and should the plug begin to
cross-thread, the hose will slip on the
spark plug, preventing thread damage.

7Detach the sump from the transmission and
lower it, being careful not to spill the
remaining fluid (see illustration).
8Carefully clean the sump-to-transmission
contact surface.
9Pour the fluid from the sump into a suitable
container, then clean the sump with solvent
and dry it with compressed air. Be sure to
clean any metal filings from the magnet, if
applicable.
10Remove the filter from inside the
transmission (see illustrations).
11Fit the O-ring and a new filter, being sure
to tighten the bolts securely.
12Make sure that the sump gasket contact
surfaces are clean, then fit the new gasket.
Offer the sump up to the transmission, and
refit the brackets and bolts. Working aroundthe sump, tighten each bolt a little at a time
until the torque listed in this Chapter’s Specifi-
cations is reached. Don’t overtighten the
bolts! Connect the dipstick tube, and tighten
the collar securely.
13Lower the vehicle, and add the specified
amount of fluid through the filler tube (see
Section 8).
14With the transmission in Park and the
handbrake applied, run the engine at fast idle,
but don’t race it.
15Move the gear selector through each
position, and back to Park. Check the fluid
level.
16Check under the vehicle for leaks after the
first few trips.
29 Cooling system -draining,
flushing and refilling
1
Warning: Do not allow antifreeze
to come in contact with your skin,
or with the painted surfaces of the
vehicle. Rinse off spills
immediately with plenty of water. Antifreeze
is highly toxic if ingested. Never leave
antifreeze lying around in an open container
or in puddles on the floor; children and pets
are attracted by its sweet smell, and may
drink it. Check with local authorities about
disposing of used antifreeze. Local
collection centres may exist to see that
antifreeze is disposed of safely.1Periodically, the cooling system should be
drained, flushed and refilled. This will restore
the effectiveness of the antifreeze mixture and
prevent formation of rust and corrosion, which
can impair the performance of the cooling
system and cause engine damage. When the
cooling system is serviced, all hoses and the
radiator cap should be checked and renewed
if necessary.
Draining
2If the vehicle has just been driven, wait
several hours to allow the engine to cool down
before beginning this procedure.
3Once the engine is completely cool, remove
the expansion tank cap or radiator cap. If the
cap must be removed while the engine is still
warm, unscrew it slowly, and take adequate
precautions to avoid scalding.
4Move a large container under the radiator to
catch the coolant. Where a drain plug is fitted,
unscrew it (a pair of pliers or screwdriver may
be required to turn it, depending on the
model) (see illustration). Where there is no
drain plug, it will be necessary to disconnect
the bottom hose from the radiator.
5While the coolant is draining, check the
condition of the radiator hoses, heater hoses
and clamps (see Section 21 if necessary).
6Renew any damaged clamps or hoses (see
Chapter 3 for detailed renewal procedures).
1•24
28.10c Remove the O-ring from the
transmission. If it is in good condition,
clean it and transfer it to the new fluid
filter; otherwise, renew it
28.10b . . . then remove the fluid filter from
the transmission28.10a Use a Torx key to remove the filter
bolts . . .
28.7 Lower the sump from the
transmission
28.6 Use a socket and extension to
remove the bolts and brackets28.5b Detach the tube and let the fluid
drain28.5a Unscrew the dipstick tube collar
Every 24 000 miles

Torque wrench settingsNm
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.
2A•2 In-car engine repair procedures

5On carburettor engines, remove the
complete air cleaner assembly (see Chap-
ter 4).
6Disconnect the coolant hoses from the
throttle body/intake manifold as applicable.
7Disconnect the throttle cable and, if
applicable, cruise control cable (see Chap-
ter 4).
8Remove the EGR valve and line where
applicable (see Chapter 6).
9At 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).
10On fuel injection engines, disconnect the
vacuum hose from the fuel pressure regulator,
and disconnect the electrical connectors from
the fuel injectors (see Chapter 4).
11Disconnect the fuel lines from the fuel rail
or carburettor, as applicable (see Chapter 4).
12On the M40 engine, unbolt and remove
the support bracket from the bottom of the
intake manifold (see illustration).
13Disconnect all remaining hoses and wires
attached between the intake manifold/throttle
body assembly and the engine or chassis.
14Remove 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/thermovalves, 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.
15Move the manifold up and down to break
the gasket seal, then lift it away from the head
and remove the gasket (see illustrations).
Refitting
16Remove 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.17Check 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).
18When refitting the manifold, always use a
new gasket. Where one side of the gasket has
a graphite surface, this must face the cylinder
head.
19Refit 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.
20The remainder of refitting is the reverse of
removal. On the M40 engine, renew the
gaskets between the upper and lower parts of
the manifold.
In-car engine repair procedures 2A•5
5.9c . . . and gaskets5.9b . . . and remove the upper part of the
intake manifold . . .5.9a On the M40 engine, remove the nuts
and special bolts . . .
5.15b Removing the lower intake manifold
gasket (M40 engine)5.15a Removing the lower intake manifold
(M40 engine)
5.14a Remove the intake manifold nuts
with a socket, ratchet and long extension
(M20 engine)5.12 Removing the support bracket from
the bottom of the intake manifold
(M40 engine)
5.14b Removing the lower intake manifold
nuts (M40 engine)
2A

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 anti-
theft 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.
1Disconnect the battery negative cable.
2On 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).
3Unplug the HT leads and set the spark plug
lead harness aside (see Chapter 1).
4Clearly label, then disconnect or remove, all
wires, hoses, fittings, etc. that are in the way.
Be sure to disconnect the oxygen sensor,
where fitted.
5Raise 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).
6Remove 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.
7Pull the manifold off the head, then remove
the old gaskets (see illustrations). Note:Be
very careful not to damage the oxygen sensor,
where fitted.8Clean the gasket mating surfaces of the
head and manifold, and make sure the
threads on the exhaust manifold studs are in
good condition.
9Check for corrosion, warping, cracks, and
other damage. Repair or renew the manifold
as necessary.
10When 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.
11The remaining steps are simply a reversal
of the removal 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
1Disconnect the battery negative cable.Caution: If the radio in your
vehicle is equipped with an anti-
theft 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.
2If 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).
3On the M10 engine only, remove the water
pump (see Chapter 3).
4On 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).
5On the M30 engine fitted with the
L-Jetronic fuel system, remove the
distributor from the upper timing cover (see
Chapter 5).
6Remove the valve cover (see Section 4).
7If 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).
8If you’ll be removing the lower timing chain
2A•6 In-car engine repair procedures
6.7c Removing the exhaust manifold-to-
downpipe gasket (M40 engine)6.7b Removing the exhaust manifold
gasket (M40 engine)6.7a Removing the exhaust manifold
(M40 engine)
6.5b Exhaust manifold-to-downpipe flange
(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
Remove the windscreen
washer reservoir from the
right-hand side of the engine
compartment to give more
working room.