heater BMW 3 SERIES 1988 E30 Workshop Manual

0•9Roadside Repairs
When jump-starting a car using a
booster battery, observe the following
precautions:
4Before connecting the booster
battery, make sure that the ignition is
switched off.
4Ensure that all electrical equipment
(lights, heater, wipers, etc) is
switched off.
4Make sure that the booster battery is
the same voltage as the discharged
one in the vehicle.
4If the battery is being jump-started
from the battery in another vehicle,
the two vehcles MUST NOT TOUCH
each other.
4Make sure that the transmission is in
neutral (or PARK, in the case of
automatic transmission).
Jump starting will get you out
of trouble, but you must correct
whatever made the battery go
flat in the first place. There are
three possibilities:
1The battery has been drained by
repeated attempts to start, or by
leaving the lights on.
2The charging system is not working
properly (alternator drivebelt slack
or broken, alternator wiring fault or
alternator itself faulty).
3The battery itself is at fault
(electrolyte low, or battery worn out).
Connect one end of the red jump lead to
the positive (+) terminal of the flat
batteryConnect the other end of the red lead to
the positive (+) terminal of the booster
battery.Connect one end of the black jump lead
to the negative (-) terminal of the
booster battery
Connect the other end of the black
jump lead to a bolt or bracket on the
engine block, well away from the
battery, on the vehicle to be started.
123
4
Make sure that the jump leads will not
come into contact with the fan, drive-
belts or other moving parts of the
engine.5
Start the engine using the booster
battery, then with the engine running at
idle speed, disconnect the jump leads in
the reverse order of connection.6
Jump starting

drag when the feeler gauge is moved back
and forth.
6If the gap is too large or too small, loosen
the locknut, insert a hook made from large-
diameter metal wire, and rotate the eccentric
to obtain the correct gap (see illustration).
7Once the gap has been set, hold the
eccentric in position with the hook, and
retighten the locknut securely. Recheck the
clearance - sometimes it’ll change slightly
when the locknut is tightened. If so, re-adjust
until it’s correct.
8On the M10 engine, the valves are adjusted
in the firing order, which is 1-3-4-2. After
adjusting No 1 cylinder valves, rotate the
crankshaft half a turn (180º), then check and
adjust the valves on No 3 cylinder. Repeat the
procedure on the remaining cylinders.
9On M20 and M30 engines, the valves are
adjusted following the firing order, which is
1-5-3-6-2-4. After adjusting No 1 cylinder
valves, rotate the crankshaft a third of a turn
(120º), then check and adjust the valves on No
5 cylinder. Repeat the procedure for the
remaining cylinders.
10Refit the valve cover (use a new gasket)
and tighten the mounting nuts evenly and
securely.
11Start the engine and check for oil leakage
between the valve cover and the cylinder
head.19 Throttle linkage -
check and lubrication
1
1The throttle linkage should be checked and
lubricated periodically to ensure its proper
operation.
2Check the linkage to make sure it isn’t
binding.
3Inspect the linkage joints for looseness, and
the connections for corrosion and damage,
renewing parts as necessary (see
illustration).
4Lubricate the connections with spray
lubricant or lithium-based grease.
20 Air filter renewal
1
Carburettor engines
1Release the spring clips, then unscrew the
centre nut and lift off the cover.
2Remove the air filter element, and wipe
clean the air cleaner body and cover
3Fit the new air filter element, then refit the
cover using a reversal of the removal
procedure.
Fuel injection engines
4Loosen the clamp on the air intake duct,
and detach the duct (see illustration).5Release the air cleaner cover retaining clips
(see illustration).
6Rotate the cover up, lift it off and lift the
element out, noting which way round it is
fitted (see illustrations).
7Wipe the inside of the air cleaner housing
with a clean cloth, then fit the new element. If
the element is marked TOP, be sure the
marked side faces up.
8Refit the cover and secure the clips.
9Connect the air duct and tighten the clamp
screw.
21 Fuel system check
1
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. 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. Work in a well-
ventilated area. 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. Mop
up spills immediately, but do not store
fuel-soaked rags where they could ignite.
1If you smell fuel while driving or after the
vehicle has been sitting in the sun, inspect the
fuel system immediately.
2Remove the fuel filler cap and inspect it for
damage and corrosion. The gasket should
have an unbroken sealing imprint. If the
gasket is damaged or corroded, fit a new cap.
3Inspect the fuel feed and return lines for
cracks. Make sure that the connections
between the fuel lines and the carburettor or
fuel injection system, and between the fuel
lines and the in-line fuel filter, are tight.
Warning: On fuel injection
models, the fuel system must be
depressurised before servicing
fuel system components, as
outlined in Chapter 4.
1•20
20.6b . . . and lift the air filter
element out20.6a Rotate the cover
upwards . . .
20.5 Use a screwdriver to detach the air
cleaner cover clips20.4 Detach the duct from the air cleaner
housing19.3 Check and lubricate the throttle
linkage at the points shown (arrowed) -
fuel injection engine shown
Every 12 000 miles

4Since some components of the fuel system
- the fuel tank and some of the fuel feed and
return lines, for example - are underneath the
vehicle, they can be inspected more easily
with the vehicle raised on a hoist. If that’s not
possible, raise the vehicle and support it on
axle stands or ramps.
5With the vehicle raised and safely
supported, inspect the fuel tank and filler neck
for punctures, cracks or other damage. The
connection between the filler neck and the
tank is particularly critical. Sometimes a
rubber filler neck will leak because of loose
clamps or deteriorated rubber. Inspect all fuel
tank mounting brackets and straps, to be sure
the tank is securely attached to the vehicle.
Warning: Do not, under any
circumstances, try to repair a fuel
tank (except rubber
components). A welding torch or
any naked flame can easily cause fuel
vapours inside the tank to explode.
6Carefully check all flexible hoses and metal
lines leading away from the fuel tank. Check
for loose connections, deteriorated hoses,
crimped lines, and other damage. Repair or
renew damaged sections as necessary (see
Chapter 4).
22 Cooling system check
1
1Many major engine failures can be
attributed to cooling system problems. If the
vehicle has automatic transmission, the
engine cooling system also plays an importantrole in prolonging transmission life, because it
cools the transmission fluid.
2The engine should be cold for the cooling
system check, so perform the following
procedure before the vehicle is driven for the
day, or after it has been switched off for at
leastthree hours.
3Remove the radiator cap, doing so slowly
and taking adequate precautions against
scalding if the engine is at all warm. Clean the
cap thoroughly, inside and out, with clean
water. Also clean the filler neck on the
radiator. The presence of rust or corrosion in
the filler neck means the coolant should be
changed (see Section 29). The coolant inside
the radiator should be relatively clean and
clear. If it’s rust-coloured, drain the system
and refill with new coolant.
4Carefully check the radiator hoses and the
smaller-diameter heater hoses. Inspect each
coolant hose along its entire length, renewing
any hose which is cracked, swollen or
deteriorated (see illustration). Cracks will
show up better if the hose is squeezed. Pay
close attention to hose clamps that secure the
hoses to cooling system components. Hose
clamps can pinch and puncture hoses,
resulting in coolant leaks.
5Make sure all hose connections are tight. A
leak in the cooling system will usually show up
as white or rust-coloured deposits on the area
adjoining the leak. If wire-type clamps are
used on the hoses, it may be a good idea to
replace them with screw-type clamps.
6Clean the front of the radiator (and, where
applicable, the air conditioning condenser)
with compressed air if available, or a soft
brush. Remove all flies, leaves, etc,
embedded in the radiator fins. Be extremely
careful not to damage the cooling fins or to
cut your fingers on them.
7If the coolant level has been dropping
consistently and no leaks are detected, have
the radiator cap and cooling system pressure-
tested.
23 Exhaust system check
1
1The engine should be cold for this check,
so perform the following procedure before the
vehicle is driven for the day, or after it has
been switched off for at leastthree hours.
Check the complete exhaust system from the
engine to the end of the tailpipe. Ideally, the
inspection should be done with the vehicle on
a hoist, to give unrestricted access. If a hoist
isn’t available, raise the vehicle and support it
securely on axle stands or ramps.
2Check the exhaust pipes and connections
for evidence of leaks, severe corrosion, and
damage. Make sure that all brackets and
mountings are in good condition, and that
they are tight (see illustration).
3At the same time, inspect the underside of
the body for holes, corrosion, open seams,etc. which may allow exhaust gases to enter
the passenger compartment. Seal all body
openings with suitable sealant.
4Rattles and other noises can often be
traced to the exhaust system, especially the
mountings and heat shields. Try to move the
pipes, silencers (and, where applicable, the
catalytic converter). If the components can
come in contact with the body or suspension
parts, re-hang the exhaust system with new
mountings.
5The running condition of the engine may be
checked by inspecting inside the end of the
tailpipe. The exhaust deposits here are an
indication of the engine’s state of tune. If the
pipe is black and sooty, the engine may be
running too rich, indicating the need for a
thorough fuel system inspection.
24 Steering and suspension
check
1
Note: The steering linkage and suspension
components should be checked periodically.
Worn or damaged suspension and steering
linkage components can result in excessive
and abnormal tyre wear, poor ride quality and
vehicle handling, and reduced fuel economy.
For detailed illustrations of the steering and
suspension components, refer to Chapter 10.
Strut/shock absorber check
1Park the vehicle on level ground, turn the
engine off and apply the handbrake. Check
the tyre pressures.
2Push down at one corner of the vehicle,
then release it while noting the movement of
the body. It should stop moving and come to
rest in a level position with one or two
bounces.
3If the vehicle continues to move up and
down, or if it fails to return to its original
position, a worn or weak strut or shock
absorber is probably the reason.
4Repeat the above check at each of the
three remaining corners of the vehicle.
5Raise the vehicle and support it on axle
stands.
6Check the struts/shock absorbers for
evidence of fluid leakage. A light film of fluid is
1•21
22.4 Hoses, like drivebelts, have a habit of
failing at the worst possible time - to
prevent the inconvenience of a blown
radiator or heater hose, inspect them
carefully as shown here
23.2 Check the exhaust system rubber
mountings for cracks
1
Every 12 000 miles

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

Flushing
7Once the system is completely drained,
flush the radiator with fresh water from a
garden hose until the water runs clear at the
drain or bottom hose. If the radiator is
severely corroded, damaged or leaking, it
should be removed (see Chapter 3) and taken
to a radiator repair specialist.
8Flushing in this way will remove sediments
from the radiator, but will not remove rust and
scale from the engine and cooling tube
surfaces. These deposits can be removed by
using a chemical cleaner. Follow the
procedure outlined in the cleaner
manufacturer’s instructions. Remove the
cylinder block drain plug before flushing the
engine.
9On models so equipped, remove the
overflow hose from the coolant recovery
reservoir. Drain the reservoir and flush it with
clean water, then reconnect the hose.
Refilling
10Tighten the radiator drain plug, or
reconnect the radiator bottom hose. Refit and
tighten the cylinder block drain plug.
Four-cylinder engines
11Slowly add new coolant (a 40%/60%
mixture of antifreeze to water) to the radiator
until it is full. Add coolant to the reservoir up
to the lower mark.
12Leave the radiator cap off, and run the
engine in a well-ventilated area until the
thermostat opens (coolant will begin flowing
through the radiator, and the upper radiator
hose will become hot).
13Turn the engine off, and let it cool. Add
more coolant mixture to bring the coolant
level back up to the lip on the radiator filler
neck. On the M40 engine, unscrew the bleed
screw from the top of the radiator, and add
coolant until it comes out of the bleed screw
hole. Refit and tighten the bleed screw.
14Squeeze the upper radiator hose to expel
air, then add more coolant mixture if
necessary. Refit the radiator cap.
15Start the engine, allow it to reach normal
operating temperature, and check for leaks.
Six-cylinder engines
16Loosen the bleed screw in the thermostat
housing (see illustration)
17Fill the radiator with a 40%/60% solution
of antifreeze and water until it comes out of
the bleed screw opening. Tighten the bleed
screw.
18Refit the radiator cap, and run the engine
until the thermostat opens (the upper radiator
hose will become hot). Slowly loosen the
bleed screw until no bubbles emerge, then
tighten the screw.
19Repeat the procedure until the air is bled
from the system.
30 Fuel filter renewal
1
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. 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.
1On fuel injection engines, depressurise the
fuel system (see Chapter 4).
2The fuel filter is located in the engine
compartment on the bulkhead, or under the
vehicle adjacent to the fuel tank.
3Because on some models the filter is
located adjacent to the starter motor, fuel
could leak onto the electrical connections. For
safety reasons, therefore, disconnect the
battery negative cable before beginning work.
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.
4Place a pan or rags under the fuel filter to
catch any spilled fuel. If suitable hose clamps
are available, clamp the inlet and outlet hoses.
5 Detach the hoses and remove the bracket
screws/nuts, then remove the filter and where
applicable the bracket assembly (see
illustration).
6Detach the filter from the bracket.
7Refitting is the reverse of removal. Be sure
the arrow on the filter points in the direction of
fuel flow.
31 Manual transmission
lubricant change
1
1Tools necessary for this job include axle
stands to support the vehicle in a raised
position, an Allen key to remove the drain
plug, a drain pan, newspapers and clean rags.
The correct amount of the specified lubricant
should also be available (see “Lubricants and
fluids”at the start of this Chapter).
2The lubricant should be drained when it is
hot (ie immediately after the vehicle has been
driven); this will remove any contaminants
better than if the lubricant were cold. Because
1•25
30.5 To renew the fuel filter, disconnect
the hoses (A), then unscrew the nut (B) and
detach the filter from the bracket (fuel
injection type shown)29.16 The bleed screw (arrowed) is
located on the thermostat housing (six-
cylinder models)29.4 Radiator drain plug location
(arrowed) - not fitted to all models
31.5 Use an Allen key to remove the drain
plug (arrowed) from the bottom of the
transmission
1
Every 24 000 miles

22Using a scraper, remove all traces of old
gasket material from the sealing surfaces of
the covers and engine block.
Caution: Be very careful not to
scratch or gouge the delicate
aluminium surfaces. Also, do not
damage the sump gasket, and
keep it clean. Gasket removal solvents are
available at motor factors, and may
prove helpful. After all gasket material has
been removed, the gasket surfaces
can be degreased by wiping them
with a rag dampened with a suitable
solvent.
23Support the cover on two blocks of wood,
and drive out the seals from behind with a
hammer and screwdriver. Be very careful not
to damage the seal bores in the process.
24Coat the outside diameters and lips of the
new seals with multi-purpose grease, and
drive the seals into the cover with a hammer
and a socket slightly smaller in diameter than
the outside diameter of the seal.
25Apply a film of RTV-type gasket sealant to
the surface of the sump gasket that mates
with the front cover. Apply extra beads of RTV
sealant to the edges where the gasket meets
the engine block. Note:If the sump gasket is
damaged, instead of fitting a whole new
gasket, you might try trimming the front
portion of the gasket off at the point where it
meets the engine block, then trim off the front
portion of a new sump gasket so it’s exactly
the same size. Cover the exposed inside area
of the sump with a rag, then clean all traces of
old gasket material off the area where the
gasket was removed. Attach the new gasket
piece to the sump with contact-cement-type
gasket adhesive, then apply RTV-type sealant
as described at the beginning of this
paragraph.
26Coat both sides of the new gasket with
RTV-type gasket sealant, then attach the front
cover to the front of the engine, carefully
working the seals over the crankshaft and
intermediate shaft. Refit the bolts and tighten
them evenly to the torque listed in this
Chapter’s Specifications. Work from bolt-to-
bolt in a criss-cross pattern, to be sure they’re
tightened evenly.Note 1:Tighten the front
cover-to-block bolts first, then tighten the
sump-to-cover bolts. Note 2:After applying
RTV-type sealant, reassembly must be
completed in about 10 minutes so the RTV
won’t prematurely harden.
27The remainder of refitting is the reverse of
removal.
Crankshaft front seal (M40 engines)
28Remove the timing belt and crankshaft
sprocket (see Section 10).
29Remove the Woodruff key from the
groove in the end of the crankshaft.
30Note the fitted position of the oil seal, then
prise it out from the front cover using a
screwdriver, but take care not to damage the
bore of the cover or the surface of thecrankshaft. If the seal is tight, drill two small
holes in the metal end of the seal, and use two
self-tapping screws to pull out the seal. Make
sure all remains of swarf are removed.
31Coat the outside diameter and lip of the
new seal with multi-purpose grease, then
drive it into the cover with a hammer and a
socket slightly smaller in diameter than the
outside diameter of the seal. Make sure the
seal enters squarely.
32The remainder of refitting is the reverse of
removal. Note that it is recommended that the
timing belt be renewed - see Section 10.
12 Cylinder head-
removal and refitting
5
Removal
1Relieve the fuel pressure on all fuel injection
engines (see Chapter 4).
2Disconnect the negative cable from the
battery. Where the battery is located in the
engine compartment, the battery may be
removed completely (see Chapter 5).
Caution: If the radio in your
vehicle is equipped with an 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.
3Remove the air cleaner assembly (see
Chapter 4).
4Disconnect the wiring from the distributor
(mark all wiring for position first, if necessary),
and the HT lead from the coil (see Chapter 5).
5Disconnect the lead from the coolant
temperature sender unit (see Chapter 3).
6Disconnect the fuel lines from the fuel rail or
carburettor as applicable (see Chapter 4).
7Drain the cooling system (see Chapter 3).
8Clearly label then disconnect all other
hoses from the throttle body, intake manifold,
carburettor and cylinder head, as applicable.
9Disconnect the throttle cable from the
throttle linkage or carburettor (see Chapter 4).
10Disconnect the exhaust manifold from the
cylinder head (see Section 6). Depending on
the engine type, It may not be necessary to
disconnect the manifold from the exhaust
pipe; however, on right-hand-drive models,
the steering column intermediate shaft may
not allow the manifold to clear the studs on
the cylinder head.
11Remove or disconnect any remaining
hoses or lines from the intake manifold,
including the ignition advance vacuum line(s),
and the coolant and heater hoses.
12On early carburettor models, disconnect
the wiring from the alternator and starter
motor.13Remove the intake manifold (see Sec-
tion 5). Do not dismantle or remove any fuel
injection system components unless it is
absolutely necessary.
14Remove the fan drivebelt and fan (see
Chapter 3).
15Remove the valve cover and gasket (see
Section 4). Remove the semi-circular rubber
seal from the front of the cylinder head, where
this is not incorporated in the valve cover
gasket.
16Set No 1 piston at Top Dead Centre on
the compression stroke (see Section 3).
17Remove the timing chain or belt (see
Section 8 or 10). Note:If you want to save
time by not removing and refitting the timing
belt or chain and re-timing the engine, you can
unfasten the camshaft sprocket and suspend
it out of the way - with the belt or chain still
attached - by a piece of rope. Be sure the
rope keeps firm tension on the belt or chain,
so it won’t become disengaged from any of
the sprockets.
18Loosen the cylinder head bolts a quarter-
turn at a time each, in the reverse of the
tightening sequence shown (see illustrations
12.30a, 12.30b, 12.30c or 12.30d). Do
notdismantle or remove the rocker arm
assembly at this time on M10, M20 and M30
engines.
19Remove the cylinder head by lifting it
straight up and off the engine block. Do not
prise between the cylinder head and the
engine block, as damage to the gasket sealing
surfaces may result. Instead, use a blunt bar
positioned in an intake port to gently prise the
head loose.
20Remove any remaining external
components from the head to allow for
thorough cleaning and inspection. See
Chapter 2B for cylinder head servicing
procedures. On the M40 engine, remove the
rubber O-ring from the groove in the top of the
oil pump/front end cover housing.
Refitting
21The mating surfaces of the cylinder head
and block must be perfectly clean when the
head is refitted.
22Use a gasket scraper to remove all traces
of carbon and old gasket material, then clean
the mating surfaces with a suitable solvent. If
there’s oil on the mating surfaces when the
head is refitted, the gasket may not seal
correctly, and leaks could develop. When
working on the block, stuff the cylinders with
clean rags to keep out debris. Use a vacuum
cleaner to remove material that falls into the
cylinders.
23Check the block and head mating
surfaces for nicks, deep scratches and other
damage. If the damage is slight, it can be
removed with a file; if it’s excessive,
machining may be the only alternative.
24Use a tap of the correct size to chase the
threads in the head bolt holes, then clean the
holes with compressed air - make sure that
In-car engine repair procedures 2A•13
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

3General
Coolant capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . See Chapter 1
Thermostat rating
Opening temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80°C (176°F)
Fully open at . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100°C (212°F)
Cooling fan thermo-switch - switching temperatures
Low-speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91°C (196°F)
High-speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99°C (210°F)
Torque wrench settingsNm
Mechanical cooling fan clutch-to-water pump securing
nut (left-hand thread) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Mechanical cooling fan-to-clutch bolts . . . . . . . . . . . . . . . . . . . . . . . . . 10
Water pump bolts
Small bolts (M6) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Large bolts (M8) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Thermostat housing bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Chapter 3
Cooling, heating and air conditioning systems
Air conditioner receiver-drier - removal and refitting . . . . . . . . . . . . 16
Air conditioning blower motor (E28/”old-shape” 5-series
models) - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Air conditioning compressor - removal and refitting . . . . . . . . . . . . . 13
Air conditioning condenser - removal and refitting . . . . . . . . . . . . . . 15
Air conditioning system - precautions and maintenance . . . . . . . . . 12
Antifreeze - general information . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Coolant level check . . . . . . . . . . . . . . . . . . . . . . . . . . See Chapter 1
Coolant temperature sender unit - check and renewal . . . . . . . . . . . 8
Cooling system check . . . . . . . . . . . . . . . . . . . . . . . . See Chapter 1
Cooling system servicing (draining, flushing and refilling)See Chapter 1Engine cooling fan(s) and clutch - check, removal and refitting . . . . 5
Evaporator matrix - removal and refitting . . . . . . . . . . . . . . . . . . . . . 17
General information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Heater and air conditioner control assembly - removal and refitting 10
Heater and air conditioning blower motor - removal,testing and
refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Heater matrix - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . 11
Radiator - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Thermostat - check and renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Water pump - check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Water pump - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . 7
3•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
1 General information
Engine cooling system
All vehicles covered by this manual employ
a pressurised engine cooling system, with
thermostatically-controlled coolant circulation.
An impeller-type water pump mounted on
the front of the block pumps coolant through
the engine. The coolant flows around each
cylinder, and towards the rear of the engine.
Cast-in coolant passages direct coolantaround the intake and exhaust ports, near the
spark plug areas, and in close proximity to the
exhaust valve guides.
A wax-pellet-type thermostat is located in-
line in the bottom hose on M10 engines, in a
housing near the front of the engine on M20
and M30 engines, or behind an elbow under
the timing belt upper cover (on the front of the
cylinder head) on M40 engines. During warm-
up, the closed thermostat prevents coolant
from circulating through the radiator. As the
engine nears normal operating temperature,
the thermostat opens and allows hot coolant
to travel through the radiator, where it’s
cooled before returning to the engine.The pressure in the system raises the
boiling point of the coolant, and increases the
cooling efficiency of the radiator. The cooling
system is sealed by a pressure-type cap. If
the system pressure exceeds the cap
pressure relief value, the excess pressure in
the system forces the spring-loaded valve
inside the cap off its seat, and allows the
coolant to escape through the overflow tube.
The pressure cap on four-cylinder models is
on the top of the radiator; on six-cylinder models,
it’s on top of a translucent plastic expansion
tank. The cap pressure rating is moulded into the
top of the cap. The pressure rating is either
1.0 bar (14 psi) or 1.2 bars (17 psi).

Warning: Do not remove the
pressure cap from the radiator or
expansion tank until the engine
has cooled completely and
there’s no pressure remaining in the
cooling system. Removing the cap from a
hot engine risks personal injury by
scalding.
Heating system
The heating system consists of a blower fan
and heater matrix located in the heater box,
with hoses connecting the heater matrix to the
engine cooling system, and the heater/air
conditioning control head on the dashboard.
Hot engine coolant is circulated through the
heater matrix passages all the time the engine
is running. Switching the heater on opens a
flap door to direct air through the heater
matrix, and the warmed air enters the
passenger compartment. A fan switch on the
control head activates the blower motor,
which forces more air through the heater
matrix, giving additional heater output for
demisting, etc.
Air conditioning system
The air conditioning system consists of a
condenser mounted in front of the radiator, an
evaporator mounted adjacent to the heater
matrix, a compressor mounted on the engine,
a filter-drier (receiver-drier) which contains a
high-pressure relief valve, and the plumbing
connecting all of the above components.
A blower fan forces the warmer air of the
passenger compartment through the
evaporator matrix (a radiator-in-reverse),
transferring the heat from the air to the
refrigerant. The liquid refrigerant boils off into
low-pressure vapour, taking the heat with it
when it leaves the evaporator.
Note: Refer to the precautions at the start
of Section 12 concerning the potential
dangers associated with the air conditioning
system.
2 Antifreeze-
general information
Warning: Do not allow antifreeze
to come in contact with your skin
or painted surfaces of the
vehicle. Rinse off spills
immediately with plenty of water. If
consumed, antifreeze can be fatal;
children and pets are attracted by its
sweet taste, so wipe up garage floor and
drip pan coolant spills immediately. Keep
antifreeze containers covered, and repair
leaks in your cooling system as soon as
they are noticed.
The cooling system should be filled with a
60/40% water/ethylene-glycol-based anti-
freeze solution, which will prevent freezing
down to approximately -27°C (-17°F). The
antifreeze also raises the boiling point of thecoolant, and (if of good quality) provides
protection against corrosion.
The cooling system should be drained,
flushed and refilled at the specified intervals
(see Chapter 1). Old or contaminated
antifreeze solutions are likely to cause
damage, and encourage the formation of rust
and scale in the system. Use distilled water
with the antifreeze, if available, or clean
rainwater. Tap water will do, but not if the
water in your area is at all “hard”.
Before adding antifreeze, check all hose
connections, because antifreeze tends to
search out and leak through very minute
openings. Engines don’t normally consume
coolant, so if the level goes down, find the
cause and correct it.
The antifreeze mixture should be
maintained at its correct proportions; adding
too much antifreeze reduces the efficiency of
the cooling system. If necessary, consult the
mixture ratio chart on the antifreeze container
before adding coolant. Hydrometers are
available at most car accessory shops to test
the coolant. Use antifreeze which meets the
vehicle manufacturer’s specifications.
3 Thermostat-
check and renewal
1
Warning: Do not remove the
radiator cap, drain the coolant, or
renew the thermostat until the
engine has cooled completely.
Check
1Before assuming the thermostat is to blame
for a cooling system problem, check the
coolant level, drivebelt tension (see Chapter 1)
and temperature gauge (or warning light)
operation.
2If the engine seems to be taking a long time
to warm up (based on heater output or
temperature gauge operation), the thermostat
is probably stuck open. Renew the
thermostat.
3If the engine runs hot, use your hand to
check the temperature of the upper radiator
hose. If the hose isn’t hot, but the engine is,
the thermostat is probably stuck closed,preventing the coolant inside the engine from
circulating to the radiator. Renew the
thermostat.
Caution: Don’t drive the vehicle
without a thermostat. The engine
will be very slow to warm-up in
cold conditions, resulting in poor
fuel economy and driveability. A new
thermostat is normally an inexpensive
component anyway.
4If the upper radiator hose is hot, it means
that the coolant is flowing and the thermostat
is at least partly open. Consult the “Fault
finding” Section at the rear of this manual for
cooling system diagnosis.
Renewal
All models
5Disconnect the negative cable from the
battery.
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.
6Drain the cooling system (see Chapter 1). If
the coolant is relatively new or in good
condition, save it and re-use it.
M10 engines
7The thermostat is located in the bottom
hose. First remove the cooling fan.
8Note the fitted position of the thermostat,
then unscrew the hose clamps and withdraw
the thermostat from the hose connections
(see illustration).
9Refit the thermostat-to-hose connections,
and tighten the hose clamps.
10Refit the cooling fan.
M20 and M30 engines
11Loosen the hose clamp (see illustration),
then detach the hose(s) from the thermostat
cover.
3•2 Cooling, heating and air conditioning systems
3.11 On M20 and M30 engine models,
loosen the hose clamp (A) and disconnect
the hose from the thermostat housing
cover - note that the coolant temperature
sender unit (barely visible behind the fuel
pressure regulator) is located at the top of
the thermostat housing (B)
3.8 On the M10 (four-cylinder) engine, the
thermostat (arrowed) is connected in-line
in the radiator hose

4If a new sender unit is to be fitted, make
sure the engine is completely cool. There will
be some coolant loss when the unit is
unscrewed, so be prepared to catch it, or
have the new unit ready to fit immediately the
old one is removed. Disconnect the wiring,
then unscrew the old unit from the engine,
and fit the new one. Use sealant on the
threads. Reconnect the wiring, and check the
coolant level on completion.
9 Heater and air conditioning
blower motor- removal,
testing and refitting
1
Removal
Note: The 3-Series models covered by this
manual have always used a single blower
motor for ventilation, heating and air
conditioning. “Old-shape” (E28) 5-Series
models use two separate blower motors: one
for ventilation and heating, and another for air
conditioning. “New-shape” (E34) 5-Series
models have a single blower motor, like the 3-
Series. The removal and refitting of the single
blower motor, and the old-shape 5-Series
vent/heat motor, is described below. The
removal and refitting of the old-shape 5-Series
air conditioning blower motor is described in
Section 14 of this Chapter.
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.
2The blower motor is located behind the
bulkhead, under an access panel. Remove the
panel securing screws (see illustrations).
3Disconnect or cut the plastic ties holding
the wiring harness to the panel, and move the
wiring out of the way.
4Remove the panel.
5Unclip the blower housing retaining clip,
and the clip securing the blower motor (see
illustrations).6Disconnect the wiring and remove the
blower motor (see illustration).
Testing
7You can test the blower motor by applying
battery voltage to the blower motor’s
terminals with fused jumper wires (be sure the
fan blades won’t hit anything when they
rotate). If the blower motor spins the fan
blades rapidly (this test simulates high-speed
operation), the blower motor is OK. If the
blower motor does not operate, or operates
slowly or noisily, renew it.
Note: If the fan blade assemblies need to be
removed, mark their relationship to the shaft.
The assemblies are balanced during
production, and excessive noise or shortened
bearing life could result if they are not refitted
in exactly the same position in relation to the
shaft.
Refitting
8Refitting is the reverse of removal. Note:
The blower motor may have to be rotated to
allow the retaining clip to line up correctly.
10 Heater and air conditioner
control assembly- removal
and refitting
1
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.
3-Series models
2Remove the centre console and side trim
pieces.
3Remove the radio (see Chapter 12), then
pull the knobs off the heater/air conditioning
control levers.
4Remove the heater trim panel to gain
access to the control cables.
5Disconnect the cables, marking them for
accurate refitting.
6Disconnect the electrical connector.
7Remove the lever assembly.
8Each lever assembly can be removed
separately.
5-Series models
9Remove the centre console (see Chap-
ter 11).
10Remove the radio (see Chapter 12), then
pull the knobs off the heater/air conditioning
control levers.
11Remove the trim bezel, and pull the
control unit from the dash. This will allow you
to disconnect the control cables from the
lever assembly.
Cooling, heating and air conditioning systems 3•7
9.5a Unclip the retaining strap to remove
the blower housing . . .
9.2b . . . a fastener from the top secure the
panel9.2a To get to the heater blower motor,
the access panel must be removed - a
fastener from the front and . . .
9.6 Lift out the assembly, and disconnect
the electrical connection from the blower
motor9.5b . . . and unclip the centre strap that
secures the blower motor assembly
3