brake rotor BMW 5 SERIES 1989 E34 Workshop Manual

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

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

1 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.

1 General information
This Part of Chapter 2 is devoted to in-
vehicle engine repair procedures. All
information concerning engine removal and
refitting and engine block and cylinder head
overhaul can be found in Chapter 2B.
The following repair procedures are based
on the assumption that the engine is still fitted
in the vehicle. If the engine has been removed
from the vehicle and mounted on a stand,
many of the steps outlined in this Part of
Chapter 2 will not apply.
The Specifications included in this Part of
Chapter 2 apply only to the procedures
contained in this Part. Chapter 2B contains
the Specifications necessary for cylinder head
and engine block rebuilding.
The single overhead camshaft four- and
six-cylinder engines covered in this manual
are very similar in design. Where there are
differences, they will be pointed out.
The means by which the overhead
camshaft is driven varies according to engine
type; M10 and M30 engines use a timing
chain, while M20 and M40 engines have a
timing belt.
2 Repair operations possible
with the engine in the vehicle
Many major repair operations can be
accomplished without removing the engine
from the vehicle.
Clean the engine compartment and the
exterior of the engine with some type of
degreaser before any work is done. It will
make the job easier, and help keep dirt out of
the internal areas of the engine.
Depending on the components involved, it
may be helpful to remove the bonnet to
improve access to the engine as repairs are
performed (see Chapter 11 if necessary).
Cover the wings to prevent damage to the
paint. Special pads are available, but an old
bedspread or blanket will also work.
If vacuum, exhaust, oil or coolant leaks
develop, indicating a need for gasket or seal
renewal, the repairs can generally be made
with the engine in the vehicle. The intake and
exhaust manifold gaskets, sump gasket,
crankshaft oil seals and cylinder head gasket
are all accessible with the engine in place.
Exterior components, such as the intake
and exhaust manifolds, the sump, the oil
pump, the water pump, the starter motor, the
alternator, the distributor and the fuel system
components, can be removed for repair with
the engine in place.
The cylinder head can be removed without
removing the engine, so this procedure is
covered in this Part of Chapter 2. Camshaft,
rocker arm and valve component servicing ismost easily accomplished with the cylinder
head removed; these procedures are covered
in Part B of this Chapter. Note, however, that
the camshaft on the M40 engine may be
removed with the engine in the vehicle since it
is retained by bearing caps.
In extreme cases caused by a lack of
necessary equipment, repair or renewal of
piston rings, pistons, connecting rods and
big-end bearings is possible with the engine in
the vehicle. However, this practice is not
recommended, because of the cleaning and
preparation work that must be done to the
components involved.
3 Top Dead Centre (TDC) for
No 1 piston- locating
2
Note 1:The following procedure is based on
the assumption that the distributor (if
applicable) is correctly fitted. If you are trying
to locate TDC to refit the distributor correctly,
piston position must be determined by feeling
for compression at the No 1 spark plug hole,
then aligning the ignition timing marks or
inserting the timing tool in the flywheel, as
applicable.
Note 2:The No 1 cylinder is the one closest to
the radiator.
1Top Dead Centre (TDC) is the highest point
in the cylinder that each piston reaches as it
travels up and down when the crankshaft
turns. Each piston reaches TDC on the
compression stroke and again on the exhaust
stroke, but TDC generally refers to piston
position on the compression stroke.
2Positioning the piston at TDC is an essential
part of many procedures, such as timing belt
or chain removal and distributor removal.
3Before beginning this procedure, be sure to
place the transmission in Neutral, and apply
the handbrake or chock the rear wheels. Also,
disable the ignition system by detaching the
coil wire from the centre terminal of the
distributor cap, and earthing it on the engine
block with a jumper wire. Remove the spark
plugs (see Chapter 1).
4In order to bring any piston to TDC, the
crankshaft must be turned using one of the
methods outlined below. When looking at the
front of the engine, normal crankshaft rotation
is clockwise.
(a) The preferred method is to turn the
crankshaft with a socket and ratchet
attached to the bolt threaded into the
front of the crankshaft.
(b) A remote starter switch, which may save
some time, can also be used. Follow the
instructions included with the switch.
Once the piston is close to TDC, use a
socket and ratchet as described in the
previous paragraph.
(c) If an assistant is available to turn the
ignition switch to the Start position in
short bursts, you can get the piston close
to TDC without a remote starter switch.Make sure your assistant is out of the
vehicle, away from the ignition switch,
then use a socket and ratchet as
described in (a) to complete the
procedure.
5Note the position of the terminal for the
No 1 spark plug lead on the distributor cap. If
the terminal isn’t marked, follow the plug lead
from the No 1 cylinder spark plug to the cap
(No 1 cylinder is nearest the radiator).
6Use a felt-tip pen or chalk to make a mark
directly below the No 1 terminal on the
distributor body or timing cover.
7Detach the distributor cap, and set it aside
(see Chapter 1 if necessary).
8Turn the crankshaft (see paragraph 4
above) until the timing marks (located at the
front of the engine) are aligned (see
illustration). The M40 engine does not have
any timing marks at the front of the engine,
but instead has a timing hole in the flywheel
which must be aligned with a hole in the rear
flange of the cylinder block. On this engine,
turn the crankshaft until the distributor rotor is
approaching the No 1 TDC position, then
continue to turn the crankshaft until a suitable
close-fitting drill can be inserted through the
hole in the cylinder block and into the
flywheel.
9Look at the distributor rotor - it should be
pointing directly at the mark you made on the
distributor body or timing cover.
10If the rotor is 180 degrees out, the No 1
piston is at TDC on the exhaust stroke.
11To get the piston to TDC on the
compression stroke, turn the crankshaft one
complete turn (360°) clockwise. The rotor
should now be pointing at the mark on the
distributor or timing cover. When the rotor is
pointing at the No 1 spark plug lead terminal
in the distributor cap and the ignition timing
marks are aligned, the No 1 piston is at TDC
on the compression stroke. Note:If it’s
impossible to align the ignition timing marks
when the rotor is pointing at the mark, the
timing belt or chain may have jumped the
teeth on the sprockets, or may have been
fitted incorrectly.
In-car engine repair procedures 2A•3
3.8 Align the notch in the pulley with the
notch on the timing plate, then check to
see if the distributor rotor is pointing to the
No 1 cylinder (if not, the camshaft is 180
degrees out - the crankshaft will have to
be rotated 360 degrees)
2A

Engine difficult to start, or fails to start (when cold)
Probable cause Corrective action
Cold start injector or thermotime switch
faulty (early Motronic system only) Test cold start injector and thermotime switch. Renew faulty components (see Section 19)
Fuel pump not running Check fuel pump fuse and fuel pump relay (see Sections 2 and 3)
Airflow meter flap (door) binding, or
stuck in open position Inspect the airflow meter for damage (see Section 16)
Fuel pressure incorrect Test system pressure (see Section 3)
Intake air leaks Inspect all vacuum lines, air ducts and oil filler and dipstick seals
Fuel injectors clogged or not operating Check fuel injectors (see Section 20) and wiring harness
Coolant temperature sensor faulty or Test coolant temperature sensor (see Chapter 6, Section 4)
wiring problem
TPS (throttle position sensor) incorrectly adjusted Check TPS adjustment (see Chapter 6, Section 4)
Dirt or other contaminants in fuel Check the fuel and drain the tank if necessary
Faulty ECU Have the ECU tested at a dealer service department or other specialist
Crankshaft position signal missing Faulty position sensor or flywheel, or reference pin missing (see Chapter 5)
Engine difficult to start, or fails to start (when warm)
Probable cause Corrective action
Cold start injector leaking or operating
continuously (early Motronic system only) Test cold start injector and thermotime switch (see Section 19)
Fuel pressure incorrect Test fuel pressure (see Section 3)
Insufficient residual fuel pressure Test fuel system hold pressure (see Section 3)
Fuel leak(s) Inspect fuel lines and fuel injectors for leaks. Correct leaks as necessary
Coolant temperature sensor faulty
or wiring problem Test coolant temperature sensor (see Chapter 6, Section 4)
Vapour lock (in warm weather) Check fuel pressure (see Section 3)
EVAP system faulty Check EVAP system (see Chapter 6, Section 6)
Faulty ECU Have the ECU tested at a dealer service department or other specialist
Idle speed control system faulty Test the idle air stabiliser valve (see Section 21)
Oxygen sensor faulty (where applicable) Check the oxygen sensor (see Chapter 6, Section 4)
Engine misses and hesitates under load
Probable cause Corrective action
Fuel injector clogged Test fuel injectors. Check for clogged injector lines. Renew faulty injectors (see Section 20)
Fuel pressure incorrect Test fuel system pressure (see Section 3). Test fuel pressure regulator (see Section 18)
Fuel leak(s) Inspect fuel lines and fuel injectors for leaks (see Chapter 4)
Engine maintenance Tune-up engine (see Chapter 1). Check the distributor cap, rotor, HT leads and spark
plugs, and renew any faulty components
Airflow meter flap (door) binding, or Inspect the airflow meter for damage (see Section 16)
stuck in open position
Intake air leaks Inspect all vacuum lines, air ducts, and oil filler and dipstick seals
Throttle position sensor (TPS) incorrectly adjusted Check TPS adjustment (see Chapter 6)
Engine idles too fast
Probable cause Corrective action
Accelerator pedal, cable or throttle valve binding Check for worn or broken components, kinked cable, or other damage. Renew faulty
components
Air leaking past throttle valve Inspect throttle valve, and adjust or renew as required
Engine has erratic idle speed
Probable cause Corrective action
Idle air stabiliser valve faulty Check the idle air stabiliser valve (see Section 21)
No power to the idle air stabiliser valve Check the idle air stabiliser relay and wiring circuit (see Chapter 12)
Idle speed control unit faulty Have the idle speed control unit checked by a dealer
Poor fuel economy
Probable cause Corrective action
Cold start injector leaking
(early Motronic system only) Test and, if necessary, renew cold start injector (see Section 19)
Oxygen sensor faulty (where applicable) Test the oxygen sensor (see Chapter 6, Section 4))
Sticking handbrake/binding brakes Check the handbrake/braking system (see Chapter 9)
Tyre pressures low Check tyre pressures (Chapter 1)
4•22 Fuel and exhaust systems

7 Ignition timing (TCI system)-
check and adjustment
4
Warning: Keep hands, equipment
and wires well clear of the
viscous cooling fan during
adjustment of the ignition timing.
Note:This Section describes the procedure
for checking and adjusting the ignition timing
on engines fitted with the TCI system. On
engines fitted with the Motronic engine
management system, the ignition timing is
controlled by the electronic control unit, and
no adjustment is possible. The timing can be
checked using the following procedure, but no
ignition timing values were available at the
time of writing. If the timing is thought to be
incorrect, refer to a BMW dealer.
1Some special tools are required for this
procedure (see illustration). The engine must
be at normal operating temperature, and the
air conditioning (where fitted) must be
switched off. Make sure the idle speed is
correct.
2Apply the handbrake, and chock the wheels
to prevent movement of the vehicle. The
transmission must be in neutral (manual) or
Park (automatic).
3The timing marks are located on the engine
flywheel (viewed through the timing checkhole in the bellhousing) and/or on the vibration
damper on the front of the engine.
4Where applicable, disconnect the vacuum
hose from the distributor vacuum advance
unit.
5Connect a tachometer and timing light
according to the equipment manufacturer’s
instructions (an inductive pick-up timing light
is preferred). Generally, the power leads for
the timing light are attached to the battery
terminals, and the pick-up lead is attached to
the No 1 spark plug HT lead. The No 1 spark
plug is the one at the front of the engine.
Caution: If an inductive pick-up
timing light isn’t available, don’t
puncture the spark plug HT lead
to attach the timing light pick-up
lead. Instead, use an adapter between the
spark plug and HT lead. If the insulation on
the HT lead is damaged, the secondary
voltage will jump to earth at the damaged
point, and the engine will misfire.
Note:On some models, a TDC transmitter is
fitted for checking the ignition system.
However, a special BMW tester must be
connected to the diagnostic socket to use it,
so unless the special tester is available, a
conventional timing light should be used. The
ignition timing mark may be on the vibration
damper, but if not, normally the TDC mark will
be. If the timing light is of the adjustable delay
type, then the ignition timing may be
determined by zeroing the adjustment, then
turning the adjustment until the TDC marks are
aligned, and then reading off the amount of
advance from the timing light. If a standard
timing light is being used, make a mark on the
vibration damper in accordance with the
specified advance, using the following formula
to calculate the distance from the TDC mark
to the timing mark:
Distance = 2Pr x advance
360
where P = 3.142
r = radius of vibration damper
advance = specified advance
BTDC in degrees
6With the ignition off, loosen the distributor
clamp nut just enough to allow the distributor
to pivot without any slipping.7Make sure the timing light wires are routed
away from the drivebelts and fan, then start
the engine.
8Raise the engine rpm to the specified
speed, and then point the flashing timing light
at the timing marks - be very careful of moving
engine components.
9The mark on the flywheel or vibration
damper will appear stationary. If it’s aligned
with the specified point on the bellhousing or
engine front cover, the ignition timing is
correct (see illustrations).
10If the marks aren’t aligned, adjustment is
required. Turn the distributor very slowly until
the marks are aligned, taking care not to
touch the HT leads.
11Tighten the nut on the distributor clamp,
and recheck the timing.
12Switch off the engine, and remove the
timing light and tachometer. Reconnect the
vacuum hose where applicable.
8 Distributor-
removal and refitting
4
TCI system
Removal
1After carefully marking them for position,
remove the coil HT lead and spark plug HT
leads from the distributor cap (see Chapter 1).
2Remove No 1 spark plug (the one nearest
you when you are standing in front of the
engine).
3Manually rotate the engine to Top Dead
Centre (TDC) on the compression stroke for
No 1 piston (see Chapter 2A)
4Carefully mark the vacuum hoses, if more
than one is present on your distributor.
5Disconnect the vacuum hose(s).
6Disconnect the primary circuit wires from
the distributor.
7Mark the relationship of the rotor tip to the
distributor housing (see illustration). Also
mark the relationship of the distributor
housing to the engine.
5•4 Engine electrical systems
7.1 Tools for checking and adjusting the
ignition timing
1Vacuum plugs- Vacuum hoses will, in
most cases, have to be disconnected and
plugged. Moulded plugs in various shapes
and sizes can be used for this, if wished
2Inductive pick-up timing light- Flashes a
bright, concentrated beam of light when
No 1 spark plug fires. Connect the leads
according to the instructions supplied with
the light
3Distributor spanner - On some models,
the hold-down bolt for the distributor is
difficult to reach and turn with conventional
spanners or sockets. A special spanner like
this must be used
7.9a Flywheel “OT” timing mark 7.9b Flywheel “OZ” timing mark

REF•11
REF
Fault Finding
Engine misses at idle speed
m mSpark plugs worn or incorrectly-gapped (Chapter 1).
m mFaulty spark plug HT leads (Chapter 1).
m mVacuum leaks (Chapter 1).
m mIncorrect ignition timing (Chapter 5).
m mUneven or low compression (Chapter 2).
m mFaulty charcoal canister, where fitted (Chapter 6).
Engine misses throughout driving speed range
m
mFuel filter clogged and/or impurities in the fuel system (Chapter 1).
m mLow fuel output at the injectors, or partially-blocked carburettor
jets (Chapter 4).
m mFaulty or incorrectly-gapped spark plugs (Chapter 1).
m mIncorrect ignition timing (Chapter 5).
m mCracked distributor cap, disconnected distributor HT leads, or
damaged distributor components (Chapter 1).
m mFaulty spark plug HT leads (Chapter 1).
m mFaulty emission system components (Chapter 6).
m mLow or uneven cylinder compression pressures (Chapter 2).
m mWeak or faulty ignition system (Chapter 5).
m mVacuum leak in fuel injection system, intake manifold or vacuum
hoses (Chapter 4).
Engine misfires on acceleration
m mSpark plugs fouled (Chapter 1).
m mFuel injection system or carburettor malfunctioning (Chapter 4).
m mFuel filter clogged (Chapters 1 and 4).
m mIncorrect ignition timing (Chapter 5).
m mIntake manifold air leak (Chapter 4).
Engine surges while holding accelerator steady
m
mIntake air leak (Chapter 4).
m mFuel pump faulty (Chapter 4).
m mLoose fuel injector harness connections (Chapters 4 and 6).
m mDefective ECU (Chapter 5).
Engine lacks power
m
mIncorrect ignition timing (Chapter 5).
m mExcessive play in distributor shaft (Chapter 5).
m mWorn rotor, distributor cap or HT leads (Chapters 1 and 5).
m mFaulty or incorrectly-gapped spark plugs (Chapter 1).
m mFuel injection system or carburettor malfunctioning (Chapter 4).
m mFaulty coil (Chapter 5).
m mBrakes binding (Chapter 1).
m mAutomatic transmission fluid level incorrect (Chapter 1).
m mClutch slipping (Chapter 8).
m mFuel filter clogged and/or impurities in the fuel system (Chapter 1).
m mEmission control system not functioning properly (Chapter 6).
m mLow or uneven cylinder compression pressures (Chapter 2).
Engine stalls
m
mIdle speed incorrect (Chapter 1).
m mFuel filter clogged and/or water and impurities in the fuel system
(Chapter 1).
m mDistributor components damp or damaged (Chapter 5).
m mFaulty emissions system components (Chapter 6).
m mFaulty or incorrectly-gapped spark plugs (Chapter 1).
m mFaulty spark plug HT leads (Chapter 1).
m mVacuum leak in the fuel injection system, intake manifold or
vacuum hoses (Chapter 4).
Engine backfires
m mEmissions system not functioning properly (Chapter 6).
m mIgnition timing incorrect (Chapter 5).
m mFaulty secondary ignition system (cracked spark plug insulator,
faulty plug HT leads, distributor cap and/or rotor) (Chapters 1 and 5).
m mFuel injection system or carburettor malfunctioning (Chapter 4).
m mVacuum leak at fuel injector(s), intake manifold or vacuum hoses
(Chapter 4).
m mValve clearances incorrect (Chapter 1), or valve(s) sticking or
damaged (Chapter 2).
Pinking or knocking engine sounds when
accelerating or driving uphill
m mIncorrect grade of fuel.
m mIgnition timing incorrect (Chapter 5).
m mFuel injection system or carburettor in need of adjustment (Chap-
ter 4).
m mDamaged spark plugs or HT leads, or incorrect type fitted (Chapter 1).
m mWorn or damaged distributor components (Chapter 5).
m mFaulty emission system (Chapter 6).
m mVacuum leak (Chapter 4).
Engine runs with oil pressure light on
Caution: Stop the engine immediately if the oil
pressure light comes on and establish the cause.
Running the engine while the oil pressure is low can
cause severe damage.
m mLow oil level (Chapter 1).
m mIdle speed too low (Chapter 1).
m mShort-circuit in wiring (Chapter 12).
m mFaulty oil pressure sender unit (Chapter 2).
m mWorn engine bearings and/or oil pump (Chapter 2).
Engine runs-on after switching off
m
mIdle speed too high (Chapter 1).
m mExcessive engine operating temperature (Chapter 3).
m mIncorrect fuel octane grade.
m mSpark plugs defective or incorrect grade (Chapter 1).
Engine electrical system
Battery will not hold charge
m
mAlternator drivebelt defective or not adjusted properly (Chapter 1).
m mElectrolyte level low (Chapter 1).
m mBattery terminals loose or corroded (Chapter 1).
m mAlternator not charging properly (Chapter 5).
m mLoose, broken or faulty wiring in the charging circuit (Chapter 5).
m mShort in vehicle wiring (Chapters 5 and 12).
m mInternally-defective battery (Chapters 1 and 5).
m mIgnition (no-charge) warning light bulb blown - on some early
models (Chapter 5)
Ignition (no-charge) warning light fails to go out
m mFaulty alternator or charging circuit (Chapter 5).
m mAlternator drivebelt defective or out of adjustment (Chapter 1).
m mAlternator voltage regulator inoperative (Chapter 5).
Ignition (no-charge) warning light fails to come on
when key is turned
m mWarning light bulb defective (Chapter 12).
m mFault in the printed circuit, wiring or bulbholder (Chapter 12).

REF•22Glossary of Technical Terms
EEGR valveA valve used to introduce exhaust
gases into the intake air stream.
Electronic control unit (ECU)A computer
which controls (for instance) ignition and fuel
injection systems, or an anti-lock braking
system. For more information refer to the
Haynes Automotive Electrical and Electronic
Systems Manual.
Electronic Fuel Injection (EFI)A computer
controlled fuel system that distributes fuel
through an injector located in each intake port
of the engine.
Emergency brakeA braking system,
independent of the main hydraulic system,
that can be used to slow or stop the vehicle if
the primary brakes fail, or to hold the vehicle
stationary even though the brake pedal isn’t
depressed. It usually consists of a hand lever
that actuates either front or rear brakes
mechanically through a series of cables and
linkages. Also known as a handbrake or
parking brake.
EndfloatThe amount of lengthwise
movement between two parts. As applied to a
crankshaft, the distance that the crankshaft
can move forward and back in the cylinder
block.
Engine management system (EMS)A
computer controlled system which manages
the fuel injection and the ignition systems in
an integrated fashion.
Exhaust manifoldA part with several
passages through which exhaust gases leave
the engine combustion chambers and enter
the exhaust pipe.
FFan clutchA viscous (fluid) drive coupling
device which permits variable engine fan
speeds in relation to engine speeds.Feeler bladeA thin strip or blade of hardened
steel, ground to an exact thickness, used to
check or measure clearances between parts.
Firing orderThe order in which the engine
cylinders fire, or deliver their power strokes,
beginning with the number one cylinder.
Flywheel A heavy spinning wheel in which
energy is absorbed and stored by means of
momentum. On cars, the flywheel is attached
to the crankshaft to smooth out firing
impulses.
Free playThe amount of travel before any
action takes place. The “looseness” in a
linkage, or an assembly of parts, between the
initial application of force and actual
movement. For example, the distance the
brake pedal moves before the pistons in the
master cylinder are actuated.
FuseAn electrical device which protects a
circuit against accidental overload. The typical
fuse contains a soft piece of metal which is
calibrated to melt at a predetermined current
flow (expressed as amps) and break the
circuit.
Fusible linkA circuit protection device
consisting of a conductor surrounded by
heat-resistant insulation. The conductor is
smaller than the wire it protects, so it acts as
the weakest link in the circuit. Unlike a blown
fuse, a failed fusible link must frequently be
cut from the wire for replacement.
GGapThe distance the spark must travel in
jumping from the centre electrode to the sideelectrode in a spark plug. Also refers to the
spacing between the points in a contact
breaker assembly in a conventional points-
type ignition, or to the distance between the
reluctor or rotor and the pickup coil in an
electronic ignition.
GasketAny thin, soft material - usually cork,
cardboard, asbestos or soft metal - installed
between two metal surfaces to ensure a good
seal. For instance, the cylinder head gasket
seals the joint between the block and the
cylinder head.
GaugeAn instrument panel display used to
monitor engine conditions. A gauge with a
movable pointer on a dial or a fixed scale is an
analogue gauge. A gauge with a numerical
readout is called a digital gauge.
HHalfshaftA rotating shaft that transmits
power from the final drive unit to a drive
wheel, usually when referring to a live rear
axle.
Harmonic balancerA device designed to
reduce torsion or twisting vibration in the
crankshaft. May be incorporated in the
crankshaft pulley. Also known as a vibration
damper.
HoneAn abrasive tool for correcting small
irregularities or differences in diameter in an
engine cylinder, brake cylinder, etc.
Hydraulic tappetA tappet that utilises
hydraulic pressure from the engine’s
lubrication system to maintain zero clearance
(constant contact with both camshaft and
valve stem). Automatically adjusts to variation
in valve stem length. Hydraulic tappets also
reduce valve noise.
IIgnition timingThe moment at which the
spark plug fires, usually expressed in the
number of crankshaft degrees before the
piston reaches the top of its stroke.
Inlet manifoldA tube or housing with
passages through which flows the air-fuel
mixture (carburettor vehicles and vehicles with
throttle body injection) or air only (port fuel-
injected vehicles) to the port openings in the
cylinder head.
Exhaust manifold
Feeler blade
Adjusting spark plug gap
Gasket
EGR valve

REF•23
REF
Glossary of Technical Terms
JJump startStarting the engine of a vehicle
with a discharged or weak battery by
attaching jump leads from the weak battery to
a charged or helper battery.
LLoad Sensing Proportioning Valve (LSPV)A
brake hydraulic system control valve that
works like a proportioning valve, but also
takes into consideration the amount of weight
carried by the rear axle.
LocknutA nut used to lock an adjustment
nut, or other threaded component, in place.
For example, a locknut is employed to keep
the adjusting nut on the rocker arm in
position.
LockwasherA form of washer designed to
prevent an attaching nut from working loose.
MMacPherson strutA type of front
suspension system devised by Earle
MacPherson at Ford of England. In its original
form, a simple lateral link with the anti-roll bar
creates the lower control arm. A long strut - an
integral coil spring and shock absorber - is
mounted between the body and the steering
knuckle. Many modern so-called MacPherson
strut systems use a conventional lower A-arm
and don’t rely on the anti-roll bar for location.
MultimeterAn electrical test instrument with
the capability to measure voltage, current and
resistance.
NNOxOxides of Nitrogen. A common toxic
pollutant emitted by petrol and diesel engines
at higher temperatures.
OOhmThe unit of electrical resistance. One
volt applied to a resistance of one ohm will
produce a current of one amp.
OhmmeterAn instrument for measuring
electrical resistance.
O-ringA type of sealing ring made of a
special rubber-like material; in use, the O-ring
is compressed into a groove to provide the
sealing action.Overhead cam (ohc) engineAn engine with
the camshaft(s) located on top of the cylinder
head(s).
Overhead valve (ohv) engineAn engine with
the valves located in the cylinder head, but
with the camshaft located in the engine block.
Oxygen sensorA device installed in the
engine exhaust manifold, which senses the
oxygen content in the exhaust and converts
this information into an electric current. Also
called a Lambda sensor.
PPhillips screwA type of screw head having a
cross instead of a slot for a corresponding
type of screwdriver.
PlastigageA thin strip of plastic thread,
available in different sizes, used for measuring
clearances. For example, a strip of Plastigage
is laid across a bearing journal. The parts are
assembled and dismantled; the width of the
crushed strip indicates the clearance between
journal and bearing.
Propeller shaftThe long hollow tube with
universal joints at both ends that carries
power from the transmission to the differential
on front-engined rear wheel drive vehicles.
Proportioning valveA hydraulic control
valve which limits the amount of pressure to
the rear brakes during panic stops to prevent
wheel lock-up.
RRack-and-pinion steeringA steering system
with a pinion gear on the end of the steering
shaft that mates with a rack (think of a geared
wheel opened up and laid flat). When the
steering wheel is turned, the pinion turns,
moving the rack to the left or right. This
movement is transmitted through the track
rods to the steering arms at the wheels.
RadiatorA liquid-to-air heat transfer device
designed to reduce the temperature of the
coolant in an internal combustion engine
cooling system.
RefrigerantAny substance used as a heat
transfer agent in an air-conditioning system.
R-12 has been the principle refrigerant for
many years; recently, however, manufacturers
have begun using R-134a, a non-CFC
substance that is considered less harmful tothe ozone in the upper atmosphere.
Rocker armA lever arm that rocks on a shaft
or pivots on a stud. In an overhead valve
engine, the rocker arm converts the upward
movement of the pushrod into a downward
movement to open a valve.
RotorIn a distributor, the rotating device
inside the cap that connects the centre
electrode and the outer terminals as it turns,
distributing the high voltage from the coil
secondary winding to the proper spark plug.
Also, that part of an alternator which rotates
inside the stator. Also, the rotating assembly
of a turbocharger, including the compressor
wheel, shaft and turbine wheel.
RunoutThe amount of wobble (in-and-out
movement) of a gear or wheel as it’s rotated.
The amount a shaft rotates “out-of-true.” The
out-of-round condition of a rotating part.
SSealantA liquid or paste used to prevent
leakage at a joint. Sometimes used in
conjunction with a gasket.
Sealed beam lampAn older headlight design
which integrates the reflector, lens and
filaments into a hermetically-sealed one-piece
unit. When a filament burns out or the lens
cracks, the entire unit is simply replaced.
Serpentine drivebeltA single, long, wide
accessory drivebelt that’s used on some
newer vehicles to drive all the accessories,
instead of a series of smaller, shorter belts.
Serpentine drivebelts are usually tensioned by
an automatic tensioner.
ShimThin spacer, commonly used to adjust
the clearance or relative positions between
two parts. For example, shims inserted into or
under bucket tappets control valve
clearances. Clearance is adjusted by
changing the thickness of the shim.
Slide hammerA special puller that screws
into or hooks onto a component such as a
shaft or bearing; a heavy sliding handle on the
shaft bottoms against the end of the shaft to
knock the component free.
SprocketA tooth or projection on the
periphery of a wheel, shaped to engage with a
chain or drivebelt. Commonly used to refer to
the sprocket wheel itself.
Starter inhibitor switchOn vehicles with an
O-ring
Serpentine drivebelt
Plastigage