1989 BMW 3 SERIES mon

Refitting
7Refitting is the reverse of removal. Tighten
the nuts and bolts securely. Adjust the
drivebelt tension (see Chapter 1).
8Top-up the fluid level in the reservoir (see
Chapter 1) and bleed the system (see Sec-
tion 23).
23 Power steering system-
bleeding
1
1To bleed the power steering system, begin
by checking the power steering fluid level and
adding fluid if necessary (see Chapter 1).
2Raise and support the front of the vehicle
on axle stands.
3Turn the steering wheel from lock-to-lock
several times. Recheck the fluid level and top
up if necessary.
4Start the engine and run it at 1000 rpm or
less. Turn the steering wheel from lock-to-
lock again (three or four times) and recheck
the fluid level one more time. Note:On 5-Series E28 (“old-shape”) models, pump the
brake pedal five or six times before turning the
steering wheel. Once the fluid level remains
constant, continue turning the wheel back and
forth until no more bubbles appear in the fluid
in the reservoir.
5Lower the vehicle to the ground. Run the
engine and again turn the wheels from lock-
to-lock several more times. Recheck the fluid
level. Position the wheels straight-ahead.24 Steering wheel-
removal and refitting
1
Warning: If the vehicle is
equipped with an airbag, do not
attempt this procedure. Have it
performed by a dealer service
department or other qualified specialist, as
there is a risk of injury if the airbag is
accidentally triggered.
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.
Removal
1Disconnect the battery negative cable.
2Using a small screwdriver, prise off the
BMW emblem in the centre of the steering
wheel.
3Remove the steering wheel nut, and mark
the relationship of the steering wheel hub to
the shaft (see illustration).
4On all 3-Series models, and on 1986 and
later 5-Series models, turn the ignition key to
the first position to unlock the ignition lock.
5Remove the steering wheel from thesteering shaft. If the wheel is difficult to
remove from the shaft, use a steering wheel
puller to remove it - don’t hammer on the
shaft.
Refitting
6Refitting is the reverse of removal. Be sure
to align the match marks you made on the
steering wheel and the shaft. Tighten the
steering wheel nut to the torque listed in this
Chapter’s Specifications.
25 Wheels and tyres-
general information
1
Note:For more information on care and
maintenance of tyres, refer to Chapter 1.
1All vehicles covered by this manual are
equipped with steel-belted radial tyres as
original equipment. Use of other types or
sizes of tyres may affect the ride and handling
of the vehicle. Don’t mix different types or
sizes of tyres, as the handling and braking
may be seriously affected. It’s recommended
that tyres be renewed in pairs on the same
axle; if only one new tyre is being fitted, be
sure it’s the same size, structure and tread
design as the other.
2Because tyre pressure has a substantial
effect on handling and wear, the pressure on
all tyres should be checked at least once a
month or before any extended trips (see
Chapter 1).
3Wheels must be renewed if they are bent,
heavily dented, leak air, or are otherwise
damaged.
4Tyre and wheel balance is important in the
overall handling, braking and performance of
the vehicle. Unbalanced wheels can adversely
affect handling and ride characteristics, as
well as tyre life. Whenever a new tyre is fitted,
the tyre and wheel should be balanced.
10•16 Suspension and steering systems
24.3 After removing the steering wheel
nut, mark the relationship of the steering
wheel to the steering shaft (arrowed) to
ensure proper alignment during
reassembly
22.6c Typical 5-Series power steering pump mounting bolts
(arrowed)22.6b . . . and mounting nut and bolt (arrowed)

11
1 General information
These models feature an all-steel welded
construction, where the floorpan and body
components are welded together and
attached to separate front and rear subframe
assemblies. Certain components are
particularly vulnerable to accident damage,
and can be unbolted and repaired or renewed.
Among these parts are the body mouldings,
bumpers, bonnet, doors, tailgate, and all
glass.
Only general body maintenance procedures
and body panel repair procedures within the
scope of the do-it-yourselfer are included in
this Chapter.
2 Bodywork and underframe-
maintenance
1
The general condition of a vehicle’s
bodywork is the one thing that significantly
affects its value. Maintenance is easy, but
needs to be regular. Neglect, particularly after
minor damage, can lead quickly to further
deterioration and costly repair bills. It is
important also to keep watch on those parts
of the vehicle not immediately visible, for
instance the underside, inside all the wheelarches, and the lower part of the engine
compartment.
The basic maintenance routine for the
bodywork is washing - preferably with a lot of
water, from a hose. This will remove all the
loose solids which may have stuck to the
vehicle. It is important to flush these off in
such a way as to prevent grit from scratching
the finish. The wheel arches and underframe
need washing in the same way, to remove any
accumulated mud, which will retain moisture
and tend to encourage rust. Paradoxically
enough, the best time to clean the underframe
and wheel arches is in wet weather, when the
mud is thoroughly wet and soft. In very wet
weather, the underframe is usually cleaned of
large accumulations automatically, and this is
a good time for inspection.
Periodically, except on vehicles with a wax-
based underbody protective coating, it is a
good idea to have the whole of the
underframe of the vehicle steam-cleaned,
engine compartment included, so that a
thorough inspection can be carried out to see
what minor repairs and renovations are
necessary. Steam-cleaning is available at
many garages, and is necessary for the
removal of the accumulation of oily grime,
which sometimes is allowed to become thick
in certain areas. If steam-cleaning facilities are
not available, there are some excellent grease
solvents available which can be brush-
applied; the dirt can then be simply hosed off.
Note that these methods should not be usedon vehicles with wax-based underbody
protective coating, or the coating will be
removed. Such vehicles should be inspected
annually, preferably just prior to Winter, when
the underbody should be washed down, and
any damage to the wax coating repaired.
Ideally, a completely fresh coat should be
applied. It would also be worth considering
the use of such wax-based protection for
injection into door panels, sills, box sections,
etc, as an additional safeguard against rust
damage, where such protection is not
provided by the vehicle manufacturer.
After washing paintwork, wipe off with a
chamois leather to give an unspotted clear
finish. A coat of clear protective wax polish will
give added protection against chemical
pollutants in the air. If the paintwork sheen has
dulled or oxidised, use a cleaner/polisher
combination to restore the brilliance of the
shine. This requires a little effort, but such
dulling is usually caused because regular
washing has been neglected. Care needs to be
taken with metallic paintwork, as special non-
abrasive cleaner/polisher is required to avoid
damage to the finish. Always check that the
door and ventilator opening drain holes and
pipes are completely clear, so that water can
be drained out. Brightwork should be treated in
the same way as paintwork. Windscreens and
windows can be kept clear of the smeary film
which often appears, by the use of proprietary
glass cleaner. Never use any form of wax or
other body or chromium polish on glass.
Chapter 11 Bodywork and fittings
Bodywork and underframe - maintenance . . . . . . . . . . . . . . . . . . . . 2
Bodywork repair - major damage . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Bodywork repair - minor damage . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Bonnet - removal, refitting and adjustment . . . . . . . . . . . . . . . . . . . . 10
Boot lid/tailgate - removal, refitting and adjustment . . . . . . . . . . . . . 14
Bumpers - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Door - removal, refitting and adjustment . . . . . . . . . . . . . . . . . . . . . 13
Door trim panel - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . 12
Door window glass - removal and refitting . . . . . . . . . . . . . . . . . . . . 16
Door window regulator - removal and refitting . . . . . . . . . . . . . . . . . 17
Exterior mirror - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . 18Fixed glass - renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
General information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Hinges and locks - maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Interior trim - maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Latch, lock cylinder and handles - removal, refitting and
adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Radiator grille - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . 9
Seat belt check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Seats - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Steering column shrouds - removal and refitting . . . . . . . . . . . . . . . 19
Upholstery and carpets - maintenance . . . . . . . . . . . . . . . . . . . . . . . 4
11•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 Contents

7 Hinges and locks-
maintenance
1
Every six months or so, the hinges and lock
assemblies on the doors, bonnet and the boot
lid/tailgate should be given a few drops of
light oil or lock lubricant. The door or tailgate
lock strikers should also be lubricated with a
thin coat of grease, to reduce wear and
ensure free movement.
8 Fixed glass- renewal
5
Renewal of the windscreen and fixed glass
requires the use of special fast-setting
adhesive materials, and some specialised
tools and techniques. These operations
should be left to a dealer service department
or windscreen specialist.
9 Radiator grille-
removal and refitting
1
3-Series
1Detach the clips along the top of the grille
(see illustration).2Remove the screws, and lift the centre and
side grilles out (see illustrations).
3Refitting is the reverse of removal.
5-Series
E28 (“old-shape”) models
6Remove the screws, and detach the centre
and side grille pieces.
7Refitting is the reverse of removal.
E34 (“new-shape”) models
Centre grille
8Remove the screws and detach the
headlight covers in the engine compartment
for access.
9Remove the screw, and lift out the plastic
cover behind the centre grille for access to the
clips.
10From the engine compartment, reach
under the headlight housings and detach the
clips retaining the centre grille valances, then
push the grille forwards (see illustration).
11Use a screwdriver to depress the clips,
detach the grille assembly and remove it by
pulling it straight out.
12Refit the centre grille by placing it in
position and pushing it straight back until it
clips into place.
Side grille
13Remove the centre grille.
14Remove the screws, and lift the side grille
assembly out (see illustration).
15Refitting is the reverse of removal.
10 Bonnet- removal, refitting and
adjustment
1
Note: The bonnet is heavy and somewhat
awkward to remove and refit - at least two
people should perform this procedure.
Removal and refitting
3-Series models
1Open the bonnet. Scribe or draw alignment
marks around the bolt heads to ensure proper
alignment on refitting (see illustration).
2Disconnect the earth cable and windscreen
washer hose from the bonnet.
3Detach the bonnet hinge rod clip and
11•4 Bodywork and fittings
10.3a Use needle-nose pliers to pull off
the hinge pin clip . . .
10.1 Use paint or a marking pen to mark
on the hinge plate around the bolt heads -
mark around the entire hinge plate, if
desired, before adjusting the bonnet
9.14 Remove the screws and pull the side
grille assembly straight out
9.10 Detach the centre grille valance by
reaching under each headlight and
pressing on the release lever
9.2b Side grille screw locations (arrowed)9.2a The centre grille is held in place by
two screws (arrowed)9.1 Open the bonnet and remove the grille
retaining clips (arrowed)

13 Headlights- adjustment
2
Note:The headlights must be aimed correctly.
If adjusted incorrectly, they could momentarily
blind the driver of an oncoming vehicle and
cause a serious accident, or seriously reduce
your ability to see the road. The headlights
should be checked for proper aim every
12 months (as is done during the MOT test),
and any time a new headlight is fitted or front-
end body work is performed. It should be
emphasised that the following procedure will
only provide a temporary setting until the
headlights can be adjusted by a properly-
equipped garage.
1Each headlight has two adjusting screws,
one controlling up-and-down movement and
one controlling left-and-right movement (see
illustration). It may be necessary to remove
the grille (see Chapter 11) for access to these
screws.
2There are several methods of adjusting the
headlights. The simplest method requires a
blank wall (or garage door) 25 feet in front of
the vehicle, and a level floor.
3Position masking tape vertically on the wall,
to mark the vehicle centreline and the
centreline of both headlights. Note:It may be
easier to position the tape on the wall with the
vehicle parked only a few inches away, and
then move the vehicle back the required
distance when all marks have been made.
4Make a horizontal line on the wall to mark
the centreline of all headlights.
5Move the vehicle back so that it is 25 feet
away from the marked wall (keep the front end
of the vehicle square to the wall). Adjustment
should be made with the vehicle sitting level,
the fuel tank half-full, and with no unusually
heavy loads in the vehicle.
6Switch on the dipped beam. The bright
spots on the wall should be two inches below
the horizontal line, and two inches to the left
of the headlight vertical lines. Adjustment is
made by turning the adjusting screw to raise
or lower the beam. The other adjusting screwshould be used in the same manner to move
the beam left or right.
7With main beam on, the bright spots on the
wall should be exactly on the vertical lines,
and just below the horizontal line. Note:It may
not be possible to position the headlight aim
exactly for both main and dipped beams. If a
compromise must be made, keep in mind that
the dipped beam is most used, and will have
the greatest effect on driver safety.
8Have the headlights adjusted by a dealer
service department or qualified garage at the
earliest opportunity.
14 Headlight housing-
removal and refitting
1
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, Refer to
the information on page 0-7 at the front of
this manual before detaching the cable.
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.
Removal
1Disconnect the battery negative cable.2Remove the side grille (see Chapter 11),
then remove the rear cover(s) where
necessary.
3Unplug the headlight (sealed beam-type) or
remove the bulb (halogen bulb-type).
4Remove the screws and detach the housing
(see illustration).
Refitting
5Refitting is the reverse of removal.
15 Bulb renewal
1
1The lenses of many lights are held in place
by screws, which makes it a simple procedure
to gain access to the bulbs.
2On some lights, the lenses are held in place
by clips. The lenses can be removed by using
a small screwdriver to prise them off.
3Several bulbs are mounted in self-earthing
holders, and are removed by pushing in and
turning them anti-clockwise (see illustration).
The bulbs can then be removed (see
illustrations).
4The tail lights on 3-Series models are
accessible after removing the housing, then
removing the bulbs (see illustrations).
5To gain access to the facia lights, the
instrument cluster will have to be removed
first (see illustration).
12•6 Body electrical systems
15.3c . . . then pull the bulb from the
holder15.3b On models with high-mounted
centre brake lights, the self-earthing
holder is accessible from the luggage area
- pull the holder out . . .15.3a The tail light bulbs on later 5-Series
models are in self-earthing holders which
can be simply pulled out of the housing -
the bulb is then removed from the holder
14.4 Remove the screws (arrowed) and
detach the headlight housing13.1 The headlight adjustment screws
(arrowed) are accessible from the back of
the headlight on 3-Series models

12Refitting is a reversal of removal. When
fitting the motor, if necessary plug in the
connector and run the motor briefly until it is
in the “neutral” (wiper parked) position.
17 Heated rear window-
check and repair
2
1The heated rear window consists of a
number of horizontal elements on the glass
surface.
2Small breaks in the element can be repaired
without removing the rear window.
Check
3Switch on the ignition and the heated rear
window.
4Place the positive lead of a voltmeter to the
heater element nearest to the incoming power
source.
5Wrap a piece of aluminium foil around the
negative lead of the voltmeter on the positive
side of the suspected broken element, and
slide it slowly towards the negative side.
Watch the voltmeter needle - when it moves
from zero, you have located the break.
Repair
6Repair the break in the line using a repair kit
recommended specifically for this purpose,
such as BMW repair kit No. 81 22 9 (or
equivalent). Included in this kit is plastic
conductive epoxy. The following paragraphs
give general instructions for this type of repair;
follow the instructions supplied with the repair
kit if they are different.
7Prior to repairing a break, switch off the
circuit and allow it to cool down for a few
minutes.
8Lightly buff the element area with fine steel
wool, then clean it thoroughly.
9Use masking tape to mask off the area of
repair, leaving a slit to which the epoxy can be
applied.
10Mix the epoxy thoroughly, according to
the instructions on the package.
11Apply the epoxy material to the slit in the
masking tape, overlapping the undamaged
area about 20 mm on each end.12Allow the repair to cure for 24 hours
before removing the tape and using the
heated rear window.
18 Supplemental Restraint
System (SRS)- general
information
Later models are equipped with a
Supplemental Restraint System (SRS),
incorporating an airbag. This system is
designed to protect the driver from serious
injury in the event of a head-on or frontal
collision. It consists of an airbag module in the
centre of the steering wheel, two crash
sensors mounted on the front inner wing
panels, and a crash safety switch located
inside the passenger compartment.
The airbag module contains a housing
incorporating the airbag and the inflator units.
The inflator assembly is mounted on the back
of the housing over a hole through which gas
is expelled, inflating the bag almost instanta-
neously when an electrical signal is sent from
the system. This signal is carried by a wire
which is specially wound with several turns,
so the signal will be transmitted regardless of
the steering wheel position.
The SRS system has three sensors: two at
the front, mounted on the inner wing panels
(see illustration), and a safety switch located
inside the passenger compartment. The crash
sensors are basically pressure-sensitive
switches, which complete an electrical circuit
during an impact of sufficient force. The
electrical signal from the crash sensors is sent
to a third sensor, which then completes the
circuit and inflates the airbag.
The module containing the safety switch
monitors the system operation. It checks the
system every time the vehicle is started,
causing the AIRBAG warning light to come on,
then go out if the system is operating
correctly. If there is a fault in the system, the
light will stay on. If the AIRBAG warning light
does stay on, or if it comes on while driving,
take the vehicle to your dealer immediately.
19 Cruise control system-
description and check
1
The cruise control system maintains vehicle
speed using a vacuum-actuated servo motor
located in the engine compartment, which is
connected to the throttle linkage by a cable.
The system consists of the servo motor,
clutch switch, brake switch, control switches,
a relay, and associated vacuum hoses.
Because of the complexity of the cruise
control system, repair should be left to a
dealer service department. However, it is
possible for the home mechanic to make
simple checks of the wiring and vacuum
connections for minor faults which can be
easily repaired. These include:
a) Inspect the cruise control actuating switches
for broken wires and loose connections.
b) Check the cruise control fuse.
c) The cruise control system is operated by
vacuum, so it’s critical that all vacuum
switches, hoses and connections are
secure. Check the hoses in the engine
compartment for loose connections,
cracks, or obvious vacuum leaks.
20 Central locking system-
description and check
2
The central door locking system operates
the door lock actuators mounted in each
door. The system consists of the switches,
actuators and associated wiring. Diagnosis is
limited to simple checks of the wiring
connections and actuators for minor faults
which can be easily repaired. These include:
a) Check the system fuse and/or circuit
breaker (where applicable).
b) Check the switch wires for damage and
loose connections. Check the switches
for continuity.
c) Remove the door trim panel(s), and check
the actuator wiring connections to see if
they’re loose or damaged. Inspect the
actuator rods to make sure they aren’t
12•8 Body electrical systems
18.3 The SRS system crash sensors
(arrowed) are located in the engine
compartment - check the wiring regularly
for damage16.11b Tailgate wiper motor (5-Series)16.11c Wiper blade and pivot mechanism
on the rear window (5-Series)

BK Black
BL Blue
BR BrownGE Yellow
GN Green
GR Green or GreyGY Grey
OR Orange
PK PinkR Red
RS Pink
RT RedSW Black
TN Tan
V VioletVI Violet
W WhiteWS White
Y Yellow
Body electrical systems 12•9
12
Colour codes bent or damaged. The actuator can be
checked by applying battery power
momentarily. A discernible click indicates
that the solenoid is operating properly.
21 Electric window system-
description and check
2
The electric window system operates the
electric motors mounted in the doors which
lower and raise the windows. The system
consists of the control switches, the motors,
window mechanisms (regulators) andassociated wiring. Removal of the motors and
regulators is described in Chapter 11.
Diagnosis is usually limited to simple
checks of the wiring connections and motors
for minor faults which can be easily repaired.
These include:
a) Check the electric window switches for
broken wires and loose connections.
b) Check the electric window fuse/and or
circuit breaker (where applicable).
c) Remove the door trim panel(s) and check
the electric window motor wires to see if
they’re loose or damaged. Inspect the
window mechanisms for damage which
could cause binding.
22 Wiring diagrams-
general information
Since it isn’t possible to include all wiring
diagrams for every model year covered by this
manual, the following diagrams are those that
are typical and most commonly needed.
Prior to checking any circuit, check the
fuses and circuit breakers to make sure they’re
in good condition. Make sure the battery is
fully charged and check the cable connections
(see Chapter 1). Make sure all connectors are
clean, with no broken or loose terminals.

REF•4MOT Test Checks
MExamine the handbrake mechanism,
checking for frayed or broken cables,
excessive corrosion, or wear or insecurity of
the linkage. Check that the mechanism works
on each relevant wheel, and releases fully,
without binding.
MIt is not possible to test brake efficiency
without special equipment, but a road test can
be carried out later to check that the vehicle
pulls up in a straight line.
Fuel and exhaust systems
MInspect the fuel tank (including the filler
cap), fuel pipes, hoses and unions. All
components must be secure and free from
leaks.
MExamine the exhaust system over its entire
length, checking for any damaged, broken or
missing mountings, security of the retaining
clamps and rust or corrosion.
Wheels and tyres
MExamine the sidewalls and tread area of
each tyre in turn. Check for cuts, tears, lumps,
bulges, separation of the tread, and exposure
of the ply or cord due to wear or damage.
Check that the tyre bead is correctly seated
on the wheel rim, that the valve is sound andproperly seated, and that the wheel is not
distorted or damaged.
MCheck that the tyres are of the correct size
for the vehicle, that they are of the same size
and type on each axle, and that the pressures
are correct.
MCheck the tyre tread depth. The legal
minimum at the time of writing is 1.6 mm over
at least three-quarters of the tread width.
Abnormal tread wear may indicate incorrect
front wheel alignment.
Body corrosion
MCheck the condition of the entire vehicle
structure for signs of corrosion in load-bearing
areas. (These include chassis box sections,
side sills, cross-members, pillars, and all
suspension, steering, braking system and
seat belt mountings and anchorages.) Any
corrosion which has seriously reduced the
thickness of a load-bearing area is likely to
cause the vehicle to fail. In this case
professional repairs are likely to be needed.
MDamage or corrosion which causes sharp
or otherwise dangerous edges to be exposed
will also cause the vehicle to fail.
Petrol models
MHave the engine at normal operating
temperature, and make sure that it is in good
tune (ignition system in good order, air filter
element clean, etc).
MBefore any measurements are carried out,
raise the engine speed to around 2500 rpm,
and hold it at this speed for 20 seconds. Allowthe engine speed to return to idle, and watch
for smoke emissions from the exhaust
tailpipe. If the idle speed is obviously much
too high, or if dense blue or clearly-visible
black smoke comes from the tailpipe for more
than 5 seconds, the vehicle will fail. As a rule
of thumb, blue smoke signifies oil being burnt
(engine wear) while black smoke signifies
unburnt fuel (dirty air cleaner element, or other
carburettor or fuel system fault).
MAn exhaust gas analyser capable of
measuring carbon monoxide (CO) and
hydrocarbons (HC) is now needed. If such an
instrument cannot be hired or borrowed, a
local garage may agree to perform the check
for a small fee.
CO emissions (mixture)
MAt the time of writing, the maximum CO
level at idle is 3.5% for vehicles first used after
August 1986 and 4.5% for older vehicles.
From January 1996 a much tighter limit
(around 0.5%) applies to catalyst-equipped
vehicles first used from August 1992. If the
CO level cannot be reduced far enough to
pass the test (and the fuel and ignition
systems are otherwise in good condition) then
the carburettor is badly worn, or there is some
problem in the fuel injection system or
catalytic converter (as applicable).
HC emissionsMWith the CO emissions within limits, HC
emissions must be no more than 1200 ppm
(parts per million). If the vehicle fails this test
at idle, it can be re-tested at around 2000 rpm;
if the HC level is then 1200 ppm or less, this
counts as a pass.
MExcessive HC emissions can be caused by
oil being burnt, but they are more likely to be
due to unburnt fuel.
Diesel models
MThe only emission test applicable to Diesel
engines is the measuring of exhaust smoke
density. The test involves accelerating the
engine several times to its maximum
unloaded speed.
Note: It is of the utmost importance that the
engine timing belt is in good condition before
the test is carried out.
M
Excessive smoke can be caused by a dirty
air cleaner element. Otherwise, professional
advice may be needed to find the cause.
4Checks carried out on
YOUR VEHICLE’S EXHAUST
EMISSION SYSTEM

REF•8General Repair Procedures
Whenever servicing, repair or overhaul work
is carried out on the car or its components,
observe the following procedures and
instructions. This will assist in carrying out the
operation efficiently and to a professional
standard of workmanship.
Joint mating faces and gaskets
When separating components at their
mating faces, never insert screwdrivers or
similar implements into the joint between the
faces in order to prise them apart. This can
cause severe damage which results in oil
leaks, coolant leaks, etc upon reassembly.
Separation is usually achieved by tapping
along the joint with a soft-faced hammer in
order to break the seal. However, note that
this method may not be suitable where
dowels are used for component location.
Where a gasket is used between the mating
faces of two components, a new one must be
fitted on reassembly; fit it dry unless otherwise
stated in the repair procedure. Make sure that
the mating faces are clean and dry, with all
traces of old gasket removed. When cleaning a
joint face, use a tool which is unlikely to score
or damage the face, and remove any burrs or
nicks with an oilstone or fine file.
Make sure that tapped holes are cleaned
with a pipe cleaner, and keep them free of
jointing compound, if this is being used,
unless specifically instructed otherwise.
Ensure that all orifices, channels or pipes
are clear, and blow through them, preferably
using compressed air.
Oil seals
Oil seals can be removed by levering them
out with a wide flat-bladed screwdriver or
similar implement. Alternatively, a number of
self-tapping screws may be screwed into the
seal, and these used as a purchase for pliers or
some similar device in order to pull the seal free.
Whenever an oil seal is removed from its
working location, either individually or as part
of an assembly, it should be renewed.
The very fine sealing lip of the seal is easily
damaged, and will not seal if the surface it
contacts is not completely clean and free from
scratches, nicks or grooves. If the original
sealing surface of the component cannot be
restored, and the manufacturer has not made
provision for slight relocation of the seal
relative to the sealing surface, the component
should be renewed.
Protect the lips of the seal from any surface
which may damage them in the course of
fitting. Use tape or a conical sleeve where
possible. Lubricate the seal lips with oil before
fitting and, on dual-lipped seals, fill the space
between the lips with grease.
Unless otherwise stated, oil seals must be
fitted with their sealing lips toward the
lubricant to be sealed.
Use a tubular drift or block of wood of the
appropriate size to install the seal and, if the
seal housing is shouldered, drive the seal
down to the shoulder. If the seal housing isunshouldered, the seal should be fitted with
its face flush with the housing top face (unless
otherwise instructed).
Screw threads and fastenings
Seized nuts, bolts and screws are quite a
common occurrence where corrosion has set
in, and the use of penetrating oil or releasing
fluid will often overcome this problem if the
offending item is soaked for a while before
attempting to release it. The use of an impact
driver may also provide a means of releasing
such stubborn fastening devices, when used
in conjunction with the appropriate
screwdriver bit or socket. If none of these
methods works, it may be necessary to resort
to the careful application of heat, or the use of
a hacksaw or nut splitter device.
Studs are usually removed by locking two
nuts together on the threaded part, and then
using a spanner on the lower nut to unscrew
the stud. Studs or bolts which have broken off
below the surface of the component in which
they are mounted can sometimes be removed
using a stud extractor. Always ensure that a
blind tapped hole is completely free from oil,
grease, water or other fluid before installing
the bolt or stud. Failure to do this could cause
the housing to crack due to the hydraulic
action of the bolt or stud as it is screwed in.
When tightening a castellated nut to accept
a split pin, tighten the nut to the specified
torque, where applicable, and then tighten
further to the next split pin hole. Never slacken
the nut to align the split pin hole, unless stated
in the repair procedure.
When checking or retightening a nut or bolt
to a specified torque setting, slacken the nut
or bolt by a quarter of a turn, and then
retighten to the specified setting. However,
this should not be attempted where angular
tightening has been used.
For some screw fastenings, notably
cylinder head bolts or nuts, torque wrench
settings are no longer specified for the latter
stages of tightening, “angle-tightening” being
called up instead. Typically, a fairly low torque
wrench setting will be applied to the
bolts/nuts in the correct sequence, followed
by one or more stages of tightening through
specified angles.
Locknuts, locktabs and washers
Any fastening which will rotate against a
component or housing during tightening
should always have a washer between it and
the relevant component or housing.
Spring or split washers should always be
renewed when they are used to lock a critical
component such as a big-end bearing
retaining bolt or nut. Locktabs which are
folded over to retain a nut or bolt should
always be renewed.
Self-locking nuts can be re-used in non-
critical areas, providing resistance can be felt
when the locking portion passes over the bolt
or stud thread. However, it should be noted
that self-locking stiffnuts tend to lose theireffectiveness after long periods of use, and
should then be renewed as a matter of course.
Split pins must always be replaced with
new ones of the correct size for the hole.
When thread-locking compound is found
on the threads of a fastener which is to be re-
used, it should be cleaned off with a wire
brush and solvent, and fresh compound
applied on reassembly.
Special tools
Some repair procedures in this manual
entail the use of special tools such as a press,
two or three-legged pullers, spring com-
pressors, etc. Wherever possible, suitable
readily-available alternatives to the manu-
facturer’s special tools are described, and are
shown in use. In some instances, where no
alternative is possible, it has been necessary
to resort to the use of a manufacturer’s tool,
and this has been done for reasons of safety
as well as the efficient completion of the repair
operation. Unless you are highly-skilled and
have a thorough understanding of the
procedures described, never attempt to
bypass the use of any special tool when the
procedure described specifies its use. Not
only is there a very great risk of personal
injury, but expensive damage could be
caused to the components involved.
Environmental considerations
When disposing of used engine oil, brake
fluid, antifreeze, etc, give due consideration to
any detrimental environmental effects. Do not,
for instance, pour any of the above liquids
down drains into the general sewage system,
or onto the ground to soak away. Many local
council refuse tips provide a facility for waste
oil disposal, as do some garages. If none of
these facilities are available, consult your local
Environmental Health Department, or the
National Rivers Authority, for further advice.
With the universal tightening-up of legis-
lation regarding the emission of environmen-
tally-harmful substances from motor vehicles,
most vehicles have tamperproof devices fitted
to the main adjustment points of the fuel
system. These devices are primarily designed
to prevent unqualified persons from adjusting
the fuel/air mixture, with the chance of a
consequent increase in toxic emissions. If
such devices are found during servicing or
overhaul, they should, wherever possible, be
renewed or refitted in accordance with the
manufacturer’s requirements or current
legislation.
Note: It is
antisocial and
illegal to dump
oil down the
drain. To find
the location of
your local oil
recycling
bank, call this
number free.