air condition BMW 3 SERIES 1990 E30 Repair Manual

Finding a short-circuit
One method of finding a short-circuit is to
remove the fuse and connect a test light or
voltmeter in its place. There should be no
voltage present in the circuit. Move the
electrical connectors from side-to-side while
watching the test light. If the bulb goes on,
there is a short to earth somewhere in that
area, probably where the insulation has been
rubbed through. The same test can be
performed on each component in a circuit,
even a switch.
Earth check
Perform a earth check to see whether a
component is properly earthed (passing
current back via the vehicle body). Disconnect
the battery, and connect one lead of a self-
powered test light (often known as a
continuity tester) to a known good earth.
Connect the other lead to the wire or earth
connection being tested. The bulb should
light, indicating a good earth connection. If
not, dismantle the connection, and clean all
relevant parts thoroughly. When re-making
the connection, use serrated (shakeproof)
washers if possible, and tighten all bolts, etc,
securely.
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.
Continuity check
A continuity check determines if there are
any breaks in a circuit - if it is conducting
electricity properly. With the circuit off (no
power in the circuit), a self-powered continuity
tester can be used to check the circuit.
Connect the test leads to both ends of the
circuit, and if the test light comes on, the
circuit is passing current properly. If the light
doesn’t come on, there is a break somewhere
in the circuit. The same procedure can be
used to test a switch, by connecting the
continuity tester to the power-in and power-
out sides of the switch. With the switch turned
on, the test light should come on.
Finding an open-circuit
When diagnosing for possible open-
circuits, it is often difficult to locate them by
sight, because oxidation or terminal
misalignment are hidden by the connectors.
Intermittent problems are often caused by
oxidised or loose connections. Merely
wiggling an electrical connector may correct
the open-circuit condition, albeit temporarily.
Dismantle the connector, and spray with a
water-dispersant aerosol. On simpler
connectors, it may be possible to carefullybend the connector pins inside, to improve
the metal-to-metal contact - don’t damage
the connector in the process, however.
3 Fuses- general information
1
The electrical circuits of the vehicle are
protected by a combination of fuses and
circuit breakers. The fusebox is located in the
left corner of the engine compartment (see
illustration). On some later models, it is
located under the rear seat cushion.
Each of the fuses is designed to protect a
specific circuit, and on some models, the
various circuits are identified on the fuse
panel itself.
Miniaturised fuses are employed in the
fuseboxes. These compact fuses, with blade
terminal design, allow fingertip removal and
renewal. If an electrical component fails,
always check the fuse first. A blown fuse is
easily identified through the clear plastic
body. Visually inspect the element for
evidence of damage. If a continuity check is
called for, the blade terminal tips are exposed
in the fuse body.
Be sure to renew blown fuses with the
correct type. Fuses of different ratings are
physically interchangeable, but only fuses of
the proper rating should be used. Replacing a
fuse with one of a higher or lower value than
specified is not recommended. Each electrical
circuit needs a specific amount of protection.
The amperage value of each fuse is moulded
into the fuse body.
If the new fuse immediately fails, don’t
renew it again until the cause of the problem
is isolated and corrected. In most cases, the
cause will be a short-circuit in the wiring
caused by a broken or deteriorated wire.
4 Relays- general information
1
Several electrical accessories in the vehicle
use relays to transmit the electrical signal to
the component. If the relay is defective, thatcomponent will not operate properly. Relays
are electrically-operated switches, which are
often used in circuits drawing high levels of
current, or where more complex switching
arrangements are required.
The various relays are grouped together for
convenience in several locations under the
dash and in the engine compartment (see
accompanying illustration and illus-
tration 3.1).
If a faulty relay is suspected, it can be
removed and tested by a dealer or qualified
automotive electrician. No overhaul is
possible. Like fuses, defective relays must be
replaced with the correct type; some relays
look identical, but perform very different
functions.
5 Direction indicator/hazard
warning flasher unit- check
and renewal
2
Warning: Some later models are
equipped with an airbag or
Supplemental Restraint System
(SRS). To avoid possible damage
to this system, the manufacturer
recommends that, on airbag-equipped
models, the following procedure should be
left to a dealer service department, or
other specialist, because of the special
tools and techniques required. There is a
risk of injury if the airbag is accidentally
triggered.
1The direction indicator/hazard flasher unit is
a small canister- or box-shaped unit located
in the wiring harness on or near the steering
column. Access is gained by removing the
steering column shrouds (see illustration).
2When the flasher unit is functioning
properly, a regular clicking noise can be heard
from it when the indicators or hazard flashers
are switched on. If the direction indicators fail
on one side or the other, and the flasher unit
does not make its characteristic clicking
sound, a faulty direction indicator bulb is
indicated.
3If both direction indicators fail to blink, the
problem may be due to a blown fuse, a faulty
flasher unit, a broken switch or a loose or open
connection. If a quick check of the fusebox
12•2 Body electrical systems
4.2 Engine compartment relays3.1 The fusebox is located in the engine
compartment under a cover - the box also
includes several relays

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.

12•24 Wiring diagrams
Typical heating and air conditioning system wiring diagram

Wiring diagrams 12•25
12
Key to wiring diagram for heated seats
Key to air conditioning system wiring diagram

REF•1
REF
MOT Test Checks
This is a guide to getting your vehicle through the MOT test.
Obviously it will not be possible to examine the vehicle to the same
standard as the professional MOT tester. However, working through
the following checks will enable you to identify any problem areas
before submitting the vehicle for the test.
Where a testable component is in borderline condition, the tester
has discretion in deciding whether to pass or fail it. The basis of such
discretion is whether the tester would be happy for a close relative or
friend to use the vehicle with the component in that condition. If the
vehicle presented is clean and evidently well cared for, the tester may
be more inclined to pass a borderline component than if the vehicle is
scruffy and apparently neglected.
It has only been possible to summarise the test requirements here,
based on the regulations in force at the time of printing. Test standards
are becoming increasingly stringent, although there are some
exemptions for older vehicles. For full details obtain a copy of the Haynes
publication Pass the MOT! (available from stockists of Haynes manuals).
An assistant will be needed to help carry out some of these checks.
The checks have been sub-divided into four categories, as follows:
HandbrakeMTest the operation of the handbrake.
Excessive travel (too many clicks) indicates
incorrect brake or cable adjustment.
MCheck that the handbrake cannot be
released by tapping the lever sideways. Check
the security of the lever mountings.
Footbrake
MDepress the brake pedal and check that it
does not creep down to the floor, indicating a
master cylinder fault. Release the pedal, wait
a few seconds, then depress it again. If the
pedal travels nearly to the floor before firm
resistance is felt, brake adjustment or repair is
necessary. If the pedal feels spongy, there is
air in the hydraulic system which must be
removed by bleeding.MCheck that the brake pedal is secure and in
good condition. Check also for signs of fluid
leaks on the pedal, floor or carpets, which
would indicate failed seals in the brake master
cylinder.
MCheck the servo unit (when applicable) by
operating the brake pedal several times, then
keeping the pedal depressed and starting the
engine. As the engine starts, the pedal will
move down slightly. If not, the vacuum hose or
the servo itself may be faulty.
Steering wheel and column
MExamine the steering wheel for fractures or
looseness of the hub, spokes or rim.
MMove the steering wheel from side to side
and then up and down. Check that the
steering wheel is not loose on the column,
indicating wear or a loose retaining nut.
Continue moving the steering wheel as before,
but also turn it slightly from left to right.
MCheck that the steering wheel is not loose
on the column, and that there is no abnormalmovement of the steering wheel, indicating
wear in the column support bearings or
couplings.
Windscreen and mirrors
MThe windscreen must be free of cracks or
other significant damage within the driver’s
field of view. (Small stone chips are
acceptable.) Rear view mirrors must be
secure, intact, and capable of being adjusted.
1Checks carried out
FROM THE DRIVER’S SEAT
1Checks carried out
FROM THE DRIVER’S
SEAT2Checks carried out
WITH THE VEHICLE
ON THE GROUND3Checks carried out
WITH THE VEHICLE
RAISED AND THE
WHEELS FREE TO
TURN4Checks carried out on
YOUR VEHICLE’S
EXHAUST EMISSION
SYSTEM

REF•3
REF
MOT Test Checks
Exhaust system
MStart the engine. With your assistant
holding a rag over the tailpipe, check the
entire system for leaks. Repair or renew
leaking sections.
Jack up the front and rear of the vehicle,
and securely support it on axle stands.
Position the stands clear of the suspension
assemblies. Ensure that the wheels are
clear of the ground and that the steering
can be turned from lock to lock.
Steering mechanism
MHave your assistant turn the steering from
lock to lock. Check that the steering turns
smoothly, and that no part of the steering
mechanism, including a wheel or tyre, fouls
any brake hose or pipe or any part of the body
structure.
MExamine the steering rack rubber gaiters
for damage or insecurity of the retaining clips.
If power steering is fitted, check for signs of
damage or leakage of the fluid hoses, pipes or
connections. Also check for excessive
stiffness or binding of the steering, a missing
split pin or locking device, or severe corrosion
of the body structure within 30 cm of any
steering component attachment point.
Front and rear suspension and
wheel bearings
MStarting at the front right-hand side, grasp
the roadwheel at the 3 o’clock and 9 o’clock
positions and shake it vigorously. Check for
free play or insecurity at the wheel bearings,
suspension balljoints, or suspension mount-
ings, pivots and attachments.
MNow grasp the wheel at the 12 o’clock and
6 o’clock positions and repeat the previous
inspection. Spin the wheel, and check for
roughness or tightness of the front wheel
bearing.
MIf excess free play is suspected at a
component pivot point, this can be confirmed
by using a large screwdriver or similar tool and
levering between the mounting and the
component attachment. This will confirm
whether the wear is in the pivot bush, its
retaining bolt, or in the mounting itself (the bolt
holes can often become elongated).
MCarry out all the above checks at the other
front wheel, and then at both rear wheels.
Springs and shock absorbers
MExamine the suspension struts (when
applicable) for serious fluid leakage, corrosion,
or damage to the casing. Also check the
security of the mounting points.
MIf coil springs are fitted, check that the
spring ends locate in their seats, and that the
spring is not corroded, cracked or broken.
MIf leaf springs are fitted, check that all
leaves are intact, that the axle is securely
attached to each spring, and that there is no
deterioration of the spring eye mountings,
bushes, and shackles.MThe same general checks apply to vehicles
fitted with other suspension types, such as
torsion bars, hydraulic displacer units, etc.
Ensure that all mountings and attachments are
secure, that there are no signs of excessive
wear, corrosion or damage, and (on hydraulic
types) that there are no fluid leaks or damaged
pipes.
MInspect the shock absorbers for signs of
serious fluid leakage. Check for wear of the
mounting bushes or attachments, or damage
to the body of the unit.
Driveshafts
(fwd vehicles only)
MRotate each front wheel in turn and inspect
the constant velocity joint gaiters for splits or
damage. Also check that each driveshaft is
straight and undamaged.
Braking system
MIf possible without dismantling, check
brake pad wear and disc condition. Ensure
that the friction lining material has not worn
excessively, (A) and that the discs are not
fractured, pitted, scored or badly worn (B).
MExamine all the rigid brake pipes
underneath the vehicle, and the flexible
hose(s) at the rear. Look for corrosion, chafing
or insecurity of the pipes, and for signs of
bulging under pressure, chafing, splits or
deterioration of the flexible hoses.
MLook for signs of fluid leaks at the brake
calipers or on the brake backplates. Repair or
renew leaking components.
MSlowly spin each wheel, while your
assistant depresses and releases the
footbrake. Ensure that each brake is operating
and does not bind when the pedal is released.
3Checks carried out
WITH THE VEHICLE RAISED
AND THE WHEELS FREE TO
TURN

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•7
REF
Tools and Working Facilities
MImpact screwdriver
MMicrometer and/or vernier calipers (see
illustrations)
MDial gauge (see illustration)
MUniversal electrical multi-meter
MCylinder compression gauge
(see illustration)
MClutch plate alignment set (see illustration)
MBrake shoe steady spring cup removal tool
(see illustration)
MBush and bearing removal/installation set
(see illustration)
MStud extractors (see illustration)
MTap and die set (see illustration)
MLifting tackle
MTrolley jack
Buying tools
For practically all tools, a tool factor is the
best source, since he will have a very
comprehensive range compared with the
average garage or accessory shop. Having
said that, accessory shops often offer
excellent quality tools at discount prices, so it
pays to shop around.
Remember, you don’t have to buy the most
expensive items on the shelf, but it is always
advisable to steer clear of the very cheap
tools. There are plenty of good tools around atreasonable prices, but always aim to
purchase items which meet the relevant
national safety standards. If in doubt, ask the
proprietor or manager of the shop for advice
before making a purchase.
Care and maintenance of tools
Having purchased a reasonable tool kit, it is
necessary to keep the tools in a clean and
serviceable condition. After use, always wipe
off any dirt, grease and metal particles using a
clean, dry cloth, before putting the tools away.
Never leave them lying around after they have
been used. A simple tool rack on the garage
or workshop wall for items such as
screwdrivers and pliers is a good idea. Store
all normal spanners and sockets in a metal
box. Any measuring instruments, gauges,
meters, etc, must be carefully stored where
they cannot be damaged or become rusty.
Take a little care when tools are used.
Hammer heads inevitably become marked,
and screwdrivers lose the keen edge on their
blades from time to time. A little timely
attention with emery cloth or a file will soon
restore items like this to a good serviceable
finish.
Working facilities
Not to be forgotten when discussing toolsis the workshop itself. If anything more than
routine maintenance is to be carried out,
some form of suitable working area becomes
essential.
It is appreciated that many an owner-
mechanic is forced by circumstances to
remove an engine or similar item without the
benefit of a garage or workshop. Having done
this, any repairs should always be done under
the cover of a roof.
Wherever possible, any dismantling should
be done on a clean, flat workbench or table at
a suitable working height.
Any workbench needs a vice; one with a
jaw opening of 100 mm is suitable for most
jobs. As mentioned previously, some clean
dry storage space is also required for tools, as
well as for any lubricants, cleaning fluids,
touch-up paints and so on, which become
necessary.
Another item which may be required, and
which has a much more general usage, is an
electric drill with a chuck capacity of at least 8
mm. This, together with a good range of twist
drills, is virtually essential for fitting
accessories.
Last, but not least, always keep a supply of
old newspapers and clean, lint-free rags
available, and try to keep any working area as
clean as possible.
Bush and bearing removal/installation setStud extractor setTap and die set

REF•12Fault Finding
Fuel system
Excessive fuel consumption
m mDirty or clogged air filter element (Chapter 1).
m mIgnition timing incorrect (Chapter 5).
m mEmissions system not functioning properly (Chapter 6).
m mFuel injection internal parts or carburettor jets excessively worn or
damaged (Chapter 4).
m mLow tyre pressure or incorrect tyre size (Chapter 1).
m mUnsympathetic driving style, or unfavourable conditions.
Fuel leakage and/or fuel odour
Warning: Don’t drive the vehicle if a fuel leak is
suspected. Leaking fuel in the engine compartment
could catch fire.
m mLeak in a fuel feed or vent line (Chapter 4).
m mTank overfilled.
m mFuel injector or carburettor parts excessively worn, or fuel system
gaskets leaking (Chapter 4).
Cooling system
Overheating
m mInsufficient coolant in system (Chapter 1).
m mWater pump drivebelt defective or out of adjustment (Chapter 1).
m mRadiator matrix blocked, or grille restricted (Chapter 3).
m mThermostat faulty (Chapter 3).
m mRadiator cap not maintaining proper pressure (Chapter 3).
m mIgnition timing incorrect (Chapter 5).
Overcooling
m
mFaulty thermostat (Chapter 3).
External coolant leakage
m
mDeteriorated/damaged hoses; loose clamps (Chapters 1 and 3).
m mWater pump seal defective (Chapters 1 and 3).
m mLeakage from radiator matrix, heater matrix or header tank
(Chapter 3).
m mRadiator/engine block drain plugs or water jacket core plugs
leaking (Chapters 2 and 3).
Internal coolant leakage
m mLeaking cylinder head gasket (Chapter 2).
m mCracked cylinder bore or cylinder head (Chapter 2).
Coolant loss
m
mToo much coolant in system (Chapter 1).
m mCoolant boiling away because of overheating (see above).
m mInternal or external leakage (see above).
m mFaulty radiator cap (Chapter 3).
Poor coolant circulation
m
mInoperative water pump (Chapter 3).
m mRestriction in cooling system (Chapters 1 and 3).
m mWater pump drivebelt defective/out of adjustment (Chapter 1).
m mThermostat sticking (Chapter 3).
Clutch
Pedal travels to floor - no pressure or very little
resistance
m mMaster or slave cylinder faulty (Chapter 8).
m mFluid line burst or leaking (Chapter 8).
m mConnections leaking (Chapter 8).
m mNo fluid in reservoir (Chapter 1).
m mIf fluid is present in master cylinder dust cover, master cylinder rear
seal has failed (Chapter 8).
m mBroken release bearing or fork (Chapter 8).
Fluid in area of master cylinder dust cover, and on
pedal
m mRear seal failure in master cylinder (Chapter 8).
Fluid on slave cylinder
m
mSlave cylinder plunger seal faulty (Chapter 8).
Pedal feels “spongy” when depressed
m
mAir in system (Chapter 8).
Unable to select gears
m
mFaulty transmission (Chapter 7).
m mFaulty clutch plate (Chapter 8).
m mFork and bearing not assembled properly (Chapter 8).
m mFaulty pressure plate (Chapter 8).
m mPressure plate-to-flywheel bolts loose (Chapter 8).
Clutch slips (engine speed increases with no
increase in vehicle speed)
m mClutch plate worn (Chapter 8).
m mClutch plate is oil-soaked by leaking rear main seal (Chapter 8).
m mWarped pressure plate or flywheel (Chapter 8).
m mWeak diaphragm spring (Chapter 8).
m mClutch plate overheated.
Grabbing (chattering) as clutch is engaged
m
mOil on clutch plate lining, burned or glazed facings (Chapter 8).
m mWorn or loose engine or transmission mountings (Chapters 2
and 7A).
m mWorn splines on clutch plate hub (Chapter 8).
m mWarped pressure plate or flywheel (Chapter 8).
Noise in clutch area
m
mFork improperly fitted (Chapter 8).
m mFaulty release bearing (Chapter 8).
Clutch pedal stays on floor
m
mFork binding in housing (Chapter 8).
m mBroken release bearing or fork (Chapter 8).
High pedal effort
m
mFork binding in housing (Chapter 8).
m mPressure plate faulty (Chapter 8).
m mIncorrect-size master or slave cylinder fitted (Chapter 8).

REF•13
REF
Fault Finding
Automatic transmission
Note:Due to the complexity of the automatic transmission, it is
difficult for the home mechanic to properly diagnose and service this
unit. For problems other than the following, the vehicle should be
taken to a dealer or transmission specialist.
Fluid leakage
m mAutomatic transmission fluid is a deep red colour. Fluid leaks
should not be confused with engine oil, which can easily be blown
by airflow onto the transmission.
m mTo pinpoint a leak, first remove all built-up dirt and grime from the
transmission housing with degreasing agents and/or by steam-
cleaning. Then drive the vehicle at low speed, so airflow will not
blow the leak far from its source. Raise the vehicle and determine
where the leak is coming from. Common areas of leakage are:
a) Transmission sump (Chapters 1 and 7B)
b) Filler pipe (Chapter 7B)
c) Transmission fluid cooler lines (Chapter 7B)
d) Speedometer sensor (Chapter 7B)
Transmission fluid brown, or has a burned smell
m mTransmission fluid burned; fluid should be changed. May indicate
transmission internal fault (Chapters 1 and 7B).
Transmission will not kickdown with accelerator
pedal pressed to the floor
m mKickdown cable out of adjustment (Chapter 7B).
General shift mechanism problems
m
mChapter 7B deals with checking and adjusting the shift linkage on
automatic transmissions. Common problems which may be
attributed to poorly-adjusted linkage are:
a) Engine starting in gears other than Park or Neutral.
b) Indicator on selector lever pointing to a gear other than the one
actually being used.
c) Vehicle moves when in Park.
m mRefer to Chapter 7B for the shift linkage adjustment procedure.
Engine will start in gears other than Park or Neutral
m
mInhibitor switch malfunctioning (Chapter 7B).
Transmission slips, shifts roughly, is noisy, or has
no drive in forward or reverse gears
m mThere are many probable causes for the above problems, but the
home mechanic should be concerned with only one possibility -
fluid level. Before taking the vehicle to an automatic transmission
specialist, check the level and condition of the fluid as described in
Chapter 1. Correct the fluid level as necessary, or change the fluid
if needed. If the problem persists, have a professional diagnose the
probable cause.
Manual transmission
Vibration
m mDamaged propeller shaft (Chapter 8).
m mOut-of-round tyres (Chapter 1).
m mTyre out-of-balance (Chapters 1 and 10).
m mWorn propeller shaft universal joint (Chapter 8).
Noisy in neutral with engine running
m
mWorn clutch release bearing (Chapter 8).
m mWorn transmission input shaft bearing (Chapter 7A).
Noisy in one particular gear
m
mDamaged or worn constant-mesh gears.
m mDamaged or worn synchronisers.
Noisy in all gears
m
mInsufficient lubricant (Chapter 1).
m mDamaged or worn bearings.
m mWorn or damaged input gear shaft and/or output gear shaft.
Slips out of gear
m
mWorn or incorrectly-adjusted linkage (Chapter 7A).
m mTransmission-to-engine mounting bolts loose (Chapter 7A).
m mShift linkage binding (Chapter 7A).
m mWorn shift fork (Chapter 7A).
Leaks lubricant
m
mExcessive amount of lubricant in transmission (Chapters 1 and 7A).
m mLoose or broken input shaft bearing retainer (Chapter 7A).
m mInput shaft bearing retainer O-ring and/or lip seal damaged
(Chapter 7A).