1988 OPEL VECTRA cooling

C16 NZ2, 1.8 and 2.0 litre models, remove the
timing belt. Details are as described in
Chapter 2A.
3Remove timing belt tension roller from oil
pump, where applicable.
4Unscrew and remove the coolant pump
securing bolts (see illustration).
5Withdraw the coolant pump from the
cylinder block, and recover the O-ring (see
illustrations). It may be necessary to tap the
pump lightly with a plastic-faced hammer to
free it from the cylinder block.
6If desired, the rear timing belt cover can be
removed from the pump by rotating the cover
to release it from the flange on the pump.
7No overhaul of the coolant pump is
possible, and if faulty, the unit must be
renewed.
Refitting
8Refitting is a reversal of removal, bearing in
mind the following points.
9Use a new O-ring when refitting the pump.
Before refitting the pump, smear the pump
mounting face in the cylinder block and the O-
ring with a silicone grease or petroleum jelly.
10Do not fully tighten the pump securing
bolts until the timing belt has been fitted and
tensioned.
11Refit and tension the timing belt, as
described in Chapter 2A.
12If the engine is in the vehicle, refill the
cooling system, as described in Section 4.
DOHC models
Removal
13Remove the engine undershield.
14If the engine is in the vehicle, drain the
cooling system, as described in Section 2.
15Remove the timing belt, camshaft
sprockets, crankshaft sprocket, timing belt
tensioner and idler rollers, and the timing belt
rear cover, as described in Chapter 2B.
16Proceed as described in paragraphs 4
and 5.
17No overhaul of the coolant pump is
possible, and if faulty, the unit must be
renewed.
Refitting
18Refitting is a reversal of removal, bearing
in mind the following points.19Always use a new O-ring. Before fitting
the pump, smear the pump mating face in the
cylinder block and the O-ring with a silicone
grease or petroleum jelly.
20Refit the pump, and ensure that the lugs
on the pump and the cylinder block are
aligned before tightening the pump securing
bolts (see illustration).
21Refit the remaining components, and
tension the timing belt, as described in
Chapter 2B.
22If the engine is in the vehicle, refill the
cooling system, as described in Section 4.
Replace the undershield.
12Cooling fan - removal and
refitting
3
Removal
1Disconnect the battery negative lead.
2Disconnect the wiring from the cooling fan,
noting the location of the wiring connector for
use when refitting.
3Unscrew the two upper fan shroud securing
bolts from the top corners of the shroud, then
tilt the assembly back slightly towards the
engine, and withdraw it upwards away from
the radiator (see illustration).
4To separate the fan motor from the shroud,
unscrew the three securing nuts. If desired,
the fan blades can be separated from the
motor by removing the securing spring clip
from the end of the motor shaft.5No spare parts are available for the motor,
and if the unit is faulty, it must be renewed.
Refitting
6Reassembly (where applicable), and
refitting are reversals of the dismantling and
removal procedures, but ensure that the lower
end of the fan shroud locates correctly on the
radiator.
7On completion, start the engine and run it
until it reaches normal operating temperature,
then continue to run the engine and check
that the cooling fan cuts in and functions
correctly.
13Expansion tank and coolant
level sensor -removal and
refitting
3
Expansion tank
Removal
1The expansion tank is secured by a single
screw at its front edge. If the tank is to be
moved for access purposes, it should be
possible to move it sufficiently within the
confines of the hoses once the securing
screw has been removed. If the tank is to be
removed completely, continue as follows.
2Disconnect the two hoses from the top of
the expansion tank, and suspend them above
the height of the engine to prevent coolant loss.
3Remove the tank securing screw, then
manipulate the tank from its location, holding
it as high as possible above the engine.
Cooling, heating and ventilation systems 3•5
11.5B . . .and recover the O-ring -
2.0 litre SOHC model
12.3 Withdrawing the fan shroud assembly
- 2.0 litre SOHC model11.20 Lugs (arrowed) on coolant pump
and cylinder block must be aligned -
DOHC models
11.5A Withdraw the coolant pump . . .11.4 Coolant pump securing bolt
(arrowed) - 2.0 litre SOHC model
3

4Position a container beneath the tank, then
disconnect the bottom hose and allow the
contents of the tank to drain into the
container. Suspend the bottom hose as high
as possible above the engine to prevent
coolant loss.
Refitting
5Refitting is a reversal of removal, but on
completion check and if necessary top-up the
coolant level, as described in Section 4. The
coolant drained from the expansion tank
during removal can be re-used, provided it
has not been contaminated.
Coolant level sensor
6The coolant level sensor, where fitted, is an
integral part of the expansion tank cap. If the
level sensor is faulty, the complete cap
assembly must be renewed.
14Temperature gauge sender -
removal and refitting
2
Removal
1The sender is screwed into the inlet
manifold on 1.4 and 1.6 litre models (except
C16 NZ2), and into the thermostat housing
on C16 NZ2, 1.8 and 2.0 litre models (see
illustrations).
2Partially drain the cooling system, as
described in Section 2, to minimise coolant
spillage.
3Disconnect the battery negative lead.4Disconnect the wiring from the switch, then
unscrew the switch from its location.
Refitting
5Refitting is a reversal of removal,
remembering the following points.
6Coat the sender threads with sealant before
fitting.
7Top-up the cooling system, as described in
Section 4.
8On completion, start the engine and check
the operation of the temperature gauge. Also
check for coolant leaks.
15Cooling fan switch -removal
and refitting
3
Note: A new sealing ring should be used
when refitting the switch
Removal
1The cooling fan switch is located at the
bottom right-hand corner of the radiator (see
illustration).
2If a faulty switch is suspected, the circuit to
the fan motor can be tested by temporarily
bridging the terminals in the switch wiring
plug, and switching on the ignition. If the
cooling fan now operates, the switch is faulty
and should be renewed. To remove the
switch, continue as follows.
3Disconnect the battery negative lead, then
disconnect the switch wiring plug if not
already done.4Drain the cooling system, as described in
Section 2.
5Unscrew the switch from the radiator and
recover the sealing ring.
Refitting
6Refitting is a reversal of removal, but use a
new sealing ring, and refill the cooling system
as described in Section 4.
7On completion, start the engine and run it
until it reaches normal operating temperature,
then continue to run the engine and check
that the cooling fan cuts in and functions
correctly.
16Heater control panel -
removal and refitting
3
Removal
1Disconnect the battery negative lead.
2Remove the passenger side footwell trim,
the steering column shrouds, and the
instrument panel lower and upper trim panels,
as described in Chapter 11.
3Remove the clock or trip computer, as
applicable, from the facia, referring to Chapter
12 if necessary.
4Remove the two heater control panel
securing screws from the clock/trip computer
aperture, and the remaining securing screw
from the right-hand end of the panel (exposed
by removing the instrument panel lower trim
panel), (see illustrations).
3•6Cooling, heating and ventilation systems
14.1A Disconnecting the wiring from the
temperature gauge sender - 1.6 litre model14.1C Temperature gauge sender location
(arrowed) - 2.0 litre DOHC model
16.4B . . . and the remaining screw from
the right-hand end of the panel16.4A Remove the two heater control
panel securing screws from the clock/trip
computer aperture . . .15.1 Cooling fan switch location -
2.0 litre SOHC model viewed from below
14.1B Temperature gauge sender location
(arrowed) - 2.0 litre SOHC model

5Working through the passenger footwell,
reach up behind the facia, and disconnect the
bowden cables from the control levers at the
rear of the heater control panel. Note that
each cable is secured by a plastic clip, and in
some cases, by an additional metal clip,
which must be released before the cable end
can be disconnected from the control lever
(see illustration). This is a tricky operation,
and some patience will be required. Mark the
cables to ensure that they are refitted in their
original positions.
6Withdraw the heater control panel from the
facia, and disconnect the wiring plugs from
the rear of the panel.
Refitting
7Refitting is a reversal of removal, but on
completion, move all the control levers
through their full extent of travel, and check
the heater mechanism for correct operation.
17Heater matrix -removal and
refitting
3
Removal
1Drain the cooling system, (Section 2).
2Working in the engine compartment,
disconnect the coolant hoses from the heater
matrix pipes at the bulkhead.
3Working inside the vehicle, remove the front
centre console section, (Chapter 11).
4Extract the two front and two rear securing
screws, and remove the plastic cover from
under the heater matrix (see illustration).5Remove the two front retaining screws from
the heater matrix securing straps, then lower
the securing straps and withdraw the heater
matrix from the facia (see illustration). The
pipes at the rear of the matrix must be fed
through the bulkhead, and the grommets in
the heater matrix housing may be displaced
as the matrix is withdrawn. Where applicable,
recover the grommets.
Refitting
6Refitting is a reversal of removal,
remembering the following points.
7Ensure that the coolant pipe grommets are
seated correctly in the heater matrix housing,
as shown (see illustration).
8Ensure that the rubber mounting strips are
correctly seated between the mounting straps
and the matrix.
9On completion, refill the cooling system, as
described in Section 4.
18Heater blower motor -
removal and refitting
3
Removal
1The heater blower motor is situated under
the windscreen cowl panel.
2Remove the windscreen cowl panel, as
described in Chapter 11.
3Remove the windscreen wiper motor and
linkage, as described in Chapter 12.
4Unclip the cover from the top of the motor
(see illustration).
5Disconnect the motor wiring plug.6Remove the two clamp screws, then lift off
the clamp and withdraw the motor assembly
from its housing (see illustration).
7It is possible to renew the motor resistor by
pressing the retaining clips together to release
the resistor bracket. Fit the new resistor,
ensuring that the retaining clips lock it into
position (see illustration).
8No overhaul of the motor assembly is
possible, and if faulty, the unit must be
renewed.
Refitting
9Refitting is a reversal of removal, ensuring
that the mounting rubber is correctly seated
between the clamp and the motor.
Cooling, heating and ventilation systems 3•7
17.5 Unscrewing a heater matrix securing
strap screw
18.6 Unscrewing a heater blower motor
clamp screw18.7 Heater blower motor resistor
retaining clip (arrowed)18.4 Unclip the cover from the heater
blower motor
17.7 Heater matrix coolant pipe grommet
location
1 Coolant pipe
2 Engine compartment bulkhead
3 Heater matrix housing
4 Grommet
17.4 Removing the plastic cover from the
heater matrix16.5 Heater control cables disconnected,
showing cable end securing clips
3

19Facia ventilation nozzles -
removal and refitting
2
Centre facia ventilation nozzles
Removal
1Using a screwdriver, carefully prise the cap
from the hazard warning flasher switch.
2Carefully prise the nozzle assembly from
the facia, using a screwdriver with a piece of
card under the blade, to avoid damage to the
facia trim (see illustrations).
3If desired, the nozzle housing can be
removed as follows.
4Move the knurled airflow adjuster wheel to
the “O” position, then pull the actuating rod
sideways from its carrier.
5Release the two lower securing clips by
levering with a screwdriver and pull the
housing from the facia.
Refitting
6Refitting is a reversal of removal, but note
that if the housing has been removed, the
airflow adjuster actuating rod must be pulled
out to its stop, then pressed into its carrier
with the adjuster wheel in the “O” position.
Passenger side facia ventilation
nozzle
Removal
7Carefully prise the nozzle from the facia,
using a screwdriver with a piece of card under
the blade, to avoid damage to the facia trim.
8If desired, the nozzle housing can be
removed as follows.
9Move the knurled airflow adjuster wheel to
the “O” position, then pull the actuating rod
sideways from its carrier.
10Extract the single screw securing the
housing to the facia, then release the securing
clips and pull the housing from the facia.
Refitting
11Refitting is a reversal of removal, with
reference to paragraph 6.
Driver’s side facia ventilation
nozzle
12The procedure is as described for the
passenger side nozzle, except that there is no
screw securing the housing to the facia.
Side window demister nozzles
Removal
13Simply prise the nozzle from the facia,
taking care not to damage the facia trim.
Refitting
14To refit, push the nozzle into position until
it locks.
3•8Cooling, heating and ventilation systems
19.2A Using a screwdriver with protected blade . . .19.2B . . . to release the centre facia ventilation nozzles

Engine
m mEngine fails to rotate when attempting to start
m mEngine rotates, but will not start
m mEngine difficult to start when cold
m mEngine difficult to start when hot
m mStarter motor noisy or excessively rough in engagement
m mEngine starts, but stops immediately
m mEngine idles erratically
m mEngine misfires at idle speed
m mEngine misfires throughout the driving speed range
m mEngine hesitates on acceleration
m mEngine stalls
m mEngine lacks power
m mEngine backfires
m mOil pressure warning light illuminated with engine running
m mEngine runs-on after switching off
m mEngine noises
Cooling system
m
mOverheating
m mOvercooling
m mExternal coolant leakage
m mInternal coolant leakage
m mCorrosion
Fuel and exhaust systems
m
mExcessive fuel consumption
m mFuel leakage and/or fuel odour
m mExcessive noise or fumes from exhaust system
Clutch
m
mPedal travels to floor - no pressure or very little resistance
m mClutch fails to disengage (unable to select gears)
m mClutch slips (engine speed increases, with no increase in vehicle
speed)
m mJudder as clutch is engaged
m mNoise when depressing or releasing clutch pedal
Manual transmission
m
mNoisy in neutral with engine running
m mNoisy in one particular gear
m mDifficulty engaging gears
m mJumps out of gear
m mVibration
m mLubricant leaks
Automatic transmission
m
mFluid leakage
m mTransmission fluid brown, or has burned smell
m mGeneral gear selection problems
m mTransmission will not downshift (kickdown) with accelerator fully
depressed
m mEngine will not start in any gear, or starts in gears other than Park
or Neutral
m mTransmission slips, shifts roughly, is noisy, or has no drive in
forward or reverse gears
Driveshafts
m mClicking or knocking noise on turns (at slow speed on full-lock)
m mVibration when accelerating or decelerating
Braking system
m
mVehicle pulls to one side under braking
m mNoise (grinding or high-pitched squeal) when brakes applied
m mExcessive brake pedal travel
m mBrake pedal feels spongy when depressed
m mExcessive brake pedal effort required to stop vehicle
m mJudder felt through brake pedal or steering wheel when braking
m mBrakes binding
m mRear wheels locking under normal braking
Suspension and steering systems
m
mVehicle pulls to one side
m mWheel wobble and vibration
m mExcessive pitching and/or rolling around corners, or during
braking
m mWandering or general instability
m mExcessively stiff steering
m mExcessive play in steering
m mLack of power assistance
m mTyre wear excessive
Electrical system
m
mBattery will not hold a charge for more than a few days
m mIgnition/no-charge warning light remains illuminated with engine
running
m mIgnition/no-charge warning light fails to come on
m mLights inoperative
m mInstrument readings inaccurate or erratic
m mHorn inoperative, or unsatisfactory in operation
m mWindscreen/tailgate wipers inoperative, or unsatisfactory in
operation
m mWindscreen/tailgate washers inoperative, or unsatisfactory in
operation
m mElectric windows inoperative, or unsatisfactory in operation
m mCentral locking system inoperative, or unsatisfactory in operation
The vehicle owner who does his or her own maintenance according to
the recommended service schedules should not have to use this section
of the manual very often. Modern component reliability is such that,
provided those items subject to wear or deterioration are inspected or
renewed at the specified intervals, sudden failure is comparatively rare.
Faults do not usually just happen as a result of sudden failure, but
develop over a period of time. Major mechanical failures in particular are
usually preceded by characteristic symptoms over hundreds or even
thousands of miles. Those components that do occasionally fail without
warning are often small and easily carried in the vehicle.
With any fault-finding, the first step is to decide where to begininvestigations. Sometimes this is obvious, but on other occasions, a
little detective work will be necessary. The owner who makes half a
dozen haphazard adjustments or replacements may be successful in
curing a fault (or its symptoms). However, will be none the wiser if the
fault recurs, and ultimately may have spent more time and money than
was necessary. A calm and logical approach will be found to be more
satisfactory in the long run. Always take into account any warning
signs or abnormalities that may have been noticed in the period
preceding the fault - power loss, high or low gauge readings, unusual
smells, etc. - and remember that failure of components such as fuses
or spark plugs may only be pointers to some underlying fault.
REF•12Fault Finding
Introduction

The pages that follow provide an easy-reference guide to the more
common problems that may occur during the operation of the vehicle.
These problems and their possible causes are grouped under headings
denoting various components or systems, such as Engine, Cooling
system, etc. The Chapter and/or Section that deals with the problem is
also shown in brackets. Whatever the fault, certain basic principles
apply. These are as follows:
Verify the fault. This is simply a matter of being sure that you know
what the symptoms are before starting work. This is particularly
important if you are investigating a fault for someone else, who may
not have described it very accurately.
Do not overlook the obvious. For example, if the vehicle will not start,
is there petrol in the tank? (Do not take anyone else’s word on this
particular point, and do not trust the fuel gauge either!) If an electrical
fault is indicated, look for loose or broken wires before digging out the
test gear.Cure the disease, not the symptom. Substituting a flat battery with a
fully charged one will get you off the hard shoulder, but if the
underlying cause is not attended to, the new battery will go the same
way. Similarly, changing oil-fouled spark plugs for a new set will get
you moving again, but remember that the reason for the fouling (if it
was not simply an incorrect grade of plug) will have to be established
and corrected.
Do not take anything for granted. Particularly, do not forget that a
“new” component may itself be defective (especially if it’s been rattling
around in the boot for months). Also do not leave components out of a
fault diagnosis sequence just because they are new or recently fitted.
When you do finally diagnose a difficult fault, you will probably realise
that all the evidence was there from the start.
Engine fails to rotate when attempting to start
MBattery terminal connections loose or corroded (Chapter 1).
MBattery discharged or faulty (Chapter 5).
MBroken, loose or disconnected wiring in the starting circuit
(Chapter 5).
MDefective starter solenoid or switch (Chapter 5).
MDefective starter motor (Chapter 5).
MStarter pinion or flywheel ring gear teeth loose or broken
(Chapters 2A and 5).
MEngine earth strap broken or disconnected (Chapter 5).
Engine rotates, but will not start
MFuel tank empty.
MBattery discharged (engine rotates slowly), (Chapter 5).
MBattery terminal connections loose or corroded (Chapter 1).
MIgnition components damp or damaged (Chapters 1 and 5).
MBroken, loose or disconnected wiring in the ignition circuit
(Chapters 1 and 5).
MWorn, faulty or incorrectly gapped spark plugs (Chapter 1).
MChoke mechanism incorrectly adjusted, worn or sticking -
carburettor models (Chapter 4A).
MFaulty fuel cut-off solenoid - carburettor models (Chapter 4A).
MFuel injection system fault - fuel-injected models (Chapter 4B).
MMajor mechanical failure (e.g. camshaft drive), (Chapter 2A or 2B).
Engine difficult to start when cold
MBattery discharged (Chapter 5).
MBattery terminal connections loose or corroded (Chapter 1).
MWorn, faulty or incorrectly gapped spark plugs (Chapter 1).
MChoke mechanism incorrectly adjusted, worn or sticking -
carburettor models (Chapter 4A).
MFuel injection system fault - fuel-injected models (Chapter 4B).
MOther ignition system fault (Chapters 1 and 5).
MLow cylinder compressions (Chapter 2A).
Engine difficult to start when hot
MAir filter element dirty or clogged (Chapter 1).
MChoke mechanism incorrectly adjusted, worn or sticking -
carburettor models (Chapter 4A).
MFuel injection system fault - fuel-injected models (Chapter 4B).
MLow cylinder compressions (Chapter 2A).
Starter motor noisy or excessively rough in
engagement
MStarter pinion or flywheel ring gear teeth loose or broken
(Chapters 2A and 5).
MStarter motor mounting bolts loose or missing (Chapter 5).
MStarter motor internal components worn or damaged (Chapter 5).
Engine starts, but stops immediately
MLoose or faulty electrical connections in the ignition circuit
(Chapters 1 and 5B).
MVacuum leak at the carburettor/throttle body or inlet manifold
(Chapter 4A or 4B).
MBlocked carburettor jet(s) or internal passages - carburettor
models (Chapter 4A).
MBlocked injector/fuel injection system fault - fuel-injected models
(Chapter 4B).
Engine idles erratically
MAir filter element clogged (Chapter 1).
MVacuum leak at the carburettor/throttle body, inlet manifold or
associated hoses (Chapter 4A or 4B).
MWorn, faulty or incorrectly gapped spark plugs (Chapter 1).
MUneven or low cylinder compressions (Chapter 2A).
MCamshaft lobes worn (Chapter 2A or 2B).
MTiming belt incorrectly tensioned (Chapter 2A or 2B).
MBlocked carburettor jet(s) or internal passages - carburettor
models (Chapter 4A).
MBlocked injector/fuel injection system fault - fuel-injected models
(Chapter 4B).
Engine misfires at idle speed
MWorn, faulty or incorrectly gapped spark plugs (Chapter 1).
MFaulty spark plug HT leads (Chapter 1).
MVacuum leak at the carburettor/throttle body, inlet manifold or
associated hoses (Chapter 4A or 4B).
MBlocked carburettor jet(s) or internal passages - carburettor
models (Chapter 4A).
MBlocked injector/fuel injection system fault - fuel-injected models
(Chapter 4B).
MDistributor cap cracked or tracking internally (where applicable),
(Chapter 1).
MUneven or low cylinder compressions (Chapter 2A).
MDisconnected, leaking, or perished crankcase ventilation hoses
(Chapter 4C).
Engine misfires throughout the driving speed
range
MFuel filter choked (Chapter 1).
MFuel pump faulty, or delivery pressure low (Chapter 4A or 4B).
MFuel tank vent blocked, or fuel pipes restricted (Chapter 4A or 4B).
MVacuum leak at the carburettor/throttle body, inlet manifold or
associated hoses (Chapter 4A or 4B).
MWorn, faulty or incorrectly gapped spark plugs (Chapter 1).
MFaulty spark plug HT leads (Chapter 1).
MDistributor cap cracked or tracking internally (where applicable),
(Chapter 1).
Fault Finding REF•13
REF
Engine

Excessive fuel consumption
MAir filter element dirty or clogged (Chapter 1).
MChoke cable incorrectly adjusted, or choke sticking - carburettor
models (Chapter 4A).
MFuel injection system fault - fuel-injected models (Chapter 4B).
MIgnition timing incorrect/ignition system fault (Chapters 1 and 5).
MTyres under-inflated (Chapter 1).
Fuel leakage and/or fuel odour
MDamaged or corroded fuel tank, pipes or connections (Chapter 4A
or 4B).
MCarburettor float chamber flooding (float height incorrect) -
carburettor models (Chapter 4A).
Excessive noise or fumes from exhaust system
MLeaking exhaust system or manifold joints (Chapters 1 and 4C).
MLeaking, corroded or damaged silencers or pipe (Chapters 1 and 4C).
MBroken mountings causing body or suspension contact (Chapter 1).
Pedal travels to floor - no pressure or very little
resistance
MBroken clutch cable (Chapter 6).
MIncorrect clutch cable adjustment (Chapter 6).
MBroken clutch release bearing or fork (Chapter 6).
MBroken diaphragm spring in clutch pressure plate (Chapter 6).
Clutch fails to disengage (unable to select gears).
MIncorrect clutch cable adjustment (Chapter 6).
MClutch disc sticking on transmission input shaft splines (Chapter 6).
MClutch disc sticking to flywheel or pressure plate (Chapter 6).
MFaulty pressure plate assembly (Chapter 6).
MClutch release mechanism worn or incorrectly assembled (Chapter 6).
Clutch slips (engine speed increases, with no
increase in vehicle speed).
MIncorrect clutch cable adjustment (Chapter 6).
MClutch disc linings excessively worn (Chapter 6).MClutch disc linings contaminated with oil or grease (Chapter 6).
MFaulty pressure plate or weak diaphragm spring (Chapter 6).
Judder as clutch is engaged
MClutch disc linings contaminated with oil or grease (Chapter 6).
MClutch disc linings excessively worn (Chapter 6).
MClutch cable sticking or frayed (Chapter 6).
MFaulty or distorted pressure plate or diaphragm spring (Chapter 6).
MWorn or loose engine or transmission mountings (Chapter 2A or 2B).
MClutch disc hub or transmission input shaft splines worn (Chapter 6).
Noise when depressing or releasing clutch pedal
MWorn clutch release bearing (Chapter 6).
MWorn or dry clutch pedal bushes (Chapter 6).
MFaulty pressure plate assembly (Chapter 6).
MPressure plate diaphragm spring broken (Chapter 6).
MBroken clutch disc cushioning springs (Chapter 6).
Fault Finding REF•15
REF
Overheating
MInsufficient coolant in system (Chapter 1).
MThermostat faulty (Chapter 3).
MRadiator core blocked, or grille restricted (Chapter 3).
MElectric cooling fan or thermoswitch faulty (Chapter 3).
MPressure cap faulty (Chapter 3).
MIgnition timing incorrect/ignition system fault (Chapters 1 and 5).
MInaccurate temperature gauge sender unit (Chapter 3).
MAirlock in cooling system (Chapter 1).
Overcooling
MThermostat faulty (Chapter 3).
MInaccurate temperature gauge sender unit (Chapter 3).
External coolant leakage
MDeteriorated or damaged hoses or hose clips (Chapter 1).
MRadiator core or heater matrix leaking (Chapter 3).
MPressure cap faulty (Chapter 3).
MWater pump seal leaking (Chapter 3).
MBoiling due to overheating (Chapter 3).
MCore plug leaking (Chapter 2A).
Internal coolant leakage
MLeaking cylinder head gasket (Chapter 2A or 2B).
MCracked cylinder head or cylinder bore (Chapter 2A or 2B).
Corrosion
MInfrequent draining and flushing (Chapter 1).
MIncorrect coolant mixture or inappropriate coolant type (Chapter 1).
Cooling system
Clutch
Fuel and exhaust systems

REF•20Glossary of Technical Terms
A
ABS (Anti-lock brake system)A system,
usually electronically controlled, that senses
incipient wheel lockup during braking and
relieves hydraulic pressure at wheels that are
about to skid.
Air bag An inflatable bag hidden in the
steering wheel (driver’s side) or the dash or
glovebox (passenger side). In a head-on
collision, the bags inflate, preventing the
driver and front passenger from being thrown
forward into the steering wheel or windscreen.
Air cleanerA metal or plastic housing,
containing a filter element, which removes
dust and dirt from the air being drawn into the
engine.
Air filter elementThe actual filter in an air
cleaner system, usually manufactured from
pleated paper and requiring renewal at regular
intervals.
Allen keyA hexagonal wrench which fits into
a recessed hexagonal hole.
Alligator clipA long-nosed spring-loaded
metal clip with meshing teeth. Used to make
temporary electrical connections.
AlternatorA component in the electrical
system which converts mechanical energy
from a drivebelt into electrical energy to
charge the battery and to operate the starting
system, ignition system and electrical
accessories.
Ampere (amp)A unit of measurement for the
flow of electric current. One amp is the
amount of current produced by one volt
acting through a resistance of one ohm.
Anaerobic sealerA substance used to
prevent bolts and screws from loosening.
Anaerobic means that it does not require
oxygen for activation. The Loctite brand is
widely used.
AntifreezeA substance (usually ethylene
glycol) mixed with water, and added to a
vehicle’s cooling system, to prevent freezing
of the coolant in winter. Antifreeze also
contains chemicals to inhibit corrosion and
the formation of rust and other deposits thatwould tend to clog the radiator and coolant
passages and reduce cooling efficiency.
Anti-seize compoundA coating that
reduces the risk of seizing on fasteners that
are subjected to high temperatures, such as
exhaust manifold bolts and nuts.
AsbestosA natural fibrous mineral with great
heat resistance, commonly used in the
composition of brake friction materials.
Asbestos is a health hazard and the dust
created by brake systems should never be
inhaled or ingested.
AxleA shaft on which a wheel revolves, or
which revolves with a wheel. Also, a solid
beam that connects the two wheels at one
end of the vehicle. An axle which also
transmits power to the wheels is known as a
live axle.
AxleshaftA single rotating shaft, on either
side of the differential, which delivers power
from the final drive assembly to the drive
wheels. Also called a driveshaft or a halfshaft.
BBall bearingAn anti-friction bearing
consisting of a hardened inner and outer race
with hardened steel balls between two races.BearingThe curved surface on a shaft or in a
bore, or the part assembled into either, that
permits relative motion between them with
minimum wear and friction.
Big-end bearingThe bearing in the end of
the connecting rod that’s attached to the
crankshaft.
Bleed nippleA valve on a brake wheel
cylinder, caliper or other hydraulic component
that is opened to purge the hydraulic system
of air. Also called a bleed screw.
Brake bleedingProcedure for removing air
from lines of a hydraulic brake system.
Brake discThe component of a disc brake
that rotates with the wheels.
Brake drumThe component of a drum brake
that rotates with the wheels.
Brake liningsThe friction material which
contacts the brake disc or drum to retard the
vehicle’s speed. The linings are bonded or
riveted to the brake pads or shoes.
Brake padsThe replaceable friction pads
that pinch the brake disc when the brakes are
applied. Brake pads consist of a friction
material bonded or riveted to a rigid backing
plate.
Brake shoeThe crescent-shaped carrier to
which the brake linings are mounted and
which forces the lining against the rotating
drum during braking.
Braking systemsFor more information on
braking systems, consult the Haynes
Automotive Brake Manual.
Breaker barA long socket wrench handle
providing greater leverage.
BulkheadThe insulated partition between
the engine and the passenger compartment.
CCaliperThe non-rotating part of a disc-brake
assembly that straddles the disc and carries
the brake pads. The caliper also contains the
hydraulic components that cause the pads to
pinch the disc when the brakes are applied. A
caliper is also a measuring tool that can be set
to measure inside or outside dimensions of an
object.
Brake bleeding
Bearing
Axle assembly
Anti-seize compound
Alternator (exploded view)
Air filter