Peugeot 405 Haynes (petrol). Manual - part 36

REF•8

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:

Handbrake

M Test the operation of the handbrake.
Excessive travel (too many clicks) indicates
incorrect brake or cable adjustment.
M Check that the handbrake cannot be
released by tapping the lever sideways. Check
the security of the lever mountings.

Footbrake

M Depress 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.

M Check 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.
M Check 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 

M Examine the steering wheel for fractures or
looseness of the hub, spokes or rim. 
M Move 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. 
M Check that the steering wheel is not loose
on the column, and that there is no abnormal

movement of the steering wheel, indicating
wear in the column support bearings or
couplings.

Windscreen and mirrors 

M The 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.

1

Checks carried out
FROM THE DRIVER’S SEAT

1

Checks carried out
FROM THE DRIVER’S
SEAT

2

Checks carried out
WITH THE VEHICLE
ON THE GROUND

3

Checks carried out
WITH THE VEHICLE
RAISED AND THE
WHEELS FREE TO
TURN

4

Checks carried out on
YOUR VEHICLE’S
EXHAUST EMISSION
SYSTEM

MOT Test Checks

REF•9

REF

Seat belts and seats 

Note: The following checks are applicable to
all seat belts, front and rear.

M Examine the webbing of all the belts
(including rear belts if fitted) for cuts, serious
fraying or deterioration. Fasten and unfasten
each belt to check the buckles. If applicable,
check the retracting mechanism. Check the
security of all seat belt mountings accessible
from inside the vehicle.
M The front seats themselves must be
securely attached and the backrests must
lock in the upright position.

Doors 

M Both front doors must be able to be opened
and closed from outside and inside, and must
latch securely when closed.

Vehicle identification

M Number plates must be in good condition,
secure and legible, with letters and numbers
correctly spaced – spacing at (A) should be
twice that at (B).

M The VIN plate (A) and homologation plate
(B) must be legible.

Electrical equipment

M Switch on the ignition and check the 
operation of the horn.
M Check the windscreen washers and wipers,
examining the wiper blades; renew damaged
or perished blades. Also check the operation
of the stop-lights.

M Check the operation of the sidelights and
number plate lights. The lenses and reflectors
must be secure, clean and undamaged. 
M Check the operation and alignment of the
headlights. The headlight reflectors must not
be tarnished and the lenses must be
undamaged.
M Switch on the ignition and check the 
operation of the direction indicators (including
the instrument panel tell-tale) and the hazard
warning lights. Operation of the sidelights and
stop-lights must not affect the indicators - if it
does, the cause is usually a bad earth at the
rear light cluster.
M Check the operation of the rear foglight(s),
including the warning light on the instrument
panel or in the switch.

Footbrake

M Examine the master cylinder, brake pipes
and servo unit for leaks, loose mountings, 
corrosion or other damage.  

M The fluid reservoir must be secure and the
fluid level must be between the upper (A) and
lower (B) markings.

M Inspect both front brake flexible hoses for
cracks or deterioration of the rubber. Turn the
steering from lock to lock, and ensure that the
hoses do not contact the wheel, tyre, or any
part of the steering or suspension mechanism.
With the brake pedal firmly depressed, check
the hoses for bulges or leaks under pressure.

Steering and suspension

M Have your assistant turn the steering wheel
from side to side slightly, up to the point where
the steering gear just begins to transmit this
movement to the roadwheels. Check for
excessive free play between the steering
wheel and the steering gear, indicating wear or
insecurity of the steering column joints, the
column-to-steering gear coupling, or the
steering gear itself.
M Have your assistant turn the steering wheel
more vigorously in each direction, so that the
roadwheels just begin to turn. As this is done,
examine all the steering joints, linkages,
fittings and attachments. Renew any
component that shows signs of wear or 
damage. On vehicles with power steering,
check the security and condition of the 
steering pump, drivebelt and hoses.
M Check that the vehicle is standing level,
and at approximately the correct ride height.

Shock absorbers

M Depress each corner of the vehicle in turn,
then release it. The vehicle should rise and
then settle in its normal position. If the vehicle
continues to rise and fall, the shock absorber
is defective. A shock absorber which has
seized will also cause the vehicle to fail.

2

Checks carried out
WITH THE VEHICLE ON THE
GROUND

REF•10

MOT Test Checks

Exhaust system

M Start 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 

M Have 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.
M Examine 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 

M Starting 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.
M Now 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.

M If 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).

M Carry out all the above checks at the other
front wheel, and then at both rear wheels.

Springs and shock absorbers 

M Examine the suspension struts (when
applicable) for serious fluid leakage, corrosion,
or damage to the casing. Also check the
security of the mounting points.
M If coil springs are fitted, check that the
spring ends locate in their seats, and that the
spring is not corroded, cracked or broken.
M If 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.

M The 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.
M Inspect 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)

M Rotate 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 

M If 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).

M Examine 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.
M Look for signs of fluid leaks at the brake
calipers or on the brake backplates. Repair or
renew leaking components.
M Slowly 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.

3

Checks carried out
WITH THE VEHICLE RAISED
AND THE WHEELS FREE TO
TURN

MOT Test Checks

REF•11

REF

M Examine 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.
M It 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

M Inspect the fuel tank (including the filler
cap), fuel pipes, hoses and unions. All
components must be secure and free from
leaks.
M Examine 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 

M Examine 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 and

properly seated, and that the wheel is not
distorted or damaged. 
M Check 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.
M Check 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

M Check 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.
M Damage or corrosion which causes sharp
or otherwise dangerous edges to be exposed
will also cause the vehicle to fail.

Petrol models

M Have 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).
M Before any measurements are carried out,
raise the engine speed to around 2500 rpm,
and hold it at this speed for 20 seconds. Allow
the 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).
M An 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)

M At 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 emissions

M With 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.
M Excessive HC emissions can be caused by
oil being burnt, but they are more likely to be
due to unburnt fuel. 

Diesel models

M The 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.

4

Checks carried out on
YOUR VEHICLE’S EXHAUST
EMISSION SYSTEM

Engine  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1

m

m

Engine fails to rotate when attempting to start

m

m

Engine rotates, but will not start

m

m

Engine difficult to start when cold

m

m

Engine difficult to start when hot

m

m

Starter motor noisy or excessively-rough in engagement

m

m

Engine starts, but stops immediately

m

m

Engine idles erratically

m

m

Engine misfires at idle speed

m

m

Engine misfires throughout the driving speed range

m

m

Engine hesitates on acceleration

m

m

Engine stalls

m

m

Engine lacks power

m

m

Engine backfires

m

m

Oil pressure warning light illuminated with engine running

m

m

Engine runs-on after switching off

m

m

Engine noises

Cooling system  . . . . . . . . . . . . . . . . . . . . . .2

m

m

Overheating

m

m

Overcooling

m

m

External coolant leakage

m

m

Internal coolant leakage

m

m

Corrosion

Fuel and exhaust systems  . . . . . . . . . . . . .3

m

m

Excessive fuel consumption

m

m

Fuel leakage and/or fuel odour

m

m

Excessive noise or fumes from exhaust system

Clutch  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

m

m

Pedal travels to floor - no pressure or very little resistance

m

m

Clutch fails to disengage (unable to select gears)

m

m

Clutch slips (engine speed increases, with no increase in vehicle 
speed)

m

m

Judder as clutch is engaged

m

m

Noise when depressing or releasing clutch pedal

Manual transmission  . . . . . . . . . . . . . . . . . .5

m

m

Noisy in neutral with engine running

m

m

Noisy in one particular gear

m

m

Difficulty engaging gears

m

m

Jumps out of gear

m

m

Vibration

m

m

Lubricant leaks

Automatic transmission  . . . . . . . . . . . . . . .6

m

m

Fluid leakage

m

m

Transmission fluid brown, or has burned smell

m

m

General gear selection problems

m

m

Transmission will not downshift (kickdown) with accelerator fully 
depressed

m

m

Engine will not start in any gear, or starts in gears other than 
Park or Neutral

m

m

Transmission slips, shifts roughly, is noisy, or has no drive in 
forward or reverse gears

Driveshafts  . . . . . . . . . . . . . . . . . . . . . . . . . .7

m

m

Clicking or knocking noise on turns (at slow speed on full-lock)

m

m

Vibration when accelerating or decelerating

Braking system  . . . . . . . . . . . . . . . . . . . . . .8

m

m

Vehicle pulls to one side under braking

m

m

Noise (grinding or high-pitched squeal) when brakes applied

m

m

Excessive brake pedal travel

m

m

Brake pedal feels spongy when depressed

m

m

Excessive brake pedal effort required to stop vehicle

m

m

Judder felt through brake pedal or steering wheel when braking

m

m

Brakes binding

m

m

Rear wheels locking under normal braking

Suspension and steering systems  . . . . . . .9

m

m

Vehicle pulls to one side

m

m

Wheel wobble and vibration

m

m

Excessive pitching and/or rolling around corners, or during
braking

m

m

Wandering or general instability

m

m

Excessively-stiff steering

m

m

Excessive play in steering

m

m

Lack of power assistance

m

m

Tyre wear excessive

Electrical system  . . . . . . . . . . . . . . . . . . . .10

m

m

Battery will not hold a charge for more than a few days

m

m

Ignition/no-charge warning light remains illuminated with engine
running

m

m

Ignition/no-charge warning light fails to come on

m

m

Lights inoperative

m

m

Instrument readings inaccurate or erratic

m

m

Horn inoperative, or unsatisfactory in operation

m

m

Windscreen/tailgate wipers inoperative, or unsatisfactory in 
operation

m

m

Windscreen/tailgate washers inoperative, or unsatisfactory in 
operation

m

m

Electric windows inoperative, or unsatisfactory in operation

m

m

Central locking system inoperative, or unsatisfactory in operation

REF•12

Fault Finding

Introduction

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 which
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 begin

investigations. 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), but 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.

The pages which follow provide an easy-reference guide to the

more common problems which 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 which 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.

Don’t overlook the obvious. For example, if the vehicle won’t start, is

there fuel in the tank? (Don’t take anyone else’s word on this particular
point, and don’t 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
wasn’t simply an incorrect grade of plug) will have to be established
and corrected.

Don’t take anything for granted. Particularly, don’t forget that a

“new” component may itself be defective (especially if it’s been
rattling around in the boot for months), and don’t 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’ll
probably realise that all the evidence was there from the start.

Fault Finding

REF•13

REF

1 Engine

Engine fails to rotate when attempting to start

m

m

Battery terminal connections loose or corroded 
(“Weekly checks”).

m

m

Battery discharged or faulty (Chapter 5A).

m

m

Broken, loose or disconnected wiring in the starting circuit
(Chapter 5A).

m

m

Defective starter solenoid or switch (Chapter 5A).

m

m

Defective starter motor (Chapter 5A).

m

m

Starter pinion or flywheel/driveplate ring gear teeth loose or
broken (Chapter 2A, 2B or 5A).

m

m

Engine earth strap broken or disconnected (Chapter 5A).

Engine rotates, but will not start

m

m

Fuel tank empty.

m

m

Battery discharged (engine rotates slowly) (Chapter 5A).

m

m

Battery terminal connections loose or corroded 
(“Weekly checks”).

m

m

Ignition components damp or damaged (Chapter 1 and 5B).

m

m

Broken, loose or disconnected wiring in the ignition circuit
(Chapters 1 and 5B).

m

m

Worn, faulty or incorrectly-gapped spark plugs (Chapter 1).

m

m

Faulty choke or carburettor (Chapter 4A).

m

m

Fuel injection system fault (Chapter 4B or 4C).

m

m

Major mechanical failure (eg broken timing chain) 
(Chapter 2A, 2B or 2C).

Engine difficult to start when cold

m

m

Battery discharged (Chapter 5A).

m

m

Battery terminal connections loose or corroded 
(“Weekly checks”).

m

m

Worn, faulty or incorrectly-gapped spark plugs (Chapter 1).

m

m

Faulty choke or carburettor (Chapter 4A).

m

m

Fuel injection system fault (Chapter 4B or 4C).

m

m

Other ignition system fault (Chapters 1 and 5B).

m

m

Low cylinder compressions (Chapter 2A, 2B or 2C).

Engine difficult to start when hot

m

m

Air filter element dirty or clogged (Chapter 1).

m

m

Faulty choke or carburettor (Chapter 4A).

m

m

Fuel injection system fault (Chapter 4B or 4C).

m

m

Low cylinder compressions (Chapter 2A or 2B).

Starter motor noisy or 
excessively-rough in engagement

m

m

Starter pinion or flywheel/driveplate ring gear teeth loose or
broken (Chapter 2A, 2B or 5A).

m

m

Starter motor mounting bolts loose or missing (Chapter 5A).

m

m

Starter motor internal components worn or damaged 
(Chapter 5A).

Engine starts, but stops immediately

m

m

Loose or faulty electrical connections in the ignition circuit
(Chapters 1 and 5B).

m

m

Vacuum leak at the carburettor, throttle body or inlet manifold
(Chapters 4A, 4B, 4C or 4D).

m

m

Faulty carburettor (Chapter 4A).

m

m

Fuel injection system fault (Chapter 4B or 4C).

Engine idles erratically

m

m

Incorrectly-adjusted idle speed (Chapter 4A, 4B or 4C).

m

m

Air filter element clogged (Chapter 1).

m

m

Vacuum leak at the carburettor, throttle body, inlet manifold or
associated hoses (Chapter 4A, 4B, 4C or 4D).

m

m

Worn, faulty or incorrectly-gapped spark plugs (Chapter 1).

m

m

Uneven or low cylinder compressions (Chapter 2A or 2B).

m

m

Camshaft lobes worn (Chapter 2A or 2B).

m

m

Timing belt incorrectly tensioned (Chapter 2A or 2B).

m

m

Faulty carburettor (Chapter 4A).

m

m

Fuel injection system fault (Chapter 4B or 4C).

Engine misfires at idle speed

m

m

Worn, faulty or incorrectly-gapped spark plugs (Chapter 1).

m

m

Faulty spark plug HT leads (Chapter 1).

m

m

Vacuum leak at the carburettor, throttle body, inlet manifold or
associated hoses (Chapter 4A, 4B, 4C or 4D).

m

m

Faulty carburettor (Chapter 4A).

m

m

Fuel injection system fault (Chapter 4B or 4C).

m

m

Distributor cap cracked or tracking internally (Chapter 1).

m

m

Uneven or low cylinder compressions (Chapter 2A or 2B).

m

m

Disconnected, leaking, or perished crankcase ventilation hoses
(Chapter 4D).

Engine misfires 
throughout the driving speed range

m

m

Fuel filter choked (Chapter 1).

m

m

Fuel pump faulty, or delivery pressure low 
(Chapter 4A, 4B or 4C).

m

m

Fuel tank vent blocked, or fuel pipes restricted 
(Chapter 4A, 4B or 4C).

m

m

Vacuum leak at the carburettor, throttle body, inlet manifold or
associated hoses (Chapter 4A, 4B, 4C or 4D).

m

m

Worn, faulty or incorrectly-gapped spark plugs (Chapter 1).

m

m

Faulty spark plug HT leads (Chapter 1).

m

m

Distributor cap cracked or tracking internally (Chapter 1).

m

m

Faulty ignition coil (Chapter 5B).

m

m

Uneven or low cylinder compressions (Chapter 2A or 2B).

m

m

Faulty carburettor (Chapter 4A).

m

m

Fuel injection system fault (Chapter 4B or 4C).

Engine hesitates on acceleration

m

m

Worn, faulty or incorrectly-gapped spark plugs (Chapter 1).

m

m

Vacuum leak at the carburettor, throttle body, inlet manifold or
associated hoses (Chapter 4A, 4B or 4C).

m

m

Faulty carburettor (Chapter 4A).

m

m

Fuel injection system fault (Chapter 4B or 4C).

Engine stalls

m

m

Vacuum leak at the carburettor, throttle body, inlet manifold or
associated hoses (Chapter 4A, 4B or 4C).

m

m

Fuel filter choked (Chapter 1).

m

m

Fuel pump faulty, or delivery pressure low 
(Chapter 4A, 4B or 4C).

m

m

Fuel tank vent blocked, or fuel pipes restricted 
(Chapter 4A, 4B or 4C).

m

m

Faulty carburettor (Chapter 4A).

m

m

Fuel injection system fault (Chapter 4B or 4C).

Engine lacks power

m

m

Timing belt incorrectly fitted or tensioned (Chapter 2A or 2B).

m

m

Fuel filter choked (Chapter 1).

m

m

Fuel pump faulty, or delivery pressure low 
(Chapter 4A, 4B or 4C).

m

m

Uneven or low cylinder compressions (Chapter 2A or 2B).

m

m

Worn, faulty or incorrectly-gapped spark plugs (Chapter 1).

m

m

Vacuum leak at the carburettor, throttle body, inlet manifold or
associated hoses (Chapter 4A, 4B or 4C).

m

m

Faulty carburettor (Chapter 4A).

m

m

Fuel injection system fault (Chapter 4B or 4C).

m

m

Brakes binding (Chapters 1 and 9).

m

m

Clutch slipping (Chapter 6).

Engine backfires

m

m

Timing belt incorrectly fitted or tensioned (Chapter 2A).

m

m

Vacuum leak at the carburettor, throttle body, inlet manifold or
associated hoses (Chapter 4A, 4B or 4C).

m

m

Faulty carburettor (Chapter 4A).

m

m

Fuel injection system fault (Chapter 4B or 4C).

Oil pressure warning light illuminated with
engine running

m

m

Low oil level, or incorrect oil grade (Chapter 1).

m

m

Faulty oil pressure sensor (Chapter 2A or 2B).

m

m

Worn engine bearings and/or oil pump (Chapter 2A, 2B or 2C).

m

m

Excessively high engine operating temperature (Chapter 3).

m

m

Oil pressure relief valve defective (Chapter 2A or 2B).

m

m

Oil pick-up strainer clogged (Chapter 2C).

Note: Low oil pressure in a high-mileage engine at tickover is not
necessarily a cause for concern. Sudden pressure loss at speed is far
more significant. In any event, check the gauge or warning light
sender before condemning the engine.

Engine runs-on after switching off

m

m

Excessive carbon build-up in engine (Chapter 2A, 2B or 2C).

m

m

Excessively high engine operating temperature (Chapter 3).

Engine noises

Pre-ignition (pinking) or knocking 
during acceleration or under load

m

m

Ignition timing incorrect/ignition system fault (Chapters 1 and 5B).

m

m

Incorrect grade of spark plug (Chapter 1).

m

m

Incorrect grade of fuel (Chapter 1).

m

m

Vacuum leak at carburettor, throttle body, inlet manifold or
associated hoses (Chapter 4A, 4B or 4C).

m

m

Excessive carbon build-up in engine (Chapter 2A, 2B or 2C).

m

m

Faulty carburettor (Chapter 4A).

m

m

Fuel injection system fault (Chapter 4B or 4C).

Whistling or wheezing noises

m

m

Leaking inlet manifold or throttle body gasket 
(Chapter 4A, 4B or 4C).

m

m

Leaking exhaust manifold gasket (Chapter 4A, 4B or 4C).

m

m

Leaking vacuum hose (Chapters 4A, 4B, and 4C).

m

m

Blowing cylinder head gasket (Chapter 2A or 2B).

Tapping or rattling noises

m

m

Worn valve gear or camshaft (Chapter 2A or 2B).

m

m

Incorrect valve clearances (Chapter 1)

m

m

Ancillary component fault (water pump, alternator, etc) 
(Chapters 3, 5A, etc).

Knocking or thumping noises

m

m

Worn big-end bearings (regular heavy knocking, perhaps less
under load) (Chapter 2C).

m

m

Worn main bearings (rumbling and knocking, perhaps worsening
under load) (Chapter 2C).

m

m

Piston slap (most noticeable when cold) (Chapter 2C).

m

m

Ancillary component fault (water pump, alternator, etc) 
(Chapters 3, 5A, etc).

REF•14

Fault Finding

1 Engine (continued)

2 Cooling system

Fault Finding

REF•15

REF

Overheating

m

m

Insufficient coolant in system (“Weekly checks”).

m

m

Thermostat faulty (Chapter 3).

m

m

Radiator core blocked, or grille restricted (Chapter 3).

m

m

Electric cooling fan or thermostatic switch faulty (Chapter 3).

m

m

Pressure cap faulty (Chapter 3).

m

m

Ignition timing incorrect, or ignition system fault 
(Chapters 1 and 5B).

m

m

Inaccurate temperature gauge sender unit (Chapter 3).

m

m

Airlock in cooling system (Chapter 1).

Overcooling

m

m

Thermostat faulty (Chapter 3).

m

m

Inaccurate temperature gauge sender unit (Chapter 3).

External coolant leakage

m

m

Deteriorated or damaged hoses or hose clips (Chapter 1).

m

m

Radiator core or heater matrix leaking (Chapter 3).

m

m

Pressure cap faulty (Chapter 3).

m

m

Water pump internal seal leaking (Chapter 3).

m

m

Water pump gasket leaking (Chapter 3).

m

m

Boiling due to overheating (Chapter 3).

m

m

Core plug leaking (Chapter 2C).

Internal coolant leakage

m

m

Leaking cylinder head gasket (Chapter 2A or 2B).

m

m

Cracked cylinder head or cylinder block (Chapter 2A, 2B or 2C).

Corrosion

m

m

Infrequent draining and flushing (Chapter 1).

m

m

Incorrect coolant mixture or inappropriate coolant type (Chapter 1).

3 Fuel and exhaust systems

Excessive fuel consumption

m

m

Air filter element dirty or clogged (Chapter 1).

m

m

Faulty carburettor (Chapter 4A).

m

m

Fuel injection system fault (Chapter 4B or 4C).

m

m

Ignition timing incorrect or ignition system fault 
(Chapters 1 and 5B).

m

m

Tyres under-inflated (“Weekly checks”).

Fuel leakage and/or fuel odour

m

m

Damaged fuel tank, pipes or connections 
(Chapters 1 and 4A, 4B or 4C).

Excessive noise or fumes from exhaust system

m

m

Leaking exhaust system or manifold joints (Chapters 1 and 4D).

m

m

Leaking, corroded or damaged silencers or pipe 
(Chapters 1 and 4D).

m

m

Broken mountings causing body or suspension contact 
(Chapter 4D).

4 Clutch

Pedal travels to floor - 
no pressure or very little resistance

m

m

Broken clutch cable (Chapter 6).

m

m

Incorrect clutch cable adjustment  (Chapter 6).

m

m

Broken clutch release bearing or arm (Chapter 6).

m

m

Broken diaphragm spring in clutch pressure plate (Chapter 6).

Clutch fails to disengage (unable to select gears)

m

m

Incorrect clutch cable adjustment (Chapter 6).

m

m

Clutch disc sticking on splines (Chapter 6).

m

m

Clutch disc sticking to flywheel or pressure plate (Chapter 6).

m

m

Faulty pressure plate assembly (Chapter 6).

m

m

Clutch release mechanism worn or incorrectly assembled
(Chapter 6).

Clutch slips (engine speed increases, 
with no increase in vehicle speed)

m

m

Incorrect clutch cable adjustment (Chapter 6).

m

m

Clutch disc linings excessively worn (Chapter 6).

m

m

Clutch disc linings contaminated with oil or grease (Chapter 6).

m

m

Faulty pressure plate or weak diaphragm spring (Chapter 6).

Judder as clutch is engaged

m

m

Clutch disc linings contaminated with oil or grease (Chapter 6).

m

m

Clutch disc linings excessively worn (Chapter 6).

m

m

Clutch cable sticking or frayed (Chapter 6).

m

m

Faulty or distorted pressure plate or diaphragm spring (Chapter 6).

m

m

Worn or loose engine or gearbox mountings (Chapter 2A or 2B).

m

m

Clutch disc hub or shaft splines worn (Chapter 6).

Noise when depressing or releasing clutch pedal

m

m

Worn clutch release bearing (Chapter 6).

m

m

Worn or dry clutch pedal bushes (Chapter 6).

m

m

Faulty pressure plate assembly (Chapter 6).

m

m

Pressure plate diaphragm spring broken (Chapter 6).

m

m

Broken clutch disc cushioning springs (Chapter 6).