1993 FORD MONDEO timing belt

Chapter 5 Engine electrical systems
Alternator - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Alternator brushes and voltage regulator - renewal . . . . . . . . . . . . . 13
Auxiliary drivebelt check and renewal . . . . . . . . . . . . . See Chapter 1
Battery - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Battery check, maintenance and charging . . . . . . . . . See Chapter 1
Battery leads - check and renewal . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Charging system - general information and precautions . . . . . . . . . 10
Charging system - testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Crankshaft speed/position sensor - checking, removal and refitting 9
Electronic control system - information and
fault diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . See Chapter 6
Electronic Control Unit (ECU) and system information
sensors - general information . . . . . . . . . . . . . . . . . See Chapter 6Engine compartment wiring check . . . . . . . . . . . . . . . See Chapter 1
General information, precautions and battery disconnection . . . . . . 1
Ignition coil - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Ignition module (automatic transmission models only) -
removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Ignition system - general information and precautions . . . . . . . . . . . 4
Ignition system - testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Ignition timing - checking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Spark plug renewal and HT lead check . . . . . . . . . . . . See Chapter 1
Starter motor - brush and solenoid renewal . . . . . . . . . . . . . . . . . . . 17
Starter motor - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . 16
Starting system - general information and precautions . . . . . . . . . . 14
Starting system - testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Battery
Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Lead-acid
Rating - Cold cranking/Reserve capacity . . . . . . . . . . . . . . . . . . . . . . . 500 A/75 RC, 590 A/95 RC, or 650 A/130 RC
Ignition timing
Nominal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10° ± 2° BTDC
Note:Ignition timing is under control of ECU - it may vary constantly at idle speed, and is not adjustable.
Ignition coil
Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37.0 kilovolts (minimum)
Primary resistances - measured at coil connector terminal pins . . . . . . 0.50 ± 0.05 ohms
Alternator
Type:Model Rated output
Bosch unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . NC 14V 60-90A 90A
Mitsubishi unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A004T 90A
Minimum brush length - all types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.0 mm
Regulated voltage @ 4000 (engine) rpm and 3 to 7 amp load - all types .13.5 to 14.6 volts
Starter motor
Type:Model Rated output
Bosch unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DW 1.1 or 1.4 kW
Lucas/Magneti Marelli unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M79 1.0 kW
Minimum brush length - all types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.0 mm
Commutator minimum diameter:
Bosch units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32.8 mm
Lucas/Magneti Marelli unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Not available
Armature endfloat:
Bosch units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.30 mm
Lucas/Magneti Marelli unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.25 mm
Torque wrench settingsNm lbf ft
Crankshaft speed/position sensor:
Sensor-to-bracket screw . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 to 9 4 to 6
Bracket-to-cylinder block crankcase screw . . . . . . . . . . . . . . . . . . . . 21 15
Ignition coil bracket-to-cylinder head screws . . . . . . . . . . . . . . . . . . . . 21 15
Alternator mounting bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 37
Starter motor mounting bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 26
5•1
Easy,suitable for
novice with little
experienceFairly easy,suitable
for beginner with
some experienceFairly difficult,suitable
for competent DIY
mechanicDifficult,suitable for
experienced DIY
mechanicVery difficult,
suitable for expert DIY
or professional
Degrees of difficulty
Specifications Contents
5
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constantly monitors the oxygen content of the
exhaust gas. If the percentage of oxygen in
the exhaust gas is incorrect, an electrical
signal is sent to the ECU. The ECU processes
this information, and then sends a command
to the fuel injection system, telling it to change
the air/fuel mixture; the end result is an air/fuel
mixture ratio which is constantly maintained
at a predetermined ratio, regardless of driving
conditions. This happens in a fraction of a
second, and goes on almost all the time while
the engine is running - the exceptions are that
the ECU cuts out the system and runs the
engine on values pre-programmed
(“mapped”) into its memory both while the
oxygen sensor is reaching its normal
operating temperature after the engine has
been started from cold, and when the throttle
is fully open for full acceleration.
In the event of a sensor malfunction, a
back-up circuit will take over, to provide
driveability until the problem is identified and
fixed.
Precautions
(a) Always disconnect the power by
uncoupling the battery terminals - see
Section 1 of Chapter 5 - before removing
any of the electronic control system’s
electrical connectors.
(b) When installing a battery, be particularly
careful to avoid reversing the positive and
negative battery leads.
(c) Do not subject any components of the
system (especially the ECU) to severe
impact during removal or installation.
(d) Do not be careless during fault diagnosis.
Even slight terminal contact can invalidate
a testing procedure, and damage one of
the numerous transistor circuits.
(e) Never attempt to work on the ECU, to test
it (with any kind of test equipment), or to
open its cover.
(f) If you are inspecting electronic control
system components during rainy weather,
make sure that water does not enter any
part. When washing the engine
compartment, do not spray these parts or
their electrical connectors with water.
General
The various components of the fuel, ignition
and emissions control systems (not forgetting
the same ECU’s control of sub-systems such
as the radiator cooling fan, air conditioning
and automatic transmission, where
appropriate) are so closely interlinked that
diagnosis of a fault in any one component is
virtually impossible using traditional methods.
Working on simpler systems in the past, the
experienced mechanic may well have been
able to use personal skill and knowledge
immediately to pinpoint the cause of a fault, or
quickly to isolate the fault, by elimination;however, with an engine management system
integrated to this degree, this is not likely to
be possible in most instances, because of the
number of symptoms that could arise from
even a minor fault.
So that the causes of faults can be quickly
and accurately traced and rectified, the ECU
is provided with a built-in self-diagnosis
facility, which detects malfunctions in the
system’s components. When a fault occurs,
three things happen: the ECU identifies the
fault, stores a corresponding code in its
memory, and (in most cases) runs the system
using back-up values pre-programmed
(“mapped”) into its memory; some form of
driveability is thus maintained, to enable the
vehicle to be driven to a garage for attention.
Any faults that may have occurred are
indicated in the form of three-digit codes
when the system is connected (via the built-in
diagnosis or self-test connectors, as
appropriate) to special diagnostic equipment -
this points the user in the direction of the
faulty circuit, so that further tests can pinpoint
the exact location of the fault.
Given below is the procedure that would be
followed by a Ford technician to trace a fault
from scratch. Should your vehicle’s engine
management system develop a fault, read
through the procedure and decide how much
you can attempt, depending on your skill and
experience and the equipment available to
you, or whether it would be simpler to have
the vehicle attended to by your local Ford
dealer. If you are concerned about the
apparent complexity of the system, however,
remember the comments made in the fourth
paragraph of Section 1 of this Chapter; the
preliminary checks require nothing but care,
patience and a few minor items of equipment,
and may well eliminate the majority of faults.
(a) Preliminary checks
(b) Fault code read-out *
(c) Check ignition timing and base idle
speed. Recheck fault codes to establish
whether fault has been cured or not *
(d) Carry out basic check of ignition system
components. Recheck fault codes to
establish whether fault has been cured or
not *
(e) Carry out basic check of fuel system
components. Recheck fault codes to
establish whether fault has been cured or
not *
(f) If fault is still not located, carry out system
test *
Note:Operations marked with an asterisk
require special test equipment.
Preliminary checks
Note:When carrying out these checks to
trace a fault, remember that if the fault has
appeared only a short time after any part of
the vehicle has been serviced or overhauled,
the first place to check is where that work was
carried out, however unrelated it may appear,
to ensure that no carelessly-refitted
components are causing the problem.If you are tracing the cause of a “partial”
engine fault, such as lack of performance, in
addition to the checks outlined below, check
the compression pressures (see Part A of
Chapter 2) and bear in mind the possibility
that one of the hydraulic tappets might be
faulty, producing an incorrect valve clearance.
Check also that the fuel filter has been
renewed at the recommended intervals.
If the system appears completely dead,
remember the possibility that the
alarm/inhibitor system may be responsible.
1The first check for anyone without special
test equipment is to switch on the ignition,
and to listen for the fuel pump (the sound of
an electric motor running, audible from
beneath the rear seats); assuming there is
sufficient fuel in the tank, the pump should
start and run for approximately one or two
seconds, then stop, each time the ignition is
switched on. If the pump runs continuously all
the time the ignition is switched on, the
electronic control system is running in the
back-up (or “limp-home”) mode referred to by
Ford as “Limited Operation Strategy” (LOS).
This almost certainly indicates a fault in the
ECU itself, and the vehicle should therefore be
taken to a Ford dealer for a full test of the
complete system using the correct diagnostic
equipment; do not waste time trying to test
the system without such facilities.
2If the fuel pump is working correctly (or not
at all), a considerable amount of fault
diagnosis is still possible without special test
equipment. Start the checking procedure as
follows.
3Open the bonnet and check the condition
of the battery connections - remake the
connections or renew the leads if a fault is
found (Chapter 5). Use the same techniques
to ensure that all earth points in the engine
compartment provide good electrical contact
through clean, metal-to-metal joints, and that
all are securely fastened. (In addition to the
earth connection at the engine lifting eye and
that from the transmission to the
body/battery, there is one earth connection
behind each headlight assembly, and one
below the power steering fluid reservoir.)
4Referring to the information given in
Chapter 12 and in the wiring diagrams at the
back of this manual, check that all fuses
protecting the circuits related to the engine
management system are in good condition.
Fit new fuses if required; while you are there,
check that all relays are securely plugged into
their sockets.
5Next work methodically around the engine
compartment, checking all visible wiring, and
the connections between sections of the
wiring loom. What you are looking for at this
stage is wiring that is obviously damaged by
chafing against sharp edges, or against
moving suspension/transmission components
and/or the auxiliary drivebelt, by being
trapped or crushed between carelessly-
refitted components, or melted by being
forced into contact with hot engine castings,
3 Diagnosis system -
general information
6•4 Emissions control systems
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Ignition timing and base idle
speed check
Note:The following procedure is a check only,
essentially of the ECU. Both the ignition timing
and the base idle speed are controlled by the
ECU. The ignition timing is not adjustable at
all; the base idle speed is set in production,
and should not be altered.
38If the fault code read-out (with any checks
resulting from it) has not eliminated the fault,
the next step is to check the ECU’s control of
the ignition timing and the base idle speed.
This task requires the use of a Ford STAR
tester (a proprietary fault code reader can be
used only if it is capable of inducing the ECU
to enter its “Service Adjustment Programme”),
coupled with an accurate tachometer and a
good-quality timing light. Without this
equipment, the task is not possible; the
vehicle must be taken to a Ford dealer for
attention.
39To make the check, apply the handbrake,
switch off the air conditioning (where fitted)
and any other electrical loads (lights, heated
rear window, etc), then select neutral (manual
transmission) or the “P” position (automatic
transmission). Start the engine, and warm it
up to normal operating temperature. The
radiator electric cooling fan must be running
continuously while the check is made; this
should be activated by the ECU, when
prompted by the tester. Switch off the engine,
and connect the test equipment as directed
by the manufacturer - refer to paragraph 26
above for details of STAR tester connection.
40Raise and support the front of the vehicle
securely, and remove the auxiliary drivebelt
cover (see Chapter 1). Emphasise the two
pairs of notches in the inner and outer rims of
the crankshaft pulley, using white paint. Note
that an ignition timing reference mark is not
provided on the pulley - in the normal
direction of crankshaft rotation (clockwise,
seen from the right-hand side of the vehicle)
the first pair of notches are irrelevant to the
vehicles covered in this manual, while the
second pair indicate Top Dead Centre (TDC)
when aligned with the rear edge of the raised
mark on the sump; when checking the ignition
timing, therefore, the (rear edge of the) sumpmark should appear just before the TDC
notches (see Part A of Chapter 2, Section 4,
for further information if required).
41Start the engine and allow it to idle. Work
through the engine-running test procedure
until the ECU enters its “Service Adjustment
Programme” - see paragraph 35 above.
42Use the timing light to check that the
timing marks appear approximately as
outlined above at idle speed. Do not spend
too much time on this check; if the timing
appears to be incorrect, the system may have
a fault, and a full system test must be carried
out (see below) to establish its cause.
43Using the tachometer, check that the
base idle speed is as given in the
Specifications Section of Chapter 4.
44If the recorded speed differs significantly
from the specified value, check for air leaks,
as described in the preliminary checks
(paragraphs 15 to 18 above), or any other
faults which might cause the discrepancy.
45The base idle speed is set in production
by means of an air bypass screw (located in
the front right-hand corner of the throttle
housing) which controls the amount of air that
is allowed to pass through a bypass passage,
past the throttle valve when it is fully closed in
the idle position; the screw is then sealed with
a white tamperproof plug (see illustration). In
service, the idle speed is controlled by the
ECU, which has the ability to compensate for
engine wear, build-up of dirt in the throttle
housing, and other factors which might
require changes in idle speed. The air bypass
screw setting should not, therefore, be
altered. If any alterations are made, a blue
tamperproof plug must be fitted, and the
engine should be allowed to idle for at least
five minutes on completion, so that the ECU
can re-learn its idle values.
46When both checks have been made and
the “Service Adjustment Programme” is
completed, follow the tester instructions to
return to the fault code read-out, and
establish whether the fault has been cured or
not.
Basic check of ignition system
47If the checks so far have not eliminated
the fault, the next step is to carry out a basic
check of the ignition system components,
using an engine analyser with an oscilloscope
- without such equipment, the only tests
possible are to remove and check each spark
plug in turn, to check the spark plug (HT) lead
connections and resistances, and to check
the connections and resistances of the
ignition coil. Refer to the relevant Sections of
Chapters 1 and 5.
Basic check of fuel system
48If the checks so far have not eliminated
the fault, the next step is to carry out a basic
check of the fuel system components.
49Assuming that the preliminary checks
have established that the fuel pump is
operating correctly, that the fuel filter isunlikely to be blocked, and also that there are
no leaks in the system, the next step is to
check the fuel pressure (see Chapter 4). If this
is correct, check the injectors (see Chapter 4)
and the Positive Crankcase Ventilation system
(see Chapter 1).
System test
50The final element of the Ford testing
procedure is to carry out a system test, using
a break-out box - this is a device that is
connected between the ECU and its electrical
connector, so that the individual circuits
indicated by the fault code read-out can be
tested while connected to the system, if
necessary with the engine running. In the case
of many of the system’s components, this
enables their output voltages to be measured
- a more accurate means of testing.
51In addition to the break-out box and the
adaptors required to connect it, several items
of specialist equipment are needed to
complete these tests. This puts them quite
beyond the scope of many smaller dealers, let
alone the DIY owner; the vehicle should be
taken to a Ford dealer for attention.
Note:This Section is concerned principally
with the sensors which give the ECU the
information it needs to control the various
engine management sub-systems - for further
details of those systems and their other
components, refer to the relevant Chapter of
this manual.
General
ECU (Electronic Control Unit)
1This component is the heart of the entire
engine management system, controlling the
fuel injection, ignition and emissions control
systems. It also controls sub-systems such as
the radiator cooling fan, air conditioning and
automatic transmission, where appropriate.
Refer to Section 2 of this Chapter for an
illustration of how it works.
Air mass meter
2This uses a “hot-wire” system, sending the
ECU a constantly-varying (analogue) voltage
signal corresponding to the mass of air
passing into the engine. Since air mass varies
with temperature (cold air being denser than
warm), measuring air mass provides the ECU
with a very accurate means of determining the
correct amount of fuel required to achieve the
ideal air/fuel mixture ratio.
Crankshaft speed/position sensor
3This is an inductive pulse generator bolted
(in a separate bracket) to the cylinder
block/crankcase, to scan the ridges between
36 holes machined in the inboard (right-hand)
face of the flywheel/driveplate. As each ridge
4 Information sensors -
general information, testing,
removal and refitting
6•10 Emissions control systems
3.45 Throttle housing air bypass screw is
sealed on production with a white
tamperproof plug (arrowed)
procarmanuals.com

REF•7
Engine fails to rotate when attempting to start
m mBattery terminal connections loose or corroded (Chapter 5).
m mBattery discharged or faulty (Chapter 5).
m mBroken, loose or disconnected wiring in the starting circuit
(Chapter 5).
m mDefective starter solenoid or switch (Chapter 5).
m mDefective starter motor (Chapter 5).
m mStarter pinion or flywheel ring gear teeth loose or broken (Chap-
ter 5).
m mEngine earth strap broken or disconnected (Chapter 5).
m mAutomatic transmission not in Park/Neutral position, or selector
lever position sensor faulty (Chapter 7, Part B).
Engine rotates but will not start
m mFuel tank empty.
m mBattery discharged (engine rotates slowly) (Chapter 5).
m mBattery terminal connections loose or corroded (Chapter 5).
m mIgnition components damp or damaged (Chapters 1 and 5).
m mBroken, loose or disconnected wiring in the ignition circuit
(Chapters 1 and 5).
m mWorn, faulty or incorrectly-gapped spark plugs (Chapter 1).
m mMajor mechanical failure (eg camshaft drive) (Chapter 2, Part A).
Engine difficult to start when cold
m
mBattery discharged (Chapter 5).
m mBattery terminal connections loose or corroded (Chapter 5).
m mWorn, faulty or incorrectly-gapped spark plugs (Chapter 1).
m mOther ignition system fault (Chapters 1 and 5).
m mEngine management system fault (Chapters 1, 4, 5 and 6)
m mLow cylinder compressions (Chapter 2, Part A).
Engine difficult to start when hot
m
mAir filter element dirty or clogged (Chapter 1).
m mEngine management system fault (Chapters 1, 4, 5 and 6)
m mLow cylinder compressions (Chapter 2, Part A).
m mFaulty hydraulic tappet(s) (Chapter 2, Part A).
Starter motor noisy or excessively-rough in
engagement
m mStarter pinion or flywheel ring gear teeth loose or broken (Chapter 5).
m mStarter motor mounting bolts loose or missing (Chapter 5).
m mStarter motor internal components worn or damaged (Chapter 5).
Engine starts but stops immediately
m
mLoose or faulty electrical connections in the ignition circuit
(Chapters 1 and 5).
m mEngine management system fault (Chapters 1, 4, 5 and 6)
m mVacuum leak at the inlet manifold (Chapters 1, 4 and 6).
Engine idles erratically
m
mIdle speed control valve faulty (Chapter 4).
m mEngine management system fault (Chapters 1, 4, 5 and 6)
m mAir filter element clogged (Chapter 1).
m mVacuum leak at the inlet manifold or associated hoses (Chap-
ters 1, 4 and 6).
m mWorn, faulty or incorrectly-gapped spark plugs (Chapter 1).
m mFaulty hydraulic tappet(s) (Chapter 2, Part A).
m mUneven or low cylinder compressions (Chapter 2, Part A).
m mCamshaft lobes worn (Chapter 2).
m mTiming belt incorrectly-tensioned (Chapter 2, Part A).
Engine misfires at idle speed
m
mWorn, faulty or incorrectly-gapped spark plugs (Chapter 1).
m mFaulty spark plug HT leads (Chapter 1).
m mIdle speed control valve faulty (Chapter 4).
m mIncorrect ignition timing (Chapters 5 and 6).
m mEngine management system fault (Chapters 1, 4, 5 and 6)
m mVacuum leak at the inlet manifold or associated hoses (Chap-
ters 1, 4 and 6).
m mFaulty hydraulic tappet(s) (Chapter 2, Part A).
m mUneven or low cylinder compressions (Chapter 2, Part A).
m mDisconnected, leaking or perished crankcase ventilation hoses
(Chapters 1 and 6).
Fault Finding
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 underheadings 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 petrol 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.
1 Engine
Introduction
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Engine misfires throughout the driving speed range
m mFuel filter choked (Chapter 1).
m mFuel pump faulty or delivery pressure low (Chapter 4).
m mFuel tank vent blocked or fuel pipes restricted (Chapter 4).
m mVacuum leak at the inlet manifold or associated hoses (Chap-
ters 1, 4 and 6).
m mWorn, faulty or incorrectly-gapped spark plugs (Chapter 1).
m mFaulty spark plug HT leads (Chapter 1).
m mFaulty ignition coil (Chapter 5).
m mEngine management system fault (Chapters 1, 4, 5 and 6)
m mUneven or low cylinder compressions (Chapter 2, Part A).
Engine hesitates on acceleration
m
mWorn, faulty or incorrectly-gapped spark plugs (Chapter 1).
m mEngine management system fault (Chapters 1, 4, 5 and 6).
m mVacuum leak at the inlet manifold or associated hoses (Chap-
ters 1, 4 and 6).
Engine stalls
m mIdle speed control valve faulty (Chapter 4).
m mEngine management system fault (Chapters 1, 4, 5 and 6).
m mVacuum leak at the inlet manifold or associated hoses (Chap-
ters 1, 4 and 6).
m mFuel filter choked (Chapter 1).
m mFuel pump faulty or delivery pressure low (Chapter 4).
m mFuel tank vent blocked or fuel pipes restricted (Chapter 4).
Engine lacks power
m
mIncorrect ignition timing (Chapters 5 and 6).
m mEngine management system fault (Chapters 1, 4, 5 and 6).
m mTiming belt incorrectly fitted or incorrectly tensioned (Chapter 2,
Part A).
m mFuel filter choked (Chapter 1).
m mFuel pump faulty or delivery pressure low (Chapter 4).
m mUneven or low cylinder compressions (Chapter 2, Part A).
m mWorn, faulty or incorrectly-gapped spark plugs (Chapter 1).
m mVacuum leak at the inlet manifold or associated hoses (Chap-
ters 1, 4 and 6).
m mBrakes binding (Chapters 1 and 9).
m mClutch slipping (Chapter 8).
m mAutomatic transmission fluid level incorrect (Chapter 1).
Engine runs-on after switching off
m
mIdle speed excessively high (Chapters 4 and 6).
m mEngine management system fault (Chapters 1, 4, 5 and 6).
m mExcessive carbon build-up in engine (Chapter 2, Part A).
m mHigh engine operating temperature (Chapter 3).
Engine backfires
m
mIgnition timing incorrect (Chapters 5 and 6).
m mEngine management system fault (Chapters 1, 4, 5 and 6).
m mTiming belt incorrectly fitted or incorrectly tensioned (Chapter 2,
Part A).
m mVacuum leak at the inlet manifold or associated hoses (Chap-
ters 1, 4 and 6).
Oil pressure warning light illuminated with engine
running
m mLow oil level or incorrect oil grade (Chapter 1).
m mFaulty oil pressure warning light switch (Chapter 2, Part A).
m mWorn engine bearings and/or oil pump (Chapter 2).
m mHigh engine operating temperature (Chapter 3).
m mOil pressure relief valve defective (Chapter 2, Part A).
m mOil pick-up strainer clogged (Chapter 2, Part A).
Engine noises
Pre-ignition (pinking) or knocking during acceleration or under
load
m mIgnition timing incorrect (Chapters 5 and 6).
m mIncorrect grade of fuel (Chapter 4).
m mVacuum leak at the inlet manifold or associated hoses (Chap-
ters 1, 4 and 6).
m mExcessive carbon build-up in engine (Chapter 2, Part A).
Whistling or wheezing noises
m mLeaking inlet manifold gasket (Chapter 2, Part A).
m mLeaking exhaust manifold gasket or downpipe-to-manifold joint
(Chapters 1, 2 Part A, and 4).
m mLeaking vacuum hose (Chapters 1, 4, 6 and 9).
m mBlowing cylinder head gasket (Chapter 2, Part A).
Tapping or rattling noises
m mFaulty hydraulic tappet(s) (Chapter 2, Part A).
m mWorn valve gear or camshaft (Chapter 2, Part A).
m mWorn timing belt or tensioner (Chapter 2, Part A).
m mAncillary component fault (water pump, alternator, etc) (Chap-
ters 3 and 5).
Knocking or thumping noises
m mWorn big-end bearings (regular heavy knocking, perhaps less
under load) (Chapter 2, Part B).
m mWorn main bearings (rumbling and knocking, perhaps worsening
under load) (Chapter 2, Part B).
m mPiston slap (most noticeable when cold) (Chapter 2, Part B).
m mAncillary component fault (water pump, alternator, etc) (Chap-
ters 3 and 5).
REF•8Fault Finding
2 Cooling system
Overheating
m mInsufficient coolant in system (Chapter 1).
m mThermostat faulty (Chapter 3).
m mRadiator core blocked or grille restricted (Chapter 3).
m mRadiator electric cooling fan(s) or coolant temperature sensor faulty
(Chapter 3).
m mEngine management system fault (Chapters 1, 4, 5 and 6).
m mPressure cap faulty (Chapter 3).
m mAuxiliary drivebelt worn or slipping (Chapter 1).
m mIgnition timing incorrect (Chapters 5 and 6).
m mInaccurate coolant temperature gauge sender (Chapter 3).
m mAir-lock in cooling system (Chapter 1).
Overcooling
m
mThermostat faulty (Chapter 3).
m mInaccurate coolant temperature gauge sender (Chapter 3).
External coolant leakage
m
mDeteriorated or damaged hoses or hose clips (Chapter 1).
m mRadiator core or heater matrix leaking (Chapter 3).
m mPressure cap faulty (Chapter 3).
m mWater pump seal leaking (Chapter 3).
m mBoiling due to overheating (Chapter 3).
m mCore plug leaking (Chapter 2, Part B).
procarmanuals.com

REF•16Glossary of Technical Terms
RotorIn a distributor, the rotating device
inside the cap that connects the centre
electrode and the outer terminals as it turns,
distributing the high voltage from the coil
secondary winding to the proper spark plug.
Also, that part of an alternator which rotates
inside the stator. Also, the rotating assembly
of a turbocharger, including the compressor
wheel, shaft and turbine wheel.
RunoutThe amount of wobble (in-and-out
movement) of a gear or wheel as it’s rotated.
The amount a shaft rotates “out-of-true.” The
out-of-round condition of a rotating part.
SSealantA liquid or paste used to prevent
leakage at a joint. Sometimes used in
conjunction with a gasket.
Sealed beam lampAn older headlight design
which integrates the reflector, lens and
filaments into a hermetically-sealed one-piece
unit. When a filament burns out or the lens
cracks, the entire unit is simply replaced.
Serpentine drivebeltA single, long, wide
accessory drivebelt that’s used on some
newer vehicles to drive all the accessories,
instead of a series of smaller, shorter belts.
Serpentine drivebelts are usually tensioned by
an automatic tensioner.
ShimThin spacer, commonly used to adjust
the clearance or relative positions between
two parts. For example, shims inserted into or
under bucket tappets control valve
clearances. Clearance is adjusted by
changing the thickness of the shim.
Slide hammerA special puller that screws
into or hooks onto a component such as a
shaft or bearing; a heavy sliding handle on the
shaft bottoms against the end of the shaft to
knock the component free.SprocketA tooth or projection on the
periphery of a wheel, shaped to engage with a
chain or drivebelt. Commonly used to refer to
the sprocket wheel itself.
Starter inhibitor switchOn vehicles with an
automatic transmission, a switch that
prevents starting if the vehicle is not in Neutral
or Park.
StrutSee MacPherson strut.
TTappetA cylindrical component which
transmits motion from the cam to the valve
stem, either directly or via a pushrod and
rocker arm. Also called a cam follower.
ThermostatA heat-controlled valve that
regulates the flow of coolant between the
cylinder block and the radiator, so maintaining
optimum engine operating temperature. A
thermostat is also used in some air cleaners in
which the temperature is regulated.
Thrust bearingThe bearing in the clutch
assembly that is moved in to the release
levers by clutch pedal action to disengage the
clutch. Also referred to as a release bearing.
Timing beltA toothed belt which drives the
camshaft. Serious engine damage may result
if it breaks in service.
Timing chainA chain which drives the
camshaft.
Toe-inThe amount the front wheels are
closer together at the front than at the rear. On
rear wheel drive vehicles, a slight amount of
toe-in is usually specified to keep the front
wheels running parallel on the road by
offsetting other forces that tend to spread the
wheels apart.
Toe-outThe amount the front wheels are
closer together at the rear than at the front. On
front wheel drive vehicles, a slight amount of
toe-out is usually specified.
ToolsFor full information on choosing and
using tools, refer to the Haynes Automotive
Tools Manual.
TracerA stripe of a second colour applied to
a wire insulator to distinguish that wire from
another one with the same colour insulator.
Tune-upA process of accurate and careful
adjustments and parts replacement to obtain
the best possible engine performance.TurbochargerA centrifugal device, driven by
exhaust gases, that pressurises the intake air.
Normally used to increase the power output
from a given engine displacement, but can
also be used primarily to reduce exhaust
emissions (as on VW’s “Umwelt” Diesel
engine).
UUniversal joint or U-jointA double-pivoted
connection for transmitting power from a
driving to a driven shaft through an angle. A
U-joint consists of two Y-shaped yokes and a
cross-shaped member called the spider.
VValveA device through which the flow of
liquid, gas, vacuum, or loose material in bulk
may be started, stopped, or regulated by a
movable part that opens, shuts, or partially
obstructs one or more ports or passageways.
A valve is also the movable part of such a
device.
Valve clearanceThe clearance between the
valve tip (the end of the valve stem) and the
rocker arm or tappet. The valve clearance is
measured when the valve is closed.
Vernier caliperA precision measuring
instrument that measures inside and outside
dimensions. Not quite as accurate as a
micrometer, but more convenient.
ViscosityThe thickness of a liquid or its
resistance to flow.
VoltA unit for expressing electrical
“pressure” in a circuit. One volt that will
produce a current of one ampere through a
resistance of one ohm.
WWeldingVarious processes used to join metal
items by heating the areas to be joined to a
molten state and fusing them together. For
more information refer to the Haynes
Automotive Welding Manual.
Wiring diagramA drawing portraying the
components and wires in a vehicle’s electrical
system, using standardised symbols. For
more information refer to the Haynes
Automotive Electrical and Electronic Systems
Manual.
Serpentine drivebelt
procarmanuals.com

REF•19Index
Oil pressure warning light switch - 2A•22
Oil pump - 2A•21
Oil seals - 2A•13, 2A•22, 7A•2, 7B•3, REF•4
Oil separator - 6•19
Open-circuit - 12•4
Overcooling - REF•8
Overhead console - 11•22
Overheating - REF•8
Oxygen sensor - 6•11, 6•12, 6•13
P
Pads - 9•3, 9•8
Pedals - 1•17, 4•5, 8•3, 9•10, 9•11
Piston rings - 2B•19
Pistons - 2B•12, 2B•17, 2B•21, 2B•22
Pitching and/or rolling around corners -
REF•11
Plastic components - 11•4
Plenum chamber - 4•3
Poisonous or irritant substances - 0•5
Pollen filter - 1•20, 3•8
Position sensor - 5•4, 6•10, 6•11, 6•12
Positive Crankcase Ventilation (PCV)
system - 1•23, 6•18, 6•19
Power steering - 1•8, 1•10, 6•11, 6•12,
6•13, 10•20, 10•21, 10•22
Power steering fluid - 1•2
Pressure-control relief valve - 9•13
Pressure-cycling and pressure-regulating
switches - 3•10
Project vehicles - 0•4
Pulse-air - 6•17, 6•18
Purge solenoid valve - 6•14
R
Radiator - 3•4, 3•5
Radiator grille - 11•5
Radio - 12•21, 12•22
Radio aerial - 12•22
Reading light - 12•11
Rear light cluster - 12•9, 12•13
Rear window - 12•8, 12•21
Relays - 12•5
Repair procedures - REF•4
Resonator (engine compartment) - 4•3
Respraying - 11•3
Reversing light switch - 7A•3
Road test - 1•20
Roadwheels - 1•17, 1•18, 1•20
Roll-over valves - 4•8
Routine maintenance and servicing- 1•1et
seq
Rubber gaiters- 1•18, 8•7, 8•9, 10•21
Rust holes in bodywork - 11•3
S
Safety first! - 0•5
Scalding - 0•5
Scratches in bodywork - 11•3
Screw threads and fastenings - REF•4
Seat belts - 0•8, 1•13, 11•19, 11•20Seats - 0•8, 11•18, 12•8
Selector assembly - 7B•2
Selector cable - 7B•2
Selector lever position sensor - 7B•2
Selector panel illumination - 12•11
Service indicator - 12•17, 12•18
Servo unit - 9•12, 9•13
Shock absorbers - 0•8, 0•9, 10•14
Shoes - 9•6
Short-circuit - 12•4
Sidelight - 12•9
Solenoid renewal - 5•8
Spare parts - REF•5
Spark plugs - 1•23
Speakers - 12•22
Speed control - 12•20
Speed sensor - 6•11, 6•12, 6•13
Speedometer - 7A•2, 7A•3, 7B•2, 7B•3,
12•15
Springs - 0•9
Starter motor - 5•7
Starter motor fault - REF•7
Starting system - 5•6
Steering - 0•7, 0•8, 0•9, 1•17, 1•20
Steering angles - 10•22
Steering column - 10•18, 10•20
Steering fault - REF•11
Steering knuckle - 10•5
Steering wheel - 10•17
Stop-light switch - 9•15
Striker - 11•13
Struts - 10•6, 10•7, 10•10, 10•12
Sump - 2A•19
Sun visor - 11•20
Sunroof - 11•18, 12•7
Suspension and steering systems- 0•8,
0•9, 1•17, 1•18, 1•20, 10•1et seq
Suspension and steering systems fault
finding - REF•11
Switches - 2A•22, 3•4, 3•5, 3•10, 4•8-
6•11, 6•12, 6•13, 7A•3, 9•15, 11•17,
12•6, 12•7, 12•8, 12•11, 12•18, 12•20
T
Tailgate - 1•8, 1•10, 11•15, 11•16, 12•17,
12•20, REF•12
Tappets - 2A•14
TCS inhibitor switch - 9•15
TCS throttle actuator - 9•15
Temperature gauge fault - REF•12
Thermostat - 3•3, 3•4
Throttle actuator - 9•15
Throttle housing - 4•9
Throttle potentiometer - 6•11, 6•13
Tie-bar - 10•13, 10•16
Timer module - 12•5
Timing - 5•4, 6•10
Timing belt - 1•26, 2A•10, 2A•13
Tools - REF•1, REF•3, REF•4
Top Dead Centre (TDC) for No 1 piston -
2A•6
Towing - 0•11
Track rod end - 10•22Traction Control System - 9•15, 12•7
Transmission- 1•11, 1•17, 2A•24, 2B•3,
2B•4, 7A•1 et seq, 7B•1 et seq, 12•11
Trim mouldings - 11•17
Trim panels - 11•6, 11•20
Trip computer - 12•17
Tyre wear - REF•11
Tyres - 0•10, 1•8
U
Underbody check - 1•19
Upper suspension arm - 10•16
V
Vacuum hoses - 1•15
Vacuum servo unit - 9•12, 9•13
Valve clearances - 2A•5
Valves - 2B•10, 2B•11
Vehicle identification - 0•8, REF•5
Vehicle pulls to one side - REF•10, REF•11
Vehicle speed sensor - 6•11, 6•12, 6•13
Ventilation system - 1•20, 3•7
Voltage regulator - 5•6
W
Warning lights - 12•11
Warning system - 12•17
Washer jets fault - REF•12
Washer nozzle - 12•21
Washer pump fault - REF•12
Washer reservoir and pump - 12•20
Washer system - 1•8, 1•10, 12•18, 12•20
Water pump - 3•6
Weights - 0•6
Wheel alignment - 10•22
Wheel arch liner - 11•24
Wheel bearings - 0•9
Wheel changing - 0•11
Wheel cylinders - 9•8
Wheel sensors - 9•14
Wheel wobble - REF•11
Wheels - 0•10, 1•17, 1•18, 1•20
Wheels locking - REF•11
Window glass - 11•8
Window regulator - 11•9
Windows - 11•17, 12•7, 12•8, 12•21,
REF•12
Windscreen - 0•7, 1•8, 1•10, 11•17, 12•6,
12•8, 12•16, 12•20, 12•21, REF•12
Wiper arms - 12•16
Wiper blade - 1•10
Wiper blade fault - REF•12
Wiper motor - 12•16, 12•17
Wipers - 12•6
Wiper fault - REF•12
Wiring - 1•15
Wiring diagrams- 12•23et seq
Working facilities - REF•3
procarmanuals.com