1997 JAGUAR XJ6 low oil pressure

6If the voltage is 6 volts, the element is okay
(there is no break). If the voltage is 12 volts,
the element is broken between the centre
of the element and the positive end. If the
voltage is 0 volts the element is broken
between the centre of the element and earth.
7To find the break, place the voltmeter
positive lead against the defogger positive
terminal. Place the voltmeter negative lead
with the foil strip against the heating element
at the positive terminal end and slide it toward
the negative terminal end. The point at which
the voltmeter deflects from zero to several
volts is the point at which the heating element
is broken (see illustration).
Repair
8Repair the break in the element using a
repair kit specifically recommended for this
purpose.
9Prior to repairing a break, turn off the system
and allow it to cool off for a few minutes.
10Lightly buff the element area with fine
steel wool, then clean it thoroughly with
rubbing alcohol.
11Use masking tape to mask off the area
being repaired.
12Thoroughly mix the epoxy, following the
instructions provided with the repair kit.
13Apply the epoxy material to the slit in the
masking tape, overlapping the undamaged
area about 3/4-inch on either end (see
illustration).
14Allow the repair to cure for 24 hours before
removing the tape and using the system.
17 Headlights- renewal
1
Warning: Later models are
equipped with halogen gas-filled
headlight bulbs which are underpressure and may shatter if the surface is
damaged or the bulb is dropped. Wear eye
protection and handle the bulbs carefully,
grasping only the base whenever possible.
Do not touch the surface of the bulb with
your fingers because the oil from your skin
could cause it to overheat and fail
prematurely. If you do touch the bulb
surface, clean it with rubbing alcohol.
Sealed beam units
1Remove the radiator grille (see Chapter 11).
2Detach the headlight bezel trim cover (see
illustration).
3Remove the headlight bezel (see
illustrations).
4Remove the screws which secure the
retaining ring and withdraw the ring. Support
the light as this is done (see illustration).
Body electrical system 12•9
12
16.13 Apply masking tape to the inside of
the window at the damaged area, then
brush on the special conductive coating17.2 Remove the screws (arrowed) and
detach the headlight bezel trim cover
17.3a Remove the two retaining screws
at the top and the one in the grille opening
(arrowed)17.3b The retaining screw at the
outside lower corner can be accessed
from under the bumper
3261 Jaguar XJ6 16.5 To determine if a heating element has broken, check the
voltage at the centre of each element. If the voltage is 6-volts, the
element is unbroken; if the voltage is 12-volts, the element is
broken between the centre and the positive end. If there is no
voltage, the element is broken between the centre and earth
16.7 To find the break, place the voltmeter positive lead against
the heated window positive terminal, place the voltmeter negative
lead with the foil strip against the heating element at the positive
terminal end and slide it toward the negative terminal end -
the point at which the voltmeter reading changes abruptly is the
point at which the element is broken

8Adjustment should be made with the
vehicle parked 25 feet from the wall, sitting
level, the petrol tank half-full and no unusually
heavy load in the vehicle.
9Starting with the low beam adjustment,
position the high intensity zone so it is two
inches below the horizontal line and two
inches to the right of the headlight vertical
line. Adjustments are made by turning the
knobs located behind the headlight housings
(see illustration 18.2).
10With the high beams on, the high intensity
zone should be vertically centred with the
exact centre just below the horizontal line.
Note:It may not be possible to position the
headlight aim exactly for both high and low
beams. If a compromise must be made, keep
in mind that the low beams are the most used
and have the greatest effect on safety.
11Have the headlights adjusted by a dealer
service department or service station at the
earliest opportunity.
19 Headlight housing
(1992 to 1994 models)-
removal and refitting
1
Warning: These vehicles are
equipped with halogen gas-filled
headlight bulbs which are under
pressure and may shatter if the
surface is damaged or the bulb is dropped.
Wear eye protection and handle the bulbs
carefully, grasping only the base whenever
possible. Do not touch the surface of the
bulb with your fingers because the oil from
your skin could cause it to overheat and
fail prematurely. If you do touch the bulb
surface, clean it with rubbing alcohol.
1Remove the headlight bulb (Section 17).
2Remove the retaining nuts, detach the
housing and withdraw it from the vehicle (see
illustration).
3Refitting is the reverse of removal.
20 Horn- check and renewal
2
Check
Note:Check the fuses before beginning
electrical diagnosis.
1Disconnect the electrical connector from
the horn.
2To test the horn, connect battery voltage to
the two terminals with a pair of jumper wires.
If the horn doesn’t sound, renew it.
3If the horn does sound, check for voltage at
the terminal when the horn button is
depressed (see illustration). If there’s voltage
at the terminal, check for a bad earth at the
horn.
4If there’s no voltage at the horn, check the
relay (see Section 6). Note that most horn
relays are either the four-terminal or externally
earthed three-terminal type.
5If the relay is OK, check for voltage to the
relay power and control circuits. If either of the
circuits are not receiving voltage, inspect the
wiring between the relay and the fuse panel.
6If both relay circuits are receiving voltage,
depress the horn button and check the circuit
from the relay to the horn button for continuityto earth. If there’s no continuity, check the
circuit for an open. If the circuit is good, renew
the horn button.
7If there’s continuity to earth through the
horn button, check for an open or short in the
circuit from the relay to the horn.Renewal
8Remove the radiator grille inserts (see
Chapter 11).
9Disconnect the electrical connector and
remove the retaining nuts securing the horn
brackets (see illustration).
10Refitting is the reverse of removal.
21 Bulb renewal
1
Front direction indicator/rear
parking and side marker lights
1Remove the lens retaining screws and the
lens (see illustration).
2Push inward and rotate the bulb anti-
clockwise to remove it from the holder.
3Renew the bulb, refit the lamp lens and test
the bulb operation.
Body electrical system 12•11
12
20.9 Disconnect the electrical connector,
remove the retaining nuts (arrowed) - then
detach the horn(s)21.1 The front direction indicator/rear
parking and side marker light bulbs are
accessible after removing the lens screws
3261 Jaguar XJ6 19.2 Remove the headlight housing retaining nuts (arrowed) from
the backside of the radiator support
20.3 Check for power at the horn terminal with the horn button
depressed

3261 Jaguar XJ6
REF•6Tools and working facilities
Introduction
A selection of good tools is a fundamental
requirement for anyone contemplating the
maintenance and repair of a motor vehicle.
For the owner who does not possess any,
their purchase will prove a considerable
expense, offsetting some of the savings made
by doing-it-yourself. However, provided that
the tools purchased meet the relevant national
safety standards and are of good quality, they
will last for many years and prove an
extremely worthwhile investment.
To help the average owner to decide which
tools are needed to carry out the various tasks
detailed in this manual, we have compiled
three lists of tools under the following
headings: Maintenance and minor repair,
Repair and overhaul, and Special. Newcomers
to practical mechanics should start off with
the Maintenance and minor repairtool kit, and
confine themselves to the simpler jobs around
the vehicle. Then, as confidence and
experience grow, more difficult tasks can be
undertaken, with extra tools being purchased
as, and when, they are needed. In this way, a
Maintenance and minor repairtool kit can be
built up into a Repair and overhaultool kit over
a considerable period of time, without any
major cash outlays. The experienced do-it-
yourselfer will have a tool kit good enough for
most repair and overhaul procedures, and will
add tools from the Specialcategory when it is
felt that the expense is justified by the amount
of use to which these tools will be put.
Maintenance
and minor repair tool kit
The tools given in this list should be
considered as a minimum requirement if
routine maintenance, servicing and minor
repair operations are to be undertaken. We
recommend the purchase of combination
spanners (ring one end, open-ended the
other); although more expensive than open-
ended ones, they do give the advantages of
both types of spanner.
MCombination spanners:
Metric - 8 to 19 mm inclusive
MAdjustable spanner - 35 mm jaw (approx.)
MSpark plug spanner (with rubber insert) -
petrol models
MSpark plug gap adjustment tool - petrol
models
MSet of feeler blades
MBrake bleed nipple spanner
MScrewdrivers:
Flat blade - 100 mm long x 6 mm dia
Cross blade - 100 mm long x 6 mm dia
MCombination pliers
MHacksaw (junior)
MTyre pump
MTyre pressure gauge
MOil can
MOil filter removal tool
MFine emery cloth
MWire brush (small)
MFunnel (medium size)
Repair and overhaul tool kit
These tools are virtually essential for
anyone undertaking any major repairs to a
motor vehicle, and are additional to those
given in the Maintenance and minor repairlist.
Included in this list is a comprehensive set of
sockets. Although these are expensive, they
will be found invaluable as they are so
versatile - particularly if various drives are
included in the set. We recommend the half-
inch square-drive type, as this can be used
with most proprietary torque wrenches.
The tools in this list will sometimes need to
be supplemented by tools from the Speciallist:
MSockets (or box spanners) to cover range in
previous list (including Torx sockets)
MReversible ratchet drive (for use with
sockets)
MExtension piece, 250 mm (for use with
sockets)
MUniversal joint (for use with sockets)
MTorque wrench (for use with sockets)
MSelf-locking grips
MBall pein hammer
MSoft-faced mallet (plastic/aluminium or
rubber)
MScrewdrivers:
Flat blade - long & sturdy, short (chubby),
and narrow (electrician’s) types
Cross blade – Long & sturdy, and short
(chubby) types
MPliers:
Long-nosed
Side cutters (electrician’s)
Circlip (internal and external)
MCold chisel - 25 mm
MScriber
MScraper
MCentre-punch
MPin punch
MHacksaw
MBrake hose clamp
MBrake/clutch bleeding kit
MSelection of twist drills
MSteel rule/straight-edge
MAllen keys (inc. splined/Torx type)
MSelection of files
MWire brush
MAxle stands
MJack (strong trolley or hydraulic type)
MLight with extension lead
Sockets and reversible ratchet drive
Clutch plate alignment setPiston ring compressorSpline bit set
Valve spring compressor

3261 Jaguar XJ6
REF•10MOT test checks
Exhaust system
MStart the engine. With your assistant
holding a rag over the tailpipe, check the
entire system for leaks. Repair or renew
leaking sections.
Jack up the front and rear of the vehicle,
and securely support it on axle stands.
Position the stands clear of the suspension
assemblies. Ensure that the wheels are
clear of the ground and that the steering
can be turned from lock to lock.
Steering mechanism
MHave your assistant turn the steering from
lock to lock. Check that the steering turns
smoothly, and that no part of the steering
mechanism, including a wheel or tyre, fouls
any brake hose or pipe or any part of the body
structure.
MExamine the steering rack rubber gaiters
for damage or insecurity of the retaining clips.
If power steering is fitted, check for signs of
damage or leakage of the fluid hoses, pipes or
connections. Also check for excessive
stiffness or binding of the steering, a missing
split pin or locking device, or severe corrosion
of the body structure within 30 cm of any
steering component attachment point.
Front and rear suspension and
wheel bearings
MStarting at the front right-hand side, grasp
the roadwheel at the 3 o’clock and 9 o’clock
positions and shake it vigorously. Check for
free play or insecurity at the wheel bearings,
suspension balljoints, or suspension mount-
ings, pivots and attachments.
MNow grasp the wheel at the 12 o’clock and
6 o’clock positions and repeat the previous
inspection. Spin the wheel, and check for
roughness or tightness of the front wheel
bearing.
MIf excess free play is suspected at a
component pivot point, this can be confirmed
by using a large screwdriver or similar tool and
levering between the mounting and the
component attachment. This will confirm
whether the wear is in the pivot bush, its
retaining bolt, or in the mounting itself (the bolt
holes can often become elongated).
MCarry out all the above checks at the other
front wheel, and then at both rear wheels.
Springs and shock absorbers
MExamine the suspension struts (when
applicable) for serious fluid leakage, corrosion,
or damage to the casing. Also check the
security of the mounting points.
MIf coil springs are fitted, check that the
spring ends locate in their seats, and that the
spring is not corroded, cracked or broken.
MIf leaf springs are fitted, check that all
leaves are intact, that the axle is securely
attached to each spring, and that there is no
deterioration of the spring eye mountings,
bushes, and shackles.MThe same general checks apply to vehicles
fitted with other suspension types, such as
torsion bars, hydraulic displacer units, etc.
Ensure that all mountings and attachments are
secure, that there are no signs of excessive
wear, corrosion or damage, and (on hydraulic
types) that there are no fluid leaks or damaged
pipes.
MInspect the shock absorbers for signs of
serious fluid leakage. Check for wear of the
mounting bushes or attachments, or damage
to the body of the unit.
Driveshafts
(fwd vehicles only)
MRotate each front wheel in turn and inspect
the constant velocity joint gaiters for splits or
damage. Also check that each driveshaft is
straight and undamaged.
Braking system
MIf possible without dismantling, check
brake pad wear and disc condition. Ensure
that the friction lining material has not worn
excessively, (A) and that the discs are not
fractured, pitted, scored or badly worn (B).
MExamine all the rigid brake pipes
underneath the vehicle, and the flexible
hose(s) at the rear. Look for corrosion, chafing
or insecurity of the pipes, and for signs of
bulging under pressure, chafing, splits or
deterioration of the flexible hoses.
MLook for signs of fluid leaks at the brake
calipers or on the brake backplates. Repair or
renew leaking components.
MSlowly spin each wheel, while your
assistant depresses and releases the
footbrake. Ensure that each brake is operating
and does not bind when the pedal is released.
3Checks carried out
WITH THE VEHICLE RAISED
AND THE WHEELS FREE TO
TURN

3261 Jaguar XJ6
MOT test checksREF•11
MExamine the handbrake mechanism,
checking for frayed or broken cables,
excessive corrosion, or wear or insecurity of
the linkage. Check that the mechanism works
on each relevant wheel, and releases fully,
without binding.
MIt is not possible to test brake efficiency
without special equipment, but a road test can
be carried out later to check that the vehicle
pulls up in a straight line.
Fuel and exhaust systems
MInspect the fuel tank (including the filler
cap), fuel pipes, hoses and unions. All
components must be secure and free from
leaks.
MExamine the exhaust system over its entire
length, checking for any damaged, broken or
missing mountings, security of the retaining
clamps and rust or corrosion.
Wheels and tyres
MExamine the sidewalls and tread area of
each tyre in turn. Check for cuts, tears, lumps,
bulges, separation of the tread, and exposure
of the ply or cord due to wear or damage.
Check that the tyre bead is correctly seated
on the wheel rim, that the valve is sound andproperly seated, and that the wheel is not
distorted or damaged.
MCheck that the tyres are of the correct size
for the vehicle, that they are of the same size
and type on each axle, and that the pressures
are correct.
MCheck the tyre tread depth. The legal
minimum at the time of writing is 1.6 mm over
at least three-quarters of the tread width.
Abnormal tread wear may indicate incorrect
front wheel alignment.
Body corrosion
MCheck the condition of the entire vehicle
structure for signs of corrosion in load-bearing
areas. (These include chassis box sections,
side sills, cross-members, pillars, and all
suspension, steering, braking system and
seat belt mountings and anchorages.) Any
corrosion which has seriously reduced the
thickness of a load-bearing area is likely to
cause the vehicle to fail. In this case
professional repairs are likely to be needed.
MDamage or corrosion which causes sharp
or otherwise dangerous edges to be exposed
will also cause the vehicle to fail.
Petrol models
MHave the engine at normal operating
temperature, and make sure that it is in good
tune (ignition system in good order, air filter
element clean, etc).
MBefore any measurements are carried out,
raise the engine speed to around 2500 rpm,
and hold it at this speed for 20 seconds. Allowthe engine speed to return to idle, and watch
for smoke emissions from the exhaust
tailpipe. If the idle speed is obviously much
too high, or if dense blue or clearly-visible
black smoke comes from the tailpipe for more
than 5 seconds, the vehicle will fail. As a rule
of thumb, blue smoke signifies oil being burnt
(engine wear) while black smoke signifies
unburnt fuel (dirty air cleaner element, or other
carburettor or fuel system fault).
MAn exhaust gas analyser capable of
measuring carbon monoxide (CO) and
hydrocarbons (HC) is now needed. If such an
instrument cannot be hired or borrowed, a
local garage may agree to perform the check
for a small fee.
CO emissions (mixture)
MAt the time of writing, the maximum CO
level at idle is 3.5% for vehicles first used after
August 1986 and 4.5% for older vehicles.
From January 1996 a much tighter limit
(around 0.5%) applies to catalyst-equipped
vehicles first used from August 1992. If the
CO level cannot be reduced far enough to
pass the test (and the fuel and ignition
systems are otherwise in good condition) then
the carburettor is badly worn, or there is some
problem in the fuel injection system or
catalytic converter (as applicable).
HC emissionsMWith the CO emissions within limits, HC
emissions must be no more than 1200 ppm
(parts per million). If the vehicle fails this test
at idle, it can be re-tested at around 2000 rpm;
if the HC level is then 1200 ppm or less, this
counts as a pass.
MExcessive HC emissions can be caused by
oil being burnt, but they are more likely to be
due to unburnt fuel.
Diesel models
MThe only emission test applicable to Diesel
engines is the measuring of exhaust smoke
density. The test involves accelerating the
engine several times to its maximum
unloaded speed.
Note: It is of the utmost importance that the
engine timing belt is in good condition before
the test is carried out.
M
Excessive smoke can be caused by a dirty
air cleaner element. Otherwise, professional
advice may be needed to find the cause.
4Checks carried out on
YOUR VEHICLE’S EXHAUST
EMISSION SYSTEM

3261 Jaguar XJ6
REF•12Fault finding
Introduction
This Section provides an easy reference guide to the more common
problems which may occur during the operation of your vehicle. These
problems and their possible causes are grouped under headings
denoting various components or systems, such as Engine, Cooling
system, etc. They also refer you to the Chapter and/or Section which
deals with the problem.
Remember that successful troubleshooting is not a mysterious
“black art” practised only by professional mechanics. It is simply the
result of the right knowledge combined with an intelligent, systematic
approach to the problem. Always work by a process of elimination,
starting with the simplest solution and working through to the mostcomplex - and never overlook the obvious. Anyone can run the petrol
tank dry or leave the lights on overnight, so don’t assume that you are
exempt from such oversights.
Finally, always establish a clear idea of why a problem has occurred
and take steps to ensure that it doesn’t happen again. If the electrical
system fails because of a poor connection, check all other connections
in the system to make sure that they don’t fail as well. If a particular
fuse continues to blow, find out why - don’t just replace one fuse after
another. Remember, failure of a small component can often be
indicative of potential failure or incorrect functioning of a more
important component or system.
Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
m mEngine backfires
m mEngine diesels (continues to run) after switching off
m mEngine hard to start when cold
m mEngine hard to start when hot
m mEngine lacks power
m mEngine lopes while idling or idles erratically
m mEngine misses at idle speed
m mEngine misses throughout driving speed range
m mEngine rattles at start-up
m mEngine rotates but will not start
m mEngine runs with oil pressure light on
m mEngine stalls
m mEngine starts but stops immediately
m mEngine stumbles on acceleration
m mEngine surges while holding accelerator steady
m mEngine will not rotate when attempting to start1
m mOil puddle under engine
m mPinking or knocking engine sounds during acceleration or uphill
m mStarter motor noisy or excessively rough in engagement
Fuel system . . . . . . . . . . . . . . . . . . . . . . . . .2
m
mExcessive fuel consumption
m mFuel leakage and/or fuel odour
Cooling system . . . . . . . . . . . . . . . . . . . . . .3
m
mCoolant loss
m mExternal coolant leakage
m mInternal coolant leakage
m mOvercooling
m mOverheating
m mPoor coolant circulation
Automatic transmission . . . . . . . . . . . . . . .4
m
mEngine will start in gears other than Park or Neutral
m mFluid leakage
m mShift cable problems
m mTransmission fluid brown or has a burned smell
m mTransmission slips, shifts roughly, is noisy or has no drive
m min forward or reverse gears
m mTransmission will not downshift with accelerator pedal
pressed to the floor
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
m mBrake pedal feels spongy when depressed
m mBrake pedal travels to the floor with little resistance
m mBrake roughness or chatter (pedal pulsates)
m mDragging brakes
m mExcessive brake pedal travel
m mExcessive pedal effort required to stop vehicle
m mGrabbing or uneven braking action
m mNoise (high-pitched squeal when the brakes are applied)
m mHandbrake does not hold
m mVehicle pulls to one side during braking
Suspension and steering systems . . . . . . .6
m
mAbnormal noise at the front end
m mAbnormal or excessive tyre wear
m mCupped tyres
m mErratic steering when braking
m mExcessive pitching and/or rolling around corners or
during braking
m mExcessive play or looseness in steering system
m mExcessive tyre wear on inside edge
m mExcessive tyre wear on outside edge
m mHard steering
m mPoor returnability of steering to centre
m mRattling or clicking noise in rack-and-pinion
m mShimmy, shake or vibration
m mSuspension bottoms
m mTyre tread worn in one place
m mVehicle pulls to one side
m mWander or poor steering stability
m mWheel makes a “thumping” noise
Electrical system . . . . . . . . . . . . . . . . . . . . .7
Battery will not hold a charge
Discharge warning light fails to come on when key is turned on
Discharge warning light fails to go out

3261 Jaguar XJ6
Fault findingREF•13
1 Engine
Engine will not rotate when attempting to start
m mBattery terminal connections loose or corroded (Chapter 1).
m mBattery discharged or faulty (Chapter 1).
m mDamaged left rear window harness shorting against glass rail
inside door, causing battery to drain (Chapter 12).
m mAutomatic transmission not completely engaged in Park
(Chapter 7).
m mBroken, loose or disconnected wiring in the starting circuit
(Chapters 5 and 12).
m mStarter motor pinion jammed in flywheel ring gear (Chapter 5).
m mStarter solenoid faulty (Chapter 5).
m mStarter motor faulty (Chapter 5).
m mIgnition switch faulty (Chapter 12).
m mStarter pinion or flywheel teeth worn or broken (Chapter 5).
m mInternal engine problem (Chapter 2B).
m mInertia switch activated (Chapter 12).
m mStarter relay defective (Chapter 5).
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 1).
m mLeaking fuel injector(s), faulty fuel pump, pressure regulator, etc.
(Chapter 4).
m mFuel not reaching fuel injection system (Chapter 4).
m mIgnition components damp or damaged (Chapter 5).
m mFuel injector stuck open (Chapter 4).
m mWorn, faulty or incorrectly gapped spark plugs (Chapter 1).
m mBroken, loose or disconnected wiring in the starting circuit
(Chapter 5).
m mLoose distributor is changing ignition timing (Chapter 1).
m mBroken, loose or disconnected wires at the ignition coil or faulty
coil (Chapter 5).
m m1988 and 1989 models may have electrical connector damage
between the fuel pump relay and the fuel pump (Chapter 12).
m mCoolant temperature sensor shorting on bonnet liner (Chapter 11).
m mDefective Mass Airflow (MAF) sensor (Chapter 6).
Engine hard to start when cold
m
mBattery discharged or low (Chapter 1).
m mFuel system malfunctioning (Chapter 4).
m mInjector(s) leaking (Chapter 4).
m mDistributor rotor carbon tracked (Chapter 5).
m mWater enters the air cleaner housing near the left front wheel arch
(Chapter 4).
Engine hard to start when hot
m mAir filter clogged (Chapter 1).
m mFuel not reaching the fuel injection system (Chapter 4).
m mCorroded battery connections, especially ground (Chapter 1).
m mFuel vaporises at fuel pump inlet. Refit dual fuel pumps
(Chapter 4).
m mFuel vapours from charcoal canister enter intake during idle and
cause idling, stalling and starting problems (Chapter 6).
Starter motor noisy or excessively rough in
engagement
m mPinion or flywheel gear teeth worn or broken (Chapter 5).
m mStarter motor mounting bolts loose or missing (Chapter 5).
Engine starts but stops immediately
m
mLoose or faulty electrical connections at distributor, coil or
alternator (Chapter 5).
m mInsufficient fuel reaching the fuel injector(s) (Chapters 1 and 4).
m mDamaged fuel injection system speed sensors (Chapter 5).
m mFaulty fuel injection relays (Chapter 5).
m mLeaking threaded adapter on the EGR valve - where fitted
(Chapter 6)
Oil puddle under engine
m mSump gasket and/or sump drain bolt seal leaking (Chapter 2).
m mOil pressure sending unit leaking (Chapter 2).
m mValve cover gaskets leaking (Chapter 2).
m mEngine oil seals leaking (Chapter 2).
m mCylinder head rear plate gasket leaking (Chapter 2).
m mAlternator mounting bolt threads leaking oil (Chapter 5).
m mOil cooler or oil cooler lines leaking (Chapter 3).
Engine misses while idling or idles erratically
m
mVacuum leakage (Chapter 2).
m mAir filter clogged (Chapter 1).
m mFuel pump not delivering sufficient fuel to the fuel injection system
(Chapter 4).
m mLeaking head gasket (Chapter 2).
m mTiming belt/chain and/or sprockets worn (Chapter 2).
m mCamshaft lobes worn (Chapter 2).
m mEGR valve stuck open - where fitted (Chapter 6).
Engine misses at idle speed
m
mSpark plugs worn or not gapped properly (Chapter 1).
m mFaulty spark plug leads (Chapter 1).
m mVacuum leaks (Chapter 1).
m mIncorrect ignition timing (Chapter 5).
m mUneven or low compression (Chapter 2).
m mRestricted EGR vacuum hose - where fitted (Chapter 6).
Engine misses throughout driving speed range
m
mFuel filter clogged and/or impurities in the fuel system (Chapter 1).
m mLow fuel output at the injectors (Chapter 4).
m mFaulty or incorrectly gapped spark plugs (Chapter 1).
m mIncorrect ignition timing (Chapter 5).
m mCracked distributor cap, disconnected distributor wires or
damaged distributor components (Chapter 1).
m mLeaking spark plug leads (Chapter 1).
m mFaulty emission system components (Chapter 6).
m mLow or uneven cylinder compression pressures (Chapter 2).
m mWeak or faulty ignition system (Chapter 5).
m mVacuum leak in fuel injection system, intake manifold or vacuum
hoses (Chapter 4).
m mCrankshaft sensor teeth damaged or missing (see Chapter 12).
m mDistributor installed incorrectly (see Chapter 5)
Engine stumbles on acceleration
m
mSpark plugs fouled (Chapter 1).
m mFuel injection system malfunctioning (Chapter 4).
m mFuel filter clogged (Chapters 1 and 4).
m mIncorrect ignition timing (Chapter 5).
m mIntake manifold air leak (Chapter 4).
m mCollapsed or damaged fuel tank caused by blocked EVAP system
- where fitted (see Chapter 6).

3261 Jaguar XJ6
REF•14Fault finding
2 Fuel system
Engine surges while holding accelerator steady
m mIntake air leak (Chapter 4).
m mFuel pump faulty (Chapter 4).
m mLoose fuel injector harness connections (Chapters 4 and 6).
m mDefective ECU (Chapter 6).
Pinking or knocking engine sounds during
acceleration or uphill
m mIncorrect grade of fuel.
m mDistributor installed incorrectly (Chapter 5).
m mFuel injection system in need of adjustment (Chapter 4).
m mImproper or damaged spark plugs or wires (Chapter 1).
m mWorn or damaged distributor components (Chapter 5).
m mFaulty emission system (Chapter 6).
m mVacuum leak (Chapter 4).
m mFuel rail feed (inlet) hose has hardened, resulting in knocking noise
near dash (see Chapter 4).
Engine lacks power
m mIncorrect ignition timing (Chapter 5).
m mExcessive play in distributor shaft (Chapter 5).
m mWorn rotor, distributor cap or wires (Chapters 1 and 5).
m mFaulty or incorrectly gapped spark plugs (Chapter 1).
m mFuel injection system malfunctioning (Chapter 4).
m mFaulty coil (Chapter 5).
m mBrakes binding (Chapter 1).
m mAutomatic transmission fluid level incorrect (Chapter 1).
m mFuel filter clogged and/or impurities in the fuel system (Chapter 1).
m mEmission control system not functioning properly (Chapter 6).
m mLow or uneven cylinder compression pressures (Chapter 2).
Engine rattles at start-up
m
mFailure of upper timing chain tensioner (Chapter 2).
Engine backfires
m
mEmissions system not functioning properly (Chapter 6).
m mIgnition timing incorrect (Chapter 1).
m mFaulty secondary ignition system (cracked spark plug insulator,
faulty plug leads, distributor cap and/or rotor) (Chapters 1 and 5).
m mFuel injection system malfunctioning (Chapter 4).
m mVacuum leak at fuel injector(s), intake manifold or vacuum hoses
(Chapter 4).
Engine stalls
m mIdle speed incorrect (Chapter 1).
m mFuel filter clogged and/or water and impurities in the fuel system
(Chapter 1).
m mDistributor components damp or damaged (Chapter 5).
m mFaulty emissions system components (Chapter 6).
m mFaulty or incorrectly gapped spark plugs (Chapter 1).
m mFaulty spark plug leads (Chapter 1).
m mVacuum leak in the fuel injection system, intake manifold or
vacuum hoses (Chapter 4).
Engine runs with oil pressure light on
m mLow oil level (Chapter 1).
m mIdle rpm too low (Chapter 1).
m mShort in wiring circuit (Chapter 12).
m mFaulty oil pressure sending unit (Chapter 2).
m mWorn engine bearings and/or oil pump (Chapter 2).
Engine diesels (continues to run)
after switching off
m mIdle speed too high (Chapter 4).
m mExcessive engine operating temperature (Chapter 3).
m mIncorrect fuel octane grade.
Excessive fuel consumption
m
mDirty or clogged air filter element (Chapter 1).
m mIncorrectly set ignition timing (Chapter 5).
m mEmissions system not functioning properly (Chapter 6).
m mFuel injection internal parts worn or damaged (Chapter 4).
m mLow tyre pressure or incorrect tyre size (Chapter 1).
Fuel leakage and/or fuel odour
m
mLeak in a fuel feed or vent line (Chapter 4).
m mTank overfilled.
m mFuel injector internal parts excessively worn (Chapter 4).
3 Cooling system
Overheating
m
mInsufficient coolant in system (Chapter 1).
m mWater pump drivebelt defective or out of adjustment (Chapter 1).
m mRadiator core blocked or grille restricted (Chapter 3).
m mThermostat faulty (Chapter 3).
m mRadiator cap not maintaining proper pressure (Chapter 3).
m mIgnition timing incorrect (Chapter 5).
Overcooling
m
mFaulty thermostat (Chapter 3).
External coolant leakage
m
mDeteriorated/damaged hoses; loose clamps (Chapters 1 and 3).
m mWater pump seal defective (Chapters 1 and 3).
m mLeakage from radiator core or manifold tank (Chapter 3).
m mEngine drain or water jacket core plugs leaking (Chapter 2).
m mHoses behind water pump leaking (Chapter 3).
Internal coolant leakage
m
mLeaking cylinder head gasket (Chapter 2).
m mCracked cylinder bore or cylinder head (Chapter 2).
Coolant loss
m
mToo much coolant in system (Chapter 1).
m mCoolant boiling away because of overheating (Chapter 3).
m mInternal or external leakage (Chapter 3).
m mFaulty radiator cap (Chapter 3).
Poor coolant circulation
m
mInoperative water pump (Chapter 3).
m mRestriction in cooling system (Chapters 1 and 3).
m mWater pump drivebelt defective/out of adjustment (Chapter 1).
m mThermostat sticking (Chapter 3).
1 Engine (continued)