3261 Jaguar XJ6
Safety first!0•5
Working on your car can be dangerous.
This page shows just some of the potential
risks and hazards, with the aim of creating a
safety-conscious attitude.
General hazards
Scalding
• Don’t remove the radiator or expansion
tank cap while the engine is hot.
• Engine oil, automatic transmission fluid or
power steering fluid may also be dangerously
hot if the engine has recently been running.
Burning
• Beware of burns from the exhaust system
and from any part of the engine. Brake discs
and drums can also be extremely hot
immediately after use.
Crushing
• When working under or near
a raised vehicle,
always
supplement the
jack with axle
stands, or use
drive-on
ramps.
Never
venture
under a car which
is only supported by a jack.
• Take care if loosening or tightening high-
torque nuts when the vehicle is on stands.
Initial loosening and final tightening should
be done with the wheels on the ground.
Fire
• Fuel is highly flammable; fuel vapour is
explosive.
• Don’t let fuel spill onto a hot engine.
• Do not smoke or allow naked lights
(including pilot lights) anywhere near a
vehicle being worked on. Also beware of
creating sparks
(electrically or by use of tools).
• Fuel vapour is heavier than air, so don’t
work on the fuel system with the vehicle over
an inspection pit.
• Another cause of fire is an electrical
overload or short-circuit. Take care when
repairing or modifying the vehicle wiring.
• Keep a fire extinguisher handy, of a type
suitable for use on fuel and electrical fires.
Electric shock
• Ignition HT
voltage can be
dangerous,
especially to
people with heart
problems or a
pacemaker. Don’t
work on or near the
ignition system with
the engine running or
the ignition switched on.• Mains voltage is also dangerous. Make
sure that any mains-operated equipment is
correctly earthed. Mains power points should
be protected by a residual current device
(RCD) circuit breaker.
Fume or gas intoxication
• Exhaust fumes are
poisonous; they often
contain carbon
monoxide, which is
rapidly fatal if inhaled.
Never run the
engine in a
confined space
such as a garage
with the doors shut.
• Fuel vapour is also
poisonous, as are the vapours from some
cleaning solvents and paint thinners.
Poisonous or irritant substances
• Avoid skin contact with battery acid and
with any fuel, fluid or lubricant, especially
antifreeze, brake hydraulic fluid and Diesel
fuel. Don’t syphon them by mouth. If such a
substance is swallowed or gets into the eyes,
seek medical advice.
• Prolonged contact with used engine oil can
cause skin cancer. Wear gloves or use a
barrier cream if necessary. Change out of oil-
soaked clothes and do not keep oily rags in
your pocket.
• Air conditioning refrigerant forms a
poisonous gas if exposed to a naked flame
(including a cigarette). It can also cause skin
burns on contact.
Asbestos
• Asbestos dust can cause cancer if inhaled
or swallowed. Asbestos may be found in
gaskets and in brake and clutch linings.
When dealing with such components it is
safest to assume that they contain asbestos.
Special hazards
Hydrofluoric acid
• This extremely corrosive acid is formed
when certain types of synthetic rubber, found
in some O-rings, oil seals, fuel hoses etc, are
exposed to temperatures above 400
0C. The
rubber changes into a charred or sticky
substance containing the acid. Once formed,
the acid remains dangerous for years. If it
gets onto the skin, it may be necessary to
amputate the limb concerned.
• When dealing with a vehicle which has
suffered a fire, or with components salvaged
from such a vehicle, wear protective gloves
and discard them after use.
The battery
• Batteries contain sulphuric acid, which
attacks clothing, eyes and skin. Take care
when topping-up or carrying the battery.
• The hydrogen gas given off by the battery
is highly explosive. Never cause a spark or
allow a naked light nearby. Be careful when
connecting and disconnecting battery
chargers or jump leads.
Air bags
• Air bags can cause injury if they go off
accidentally. Take care when removing the
steering wheel and/or facia. Special storage
instructions may apply.
Diesel injection equipment
• Diesel injection pumps supply fuel at very
high pressure. Take care when working on
the fuel injectors and fuel pipes.
Warning: Never expose the hands,
face or any other part of the body
to injector spray; the fuel can
penetrate the skin with potentially fatal
results.
Remember...
DO
• Do use eye protection when using power
tools, and when working under the vehicle.
• Do wear gloves or use barrier cream to
protect your hands when necessary.
• Do get someone to check periodically
that all is well when working alone on the
vehicle.
• Do keep loose clothing and long hair well
out of the way of moving mechanical parts.
• Do remove rings, wristwatch etc, before
working on the vehicle – especially the
electrical system.
• Do ensure that any lifting or jacking
equipment has a safe working load rating
adequate for the job.
A few tips
DON’T
• Don’t attempt to lift a heavy component
which may be beyond your capability – get
assistance.
• Don’t rush to finish a job, or take
unverified short cuts.
• Don’t use ill-fitting tools which may slip
and cause injury.
• Don’t leave tools or parts lying around
where someone can trip over them. Mop
up oil and fuel spills at once.
• Don’t allow children or pets to play in or
near a vehicle being worked on.
3261 Jaguar XJ6
0•6Roadside repairs
The following pages are intended to help in dealing with
common roadside emergencies and breakdowns. You will find
more detailed fault finding information at the back of the
manual, and repair information in the main chapters.
If your car won’t start
and the starter motor
doesn’t turn
MIf it’s a model with automatic transmission, make sure the
selector is in ‘P’ or ‘N’.
MOpen the bonnet and make sure that the battery terminals
are clean and tight.
MSwitch on the headlights and try to start the engine. If the
headlights go very dim when you’re trying to start, the
battery is probably flat. Get out of trouble by jump starting
(see next page) using a friend’s car.
If your car won’t start
even though the starter
motor turns as normal
MIs there fuel in the tank?
MIs there moisture on electrical components under the
bonnet? Switch off the ignition, then wipe off any obvious
dampness with a dry cloth. Spray a water-repellent aerosol
product (WD-40 or equivalent) on ignition and fuel system
electrical connectors like those shown in the photos.
Pay special attention to the ignition coil wiring connector
and HT leads.
Check the condition and security of the
battery connections.ACheck that the spark plug HT leads are
securely connected by pushing them onto
the plugs and distributorery connections.BCheck that the HT leads and wiring
connectors are securely connected to
the ignition coil.C
Check that the wiring connectors are
securely connected to the injectors and
various fuel system sensors and switches.D
Check that electrical connections are secure (with the ignition switched off) and spray them
with a water dispersant spray like WD40 if you suspect a problem due to damp
3261 Jaguar XJ6
Roadside repairs0•7
When jump-starting a car using a
booster battery, observe the following
precautions:
4Before connecting the booster
battery, make sure that the ignition
is switched off.
4Ensure that all electrical equipment
(lights, heater, wipers, etc) is
switched off.
4Take note of any special precautions
printed on the battery case.4Make sure that the booster battery
is the same voltage as the
discharged one in the vehicle.
4If the battery is being jump-started
from the battery in another vehicle,
the two vehicles MUST NOT TOUCH
each other.
4Make sure that the transmission is in
neutral (or PARK, in the case of
automatic transmission).
Jump starting will get you
out of trouble, but you must
correct whatever made the
battery go flat in the first
place. There are three possibilities:
1) The battery has been drained by
repeated attempts to start, or by
leaving the lights on.
2) The charging system is not working
properly (alternator drivebelt slack or
broken, alternator wiring fault or
alternator itself faulty).
3) The battery itself is at fault (electrolyte
low, or battery worn out).
Connect one end of the red jump lead
to the positive (+) terminal of the flat
batteryConnect the other end of the red lead
to the positive (+) terminal of the
booster batteryConnect one end of the black jump lead
to the negative (-) terminal of the
booster battery
Connect the other end of the black
jump lead to a bolt or bracket on the
engine block, well away from the
battery, on the vehicle to be started
123
4
Make sure that the jump leads will not
come into contact with the fan,
drivebelts or other moving parts of the
engine5
Start the engine using the booster
battery, then with the engine running at
idle speed, disconnect the jump leads
in the reverse order of connection6
Jump starting
3261 Jaguar XJ6
0•8Roadside repairs
The spare wheel and tools are stored in
the boot. Remove the carpet cover then
unscrew the retainer and lift out the spare
wheel from the boot.
Wheel changing
Some of the details shown here will vary
according to model. For instance, the location
of the spare wheel and jack is not the same
on all cars. However, the basic principles
apply to all vehicles.Warning: Do not change a wheel in a situation where you risk being hit by
other traffic. On busy roads, try to stop in a lay-by or a gateway. Be wary of
passing traffic while changing the wheel – it is easy to become distracted by
the job in hand.
Finally...
MRemove the wheel chocks.
MCheck the tyre pressure on the wheel just
fitted. If it is low, or if you don’t have a
pressure gauge with you, drive slowly to
the nearest garage and inflate the tyre to
the right pressure.
MHave the damaged tyre or wheel repaired
as soon as possible.
Remove the plastic cover from the end of
the vehicle jack lifting point tube, nearest
to the wheel that is being changed.Slide the lifting bracket of the jack fully
into the lifting point tube. Make sure the
jack is located on firm ground.Raise the jack until the wheel is raised
clear of the ground. Unscrew the wheel
nuts and remove the wheel. Fit the spare
wheel and screw on the nuts. Lightly tighten
the nuts then lower the vehicle to the ground.
With the vehicle on the ground, remove
the trim cap (where fitted) and slacken
each wheel nut by half a turn.Remove the jack and wheelbrace its
holder which is located behind the spare
wheel.123
4
Securely tighten the wheel nuts in a
diagonal sequence then (where necessary)
refit the wheel trim cap. Stow the tolls and
punctured wheel and back in the luggage
compartment and secure them in position.
Note that the wheel nuts should be slackened
and retightened to the specified torque at the
earliest possible opportunity.7
56
Preparation
MWhen a puncture occurs, stop as soon as
it is safe to do so.
MPark on firm level ground, if possible,
and well out of the way of other traffic.
MUse hazard warning lights if necessary. MIf you have one, use a warning triangle to
alert other drivers of your presence.
MApply the handbrake and engage first or
reverse gear (or Park on models with
automatic transmission.MChock the wheel diagonally opposite the
one being removed – a couple of large
stones will do for this.
MIf the ground is soft, use a flat piece of
wood to spread the load under the jack.
Changing the wheel
3261 Jaguar XJ6
Roadside repairs0•9
When all else fails, you may find yourself
having to get a tow home – or of course you
may be helping somebody else. Long-distance
recovery should only be done by a garage or
breakdown service. For shorter distances, DIY
towing using another car is easy enough, but
observe the following points:
MUse a proper tow-rope – they are not
expensive. The vehicle being towed must
display an ‘ON TOW’ sign in its rear window.
MAlways turn the ignition key to the ‘on’
position when the vehicle is being towed, so
that the steering lock is released, and that the
direction indicator and brake lights will work.
MOnly attach the tow-rope to the towing
eyes provided. On some models with energy-
absorbing bumpers there are no front towing
eyes; on these vehicles the tow-rope shouldbe attached around the rear arm of the lower
control arm so that the rope passes on the
inside of the coil spring.
MBefore being towed, release the handbrake
and select neutral on the transmission.
MNote that greater-than-usual pedal
pressure will be required to operate the
brakes, since the vacuum servo unit is only
operational with the engine running.
MOn models with power steering, greater-
than-usual steering effort will also be required.
MThe driver of the car being towed must
keep the tow-rope taut at all times to avoid
snatching.
MMake sure that both drivers know the route
before setting off.
MOnly drive at moderate speeds and keep
the distance towed to a minimum. Drivesmoothly and allow plenty of time for slowing
down at junctions.
MOn models with automatic transmission,
special precautions apply. If in doubt, do not
tow, or transmission damage may result.
Caution: On models with automatic
transmission, if the vehicle is to be towed
with its rear wheels on the ground, and
extra 1.7 litres of fluid should be added to
the transmission, prior to towing (this extra
fluid must be drained before driving the
vehicle). Even with the extra fluid added to
the transmission, do not tow the vehicle at
speeds in excess of 30 mph (50 kmh) or for
a distance of greater than 15 miles (25 km).
If towing speed/distance are to exceed
these limits, then the vehicle must be
towed with its rear wheels off the ground.
Towing
Puddles on the garage floor or drive, or
obvious wetness under the bonnet or
underneath the car, suggest a leak that needs
investigating. It can sometimes be difficult to
decide where the leak is coming from,
especially if the engine bay is very dirty
already. Leaking oil or fluid can also be blown
rearwards by the passage of air under the car,
giving a false impression of where the
problem lies.Warning: Most automotive oils
and fluids are poisonous. Wash
them off skin, and change out of
contaminated clothing, without
delay.The smell of a fluid leaking
from the car may provide a
clue to what’s leaking. Some
fluids are distinctively
coloured. It may help to clean the car and
to park it over some clean paper as an
aid to locating the source of the leak.
Remember that some leaks may only
occur while the engine is running.
Sump oil Gearbox oil
Brake fluid
Power steering fluid
Oil from filter
Antifreeze
Engine oil may leak from the drain plug......or from the base of the oil filter.
Leaking antifreeze often leaves a crystalline
deposit like this.Gearbox oil can leak from the seals at the
inboard ends of the driveshafts.
A leak occurring at a wheel is almost
certainly brake fluid.Power steering fluid may leak from the pipe
connectors on the steering rack.
3261 Jaguar XJ6
Weekly checks0•15
Battery
Caution:Before carrying out any work on the
vehicle battery, read the precautions given in
"Safety first" at the start of this manual.
4Make sure that the battery tray is in good
condition, and that the clamp is tight.
Corrosion on the tray, retaining clamp and the
battery itself can be removed with a solution
of water and baking soda. Thoroughly rinse all
cleaned areas with water. Any metal parts
damaged by corrosion should be covered
with a zinc-based primer, then painted.
4Periodically (approximately every three
months), check the charge condition of the
battery as described in Chapter 5.
4If the battery is flat, and you need to jump
start your vehicle, see Roadside Repairs.
The battery is located in the left-hand,
rear corner of the engine compartment.
Check the battery terminals for signs of
corrosion and examine the battery leads
closely for signs of damage.1Check the battery lead clamps for
tightness to ensure good electrical
connections.2
Battery corrosion can be kept to a
minimum by applying a layer of
petroleum jelly to the clamps and
terminals after they are reconnected.If corrosion (white, fluffy deposits) is
evident, remove the cables from the
battery terminals, clean them with a small
wire brush, then refit them. Automotive stores
sell a tool for cleaning the battery post . . .3. . . as well as the battery cable clamps4
Bulbs and fuses
4Check all external lights and the horn. Refer
to the appropriate Sections of Chapter 12 for
details if any of the circuits are found to be
inoperative.4Visually check all accessible wiring
connectors, harnesses and retaining clips for
security, and for signs of chafing or damage.
If you need to check your
brake lights and indicators
unaided, back up to a wall or
garage door and operate the
lights. The reflected light should show if
they are working properly.
If a single indicator light, stop light or
headlight has failed, it is likely that a bulb
has blown and will need to be replaced.
Refer to Chapter 12 for details. If both stop
lights have failed, it is possible that the switch
has failed (see Chapter 9).If more than one indicator light or tail light
has failed it is likely that either a fuse has
blown or that there is a fault in the circuit.
The fuseboxes are located behind the left and
right side kick panels and in the centre
console glove box (see Chapter 12).
2
To replace a blown fuse, simply pull it out
and fit a new fuse of the correct rating
(see Chapter 12). If the fuse blows again,
it is important that you find out why - a
complete checking procedure is given in
Chapter 12.31
4Refitting is the reverse of the removal
procedure.
5Run the engine and check for proper
functioning of the heater (and air conditioning,
if equipped).
Control checks
6The climate-control system uses an all-
electronic control panel that sends digital
information to the climate control computer.
There is little the home mechanic can do to
troubleshoot or test the system. The factory
recommends that diagnosis be performed at a
dealership.
7If there is a problem in just one area of
climate control, put the controls through their
entire range of operation and check the
system responses, i.e. set the controls to
COLD, the fan to low and the temperature to
65° F. In this mode the Manual LED should be
lit and the air conditioning compressor should
engage. Try all of the fan speeds and try the
temperature on HOT, then feel for warm air
coming from the ducts. Note:Between each
try of the different controls, wait 20 seconds or
so for the heater/air conditioning system to
adjust before checking for a response.
8When each control button is pushed two
times, its LED light should go on or off. Renew
the control assembly if any of the warning
lights don’t work.
9On 1988 and 1989 models, if the climate
controls do not respond to any driver input,
check with your Jaguar dealer before
renewing the ECU or control panel. A service
part is available (a resistor, #JLM 1901) that
can be installed at one of the control panel
terminals that may fix the problem without any
other parts being renewed. Instructions are
included with the part.
10Check the vacuum lines to the several
vacuum motors that operate the heater/air
conditioning functions. Look for pinched or
blocked hoses and leaks.11Each of the vacuum “servo motors” in the
system can be checked with a hand-held
vacuum pump (see illustration). Apply vacuum
and watch that the door or control it operates is
working.
12Further diagnosis of the controls or
climate control ECU are best left to a Jaguar
dealership or other qualified repair facility.
13 Air conditioning and heating
system- check and
maintenance
1
Air conditioning system
Warning: The air conditioning
system is under high pressure.
Do not loosen any hose fittings
or remove any components until
the system has been discharged. Air
conditioning refrigerant should be properly
discharged into an EPA-approved
recovery/recycling unit by a dealer service
department or an automotive air
conditioning repair facility. Always wear
eye protection when working near air
conditioning system fittings.
1The following maintenance checks should
be performed on a regular basis to ensure that
the air conditioner continues to operate at
peak efficiency:
a) Inspect the condition of the compressor
drivebelt. If it is worn or deteriorated,
renew it (see Chapter 1).
b) Check the drivebelt tension and, if
necessary, adjust it (see Chapter 1).
c) Inspect the system hoses. Look for
cracks, bubbles, hardening and
deterioration. Inspect the hoses and all
fittings for oil bubbles or seepage. If there
is any evidence of wear, damage or
leakage, renew the hose(s).d) Inspect the condenser fins for leaves,
bugs and any other foreign material that
may have embedded itself in the fins. Use
a “fin comb” or compressed air to remove
debris from the condenser.
e) Make sure the system has the correct
refrigerant charge.
2It’s a good idea to operate the system for
about ten minutes at least once a month. This
is particularly important during the winter
months because long term non-use can
cause hardening, and subsequent failure, of
the seals.
3Leaks in the air conditioning system are
best spotted when the system is brought up
to operating temperature and pressure, by
running the engine with the air conditioning
ON for five minutes. Shut the engine off and
inspect the air conditioning hoses and
connections. Traces of oil usually indicate
refrigerant leaks.
4Because of the complexity of the air
conditioning system and the special
equipment required to effectively work on it,
accurate troubleshooting of the system
should be left to a professional technician.
5If the air conditioning system doesn’t
operate at all, check the fuse panel and the air
conditioning relay (refer to Chapter 12 for
relay locations and testing). See Sections 4, 9
and 12 for electrical checks of heating/air
conditioning system components.
6The most common cause of poor cooling is
simply a low system refrigerant charge. If a
noticeable drop in cool air output occurs, the
following quick check will help you determine
if the refrigerant level is low.
Checking the refrigerant charge
7Warm the engine up to normal operating
temperature.
8Place the air conditioning temperature
selector at the coldest setting and put the
Cooling, heating and air conditioning systems 3•11
3
3261 Jaguar XJ6 12.3b Remove the four screws (three are shown here) holding the
control assembly in the control/radio housing
12.11 Check the operation of the vacuum servo motors; in this
case, vacuum is applied to the servo on the right blower case -
the flapper door (arrowed) should operate
headlights or heated rear window and confirm
that the engine rpm decreases at first and
then increases. This check monitors the ISC
motor as it is signalled by the computer to
increase idle speed due to additional
amperage required from the charging system.
As the headlights draw current from the
charging system, the alternator will create
resistance on the belt as it works to produce
the additional energy. If the rpm does not
increase, check the ISC motor.
23Check for approximately 11.2 volts to the
ISC stepper motor (see illustrations).
Disconnect the ISC harness connector and
working on the harness side, check for
11.2 volts with the ignition key ON (engine not
running). Also, check the corresponding
terminals for the correct voltage amounts. If
the correct voltage does not exist, check the
wiring harness. Refer to the wiring diagrams
at the end of Chapter 12.24The ISC motor or stepper motor can be
checked for correct operation but a special tool
is required to activate the internal coils. Have
the stepper motor checked by a dealer service
department or other qualified repair workshop.
25Reconnect the ISC motor electrical
connector.
Renewal
26Detach the cable from the negative
terminal of the battery (see Cautionat the
beginning of this Section).
27Use a large open-end spanner and
unscrew the ISC motor from the housing (see
illustration).
28Refitting is the reverse of removal, but be
sure to use a new gasket.
Fuel rail and fuel injectors
Note:If there is a distinct knocking noise
coming from the dash when the engine is
idling, the fuel feed hose may have hardenedrestricting fuel flow and causing abnormal
sounds. Replace the fuel inlet (feed) hose with
a new part from the dealer parts department.
Check
29Refer to the fuel injection system checking
procedure (see Section 12).
Renewal
30Relieve the fuel pressure (see Section 2).
31Detach the cable from the negative
terminal of the battery (see Cautionat the
beginning of this Section).
32Disconnect the fuel injector wiring con-
nectors and set the injector wire harness aside.
33Detach the vacuum sensing hose from the
fuel pressure regulator.
34Disconnect the fuel lines from the fuel
pressure regulator and the fuel rail (see
illustration 3.6a)
35Remove the fuel rail mounting bolts (see
illustration).
4•12 Fuel and exhaust systems
3261 Jaguar XJ6 13.23a To check the ISC motor, turn the ignition key ON
(engine not running) and check for the proper voltage amounts
at the harness connector (1989 model shown)
13.23b Later models are equipped with a different shape
ISC connector but the voltage values should be the same
as the early style
13.27 Use a large open end spanner to remove the ISC motor
from the intake manifold13.35 Remove the fuel rail mounting bolts (arrowed) . . .