water pump JAGUAR XJ6 1997 2.G User Guide

Heating system
The heating system consists of two blower
fans, one under the dash on the right and one
on the left, and a heater core located within
the heater/air conditioning assembly which is
under the dash and behind the console.
Hoses connect the heater core to the engine
cooling system. Heater function is controlled
by the heater/air conditioning control head on
the dashboard. Hot engine coolant is
circulated through the heater core. When the
heater mode is activated, a flap door opens to
expose the heater box to the passenger
compartment. A fan switch on the control
head activates the blower motor, which forces
air through the core, heating the air.
Air conditioning system
The air conditioning system consists of a
condenser mounted in front of the radiator, an
evaporator mounted in the heat/air
conditioning assembly behind the console and
under the centre of the dash, a compressor
mounted on the engine, a filter-drier which
contains a high pressure relief valve and the
plumbing connecting all of the above.
A blower fan forces the warmer air of the
passenger compartment through the
evaporator core (sort of a radiator-in-reverse),
transferring the heat from the air to the
refrigerant. The liquid refrigerant boils off into
low pressure vapour, taking the heat with it
when it leaves the evaporator. The
compressor keeps refrigerant circulating
through the system, pumping the warmed
coolant through the condenser where it is
cooled and then circulated back to the
evaporator.
2 Antifreeze/coolant-
general information
Warning: Do not allow antifreeze
to come in contact with your
skin or painted surfaces of the
vehicle. Rinse off spills immediately withplenty of water. Antifreeze is highly toxic if
ingested. Never leave antifreeze lying
around in an open container or in puddles
on the floor; children and pets are
attracted by it’s sweet smell and may drink
it. Check with local authorities about
disposing of used antifreeze. Many
communities have collection centres which
will see that antifreeze is disposed of
safely. Never dump used antifreeze on the
ground or into drains.
Note:Non-toxic antifreeze is now
manufactured and available at local car
accessory outlets, but even these types
should be disposed of properly.
The cooling system should be filled with a
water/ethylene-glycol based antifreeze
solution, which will prevent freezing down to
at least -20° F, or lower if local climate
requires it. It also provides protection against
corrosion and increases the coolant boiling
point.
The cooling system should be drained,
flushed and refilled every 24,000 miles or
every two years (see Chapter 1). The use of
antifreeze solutions for periods of longer than
two years is likely to cause damage and
encourage the formation of rust and scale in
the system. If your tap water is “hard”, i.e.
contains a lot of dissolved minerals, use
distilled water with the antifreeze.
Before adding antifreeze to the system,
check all hose connections, because
antifreeze tends to leak through very minute
openings. Engines do not normally consume
coolant. Therefore, if the level goes down, find
the cause and correct it.
The exact mixture of antifreeze-to-water
you should use depends on the relative
weather conditions. The mixture should
contain at least 50-percent antifreeze, but
should never contain more than 70-percent
antifreeze. Consult the mixture ratio chart on
the antifreeze container before adding
coolant. Hydrometers are available at most
car accessory outlets to test the ratio
of antifreeze to water (see illustration). Use
antifreeze which meets the vehicle
manufacturer’s specifications.
3 Thermostat-
check and renewal
2
Warning: Do not attempt to
remove the radiator cap, coolant
or thermostat until the engine
has cooled completely.
Check
1Before assuming the thermostat is
responsible for a cooling system problem,
check the coolant level (Chapter 1), drivebelt
tension (Chapter 1) and temperature gauge (or
light) operation.
2If the engine takes a long time to warm up
(as indicated by the temperature gauge or
heater operation), the thermostat is probably
stuck open. Renew the thermostat.
3If the engine runs hot, use your hand to
check the temperature of the lower radiator
hose.
Warning: Do this check with the
engine off. Do not get your
hands near the fan blades. If the
hose is not hot, but the engine
is, the thermostat is probably stuck in the
closed position, preventing the coolant
inside the engine from travelling through
the radiator. Renew the thermostat. Do not
drive the vehicle without a thermostat. The
computer may stay in open loop and
emissions and fuel economy will suffer.
4If the lower radiator hose is hot, it means
that the coolant is flowing and the thermostat
is open. Consult the Troubleshootingsection
at the front of this manual for further diagnosis.
Renewal
5Disconnect the battery negative cable.
Caution: If the stereo in your vehicle is
equipped with an anti-theft system, make
sure you have the correct activation code
before disconnecting the battery.
6Drain the coolant from the radiator (see
Chapter 1).
7Remove the bolts from the thermostat
cover (see illustration). If the cover doesn’t
3•2 Cooling, heating and air conditioning systems
3261 Jaguar XJ6 2.4 An inexpensive hydrometer can be
used to test the condition of your coolant
3.7 Remove the two bolts (small arrows)
holding the thermostat cover to the
housing (large arrow)

pull loose, tap it with a soft-faced hammer. Do
not use a screwdriver between the cover and
the thermostat housing.
8Remove the thermostat, noting the
direction in which it was installed in the
housing, and thoroughly clean the sealing
surfaces.
9Refit a new O-ring onto the thermostat (see
illustration). Make sure it is evenly fitted all
the way around.
10Apply a bead of RTV sealant to the
thermostat housing. Refit the thermostat and
housing, positioning the jiggle pin at the
highest point. Note:The thermostat is usually
marked TOP on the radiator side for proper
orientation.
11Tighten the cover fasteners to the torque
listed in this Chapter’s Specifications.
12Refill the cooling system, run the engine
and check for leaks and proper operation.
4 Engine cooling fans-
check and renewal
3
Mechanical fan
(1988 to 1992 models)
Warning: Keep hands, hair, tools
and clothing away from the fan
when the engine is running. Toavoid injury or damage DO NOT operate
the engine with a damaged fan. Do not
attempt to repair fan blades - renew a
damaged fan .
Check
Warning: In order to check the
fan clutch, the engine will need
to be at operating temperature,
so while going through checks
prior to Step 6 be careful that the ignition is
NOT switched on. Severe personal injury
can result!
1Symptoms of failure of the fan clutch are
continuous noisy operation, looseness,
vibration and evidence of silicone fluid leaks.
2Rock the fan back and forth by hand to
check for excessive bearing play.
3With the engine cold, turn the blades by
hand. The fan should turn freely.
4Visually inspect for substantial fluid leakage
from the fan clutch assembly, a deformed bi-
metal spring or grease leakage from the
cooling fan bearing. If any of these conditions
exist, renew the fan clutch.
5When the engine is fully warmed up, turn off
the ignition switch and disconnect the cable
from the negative battery terminal. Turn the
fan by hand. Some resistance should be felt. If
the fan turns easily, renew the fan clutch.
Caution: If the stereo in your vehicle is
equipped with an anti-theft system, makesure you have the correct activation code
before disconnecting the battery.
Removal and refitting
6Leave the battery cable disconnected (see
the Caution in Step 5).
7Remove the fan’s drivebelt (see Chapter 1).
8Remove the nuts holding the fan assembly
to the water pump (see illustration). Note:
You’ll have to “walk” the fan assembly forward
as you loosen the nuts. There is not enough
room to remove them all the way at one time.
9The fan can be removed without removing
the shroud, if you are only renewing the fan or
clutch (see illustration). Be careful not to
allow the blades contact the radiator fins.
10Remove the two fan shroud mounting
clips at the top of the shroud (see illustration).
11Lift the shroud up and out of the engine
compartment. The bottom of the fan shroud
does not have any fasteners. It has two tangs
on the bottom that slip out of slots in the body
when pulled up.
12The fan clutch can be unbolted from the
fan blade assembly for renewal (see
illustration).
Caution: To prevent silicone fluid from
draining from the clutch assembly into the
fan drive bearing and ruining the lubricant,
DON’T place the clutch in a position with
the rear pointing down. Store the clutch in
its upright position if possible.
Cooling, heating and air conditioning systems 3•3
3
4.9 The fan can be removed with the
shroud in place by angling it out of
the shroud4.10 Pry out the two clips (arrow indicates
the left one) at the top of the fan shroud
and lift out the shroud
3261 Jaguar XJ6 3.9 The thermostat is fitted with the spring end towards the
cylinder head - use a new O-ring (A) and position jiggle pin (B) up
4.8 Remove the four nuts (arrows indicate three shown here)
holding the fan/clutch assembly to the front of the water pump
4.12 Separate the fan clutch from the fan
by removing the four bolts (arrowed)

5If equipped with an automatic transmission,
disconnect the cooler lines from the radiator
(see illustrations). Disconnect the cooling fan
switch connector (see illustration 4.15).
Place a drip pan to catch the fluid and cap the
fittings. Note:The transmission oil cooler lines
enter the radiator on the left, while the power
steering cooler lines attach on the right side of
the radiator. On 1993 and 1994 models, the
cooler fittings require a spring-lock coupling
tool, normally used on fuel lines or air
conditioning lines.
6Remove the four bolts from the radiator
cowl panel and take off the panel (see
illustration).
7Lift out the radiator. Be aware of dripping
fluids and the sharp fins. Take care not to
damage the radiator fins by contact with other
parts.
8With the radiator removed, it can be
inspected for leaks, damage and internal
blockage. If repairs are necessary, have a
radiator specialist or dealer service department
perform the work, as special techniques are
required. Check the rubber mounting pads on
the bottom of the radiator (see illustration). If
they’re cracked or damaged, get new ones
before refitting the radiator.
9Bugs and dirt can be cleaned from the
radiator with compressed air and a soft brush.
Don’t bend the cooling fins as this is done.
Warning: Wear eye protection.
Refitting
10Refitting is the reverse of the removal
procedure. Be sure the rubber mounts are in
place on the bottom of the radiator.
11After refitting, fill the cooling system with
the proper mixture of antifreeze and water.
Refer to Chapter 1 if necessary.
12Start the engine and check for leaks.
Allow the engine to reach normal operating
temperature, indicated by both radiator hoses
becoming hot. Recheck the coolant level and
add more if required.
13On automatic transmission equipped
models, check and add fluid as needed and
check the power steering fluid level as well.
Expansion tank and coolant
reservoir, removal and refitting
14The expansion tank is located at the top
of the left-hand side inner wing. With the
cooling system drained below the level of the
expansion tank, remove the hoses, the
coolant level probe and the two screws
mounting it to the body (see illustration).
15Wash out and inspect the reservoir for
cracks and chafing. Renew it if damaged.16If the low-coolant level light has been
showing on the instrument panel, even when
the coolant level is correct, disconnect the
sensor’s connector and test it with an
ohmmeter (see illustration). The sensor
should be renewed if the resistance at the
connections is over 150 ohms.
Caution: Using a long-necked funnel to
add coolant can damage the sensor, which
is just below the expansion tank filler neck.
Cooling, heating and air conditioning systems 3•5
3
5.5a At the left side of the radiator,
disconnect the automatic transmission
cooler lines (small arrows) and the lower
radiator hose (larger arrow)5.5b Disconnect the power steering cooler
lines (small arrows) at the right side of the
radiator, and the upper radiator hose
(large arrow)
3261 Jaguar XJ6 5.3 Remove the clamp and the hose going
to the expansion tank
5.6 Remove the bolts (arrowed) and take
off the radiator cowl panel
5.14 The expansion tank is located on the
left inner wing
A Hose to recovery tank (where applicable)
B Hose to radiator
C Hose to thermostat housing
D Hose to water pump housing
E Mounting screws
F Low-coolant-level sensor
5.8 There are rubber mounts (arrowed)
for the radiator and the condenser -
they must be in place when these
components are reinstalled
5.16 The low-coolant-level sensor can be
tested with an ohmmeter - resistance
should be below 150 ohms - gently use a
pair of long-neck pliers to move the sensor
up and down in the tank to get a reading

17A coolant recovery bottle is used on 1988
and 1989 models, located in the passenger’s
inner wing. The plastic inner wing splash
shield must be removed for access to the
recovery bottle (see Chapter 11). Disconnect
the recovery hose and remove the mounting
screws to renew the recovery bottle (see
illustration). Models from 1990 on do not
have the recovery bottle, but do have a larger
expansion tank.
18Refitting of either expansion tank or
recovery bottle is the reverse of removal.
6 Engine oil cooler- renewal
2
1Models from 1988 through 1991 have a
engine oil cooler, mounted ahead of the
radiator. The engine’s mechanical fan draws
air through the oil cooler, cooling off hot
engine oil that is circulated from the engine by
steel tubes. Access to the cooler is with the
grille removed (refer to Chapter 11 for grille
removal).
2To renew the oil cooler, first disconnect thetwo fittings connecting the lines to the cooler
(see illustration).
Caution: The engine should be cool for this
procedure, and you should have a small
drain pan handy because the fittings are
on the bottom of the cooler and will
probably drip some oil on dismantling.
3Remove the mounting nuts to take the
cooler out of the vehicle (see illustration).
4The other ends of the oil cooler tubes
mount to a block just below the oil filter. With
a drain pan handy, remove the nut retaining
both pipes to the block.
5Refitting the oil cooler and oil lines is the
reverse of removal. When refitting the lines to
the block or the cooler, use new O-rings.7 Water pump- check
1
1A failure in the water pump can cause
serious engine damage due to overheating.
2With the engine running and warmed to
normal operating temperature, squeeze the
upper radiator hose. If the water pump is
working properly, a pressure surge should be
felt as the hose is released.
Warning: Keep hands away from
fan blades!
3Water pumps are equipped with weep or
vent holes (see illustration). If a failure occurs
in the pump seal, coolant will leak from this
hole. In most cases it will be necessary to use
a flashlight to find the hole on the water pump
by looking through the space behind the
pulley just below the water pump shaft.
4If the water pump shaft bearings fail there
may be a howling sound at the front of the
engine while it is running. Bearing wear can be
felt if the water pump pulley is rocked up anddown. Do not mistake drivebelt slippage,
which causes a squealing sound, for water
pump failure. Spray automotive drivebelt
dressing on the belts to eliminate the belt as a
possible cause of the noise.
8 Water pump and pipes-
renewal
3
Warning: Do not start this
procedure until the engine is
completely cool.
1Disconnect the negative battery cable and
drain the cooling system (see Chapter 1).
Caution: If the stereo in your vehicle is
equipped with an anti-theft system, make
sure you have the correct activation code
before disconnecting the battery.
2Refer to Section 4 to remove the
mechanical fan and clutch (if applicable to
your model).
3Refer to Chapter 1 for removal of the
drivebelts.
3•6 Cooling, heating and air conditioning systems
6.3 Remove the mounting nuts (arrowed)
to take the oil cooler out
7.3 Check the weep hole (arrowed) for
signs of leakage (pump removed for
clarity) - grey discolouration is normal,
large brown stains indicates seal failure
3261 Jaguar XJ6 5.17 The recovery bottle (arrowed) on 1988 and 1989 models is
located in the footwell - disconnect the hoses and the two
mounting screws
6.2 Disconnect the two metal oil lines (arrowed) where they
mount to the bottom of the cooler - use two spanners

4Remove the water pump mounting bolts
(see illustration).
Note 1:The water pump is sold as a complete
assembly, including the rear housing with the
hose connections. Unless the rear housing is
corroded or cracked, many Jaguar mechanics
only refit the pump assembly itself, using the
original rear housing with all its hoses intact.
However, if the engine has a great deal of
years or mileage on it, it would be a good idea
to renew those hoses as well, in which case
the new rear housing can be installed.
Note 2:There are three different lengths of
water pump bolts. The longer bolts retain the
pump and rear housing to the engine(see
illustration 7.3).
5If the pump doesn’t come loose right away,
tap it with a soft-faced hammer to break the
gasket seal. Be careful not to hit the radiator
fins with the pump during removal.
6Thoroughly clean all sealing surfaces,
removing all traces of gasket or sealant from
the back of the pump and the face of the
housing.
7Apply a bead of RTV sealant to the sealing
surface on the back of the pump. Refit the
pump and bolts, tightening the bolts to the
torque listed in this Chapter’s Specifications.
8Refit the remaining parts in the reverse
order of removal. Note:If the pump has been
renewed after many miles of usage, it’s a good
idea to also renew the hoses connected to the
water pump housing(see illustrations). Refer
to Chapter 2A for intake manifold removal to
access the coolant pipes and hoses. If you
have noticed water leaks or stains on the left
side of the engine, the leaks may be coming
from these pipes and hoses.
9Refill the cooling system (see Chapter 1),
run the engine and check for leaks and proper
operation.
9 Coolant temperature
sender unit- check and
renewal
2
Warning: Do not start this
procedure until the engine is
completely cool.
Check
1If the coolant temperature gauge is
inoperative, check the fuses first (Chapter 12).
2If the temperature gauge indicates
excessive temperature after running awhile,
see the Fault finding section at the rear of the
manual.
3If the temperature gauge indicates Hot as
soon as the engine is started cold, disconnect
the wire at the coolant temperature sender
(see illustration). If the gauge reading drops,
renew the sender unit. If the reading remains
high, the wire to the gauge may be shorted to
ground, or the gauge is faulty.
4If the coolant temperature gauge fails to
show any indication after the engine has been
warmed up, (approx. 10 minutes) and the
fuses checked out OK, shut off the engine.
Disconnect the wire at the sender unit and,
using a jumper wire, connect the wire to a
clean ground on the engine. Briefly turn on the
ignition without starting the engine. If the
gauge now indicates Hot, renew the sender
unit.
5If the gauge fails to respond, the circuit may
be open or the gauge may be faulty - see
Chapter 12 for additional information.
Renewal
6Drain the coolant (see Chapter 1).
7Disconnect the electrical connector from
the sender unit.8Using a deep socket or a spanner, remove
the sender unit.
9Refit the new unit and tighten it securely.
Do not use thread sealant as it may
electrically insulate the sender unit.
10Reconnect the wiring connector, refill the
cooling system and check for coolant leakage
and proper gauge function.
10 Heating and air conditioning
blower motors- circuit check
and component renewal
3
Warning: Later models are
equipped with airbags. To
prevent accidental deployment
of the airbag, which could cause
personal injury or damage to the airbag
system, DO NOT work in the vicinity of the
steering wheel or instrument panel. Jaguar
recommends that, on airbag-equipped
models, the following procedure should be
left to a dealer service department or other
repair workshop because of the special
tools and techniques required to disable
the airbag system.
1Disconnect the battery negative cable.
Caution: If the stereo in your vehicle is
equipped with an anti-theft system, make
sure you have the correct activation code
before disconnecting the battery.
2There are two blower motors, one under the
left side of the dash and one behind the glove
compartment (see illustration). If the blower
doesn’t work, check the fuse and all
connections in the circuit for looseness and
corrosion. Make sure the battery is fully
charged. To access the right blower, remove
the glove compartment liner, the glove
compartment door and the right lower dash
panel (see Chapter 11).
Warning: When working around
the area behind the glove box,
watch out for a strip of sheet
metal bracing that has a very
sharp edge (see illustration). Apply some
heavy duct tape to the edge of the brace
before beginning work in this area, or you
could injure your hands.
Cooling, heating and air conditioning systems 3•7
3
8.4 Remove the water pump mounting
bolts (arrows indicate five visible here)8.8a Once the water pump is removed, the
rear housing (arrowed) is held in place only
by the hoses - check them for leakage and
condition whenever the pump is disturbed8.8b The water pipe (arrowed) may need
new gaskets where it meets the block - the
pipe is best accessed from below or with
the intake manifold unbolted
9.3 The coolant temperature sender unit
(arrowed) is located in the top of the
thermostat housing - it is the sender unit
with the single wire
3261 Jaguar XJ6

special electrical device that provides circuit
protection by switching off the ignition and
fuel pump upon impact in the event of vehicle
collision. Later Jaguar models are equipped
with an additional specialised inertia switch.
This later device switches OFF all ignition fed
circuits, locks the fuel filler cap, locks the boot
(only if doors are locked) and unlocks the
doors if they are locked during the accident.
All these functions are directed by the inertia
switch. The inertia switch is located behind
the left kick panel. Refer to Chapter 12 for
more information.
Exhaust system
The exhaust system includes an exhaust
manifold equipped with an exhaust oxygen
sensor, a catalytic converter, an exhaust pipe,
and a silencer.
The catalytic converter is an emission
control device added to the exhaust system to
reduce pollutants. A single-bed converter is
used in combination with a three-way
(reduction) catalyst. See Chapter 6 for more
information regarding the catalytic converter.
2 Fuel pressure relief
1
Warning: Petrol is extremely
flammable, so take extra
precautions when you work on
any part of the fuel system.
Don’t smoke or allow open flames or bare
light bulbs near the work area, and don’t
work in a garage where a natural gas-type
appliance (such as a water heater or a
clothes dryer) with a pilot light is present.
Since petrol is carcinogenic, wear latex
gloves when there’s a possibility of being
exposed to fuel, and, if you spill any fuel on
your skin, rinse it off immediately with soap
and water. Mop up any spills immediately
and do not store fuel-soaked rags wherethey could ignite. The fuel system is under
constant pressure, so, if any fuel lines are
to be disconnected, the fuel pressure in
the system must be relieved first. When
you perform any kind of work on the fuel
system, wear safety glasses and have a
Class B type fire extinguisher on hand.
1Before servicing any fuel system
component, you must relieve the fuel pressure
to minimise the risk of fire or personal injury.
2Remove the fuel filler cap - this will relieve
any pressure built up in the tank.
3Remove the fuel pump relay from the main
relay panel (see illustrations). Note:These
models are equipped with a fuel pump relay
that is located in various areas of the vehicle
depending on the year. On 1988 and 1989
models, the fuel pump relay is under the
glovebox. On 1990 to 1992 models, the fuel
pump relay is in the engine compartment on
the left side, attached to the brake pedal
hanger. On 1993 models, the fuel pump relay
is in the boot. On 1994 models, it’s in the
engine compartment on the right side of the
bulkhead. Refer to the relay location charts in
Chapter 12 for additional information.
4Start the engine and wait for the engine to
stall, then turn the ignition key to Off.
Disconnect the cable from the negativeterminal of the battery before beginning any
work on the fuel system.
Caution: If the stereo in your vehicle is
equipped with an anti-theft system, make
sure you have the correct activation code
before disconnecting the battery.
5The fuel system is now depressurised.
Note:Place a rag around the fuel line before
removing any hose clamp or fitting to prevent
any residual fuel from spilling onto the engine.
3 Fuel pump/fuel pressure-
check
2
Warning: Petrol is extremely
flammable, so take extra
precautions when you work on
any part of the fuel system. See
the Warning in Section 2.
Note: To perform the fuel pressure test, you
will need to obtain a fuel pressure gauge and
adapter set (fuel line fittings).
Note: On 1988 to 1990 models, the fuel pump
may chatter excessively and the engine may
stall frequently during hot weather. If stalling
occurs, the engine will restart after a cool-
down period. Dual fuel pumps can be installed
by a dealer service department or other
qualified repair facility to remedy this problem.
Preliminary inspection
1Should the fuel system fail to deliver the
proper amount of fuel, or any fuel at all,
inspect it as follows. Remove the fuel filler
cap. Have an assistant turn the ignition key to
the ON position (engine not running) while you
listen at the fuel filler opening. You should
hear a whirring sound that lasts for a couple of
seconds. On 1988 to 1990 models, listen
behind the left rear wheel (external fuel pump)
for the fuel pump sound.
2If you don’t hear anything, check the fuel
pump relay (see illustration 2.3a, b or c)and
4•2 Fuel and exhaust systems
2.3c On 1992 models, the fuel pump relay
is located in the left rear corner of the
engine compartment
3261 Jaguar XJ6 2.3a Relay locations on a 1988 model
2.3b Relay locations on a 1989 model

5 Air Injector Reactor
(AIR) system
General information
1The air injection reactor system reduces
carbon monoxide and hydrocarbon content
in the exhaust gases by injecting fresh air into
the hot exhaust gases leaving the exhaust
ports. When fresh air is mixed with hot
exhaust gases, oxidation is increased,
reducing the concentration of hydrocarbons
and carbon monoxide and converting them
into harmless carbon dioxide and water.
2The air injection system is composed of an
air pump, diverter valve (bypass), check valve,
air injection manifold, vacuum delay valve,
vacuum control solenoid, air pump magnetic
clutch, air pump clutch relay and hoses (see
illustration). The air pump is driven by a belt
from the crankshaft and supplies compressed
air to the exhaust manifold(s). The check valve
prevents the reverse flow of exhaust gases into
the system. The vacuum-operated (early
models) or electrically-operated (later models)air cut-off valve prevents air from being drawn
into the exhaust when the air pump is switched
off. System vacuum to the air cut-off valve is
controlled by the solenoid vacuum valve in
parallel circuit with the air pump. A delay valve
prevents vacuum loss to the solenoid valve
during wide open throttle operation.
3Injected air is controlled by the computer,
the air pump clutch and the air pump clutch
relay. The AIR system is used during warm-up
(58 to 83° F) to control emissions while the
engine is running rich. The oxygen sensor
feedback system cannot function while the AIR
system is operating. The computer controls
both systems during warm-up and operating
temperatures. If problems occur with the
AIR system relay or circuit, the on-board
diagnosis system will set a code 66.
Check
4Check the condition of the air pump
drivebelt, the injection hoses and the injection
manifold. Make sure that all components are
intact and there are no leaks.
5Check the operation of the air pump clutch
relay (see illustration)and the air pump
clutch. First remove the relay and check forbattery voltage to the relay. Also, check the
relay itself. Refer to the relay checking
procedure in Chapter 12. Extract codes from
the self-diagnosis system (see Section 3) and
check for a code 66, AIR relay malfunction.
6Make sure the electrical connector is
securely fastened to the diverter valve (see
illustration). If everything appears OK but a
fault code still sets, have the system
diagnosed by a dealer service department or
other qualified repair workshop.
Air pump renewal
7Disconnect the cable from the negative
terminal of the battery.
Caution: If the stereo in your vehicle is
equipped with an anti-theft system, make
sure you have the correct activation code
before disconnecting the battery.
8Disconnect the electrical connector from
the air pump clutch.
9Loosen the clips from the air inlet and outlet
hose and separate them from the air injection
pump.
10Loosen the adjuster and pivot bolts (see
illustration)and nuts but do not remove them
from the air injection pump brackets.
6•8 Emissions and engine control systems
3261 Jaguar XJ6 5.2 Schematic of the Air Injection Reactor (AIR) system
5.6 Location of the AIR diverter valve on a 1992 model - check the
hoses for cracking and the electrical connector for security5.10 Loosen the pivot bolt and then the adjustment nut to remove
the drivebelt from the air pump. The adjustment nut has a lock bolt
that must be loosened before the pump will move down the adjuster
5.5 Location of the AIR pump relay on a 1992 model

6Carefully check to make sure the
suspension and steering components do not
make contact with the hoses. Have an
assistant push on the vehicle and also turn the
steering wheel from lock-to-lock during
inspection.
7Bleed the brake system (see Section 9).
Metal brake line renewal
8When replacing brake lines, use the proper
parts only. Do not use copper line for any
brake system connections. Purchase steel
brake lines from a dealer or motor factors..
9Unless you’re using factory renewal brake
lines, you may need a tubing bender to bend
the lines to the proper shape.
10First, remove the line you intend to renew,
lay it on a clean workbench and measure it
carefully. Obtain a new line of the same length
and bend it to match the pattern of the old
line.
Warning: Do not crimp or
damage the line. No bend should
have a smaller radius than
9/16-inch. Make sure the
protective coating on the new line is
undamaged at the bends.
11When refitting the new line, make sure it’s
well supported by the brackets, the routing
matches the original and there’s plenty of
clearance between moving or hot
components.
12After refitting, check the master cylinder
fluid level and add fluid as necessary. Bleed
the brake system as outlined in Section 9 and
test the brakes carefully before driving the
vehicle. Be sure there are no leaks.
9 Brake hydraulic system-
bleeding
2
Warning: Wear eye protection
when bleeding the brake
system. If the fluid comes in
contact with your eyes,
immediately rinse them with water and
seek medical attention.Note:Bleeding the hydraulic system is
necessary to remove any air which has entered
the system during removal and refitting of a
hose, line, caliper or master cylinder.
1It will probably be necessary to bleed the
system at all four brakes if air has entered the
system due to low fluid level or if the brake
lines have been disconnected at the master
cylinder.
2If a brake line was disconnected at only one
wheel, then only that caliper or wheel cylinder
must be bled.
3If a brake line is disconnected at a fitting
located between the master cylinder and any
of the brakes, that part of the system served
by the disconnected line must be bled.
4Bleed the right rear, the left rear, the right
front and the left front caliper, in that order,
when the entire system is involved.
5Remove any residual vacuum from the
servo and pressure in the anti-lock braking
system (if equipped) by applying the brake
about 30 times with the engine off.
6Remove the master cylinder reservoir cover
and fill the reservoir with brake fluid. Refit the
cover. Note:Check the fluid level often during
the bleeding operation and add fluid as
necessary to prevent the fluid level from falling
low enough to allow air into the master
cylinder.
7Have an assistant on hand, as well as a
supply of new brake fluid, an empty clear
plastic container, a length of 3/16-inch clear
tubing to fit over the bleed screws and a
spanner to open and close the bleed screws.
8Beginning at the right rear wheel, loosen the
bleed screw slightly, then tighten it to a point
where it is snug but can still be loosened
quickly and easily.
9Place one end of the tubing over the bleed
valve and submerge the other end in brake
fluid in the container (see illustration).
10Have the assistant pump the brakes a few
times to build pressure in the system, then
hold the pedal firmly depressed.
11While the pedal is held depressed, open
the bleed screw just enough to allow fluid to
flow from the caliper. Watch for air bubbles toexit the submerged end of the tube. When the
fluid flow slows after a couple of seconds,
close the screw and have your assistant
release the pedal.
12Repeat Steps 10 and 11 until no more air
is seen leaving the tube, then tighten the
bleed screw and proceed to the left rear
wheel, the right front wheel and the left
front wheel, in that order, and perform the
same procedure. Be sure to check the fluid in
the master cylinder reservoir frequently.
13Never reuse old brake fluid. It contains
contaminates and moisture which could
damage the braking system.
14Refill the master cylinder with fluid at the
end of the operation.
15Check the operation of the brakes. The
pedal should feel solid when depressed, with
no sponginess. If necessary, repeat the entire
process.
Warning: Do not drive the car if
in doubt about the effectiveness
of the brake system.
10 Handbrake cable-
adjustment
1
1Slowly apply the handbrake and count the
number of clicks at the lever. It should be fully
applied within three to five clicks. If the lever is
still not fully applied by the fifth click, adjust
the handbrake cable as follows:
2Raise the vehicle and place it securely on
axle stands.
3Loosen the locknut (see illustration)and
tighten the cable adjuster until all slack has
been removed. Tighten the locknut. Make
sure the wheels turn freely with the handbrake
lever released
4Lower the vehicle and recheck the
handbrake lever. It should now be properly
adjusted. If it’s now fully applied within three
to five clicks, raise the vehicle again and
readjust the cable at the adjuster.
5Make sure the handbrake holds the vehicle
on an incline.
9•10 Braking system
8.3b The connection (arrowed) for the rear
hose and line is located right above the
mounting bracket for the front corner of
the differential crossmember; remove the
hose as described in the previous
illustration9.9 When bleeding the brakes, a hose is
connected to the bleed screw at the caliper
or wheel cylinder and then submerged in
brake fluid - air will be seen as bubbles in
the tube and container (all air must be
expelled before moving to the next brake)
10.3 To adjust the handbrake cable,
loosen the locknut, then turn the adjuster
to remove any slack in the cable; be sure
to tighten the locknut when the cable is
properly adjusted
3261 Jaguar XJ6

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)