1997 JAGUAR XJ6 fuel filter

working up to it in three steps. Note:Use the
old bolts for this step (save the new bolts for
final refitting).Use a thin-wall socket to avoid
erroneous torque readings that can result if
the socket is wedged between the rod cap
and nut. If the socket tends to wedge itself
between the nut and the cap, lift up on it
slightly until it no longer contacts the cap. Do
not rotate the crankshaft at any time during
this operation.
16Remove the nuts and detach the rod cap,
being careful not to disturb the Plastigauge.
17Compare the width of the crushed
Plastigauge to the scale printed on the
envelope to obtain the oil clearance (see
illustration). Compare it to this Chapter’s
Specifications to make sure the clearance is
correct.
18If the clearance is not as specified, the
bearing inserts may be the wrong size (which
means different ones will be required). Before
deciding that different inserts are needed,
make sure that no dirt or oil was between the
bearing inserts and the connecting rod or cap
when the clearance was measured. Also,
recheck the journal diameter. If the Plastigauge
was wider at one end than the other, the journal
may be tapered (refer to Section 19).
Final connecting rod refitting
19Carefully scrape all traces of the
Plastigauge material off the rod journal and/or
bearing face. Be very careful not to scratchthe bearing, use your fingernail or the edge of
a credit card to remove the Plastigauge.
20Make sure the bearing faces are perfectly
clean, then apply a uniform layer of clean
moly-base grease or engine assembly lube to
both of them. You’ll have to push the piston
higher into the cylinder to expose the face of
the bearing insert in the connecting rod, be
sure to slip the protective hoses over the
connecting rod bolts first.
21At this time, remove the original
connecting rod bolts/nuts and replace them
with new bolts/nuts. They are of a design
which requires they be used only once. The
old ones are OK for Plastigauge checking, but
for final assembly use only new connecting
rod bolts/nuts. Refit the rod cap and tighten
the nuts to the torque listed in this Chapter’s
Specifications. Again, work up to the torque in
three steps.
22Repeat the entire procedure for the
remaining pistons/connecting rod assemblies.
23The important points to remember are:
a) Keep the back sides of the bearing inserts
and the insides of the connecting rods and
caps perfectly clean during assembly..
b) Make sure you have the correct piston/
connecting rod assembly for each
cylinder.
c) The dimple on the piston must face the
front of the engine.
d) Lubricate the cylinder walls with clean oil.
e) Lubricate the bearing faces when refitting
the rod caps after the oil clearance has
been checked.
24After all the piston/connecting rod
assemblies have been properly installed,
rotate the crankshaft a number of times by
hand to check for any obvious binding.
25As a final step, the connecting rod
endplay must be checked. Refer to Section 13
for this procedure.
26Compare the measured endplay to this
Chapter’s Specifications to make sure it’s
correct. If it was correct before dismantling
and the original crankshaft and connecting
rods were reinstalled, it should still be right.
However, if new connecting rods or a new
crankshaft were installed, the endplay may beinadequate. If so, the connecting rods will
have to be removed and taken to an
automotive machine workshop for resizing.
26 Initial start-up
and running-in after overhaul
1
Warning: Have a suitable fire
extinguisher handy when starting
the engine for the first time.
1Once the engine has been installed in the
vehicle, double-check the engine oil and
coolant levels.
2With the spark plugs out of the engine and
the ignition system and fuel pump disabled,
crank the engine until oil pressure registers on
the gauge or the light goes out.
3Refit the spark plugs, hook up the plug
leads and restore the ignition system and fuel
pump functions.
4Start the engine. It may take a few
moments for the fuel system to build up
pressure, but the engine should start without
a great deal of effort.
5After the engine starts, it should be allowed
to warm up to normal operating temperature.
While the engine is warming up, make a
thorough check for fuel, oil and coolant leaks.
6Shut the engine off and recheck the engine
oil and coolant levels.
7Drive the vehicle to an area with no traffic,
accelerate from 30 to 50 mph, then allow the
vehicle to slow to 30 mph with the throttle
closed. Repeat the procedure 10 or 12 times.
This will load the piston rings and cause them
to seat properly against the cylinder walls.
Check again for oil and coolant leaks.
8Drive the vehicle gently for the first
500 miles (no sustained high speeds) and
keep a constant check on the oil level. It is not
unusual for an engine to use oil during the
running-in period.
9At approximately 500 to 600 miles, change
the oil and filter.
10For the next few hundred miles, drive the
vehicle normally. Do not pamper it or abuse it.
11After 2000 miles, change the oil and filter
again and consider the engine run-in.
2B•18 Engine removal and overhaul procedures
25.17 Measure the width of the crushed
Plastigauge to determine the big-end
bearing oil clearance
3261 Jaguar XJ6

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)

3261 Jaguar XJ6
4
Chapter 4
Fuel and exhaust systems
Fuel system
Fuel pressure:kPa psi
Ignition ON, engine not running . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260 to 300 38 to 44
Engine idling:
Vacuum hose detached from fuel pressure regulator . . . . . . . . . . . 280 to 320 40 to 46
Vacuum hose attached to fuel pressure regulator . . . . . . . . . . . . . 210 to 260 30 to 38
Fuel system hold pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145 21
Fuel injector resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.0 to 3.0 ohms
Idle speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Must be set by authorised service department
Torque wrench settingsNm lbf ft
Throttle body mounting bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 14
Fuel rail mounting bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 9 Accelerator cable - removal, refitting and adjustment . . . . . . . . . . . 10
Air cleaner assembly - removal and refitting . . . . . . . . . . . . . . . . . . . 9
Catalytic converter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . See Chapter 6
CHECK ENGINE light . . . . . . . . . . . . . . . . . . . . . . . . . . . See Chapter 6
Electronic Fuel Injection (EFI) system - check . . . . . . . . . . . . . . . . . . 12
Electronic Fuel Injection (EFI) system - component check
and renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Electronic Fuel Injection (EFI) system - general information . . . . . . . 11
Exhaust manifold - removal and refitting . . . . . . . . . . . See Chapter 2A
Exhaust system check . . . . . . . . . . . . . . . . . . . . . . . . . . See Chapter 1
Exhaust system servicing - general information . . . . . . . . . . . . . . . . 14
Fuel filter renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . See Chapter 1Fuel level sender unit - check and renewal . . . . . . . . . . . . . . . . . . . . 5
Fuel lines and fittings - inspection and renewal . . . . . . . . . . . . . . . . 6
Fuel pressure relief . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Fuel pump - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Fuel pump/fuel pressure - check . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Fuel system check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . See Chapter 1
Fuel tank - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Fuel tank cap gasket renewal . . . . . . . . . . . . . . . . . . . . . See Chapter 1
Fuel tank cleaning and repair - general information . . . . . . . . . . . . . 8
General information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Intake manifold - removal and refitting . . . . . . . . . . . . See Chapter 2A
Underbonnet hose check and renewal . . . . . . . . . . . . . . See Chapter 1
4•1
Specifications Contents
Easy,suitable for
novice with little
experienceFairly easy,suitable
for beginner with
some experienceFairly difficult,
suitable for competent
DIY mechanic
Difficult,suitable for
experienced DIY
mechanicVery difficult,
suitable for expert DIY
or professional
Degrees of difficulty
54321
1 General information
The fuel system consists of a fuel tank, an
electric fuel pump either located externally,
next to the fuel tank (1988 to 1990 models) or
in the fuel tank (1991 to 1994 models), an EFI
fuel pump relay and main relay, an inertia
switch, fuel injectors and fuel rail, an air
cleaner assembly and a throttle body unit.
Multi Point Fuel Injection (MPFI)
system
Multi point fuel injection uses timed
impulses to sequentially inject the fuel directly
into the intake port of each cylinder. Theinjectors are controlled by the Electronic
Control Unit (ECU). The ECU monitors various
engine parameters and delivers the exact
amount of fuel, in the correct sequence, into
the intake ports. The throttle body serves only
to control the amount of air passing into the
system. Because each cylinder is equipped
with an injector mounted immediately
adjacent to the intake valve, much better
control of the fuel/air mixture ratio is possible.
Fuel pump and lines
Fuel is circulated from the fuel tank to the
fuel injection system, and back to the fuel
tank, through a pair of metal lines running
along the underside of the vehicle. On early
models (1988 to 1990), an electric fuel pump
is attached to the chassis next to the fueltank. On later models (1991 to 1994), the fuel
pump and fuel level sender unit are located
inside the fuel tank. A vapour return system
routes all vapours and hot fuel back to the fuel
tank through a separate return line.
The fuel pump will operate as long as the
engine is cranking or running and the ECU is
receiving ignition reference pulses from the
electronic ignition system (see Chapter 5). If
there are no reference pulses, the fuel pump
will shut off after 2 or 3 seconds.Inertia switch
These models are equipped with an inertia
switch that is wired in the circuit between the
fuel pump relay, the ignition switch and the
fuel pump (refer to the wiring diagrams at the
end of Chapter 12). The inertia switch is a

water in the fuel filler cap recess could flow
into the boot, causing a dangerous condition
and/or an unpleasant mess. To correct this
condition, direct low-pressure compressed air
into the overflow hole (see illustration), which
should be enough to clear any obstruction in
the line.
8Remove the spare tyre and the spare tyre
bracket assembly (see illustration).
9Disconnect the fuel lines, the vapour return
line and the canister vent line (see
illustrations). Note:Be sure to plug the hoses
to prevent leakage and contamination of the
fuel system.Remove the driveline to gain
access to the fuel line connectors next to the
tank (see Chapter 8). Working under the
vehicle, remove the pins using a needle-nose
pliers, turn the connectors slightly to loosen
them from the grommets and pull the fuel lines
out of the tank.10Remove the retaining bolts from the
fuel tank retaining straps (see illustration).
11Pull the fuel tank out into the boot area.Be careful to angle the fuel filler neck away
from the body.
12Remove the tank from the vehicle.
13Refitting is the reverse of removal.
8 Fuel tank cleaning
and repair-
general information
5
1Any repairs to the fuel tank or filler neck
should be carried out by a professional who
has experience in this critical and potentially
dangerous work. Even after cleaning and
flushing of the fuel system, explosive fumes
can remain and ignite during repair of the tank.
2If the fuel tank is removed from the vehicle,
it should not be placed in an area where
sparks or open flames could ignite the fumes
coming out of the tank. Be especially careful
inside garages where a natural petrol-type
appliance is located, because the pilot light
could cause an explosion.
9 Air cleaner assembly-
removal and refitting
1
1Detach the clips and remove the air filter
cover and the filter element (see Chapter 1).
2Remove the bolts and remove the air cleaner
assembly from the engine compartment (see
illustrations).
3Refitting is the reverse of removal.
Fuel and exhaust systems 4•7
4
7.7b Direct low pressure compressed air
into the hole for the overflow line if clogged7.8 Remove the bolts (arrowed) from the
spare tyre bracket and lift out the assembly7.9a Disconnect the flexible fuel lines from
the metal fuel lines
7.9b Disconnect the vapour return line
from the fuel tank7.9c Disconnect the canister purge line
from the fuel tank
7.9d Remove the clips (arrowed) that
retain the fuel lines to the fuel tank using
needle-nose pliers
3261 Jaguar XJ6
7.10 Remove the tank strap bolts
(arrowed) from the body
9.2a Remove the bolts (arrowed) from the
air cleaner assembly9.2b Also, remove the bolt that retains the
air intake duct to the MAF sensor and lift
the assembly from the compartment

13Allow the bellcrank to return to the idle
position and test the adjustment once again
until the correct adjustment has been attained.
11 Electronic Fuel Injection
(EFI) system-
general information
1These models are equipped with an
Electronic Fuel Injection (EFI) system. This fuel
injection system is designed by Bosch butlicensed by Lucas and is called the Lucas LH
Engine Management system. The EFI system
is composed of three basic sub systems: fuel
system, air induction system and electronic
control system (see illustration).
Fuel system
2An electric fuel pump is located on the
chassis of the rear suspension (external) (1988
to 1990) or inside the fuel tank (1991 to 1994)
The fuel pump supplies fuel under constant
pressure to the fuel rail, which distributes fuel
evenly to all injectors. From the fuel rail, fuel is
injected into the intake ports, just above the
intake valves, by fuel injectors. The amount of
fuel supplied by the injectors is precisely
controlled by an Electronic Control Unit (ECU).
A pressure regulator controls system pressure
in relation to intake manifold vacuum. A fuel
filter between the fuel pump and the fuel rail
filters fuel to protect the components of the
system.
Air induction system
3The air system consists of an air filter
housing, a Mass Air Flow (MAF) sensor
(airflow meter), Intake Air Temperature (IAT)
sensor and a throttle body. The MAF sensor is
an information gathering device for the ECU.A heated element determines the temperature
differential by measuring the current changes
which in turn measures the mass (weight and
volume) of air entering the engine. This
information helps the ECU determine the
amount of fuel to be injected by the injectors.
The throttle plate inside the throttle body is
controlled by the driver. As the throttle plate
opens, the amount of air that can pass
through the system increases, so the
potentiometer opens further and the ECU
signals the injectors to increase the amount of
fuel delivered to the intake ports. Refer to
Chapter 6 for additional information on the
fuel injection system sensors, test procedures
and renewal procedures.
Electronic control system
4The Computer Control System controls the
EFI and other systems by means of an
Electronic Control Unit (ECU), which employs
a microcomputer. The ECU receives signals
from a number of information sensors which
monitor such variables as intake air volume,
intake air temperature, coolant temperature,
engine rpm, acceleration/deceleration and
exhaust oxygen content. These signals help
the ECU determine the injection duration
necessary for the optimum air/fuel ratio. Some
Fuel and exhaust systems 4•9
4
10.11 Rotate the bellcrank until it reaches
wide open throttle and make sure the
pointer aligns with the A on the bellcrank.
Adjust if necessary
11.1 Fuel injection and emission control component locations for the 3.6 litre 1989 XJ6
3261 Jaguar XJ6 1 Fuel pressure regulator (under
fuel rail)
2 Idle Speed Control (ISC) motor
3 Fuel pressure damper4 Bellcrank
5 Throttle body (below bellcrank)
6 Intake Air Temp. (IAT) sensor
7 Supplementary air valve8 Mass Airflow (MAF) sensor
9 Throttle potentiometer (under
throttle body)
10 Fuel rail11 Fuel injector
13 Ignition amplifier (below block
valve)
14 Distributor

of these sensors and their corresponding
ECU-controlled relays are not contained
within EFI components, but are located
throughout the engine compartment. For
further information regarding the ECU and its
relationship to the engine electrical and
ignition system, see Chapter 6.
12 Electronic Fuel Injection
(EFI) system- check
2
1Check the earth wire connections for
tightness. Check all wiring and electrical
connectors that are related to the system.
Loose electrical connectors and poor grounds
can cause many problems that resemble
more serious malfunctions.
2Check to see that the battery is fully
charged, as the control unit and sensors
depend on an accurate supply voltage in
order to properly meter the fuel.
3Check the air filter element - a dirty or
partially blocked filter will severely impede
performance and economy (see Chapter 1).
4If a blown fuse is found, renew it and see if
it blows again. If it does, search for a shorted
wire in the harness related to the system.
5Check the air intake duct from the MAF
sensor to the intake manifold for leaks, which
will result in an excessively lean mixture. Also
check the condition of the vacuum hoses
connected to the intake manifold.
6Remove the air intake duct from the throttle
body and check for carbon and residue build-
up. If it’s dirty, clean with aerosol carburettor
cleaner (make sure the can says it’s safe for
use with oxygen sensors and catalytic
converters) and a toothbrush.
7With the engine running, place a
stethoscope against each injector, one at a
time, and listen for a clicking sound, indicating
operation (see illustration).8If there is a problem with an injector,
purchase a special injector test light (noid
light) and refit it into the injector electrical
connector (see illustration). Start the engine
and make sure that each injector connector
flashes the noid light. This will test for the
proper voltage signal to the injector.Caution:
If the engine will not start and the noid
light indicates that each injector is
receiving the proper signal, there is a good
possibility that the injector(s) is stuck open
and allowing fuel into the combustion
chamber in excessive amounts. If the spark
plugs are fouled, detach the primary (low
voltage) wires from the ignition coil, disable
the fuel pump by removing the fuel pump
relay (see Section 2), remove the spark plugs
and crank the engine over. If fuel sprays from
the spark plug holes, the engine is flooded
and the fuel must be removed from the
combustion chambers.
9With the engine OFF and the fuel injector
electrical connectors disconnected, measure
the resistance of each injector (see
illustration). Each injector should measure
about 2.0 to 3.0 ohms. If not, the injector is
probably faulty.10The remainder of the system checks
should be left to a Jaguar service department
or other qualified repair workshop, as there is
a chance that the control unit may be
damaged if not performed properly.
13 Electronic Fuel Injection
(EFI) system- component
check and renewal
3
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.
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.
Throttle body
Check
1Verify that the throttle linkage operates
smoothly.
2Start the engine, detach each vacuum hose
and, using your finger, check the vacuum at
each port on the throttle body with the engine
at idle and above idle. The vacuum available
from the throttle body is ported. Raise the
engine rpm and watch as vacuum increases.
It may be necessary to use a vacuum gauge.
Refer to Chapter 2B for additional information
concerning vacuum checks.
Renewal
Warning: Wait until the engine is
completely cool before
beginning this procedure.
3Detach the cable from the negative terminal
of the battery (see the Cautionat the
beginning of this Section).
4Drain the radiator (see Chapter 1).
4•10 Fuel and exhaust systems
12.9 Using an ohmmeter, measure the
resistance across both terminals
of the injector
3261 Jaguar XJ6 12.7 Use a stethoscope or a screwdriver to determine if the
injectors are working properly - they should make a steady
clicking sound that rises and falls with engine speed changes
12.8 Refit the “noid” light into the fuel injector electrical
connector and check to see that it blinks with the engine running

canister. If fuel is leaking, renew the canister
and check the hoses and hose routing.
9Inspect the canister. If it’s cracked or
damaged, renew it.
10Check for a clogged filter or a damaged
pressure relief valve. Using low pressure
compressed air (such as from a tyre pump),
blow into the canister tank pipe. Air should
flow freely from the other pipes. If a problem is
found, renew the canister.
11Check the operation of the thermal
vacuum valve (TVV). With the engine cold and
idling, check for ported vacuum to the
temperature vacuum switch. Vacuum should
be present (see illustration). Now warm the
engine to operating temperature (above
115°F/43°C) and confirm that ported vacuum
passes through the TVV (see illustration).
Renew the valve if the test results are
incorrect.
12Check the operation of the purge control
valve. Apply vacuum to the purge control valve
using a hand-held vacuum pump and observe
that the valve holds vacuum steadily (see
illustration). If the valve holds vacuum and the
valve is opening, it is working properly.
Charcoal canister renewal
13Clearly label, then detach the vacuum
hoses from the canister.
14Remove the mounting clamp bolts (see
illustration), lower the canister with thebracket, disconnect the hoses from the check
valve and remove it from the vehicle.
15Refitting is the reverse of removal.
8 Crankcase ventilation
system
General information
1The crankcase ventilation system reduces
hydrocarbon emissions by scavenging
crankcase vapours. It does this by circulating
fresh air from the air cleaner through the
crankcase, where it mixes with blow-by gases
and is then re-routed through a heating
element to the intake manifold(see
illustration).
2The main components of the crankcase
ventilation system are the control orifice, a
heating element and the vacuum hoses
connecting these components with the engine.
3Piston blow-by gasses are collected from
the crankcase and the camshaft housing
via the oil filler tube. These gasses are fed into
the intake manifold at part throttle through the
part throttle orifice and when the engine is at
full throttle, the gasses are fed through the air
intake elbow.
4To prevent possible icing-up during cold
weather operation, the control orifice and the
hose to the intake system is electronically
heated. The heater element is energised by a
relay signal from the windscreen washer jet
temperature sensor.
Check
5Remove the tubes and elbows that connect
the crankcase ventilation system and inspect
them for obstructions, oil deposits or clogging.
Make sure the ventilation system is free of all
Emissions and engine control systems 6•11
6
7.11a Check for vacuum to the thermal
vacuum valve (TVV)7.11b Check for vacuum from the TVV
before and after the engine has reached
normal operating temperature
7.12 Remove the front spoiler to gain
access to the purge control valve (see
Chapter 11). Apply vacuum to the valve and
make sure the valve holds vacuum7.14 Remove the bolts (arrowed) and lower
the charcoal canister from the wing
8.1 Schematic of the crankcase ventilation system
3261 Jaguar XJ6

3261 Jaguar XJ6
REF•4Buying spare parts
Spare parts are available from many
sources, including maker’s appointed
garages, accessory shops, and motor factors.
To be sure of obtaining the correct parts, it
will sometimes be necessary to quote the
vehicle identification number. If possible, it
can also be useful to take the old parts along
for positive identification. Items such as
starter motors and alternators may be
available under a service exchange scheme -
any parts returned should be clean.
Our advice regarding spare parts is as
follows.
Officially appointed garages
This is the best source of parts which are
peculiar to your car, and which are not
otherwise generally available (eg, badges,
interior trim, certain body panels, etc). It is
also the only place at which you should buy
parts if the vehicle is still under warranty.
Accessory shops
These are very good places to buy
materials and components needed for themaintenance of your car (oil, air and fuel
filters, light bulbs, drivebelts, greases, brake
pads, touch-up paint, etc). Components of
this nature sold by a reputable shop are
usually of the same standard as those used
by the car manufacturer.
Besides components, these shops also sell
tools and general accessories, usually have
convenient opening hours, charge lower
prices, and can often be found close to home.
Some accessory shops have parts counters
where components needed for almost any
repair job can be purchased or ordered.
Motor factors
Good factors will stock all the more
important components which wear out
comparatively quickly, and can sometimes
supply individual components needed for the
overhaul of a larger assembly (eg, brake seals
and hydraulic parts, bearing shells, pistons,
valves). They may also handle work such as
cylinder block reboring, crankshaft regrinding,
etc.
Tyre and exhaust specialists
These outlets may be independent, or
members of a local or national chain. They
frequently offer competitive prices when
compared with a main dealer or local garage,
but it will pay to obtain several quotes before
making a decision. When researching prices,
also ask what “extras” may be added - for
instance fitting a new valve and balancing the
wheel are both commonly charged on top of
the price of a new tyre.
Other sources
Beware of parts or materials obtained from
market stalls, car boot sales or similar outlets.
Such items are not invariably sub-standard,
but there is little chance of compensation if
they do prove unsatisfactory. In the case of
safety-critical components such as brake
pads, there is the risk of financial loss, and
also of an accident causing injury or death.
Second-hand parts or assemblies obtained
from a car breaker can be a good buy in some
circumstances, but this sort of purchase is
best made by the experienced DIY mechanic.
Vehicle identification
Modifications are a continuing and
unpublicised process in vehicle manufacture,
quite apart from major model changes. Spare
parts manuals and lists are compiled upon a
numerical basis, the individual vehicle
identification numbers being essential to
correct identification of the part concerned.
When ordering spare parts, always give as
much information as possible. Quote the car
model, year of manufacture and registration,
chassis and engine numbers as appropriate.
The Vehicle Identification Number (VIN)
plate is attached to the base of the driver’s
door pillar left-hand wing valance and is
visible once the bonnet has been opened. The
vehicle identification (chassis) number is also
stamped onto a plate located inside the
windscreen and may also be stamped onto
the right-hand inner wing panel in the engine
compartment (see illustrations).
The trim code and paint codeare also
stamped onto the VIN plate.
The engine numberis stamped onto the
right-hand side of the cylinder block, next to
the distributor (see illustration).
The automatic transmission numberis
stamped onto a metal label attached to the
left-hand side of the transmission housing,
just above the sump (see illustration).The VIN is stamped on the right inner wing
panel of the engine compartment
The engine identification number is
stamped on the right side of the engine
block just behind the distributorThe transmission identification number is
located on the left side of the transmission
housing just above the sump
The VIN is also present on the left side of
the dashboard