1997 JAGUAR XJ6 checking oil

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) . . .

3261 Jaguar XJ6
12
Chapter 12
Body electrical system
1 General information
The electrical system is a 12-volt, negative
earth type. Power for the lights and all
electrical accessories is supplied by a
lead/acid-type battery which is charged by
the alternator.
This Chapter covers repair and service
procedures for the various electrical
components not associated with the engine.
Information on the battery, alternator,
distributor and starter motor will be found in
Chapter 5.
It should be noted that when portions of the
electrical system are serviced, the cable
should be disconnected from the negative
battery terminal to prevent electrical shorts
and/or fires.
2 Electrical fault finding-
general information
A typical electrical circuit consists of an
electrical component, any switches, relays,
motors, fuses, fusible links, in-line fuses or
circuit breakers related to that component
and the wiring and electrical connectors that
link the component to both the battery andthe chassis. To help you pinpoint an electrical
circuit problem, wiring diagrams are included
at the end of this Chapter.
Before tackling any troublesome electrical
circuit, first study the appropriate wiring
diagrams to get a complete understanding of
what makes up that individual circuit. Trouble
spots, for instance, can often be narrowed
down by noting if other components related to
the circuit are operating properly. If several
components or circuits fail at one time,
chances are the problem is in a fuse or earth
connection, because several circuits are often
routed through the same fuse and earth
connections.
Electrical problems usually stem from
simple causes, such as loose or corroded
connections, a blown fuse, a melted fusible
link or a bad relay. Visually inspect the
condition of all fuses, wires and connections
in a problem circuit before diagnosing it.
If testing instruments are going to be
utilised, use the diagrams to plan ahead of
time where you will make the necessary
connections in order to accurately pinpoint
the trouble spot.
The basic tools needed for electrical fault
finding include a circuit tester or voltmeter (a
12-volt bulb with a set of test leads can also
be used), a continuity tester, which includes a
bulb, battery and set of test leads, and a
jumper wire, preferably with a circuit breaker
incorporated, which can be used to bypasselectrical components. Before attempting to
locate a problem with test instruments,
use the wiring diagram(s) to decide where to
make the connections.
Voltage checks
Voltage checks should be performed if a
circuit is not functioning properly. Connect
one lead of a circuit tester to either the
negative battery terminal or a known good
earth. Connect the other lead to a electrical
connector in the circuit being tested,
preferably nearest to the battery or fuse. If the
bulb of the tester lights, voltage is present,
which means that the part of the circuit
between the electrical connector and the
battery is problem free. Continue checking the
rest of the circuit in the same fashion. When
you reach a point at which no voltage is
present, the problem lies between that point
and the last test point with voltage. Most of
the time the problem can be traced to a loose
connection. Note:Keep in mind that some
circuits receive voltage only when the ignition
key is in the Accessory or Run position.
Finding a short
One method of finding shorts in a circuit is
to remove the fuse and connect a test light or
voltmeter in its place. There should be no
voltage present in the circuit. Move the wiring
harness from side to side while watching the
test light. If the bulb goes on, there is a short Airbag system - general information . . . . . . . . . . . . . . . . . . . . . . . . . 28
Bulb renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Central locking system - description and check . . . . . . . . . . . . . . . . 25
Circuit breakers - general information . . . . . . . . . . . . . . . . . . . . . . . . 5
Cruise control system - description and check . . . . . . . . . . . . . . . . . 23
Direction indicators/hazard flashers - general information . . . . . . . . 7
Electric aerial - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . 14
Electric side view mirrors - description and check . . . . . . . . . . . . . . 26
Electric sunroof - description and check . . . . . . . . . . . . . . . . . . . . . . 27
Electric window system - description and check . . . . . . . . . . . . . . . 24
Electrical fault finding - general information . . . . . . . . . . . . . . . . . . . 2
Fuel, oil and temperature gauges - check . . . . . . . . . . . . . . . . . . . . . 11
Fuses - general information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
General information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Headlight housing (1992 to 1994 models) - removal and refitting . . . 19Headlights - adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Headlights - renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Heated rear window - check and repair . . . . . . . . . . . . . . . . . . . . . . 16
Horn - check and renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Ignition switch and key lock cylinder - removal and refitting . . . . . . 9
Inertia switch - description and check . . . . . . . . . . . . . . . . . . . . . . . . 22
In-line fuses - general information . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Instrument cluster - removal and refitting . . . . . . . . . . . . . . . . . . . . . 12
Instrument panel switches - removal and refitting . . . . . . . . . . . . . . 10
Radio and speakers - removal and refitting . . . . . . . . . . . . . . . . . . . 13
Relays - general information and testing . . . . . . . . . . . . . . . . . . . . . . 6
Steering column switches - removal and refitting . . . . . . . . . . . . . . . 8
Windscreen wiper motor - removal and refitting . . . . . . . . . . . . . . . . 15
Wiring diagrams - general information . . . . . . . . . . . . . . . . . . . . . . . 29
12•1
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

3261 Jaguar XJ6
General repair proceduresREF•5
Whenever servicing, repair or overhaul work
is carried out on the car or its components, it
is necessary to observe the following
procedures and instructions. This will assist in
carrying out the operation efficiently and to a
professional standard of workmanship.
Joint mating faces and gaskets
When separating components at their
mating faces, never insert screwdrivers or
similar implements into the joint between the
faces in order to prise them apart. This can
cause severe damage which results in oil
leaks, coolant leaks, etc upon reassembly.
Separation is usually achieved by tapping
along the joint with a soft-faced hammer in
order to break the seal. However, note that
this method may not be suitable where
dowels are used for component location.
Where a gasket is used between the mating
faces of two components, ensure that it is
renewed on reassembly, and fit it dry unless
otherwise stated in the repair procedure. Make
sure that the mating faces are clean and dry,
with all traces of old gasket removed. When
cleaning a joint face, use a tool which is not
likely to score or damage the face, and remove
any burrs or nicks with an oilstone or fine file.
Make sure that tapped holes are cleaned
with a pipe cleaner, and keep them free of
jointing compound, if this is being used,
unless specifically instructed otherwise.
Ensure that all orifices, channels or pipes
are clear, and blow through them, preferably
using compressed air.
Oil seals
Oil seals can be removed by levering them
out with a wide flat-bladed screwdriver or
similar tool. Alternatively, a number of self-
tapping screws may be screwed into the seal,
and these used as a purchase for pliers or
similar in order to pull the seal free.
Whenever an oil seal is removed from its
working location, either individually or as part
of an assembly, it should be renewed.
The very fine sealing lip of the seal is easily
damaged, and will not seal if the surface it
contacts is not completely clean and free from
scratches, nicks or grooves. If the original
sealing surface of the component cannot be
restored, and the manufacturer has not made
provision for slight relocation of the seal
relative to the sealing surface, the component
should be renewed.
Protect the lips of the seal from any surface
which may damage them in the course of
fitting. Use tape or a conical sleeve where
possible. Lubricate the seal lips with oil before
fitting and, on dual-lipped seals, fill the space
between the lips with grease.
Unless otherwise stated, oil seals must be
fitted with their sealing lips toward the
lubricant to be sealed.
Use a tubular drift or block of wood of the
appropriate size to install the seal and, if the
seal housing is shouldered, drive the seal
down to the shoulder. If the seal housing isunshouldered, the seal should be fitted with
its face flush with the housing top face (unless
otherwise instructed).
Screw threads and fastenings
Seized nuts, bolts and screws are quite a
common occurrence where corrosion has set
in, and the use of penetrating oil or releasing
fluid will often overcome this problem if the
offending item is soaked for a while before
attempting to release it. The use of an impact
driver may also provide a means of releasing
such stubborn fastening devices, when used
in conjunction with the appropriate
screwdriver bit or socket. If none of these
methods works, it may be necessary to resort
to the careful application of heat, or the use of
a hacksaw or nut splitter device.
Studs are usually removed by locking two
nuts together on the threaded part, and then
using a spanner on the lower nut to unscrew
the stud. Studs or bolts which have broken off
below the surface of the component in which
they are mounted can sometimes be removed
using a stud extractor. Always ensure that a
blind tapped hole is completely free from oil,
grease, water or other fluid before installing
the bolt or stud. Failure to do this could cause
the housing to crack due to the hydraulic
action of the bolt or stud as it is screwed in.
When tightening a castellated nut to accept
a split pin, tighten the nut to the specified
torque, where applicable, and then tighten
further to the next split pin hole. Never
slacken the nut to align the split pin hole,
unless stated in the repair procedure.
When checking or retightening a nut or bolt
to a specified torque setting, slacken the nut
or bolt by a quarter of a turn, and then
retighten to the specified setting. However,
this should not be attempted where angular
tightening has been used.
For some screw fastenings, notably
cylinder head bolts or nuts, torque wrench
settings are no longer specified for the latter
stages of tightening, “angle-tightening” being
called up instead. Typically, a fairly low torque
wrench setting will be applied to the
bolts/nuts in the correct sequence, followed
by one or more stages of tightening through
specified angles.
Locknuts, locktabs and washers
Any fastening which will rotate against a
component or housing during tightening
should always have a washer between it and
the relevant component or housing.
Spring or split washers should always be
renewed when they are used to lock a critical
component such as a big-end bearing
retaining bolt or nut. Locktabs which are
folded over to retain a nut or bolt should
always be renewed.
Self-locking nuts can be re-used in non-
critical areas, providing resistance can be felt
when the locking portion passes over the bolt
or stud thread. However, it should be noted
that self-locking stiffnuts tend to lose theireffectiveness after long periods of use, and
should be renewed as a matter of course.
Split pins must always be replaced with
new ones of the correct size for the hole.
When thread-locking compound is found
on the threads of a fastener which is to be re-
used, it should be cleaned off with a wire
brush and solvent, and fresh compound
applied on reassembly.
Special tools
Some repair procedures in this manual
entail the use of special tools such as a press,
two or three-legged pullers, spring
compressors, etc. Wherever possible, suitable
readily-available alternatives to the
manufacturer’s special tools are described,
and are shown in use. In some instances,
where no alternative is possible, it has been
necessary to resort to the use of a
manufacturer’s tool, and this has been done
for reasons of safety as well as the efficient
completion of the repair operation. Unless you
are highly-skilled and have a thorough
understanding of the procedures described,
never attempt to bypass the use of any
special tool when the procedure described
specifies its use. Not only is there a very great
risk of personal injury, but expensive damage
could be caused to the components involved.
Environmental considerations
When disposing of used engine oil, brake
fluid, antifreeze, etc, give due consideration to
any detrimental environmental effects. Do not,
for instance, pour any of the above liquids
down drains into the general sewage system,
or onto the ground to soak away. Many local
council refuse tips provide a facility for waste
oil disposal, as do some garages. If none of
these facilities are available, consult your local
Environmental Health Department, or the
National Rivers Authority, for further advice.
With the universal tightening-up of
legislation regarding the emission of
environmentally-harmful substances from
motor vehicles, most current vehicles have
tamperproof devices fitted to the main
adjustment points of the fuel system. These
devices are primarily designed to prevent
unqualified persons from adjusting the fuel/air
mixture, with the chance of a consequent
increase in toxic emissions. If such devices
are encountered during servicing or overhaul,
they should, wherever possible, be renewed
or refitted in accordance with the vehicle
manufacturer’s requirements or current
legislation.
Note: It is
antisocial and
illegal to dump oil
down the drain.
To find the
location of your
local oil recycling
bank, call this
number free.

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