tyre pressure JAGUAR XJ6 1997 2.G Workshop Manual

3261 Jaguar XJ6
LIVING WITH YOUR JAGUAR XJ6
IntroductionPage 0•4
Notes for UK readersPage 0•4
Safety first!Page 0•5
Roadside repairs
IntroductionPage 0•6
If your car won’t startPage 0•6
Jump startingPage 0•7
Wheel changingPage 0•8
Identifying leaksPage 0•9
TowingPage 0•9
Weekly checks
IntroductionPage 0•10
Underbonnet check points Page 0•10
Engine oil levelPage 0•11
Coolant levelPage 0•11
Brake fluid levelPage 0•12
Screen washer fluid level Page 0•12
Power steering fluid level Page 0•13
Wiper bladesPage 0•13
Tyre condition and pressure Page 0•14
BatteryPage 0•15
Bulbs and fusesPage 0•15
Lubricants, fluids and tyre pressuresPage 0•16
MAINTENANCE
Routine maintenance and servicingPage 1•1
Servicing specificationsPage 1•2
Maintenance schedulePage 1•3
Maintenance procedures Page 1•6
Contents

3261 Jaguar XJ6
0•8Roadside repairs
The spare wheel and tools are stored in
the boot. Remove the carpet cover then
unscrew the retainer and lift out the spare
wheel from the boot.
Wheel changing
Some of the details shown here will vary
according to model. For instance, the location
of the spare wheel and jack is not the same
on all cars. However, the basic principles
apply to all vehicles.Warning: Do not change a wheel in a situation where you risk being hit by
other traffic. On busy roads, try to stop in a lay-by or a gateway. Be wary of
passing traffic while changing the wheel – it is easy to become distracted by
the job in hand.
Finally...
MRemove the wheel chocks.
MCheck the tyre pressure on the wheel just
fitted. If it is low, or if you don’t have a
pressure gauge with you, drive slowly to
the nearest garage and inflate the tyre to
the right pressure.
MHave the damaged tyre or wheel repaired
as soon as possible.
Remove the plastic cover from the end of
the vehicle jack lifting point tube, nearest
to the wheel that is being changed.Slide the lifting bracket of the jack fully
into the lifting point tube. Make sure the
jack is located on firm ground.Raise the jack until the wheel is raised
clear of the ground. Unscrew the wheel
nuts and remove the wheel. Fit the spare
wheel and screw on the nuts. Lightly tighten
the nuts then lower the vehicle to the ground.
With the vehicle on the ground, remove
the trim cap (where fitted) and slacken
each wheel nut by half a turn.Remove the jack and wheelbrace its
holder which is located behind the spare
wheel.123
4
Securely tighten the wheel nuts in a
diagonal sequence then (where necessary)
refit the wheel trim cap. Stow the tolls and
punctured wheel and back in the luggage
compartment and secure them in position.
Note that the wheel nuts should be slackened
and retightened to the specified torque at the
earliest possible opportunity.7
56
Preparation
MWhen a puncture occurs, stop as soon as
it is safe to do so.
MPark on firm level ground, if possible,
and well out of the way of other traffic.
MUse hazard warning lights if necessary. MIf you have one, use a warning triangle to
alert other drivers of your presence.
MApply the handbrake and engage first or
reverse gear (or Park on models with
automatic transmission.MChock the wheel diagonally opposite the
one being removed – a couple of large
stones will do for this.
MIf the ground is soft, use a flat piece of
wood to spread the load under the jack.
Changing the wheel

3261 Jaguar XJ6
0•10Weekly checks
There are some very simple checks which
need only take a few minutes to carry out, but
which could save you a lot of inconvenience
and expense.
These "Weekly checks" require no great skill
or special tools, and the small amount of time
they take to perform could prove to be very
well spent, for example;MKeeping an eye on tyre condition and
pressures, will not only help to stop them
wearing out prematurely, but could also save
your life.
M
Many breakdowns are caused by electrical
problems. Battery-related faults are particularly
common, and a quick check on a regular basis
will often prevent the majority of
these.MIf your car develops a brake fluid leak, the
first time you might know about it is when
your brakes don't work properly. Checking
the level regularly will give advance warning of
this kind of problem.
MIf the oil or coolant levels run low, the cost
of repairing any engine damage will be far
greater than fixing the leak, for example.
Introduction
§3.6 litre engine
(others similar)
Viewed from right-hand side
AEngine oil level dipstick
BEngine oil filler cap
CCoolant expansion tank
DBrake fluid reservoir
EScreen washer fluid reservoir
FBattery
GPower steering fluid reservoir
Underbonnet check points

3261 Jaguar XJ6
Weekly checks0•11
Engine oil level
Before you start
4Make sure that your car is on level ground.
4Check the oil level before the car is driven,
or at least 5 minutes after the engine has been
switched off.
The correct oilModern engines place great demands on their
oil. It is very important that the correct oil for
your car is used (See “Lubricants, fluids and
tyre pressures”).
Car care
l If you have to add oil frequently, you should
check whether you have any oil leaks. Place
some clean paper under the car overnight,
and check for stains in the morning. If there
are no leaks, the engine may be burning oil
(see “Fault finding”).
lAlways maintain the level between the
upper and lower dipstick marks (see photo 3).
If the level is too low severe engine damage
may occur. Oil seal failure may result if the
engine is overfilled by adding too much oil.
If the oil level is checked
immediately after driving the
vehicle, some of the oil will
remain in the upper engine
components, resulting in an inaccurate
reading on the dipstick!
The dipstick is located at the rear of the
engine on the left-hand side (see “Under-
bonnet check points” on page 0•10 for
exact location). Withdraw the dipstick.Using a clean rag or paper towel remove
all oil from the dipstick. Insert the clean
dipstick into the tube as far as it will go,
then withdraw it again.
Note the oil level on the end of the
dipstick which should be between the
upper and lower marks. The “M” mark is
for use when checking the oil level after the
vehicle has been standing overnight; in this
case the oil level should be between the “M”
and upper level markings.Oil is added through the filler cap.
Unscrew the cap and top-up the level; a
funnel may help to reduce spillage. Add
the oil slowly, checking the level on the dipstick
often. Don’t overfill (see “Car care” left).
12
34
Warning: DO NOT attempt to
remove the expansion tank
pressure cap when the engine
is hot, as there is a very great
risk of scalding. Do not leave
open containers of coolant
about, as it is poisonous.
Car care
lAdding coolant should not be necessary on
a regular basis. If frequent topping-up is
required, it is likely there is a leak. Check the
radiator, all hoses and joint faces for signs of
staining or wetness, and rectify as necessary.
lIt is important that antifreeze is used in the
cooling system all year round, not just during
the winter months. Don’t top-up with water
alone, as the antifreeze will become too
diluted.
Coolant level
The coolant level should be checked only
with the engine cold. The level is checked
in the expansion tank on the left-hand
side of the engine compartment. Remove the
expansion tank pressure cap and check that
the coolant level is upto the base of filler neck.If topping up is necessary, add a mixture
of water and antifreeze to the expansion
tank until the coolant level is upto the
base of the filler neck. Once the level is
correct, securely refit the pressure cap.12

3261 Jaguar XJ6
Weekly checks0•13
Power steering
fluid level
Before you start:
4Park the vehicle on level ground.
4Set the steering wheel straight-ahead.
4The engine should be turned off.
Safety first!
lThe need for frequent topping-up indicates
a leak, which should be investigated
immediately.
For the check to be
accurate, the steering must
not be turned once the
engine has been stopped.
Wipe clean the area around the reservoir
cap then remove the cap noting that it
unscrews in a clockwise direction (see
arrow on cap).1Wipe clean the cap dipstick then insert it
fully into the reservoir and withdraw it.2
Note the fluid level on the end of the
dipstick. If the fluid is cold (vehicle not
having been used) the fluid level should
be upto the COLD level marking (1). If the
vehicle has been driven and the fluid is hot
then the fluid level should be upto the upper
(HOT) level marking (2).3If necessary, top-up the reservoir with the
specified type of fluid (note that the type
of fluid differs according to model - see
“Lubricants, fluids and tyre pressures” on
page 0•16). Once the level is correct, securely
refit the reservoir cap. Do not overfill the
reservoir.4
Wiper blades
Check the condition of the wiper blades:
if they are cracked or show signs of
deterioration, or if the glass swept area is
smeared, renew them. For maximum clarity of
vision, wiper blades should be renewed
annually.1To remove a wiper blade, pull the arm
fully away from the screen until it locks.
Swivel the blade then depress the locking
clip at the base of the mounting block and
slide the blade off the arm.2
Warning:
l This check applies only to
vehicles fitted with a separate
power steering system. For
vehicles fitted with power
steering where the fluid
reservoir is part of the power hydraulic
system, this weekly check is not
applicable.
l It is essential to use the correct power
steering fluid, this being dependent on the
year of manufacture and type of system
fitted. A label attached to the fluid
reservoir will indicate the specification of
fluid. However, if necessary refer to the
driver’s handbook supplied with the
vehicle or to your local Jaguar dealer.

3261 Jaguar XJ6
0•14Weekly checks
Tyre condition and pressure
It is very important that tyres are in good
condition, and at the correct pressure - having
a tyre failure at any speed is highly dangerous.
Tyre wear is influenced by driving style - harsh
braking and acceleration, or fast cornering,
will all produce more rapid tyre wear. As a
general rule, the front tyres wear out faster
than the rears. Interchanging the tyres from
front to rear ("rotating" the tyres) may result in
more even wear. However, if this is
completely effective, you may have the
expense of replacing all four tyres at once!
Remove any nails or stones embedded in the
tread before they penetrate the tyre to cause
deflation. If removal of a nail does reveal thatthe tyre has been punctured, refit the nail so
that its point of penetration is marked. Then
immediately change the wheel, and have the
tyre repaired by a tyre dealer.
Regularly check the tyres for damage in the
form of cuts or bulges, especially in the
sidewalls. Periodically remove the wheels,
and clean any dirt or mud from the inside and
outside surfaces. Examine the wheel rims for
signs of rusting, corrosion or other damage.
Light alloy wheels are easily damaged by
"kerbing" whilst parking; steel wheels may
also become dented or buckled. A new wheel
is very often the only way to overcome severe
damage.New tyres should be balanced when they are
fitted, but it may become necessary to re-
balance them as they wear, or if the balance
weights fitted to the wheel rim should fall off.
Unbalanced tyres will wear more quickly, as
will the steering and suspension components.
Wheel imbalance is normally signified by
vibration, particularly at a certain speed
(typically around 50 mph). If this vibration is
felt only through the steering, then it is likely
that just the front wheels need balancing. If,
however, the vibration is felt through the
whole car, the rear wheels could be out of
balance. Wheel balancing should be carried
out by a tyre dealer or garage.
Tread Depth - visual check
The original tyres have tread wear safety
bands (B), which will appear when the tread
depth reaches approximately 1.6 mm. The
band positions are indicated by a triangular
mark on the tyre sidewall (A).1Tread Depth - manual check
Alternatively, tread wear can be
monitored with a simple, inexpensive device
known as a tread depth indicator gauge.2Tyre Pressure Check
Check the tyre pressures regularly with
the tyres cold. Do not adjust the tyre
pressures immediately after the vehicle has
been used, or an inaccurate setting will result.3
Tyre tread wear patterns
Shoulder Wear
Underinflation (wear on both sides)
Under-inflation will cause overheating of the
tyre, because the tyre will flex too much, and
the tread will not sit correctly on the road
surface. This will cause a loss of grip and
excessive wear, not to mention the danger of
sudden tyre failure due to heat build-up.
Check and adjust pressures
Incorrect wheel camber (wear on one side)
Repair or renew suspension parts
Hard cornering
Reduce speed!
Centre Wear
Overinflation
Over-inflation will cause rapid wear of the
centre part of the tyre tread, coupled with
reduced grip, harsher ride, and the danger of
shock damage occurring in the tyre casing.
Check and adjust pressures
If you sometimes have to inflate your car’s
tyres to the higher pressures specified for
maximum load or sustained high speed, don’t
forget to reduce the pressures to normal
afterwards.
Uneven Wear
Front tyres may wear unevenly as a result of
wheel misalignment. Most tyre dealers and
garages can check and adjust the wheel
alignment (or "tracking") for a modest charge.
Incorrect camber or castor
Repair or renew suspension parts
Malfunctioning suspension
Repair or renew suspension parts
Unbalanced wheel
Balance tyres
Incorrect toe setting
Adjust front wheel alignment
Note: The feathered edge of the tread which
typifies toe wear is best checked by feel.

0•16Lubricants, fluids and tyre pressures
3261 Jaguar XJ6
Lubricants and fluids
Engine . . . . . . . . . . . . . . . . . . . . . . . . . . Multigrade engine oil to API SG or higher (Duckhams QS, QXR, Hypergrade Plus,
Hypergrade, or 10W-40 Motor Oil)
Cooling system . . . . . . . . . . . . . . . . . . . Ethylene glycol based (phosphate free) antifreeze
(Duckhams Antifreeze and Summer Coolant)
Automatic transmission . . . . . . . . . . . . Dexron type II automatic transmission fluid (ATF) (Duckhams Uni-Matic)
Differential:
Standard differential . . . . . . . . . . . . . . SAE EP90 to API GL5 (Duckhams 80W-90S Gear Oil)
Powr-lok differential . . . . . . . . . . . . . . . SAE 90 to API GL5 (Duckhams Hypoid 90 DL)
Braking system . . . . . . . . . . . . . . . . . . . Hydraulic fluid to DOT 4 (Duckhams Universal Brake and Clutch Fluid)
Power steering (with separate reservoir) .dependent on year of manufacture and system fitted - refer to your Jaguar dealer
Power hydraulic system . . . . . . . . . . . . . Castrol or Jaguar hydraulic system mineral oil (HSMO) Refer to your Jaguar dealer
Tyre pressures
Note:Tyre pressures must always be checked with the tyres cold to ensure accuracy.
Front . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 psi (2.3 bar)
Rear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 psi (2.3 bar)
Note:Jaguar state that the tyre pressures maybe reduced by up to 8 psi (0.6 bar) on the front tyres and 6 psi (0.4 bar) on the rear
tyres to increase the ride comfort. This is only allowable if the vehicle is not to be driven at speeds in excess of 100 mph (160 kmh);
if speeds are to exceed this, the tyres must be run at the specified pressures.
Oils perform vital tasks in all engines. The
higher the engine’s performance, the greater
the demand on lubricants to minimise wear as
well as optimise power and economy.
Duckhams tailors lubricants to the highest
technical standards, meeting and exceeding
the demands of all modern engines.
HOW ENGINE OIL WORKS
• Beating friction
Without oil, the surfaces inside your engine
which rub together will heat, fuse and quickly
cause engine seizure. Oil, and its special
additives, forms a molecular barrier between
moving parts, to stop wear and minimise heat
build-up.
• Cooling hot spots
Oil cools parts that the engine’s water-based
coolant cannot reach, bathing the combustion
chamber and pistons, where temperatures
may exceed 1000°C. The oil assists intransferring the heat to the engine cooling
system. Heat in the oil is also lost by air flow
over the sump, and via any auxiliary oil cooler.
• Cleaning the inner engine
Oil washes away combustion by-products
(mainly carbon) on pistons and cylinders,
transporting them to the oil filter, and holding
the smallest particles in suspension until they
are flushed out by an oil change. Duckhams
oils undergo extensive tests in the laboratory,
and on the road.
Engine oil types
Mineral oilsare the “traditional” oils,
generally suited to older engines and cars not
used in harsh conditions. Duckhams
Hypergrade Plus and Hypergradeare well
suited for use in most popular family cars.
Diesel oilssuch as Duckhams Dieselare
specially formulated for Diesel engines,
including turbocharged models and 4x4s.
Synthetic oilsare the state-of-the-art in
lubricants, offering ultimate protection, but at
a fairly high price. One such is Duckhams QS,
for use in ultra-high performance engines.
Semi-synthetic oilsoffer high performance
engine protection, but at less cost than full
synthetic oils. Duckhams QXRis an ideal choice
for hot hatches and hard-driven cars.
For help with technical
queries on lubricants,
call Duckhams Oils
on 0181 290 8207
Choosing your engine oil
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.

silencer and catalytic converter. If the
components can come in contact with the
body or suspension parts, secure the exhaust
system with new mounts.
5Check the running condition of the engine
by inspecting inside the end of the tailpipe.
The exhaust deposits here are an indication of
engine state-of-tune. If the pipe is black and
sooty or coated with white deposits, the
engine is in need of a tune-up, including a
thorough fuel system inspection.
11 Braking system - general
check and adjustment
2
Warning: The dust created by
the brake system may contain
asbestos, which is harmful to
your health. Never blow it out
with compressed air and don’t inhale any
of it. An approved filtering mask should be
worn when working on the brakes. Do not,
under any circumstances, use petroleum-
based solvents to clean brake parts. Use
brake system cleaner only! Try to use non-
asbestos replacement parts whenever
possible.
Note: For detailed photographs of the brake
system, refer to Chapter 9.
1In addition to the specified intervals, the
brakes should be inspected every time the
wheels are removed or whenever a defect is
suspected. Any of the following symptoms
could indicate a potential brake system
defect: The vehicle pulls to one side when the
brake pedal is depressed; the brakes make
squealing or dragging noises when applied;
brake pedal travel is excessive; the pedal
pulsates; brake fluid leaks, usually onto the
inside of the tyre or wheel.
2The disc brakes have built-in electrical wear
indicators which cause a warning lamp to
illuminate on the instrument panel when
they’re worn to the renewal point. When the
warning light comes on, replace the pads
immediately or expensive damage to the
discs can result.
3Loosen the wheel nuts.
4Raise the vehicle and place it securely on
axle stands.
5Remove the wheels.
Disc brakes
6There are two pads (an outer and an inner)
in each caliper. The pads are visible through
inspection holes in each caliper (see Haynes
Hint).
7Check the pad thickness by looking at each
end of the caliper and through the inspection
hole in the caliper body. If the lining material is
less than the thickness listed in this Chapter’s
Specifications, replace the pads. Note:Keep
in mind that the lining material is riveted or
bonded to a metal backing plate and the metal
portion is not included in this measurement.8If it is difficult to determine the exact
thickness of the remaining pad material by the
above method, or if you are at all concerned
about the condition of the pads, remove the
caliper(s), then remove the pads from the
calipers for further inspection (see Chapter 9).
9Once the pads are removed from the
calipers, clean them with brake cleaner and
re-measure them with a ruler or a vernier
caliper.
10Measure the disc thickness with a
micrometer to make sure that it still has
service life remaining. If any disc is thinner
than the specified minimum thickness,
replace it (refer to Chapter 9). Even if the disc
has service life remaining, check its condition.
Look for scoring, gouging and burned spots. If
these conditions exist, remove the disc and
have it resurfaced (see Chapter 9).
11Before refitting the wheels, check all
brake lines and hoses for damage, wear,
deformation, cracks, corrosion, leakage,
bends and twists, particularly in the vicinity of
the rubber hoses at the calipers (see
illustration). Check the clamps for tightness
and the connections for leakage. Make sure
that all hoses and lines are clear of sharp
edges, moving parts and the exhaust system.
If any of the above conditions are noted,
repair, reroute or replace the lines and/or
fittings as necessary (see Chapter 9).
Hydraulic brake servo check
12Sit in the driver’s seat and perform the
following sequence of tests.
13Start the engine, run it for about a minute
and turn it off. Then firmly depress the brake
several times - the pedal travel should
decrease with each application.
14With the brake fully depressed, start the
engine - the pedal should move down a little
when the engine starts.
15Depress the brake, stop the engine and
hold the pedal in for about 30 seconds - the
pedal should neither sink nor rise.
16If your brakes do not operate as
described above when the preceding tests
are performed, the brake servo is either in
need of repair or has failed. Refer to Chapter 9
for the removal procedure.
Handbrake
17Slowly pull up on the handbrake and
count the number of clicks you hear until the
handle is up as far as it will go. The
adjustment should be within the specified
number of clicks listed in this Chapter’s
Specifications. If you hear more or fewer
clicks, it’s time to adjust the handbrake (refer
to Chapter 9).
18An alternative method of checking the
handbrake is to park the vehicle on a steep hill
with the handbrake set and the transmission
in Neutral (be sure to stay in the vehicle during
this check!). If the handbrake cannot prevent
the vehicle from rolling, it is in need of
adjustment (see Chapter 9). Whenever a fault
is suspected, the brake discs should be
removed and the handbrake assemblies
themselves should be visually inspected.
12 Steering
and suspension check
2
Note: The steering linkage and suspension
components should be checked periodically.
Worn or damaged suspension and steering
linkage components can result in excessive
and abnormal tyre wear, poor ride quality and
vehicle handling and reduced fuel economy.
For detailed illustrations of the steering and
suspension components, refer to Chapter 10.
With the wheels on the ground
1Park the vehicle on level ground, turn the
engine off and set the handbrake. Check the
tyre pressures and check that the wheel nuts
are tightened to the specified torque.
2Push down at one corner of the vehicle,
then release it while noting the movement of
the body. It should stop moving and come to
rest in a level position with one or two
bounces. When bouncing the vehicle up and
down, listen for squeaks and noises from the
suspension components.
3If the vehicle continues to move up-and-
down or if it fails to return to its original
1•12Every 7500 miles or 6 months
11.11 Check along the brake hoses
and at each fitting (arrowed) for
deterioration and cracks
3261 Jaguar XJ6
You will find an inspection hole like this
in each caliper - placing a ruler across
the hole should enable you to determine
the thickness of remaining pad material
for both inner and outer pads

16 Spark plug renewal
2
Refer to Section 4, renewing the plugs
regardless of their apparent condition.
17 Air cleaner element renewal
1
1The air filter is located inside a housing at
the left side of the engine compartment. To
remove the air filter, release the four spring
clips that secure the two halves of the air
cleaner housing together, then lift the cover
up and remove the air filter element (see
illustration).
Caution: Never drive the car with the air
cleaner removed. Excessive engine wear
could result and backfiring could even
cause a fire under the bonnet.
2Wipe out the inside of the air cleaner
housing.
3Place the new filter into the air cleaner
housing, making sure it seats properly.
4Refitting the cover is the reverse of removal.
18 Fuel filter renewal
2
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-typeappliance (such as a water heater or
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 where
they 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 (see
Chapter 4 for more information). When you
perform any kind of work on the fuel
system, wear safety glasses and have a
Class B type fire extinguisher on hand.
1The canister type filter is mounted
underneath the car on the passenger’s side
frame rail just in front of the left rear tyre.
2Depressurise the fuel system (refer to
Chapter 4), then disconnect the cable from
the negative terminal of the battery.
3On 1988 to 1990 models, detach the banjo
bolt from the outlet side of the filter then
remove the union from the inlet side of the
filter. Unscrew the filter mounting bolt and
remove the filter (see illustration).
4On 1991 to 1994 models, the fuel filter has
quick-disconnect fittings that do not require 8Clean and lubricate the handbrake cable,
along with the cable guides and levers. This
can be done by smearing some of the chassis
grease onto the cable and its related parts
with your fingers.
9Open the bonnet and smear a little chassis
grease on the bonnet latch mechanism. Have
an assistant pull the bonnet release lever from
inside the car as you lubricate the cable at the
latch.
10Lubricate all the hinges (door, bonnet,
etc.) with engine oil to keep them in proper
working order.
11The key lock cylinders can be lubricated
with spray graphite or silicone lubricant, which
is available at motor factors.12Lubricate the door weather-stripping with
silicone spray. This will reduce chafing and
retard wear.
15 Road test
1
Instruments and electrical
equipment
1Check the operation of all instruments and
electrical equipment.
2Make sure that all instruments read
correctly, and switch on all electrical
equipment in turn, to check that it functions
properly.
Steering and suspension
3Check for any abnormalities in the steering,
suspension, handling or road “feel”.
4Drive the car, and check that there are no
unusual vibrations or noises.
5Check that the steering feels positive, with
no excessive “sloppiness”, or roughness, and
check for any suspension noises when
cornering and driving over bumps.
Drivetrain
6Check the performance of the engine and
transmission, listening for any unusual noises.7Make sure that the engine runs smoothly
when idling, and that there is no hesitation
when accelerating.
8Check that the gear changing action of the
transmission is smooth and progressive and
that the drive is taken up smoothly from a
standing start.
Braking system
9Make sure that the car does not pull to one
side when braking, and that the wheels do not
lock prematurely when braking hard.
10Check that there is no vibration through
the steering when braking.
11Check that the handbrake operates
correctly without excessive movement of the
lever, and that it holds the car stationary on a
slope.
12Test the operation of the brake servo unit
as follows. With the engine off, depress the
footbrake four or five times to exhaust the
vacuum. Hold the brake pedal depressed, then
start the engine. As the engine starts, there
should be a noticeable “give” in the brake
pedal as vacuum builds up. Allow the engine to
run for at least two minutes, and then switch it
off. If the brake pedal is depressed now, it
should be possible to detect a hiss from the
servo as the pedal is depressed. After about
four or five depressions, no further hissing
should be heard, and the pedal should feel
considerably harder.
1•14Every 7500 miles or 6 months
17.1 Detach the clips and separate the
cover, then slide the filter element out of
the housing
3261 Jaguar XJ6
14.6 Grease fittings for the rear
driveshafts are located in the centre
on each U-joint
Every 15 000 miles (24 000 km) or 12 months

rebuilt engine or short block, some rebuilders
will not warranty their engines unless the
radiator has been professionally flushed. Also,
we don’t recommend overhauling the oil
pump - always refit a new one when an engine
is rebuilt.
Before beginning the engine overhaul, read
through the entire procedure to familiarise
yourself with the scope and requirements of
the job. Overhauling an engine isn’t difficult,
but it is time-consuming. Plan on the vehicle
being tied up for a minimum of two weeks,
especially if parts must be taken to an
automotive machine workshop for repair or
reconditioning. Check on availability of parts
and make sure that any necessary special
tools and equipment are obtained in advance.
Most work can be done with typical hand
tools, although a number of precision
measuring tools are required for inspecting
parts to determine if they must be renewed.
Often an automotive machine workshop will
handle the inspection of parts and offer
advice concerning reconditioning and
renewal. Note:Always wait until the engine
has been completely dismantled and all
components, especially the engine block,
have been inspected before deciding what
service and repair operations must be
performed by an automotive machine
workshop. Since the engine block’s condition
will be the major factor to consider when
determining whether to overhaul the original
engine or buy a rebuilt one, never purchase
parts or have machine work done on other
components until the engine block has been
thoroughly inspected. As a general rule, time
is the primary cost of an overhaul, so it
doesn’t pay to refit worn or substandard
parts.
If it turns out that a number of major
components are beyond reconditioning, it
may be cost effective to buy a factory-rebuilt
engine from a Jaguar dealership.
As a final note, to ensure maximum life and
minimum trouble from a rebuilt engine,
everything must be assembled with care in a
spotlessly-clean environment.
3 Vacuum gauge
diagnostic checks
2
A vacuum gauge provides valuable
information about what is going on in the
engine at a low cost. You can check for worn
rings or cylinder walls, leaking cylinder head or
intake manifold gaskets, incorrect carburettor
adjustments, restricted exhaust, stuck or
burned valves, weak valve springs, improper
ignition or valve timing and ignition problems.
Unfortunately, vacuum gauge readings are
easy to misinterpret, so they should be used
with other tests to confirm the diagnosis.
Both the absolute readings and the rate of
needle movement are important for accurate
interpretation. Most gauges measure vacuumin inches of mercury (in-Hg). As vacuum
increases (or atmospheric pressure decreases),
the reading will decrease. Also, for every
1000 foot increase in elevation above sea level;
the gauge readings will decrease about one
inch of mercury.
Connect the vacuum gauge directly to
intake manifold vacuum, not to ported (above
the throttle plate) vacuum (see illustration).
Be sure no hoses are left disconnected during
the test or false readings will result.
Before you begin the test, allow the engine
to warm up completely. Block the wheels and
set the handbrake. With the transmission in
Park, start the engine and allow it to run at
normal idle speed.
Warning: Carefully inspect the
fan blades for cracks or damage
before starting the engine. Keep
your hands and the vacuum
tester clear of the fan and do not stand in
front of the vehicle or in line with the fan
when the engine is running.
Read the vacuum gauge; an average,
healthy engine should normally produce
between 17 and 22 inches of vacuum with a
fairly steady needle.
Refer to the following vacuum gauge
readings and what they indicate about the
engines condition:
1A low steady reading usually indicates a
leaking gasket between the intake manifold
and carburettor or throttle body, a leaky
vacuum hose, late ignition timing or incorrect
camshaft timing. Check ignition timing with a
timing light and eliminate all other possible
causes, utilising the tests provided in this
Chapter before you remove the timing belt
cover to check the timing marks.
2If the reading is three to eight inches below
normal and it fluctuates at that low reading,
suspect an intake manifold gasket leak at an
intake port or a faulty injector.
3If the needle has regular drops of about two
to four inches at a steady rate the valves are
probably leaking. Perform a compression or
leak-down test to confirm this.
4An irregular drop or down-flick of the
needle can be caused by a sticking valve or
an ignition misfire. Perform a compression or
leak-down test and read the spark plugs.5A rapid vibration of about four in-Hg
vibration at idle combined with exhaust
smoke indicates worn valve guides. Perform a
leak-down test to confirm this. If the rapid
vibration occurs with an increase in engine
speed, check for a leaking intake manifold
gasket or cylinder head gasket, weak valve
springs, burned valves or ignition misfire.
6A slight fluctuation, say one inch up and
down, may mean ignition problems. Check all
the usual tune-up items and, if necessary, run
the engine on an ignition analyser.
7If there is a large fluctuation, perform a
compression or leak-down test to look for a
weak or dead cylinder or a blown cylinder
head gasket.
8If the needle moves slowly through a wide
range, check for a clogged PCV system,
incorrect idle fuel mixture, throttle body or
intake manifold gasket leaks.
9Check for a slow return after revving the
engine by quickly snapping the throttle open
until the engine reaches about 2,500 rpm and
let it shut. Normally the reading should drop to
near zero, rise above normal idle reading
(about 5 in.-Hg over) and then return to the
previous idle reading. If the vacuum returns
slowly and doesn’t peak when the throttle is
snapped shut, the rings may be worn. If there
is a long delay, look for a restricted exhaust
system (often the silencer or catalytic
converter). An easy way to check this is to
temporarily disconnect the exhaust ahead of
the suspected part and redo the test.
4 Cylinder compression check
2
1A compression check will tell you what
mechanical condition the upper end (pistons,
rings, valves, cylinder head gasket) of your
engine is in. Specifically, it can tell you if the
compression is down due to leakage caused
by worn piston rings, defective valves and
seats or a blown cylinder head gasket. Note:
The engine must be at normal operating
temperature and the battery must be fully
charged for this check.
2Begin by cleaning the area around the
spark plugs before you remove them
(compressed air should be used, if available,
otherwise a small brush or even a bicycle tyre
pump will work). The idea is to prevent dirt
from getting into the cylinders as the
compression check is being done.
3Remove all of the spark plugs from the
engine (see Chapter 1).
4Block the throttle wide open.
5Detach the coil wire from the centre of the
distributor cap and ground it on the engine
block. Use a jumper wire with alligator clips on
each end to ensure a good earth. Also,
remove the fuel pump relay (see Chapter 4) to
disable the fuel pump during the compression
test.
Engine removal and overhaul procedures 2B•3
2B
3.4 The vacuum gauge is easily attached
to a port on the intake manifold, and can
tell a lot about an engine’s state of tune
3261 Jaguar XJ6