1997 JAGUAR XJ6 seat removal

exhaust components will be warm during the
actual work, so try to anticipate any potential
problems before the engine and accessories
are hot.
5Park the vehicle on a level spot. Start the
engine and allow it to reach its normal
operating temperature (the needle on the
temperature gauge should be at least above
the bottom mark). Warm oil and contaminates
will flow out more easily. Turn off the engine
when it’s warmed up. Remove the oil filler cap
located next to the valve cover.
6Raise the vehicle and support it on axle
stands.
Warning: To avoid personal
injury, never get beneath the
vehicle when it is supported by
only by a jack. The jack provided
with your vehicle is designed solely for
raising the vehicle to remove and replace
the wheels. Always use axle stands to
support the vehicle when it becomes
necessary to place your body underneath
the vehicle.
7Being careful not to touch the hot exhaust
components, place the drain pan under the
drain plug in the bottom of the pan and
remove the plug (see illustration). You may
want to wear gloves while unscrewing the
plug the final few turns if the engine is really
hot.
8Allow the old oil to drain into the pan. It may
be necessary to move the pan farther under
the engine as the oil flow slows to a trickle.
Inspect the old oil for the presence of metal
shavings and chips.
9After all the oil has drained, wipe off the
drain plug with a clean rag. Even minute metal
particles clinging to the plug would
immediately contaminate the new oil.
10Clean the area around the drain plug
opening, refit the plug and tighten it securely,
but do not strip the threads.
11Move the drain pan into position under the
oil filter.
12Remove all tools, rags, etc. from under
the vehicle, being careful not to spill the oil in
the drain pan, then lower the vehicle.
13Loosen the oil filter (see illustration)by
turning it anti-clockwise with the filter wrench.
Any standard filter wrench should work. Oncethe filter is loose, use your hands to unscrew
it from the block. Just as the filter comes
away from the block, immediately tilt the open
end up to prevent the oil inside the filter from
spilling out.
Warning: The engine exhaust
pipes may still be hot, so be
careful.
14With a clean rag, wipe off the mounting
surface on the block. If a residue of old oil is
allowed to remain, it will smoke when the
block is heated up. It will also prevent the new
filter from seating properly. Also make sure
that the none of the old gasket remains stuck
to the mounting surface. It can be removed
with a scraper if necessary.
15Compare the old filter with the new one to
make sure they are the same type. Smear
some engine oil on the rubber gasket of the
new filter and screw it into place (see
illustration). Because over-tightening the
filter will damage the gasket, do not use
a filter wrench to tighten the filter. Tighten it by
hand until the gasket contacts the seating
surface. Then seat the filter by giving it an
additional 3/4-turn.
16Add new oil to the engine through the oil
filler cap next to the valve cover. Use a spout
or funnel to prevent oil from spilling onto the
top of the engine. Pour three litres of fresh oil
into the engine. Wait a few minutes to allow
the oil to drain into the pan, then check the
level on the oil dipstick (see “Weekly checks”).
If the oil level is at or near the H mark, refit the
filler cap hand tight, start the engine and allow
the new oil to circulate.
17Allow the engine to run for about a minute.
While the engine is running, look under the
vehicle and check for leaks at the sump drain
plug and around the oil filter. If either isleaking, stop the engine and tighten the plug
or filter slightly.
18Wait a few minutes to allow the oil to
trickle down into the pan, then recheck the
level on the dipstick and, if necessary, add
enough oil to bring the level to the H mark.
19During the first few trips after an oil
change, make it a point to check frequently
for leaks and proper oil level.
20The old oil drained from the engine cannot
be reused in its present state and should be
disposed of. Check with your local authority,
or with a local garage to see whether they will
accept the oil for recycling. Don’tpour used
oil into drains or onto the ground. After the oil
has cooled, it can be drained into a suitable
container (capped plastic jugs, topped
bottles, etc.) for transport to an approved
disposal site.
4 Spark plug check
2
1Spark plug renewal requires a spark plug
socket which fits onto a ratchet spanner. This
socket is lined with a rubber grommet to
protect the porcelain insulator of the spark
plug and to hold the plug while you insert it
into the spark plug hole. You will also need a
wire-type feeler gauge to check and adjust
the spark plug gap and a torque wrench to
tighten the new plugs to the specified torque
(see illustration).
2If you are replacing the plugs, purchase the
new plugs, adjust them to the proper gap and
then replace each plug one at a time. Note:
When buying new spark plugs, it’s essential
that you obtain the correct plugs for your
specific vehicle. This information can be found
in the Specifications Section at the beginning
of this Chapter, on the Vehicle Emissions
Control Information (VECI) label located on the
underside of the bonnet (where fitted)or in the
owner’s manual. If these sources specify
different plugs, purchase the spark plug type
specified on the VECI label because that
information is provided specifically for your
engine.
Every 7500 miles or 6 months 1•7
1
3.7 The oil drain plug (arrowed) is located
at the rear of the sump - use a ring
spanner or socket to remove it3.13 The oil filter is located on the left side
of the engine - use a filter wrench for
removal (tighten the new filter by hand)3.15 Lubricate the oil filter gasket with
clean engine oil before refitting the filter
3261 Jaguar XJ6
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.

3Inspect each of the new plugs for defects. If
there are any signs of cracks in the porcelain
insulator of a plug, don’t use it.
4Check the electrode gaps of the new plugs.
Check the gap by inserting the wire gauge of
the proper thickness between the electrodes
at the tip of the plug (see illustration). The
gap between the electrodes should be
identical to that listed in this Chapter’s
Specifications or on the VECI label (as
applicable). If the gap is incorrect, use the
notched adjuster on the feeler gauge body to
bend the curved side electrode slightly (see
illustration).
5If the side electrode is not exactly over the
centre electrode, use the notched adjuster to
align them.Caution: If the gap of a new plug must be
adjusted, bend only the base of the earth
electrode - do not touch the tip.
Removal
6To prevent the possibility of mixing up
spark plug leads, work on one spark plug at a
time. Remove the lead and boot from one
spark plug. Grasp the boot - not the lead - as
shown, give it a half twisting motion and pull
straight up (see illustration).
7If compressed air is available, blow any dirt
or foreign material away from the spark plug
area before proceeding (a common bicycle
pump will also work).
8Remove the spark plug (see illustration).9Whether you are replacing the plugs at this
time or intend to re-use the old plugs,
compare each old spark plug with the chart
shown on the inside back cover of this manual
to determine the overall running condition of
the engine.
Refitting
10Prior to refitting, apply a coat of anti-seize
compound to the plug threads (see
illustration). It’s often difficult to insert spark
plugs into their holes without cross-threading
them. To avoid this possibility, fit a short piece
of 3/8-inch internal diameter (ID) rubber hose
over the end of the spark plug (see Haynes
Hint). The flexible hose acts as a universal
joint to help align the plug with the plug hole.
Should the plug begin to cross-thread, the
hose will slip on the spark plug, preventing
thread damage. Tighten the plug to the torque
listed in this Chapter’s Specifications. In the
absence of a torque wrench, tighten each
plug until you feel it seat, and then by a further
quarter-turn only. Do not overtighten the
spark plugs.
11Attach the plug lead to the new spark
plug, again using a twisting motion on the
boot until it is firmly seated on the end of the
spark plug.
12Follow the above procedure for the
remaining spark plugs, replacing them one at
a time to prevent mixing up the spark plug
leads.
1•8Every 7500 miles or 6 months
4.4a Spark plug manufacturers
recommend using a wire-type gauge when
checking the gap - if the wire does not
slide between the electrodes with a slight
drag, adjustment is required4.4b To change the gap, bend the side
electrode only, as indicated by the arrows,
and be very careful not to crack or chip the
porcelain insulator surrounding the
centre electrode4.6 When removing the spark plug leads,
grasp only the boot and use a
twisting/pulling motion
4.8 Use a spark plug socket with a long
extension to unscrew the spark plugs
3261 Jaguar XJ6
4.1 Tools required for changing
spark plugs
1 Spark plug socket - This will have special
padding inside to protect the spark plug
porcelain insulator
2 Torque wrench - Although not mandatory,
use of this tool is the best way to ensure
that the plugs are tightened properly
3 Ratchet - to fit the plug socket
4 Extension - Depending on model and
accessories, you may need special
extensions and universal joints to reach
one or more of the plugs
5 Spark plug gap gauge - This gauge for
checking the gap comes in a variety of
styles. Make sure the gap for your engine
is included
4.10 Apply a coat of anti-seize compound
to the spark plug threads
A length of 3/8-inch ID rubber hose will
save time and prevent damaged
threads when refitting the spark plugs

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

and old bearings should never be installed on
new races.
15Use high-temperature front wheel bearing
grease to pack the bearings. Work the grease
completely into the bearings, forcing it
between the rollers, cone and cage from the
back side (see illustration).
16Apply a thin coat of grease to the spindle
at the outer bearing seat, inner bearing seat,
shoulder and seal seat.
17Put a small quantity of grease inboard of
each bearing race inside the hub. Using your
finger, form a dam at these points to provide
extra grease availability and to keep thinned
grease from flowing out of the bearing (see
illustration).
18Place the grease-packed inner bearing
into the rear of the hub and put a little more
grease outboard of the bearing.
19Place a new seal over the inner bearing
and tap the seal evenly into place until it’s
flush with the hub (see illustration).
20Carefully place the hub assembly onto the
spindle and push the grease-packed outer
bearing into position (see illustration).
Adjustment
21Refit the washer and spindle nut. Tighten
the nut only slightly (no more than 16Nm/12
lbf ft of torque).
22Rotate the hub slowly in a forward
direction while tightening the spindle nut toapproximately 27Nm (20 lbf ft) to seat the
bearings. Remove any grease or burrs which
could cause excessive bearing play later.
23Loosen the spindle nut 1/4-turn, then
using your hand (not a spanner of any kind),
tighten the nut until it’s snug. Refit the nut lock
and a new cotter pin through the hole in the
spindle and the slots in the nut lock. If the
nut lock slots don’t line up, remove the nut
lock and turn it slightly until they do (see
illustration).
24Bend the ends of the cotter pin until
they’re flat against the nut. Cut off any extra
length which could interfere with the dust cap.
25Refit the dust cap, tapping it into place
with a hammer.
26Refit the brake disc and caliper in the
reverse order of removal (see Chapter 9).
27Refit the wheel on the hub and tighten the
wheel nuts.
28Grasp the top and bottom of the tyre and
check the bearings in the manner described
earlier in this Section.
29Lower the vehicle and tighten the wheel
nuts to the torque listed in this Chapter’s
Specifications.
23 Propshaft check
2
1Referring to Chapter 8, check the propshaft
centre bearing, universal joint and flexible
coupling for signs of wear or damage and
check that the propshaft fixings are tightened
to the specified torque.
24 Front wheel alignment check
5
1Accurate wheel alignment requires access
to specialised test equipment and as such
should be entrusted to a suitably equipped
Jaguar dealer or a tyre specialist (refer to
Chapter 10).
25 Headlight beam check
5
1Accurate adjustment of the headlight beam
is only possible using optical beam-setting
equipment, and this work should therefore be
carried out by a Jaguar dealer or garage with
the necessary facilities (see Chapter 12).
1•18Every 15 000 miles or 12 months
22.15 Work the grease completely into the
bearing rollers22.17 Apply a thin layer of grease to the
inner and outer bearing races22.19 After refitting the inner wheel
bearing into the hub - press the grease
seal into place
22.20 Refit the hub assembly onto the
spindle - then push the grease-packed
outer bearing into position22.23 Position the nut lock on the spindle
nut so that it lines up with the cotter pin
hole - DO NOT loosen the spindle nut from
its snug position
3261 Jaguar XJ6

6Slowly and carefully press the seal and
retainer squarely onto the crankshaft (see
illustration). The plastic sleeve may be
pushed out as the retainer seats on the engine
block. Remove the plastic sleeve.
7Refit and tighten the retainer bolts to the
torque listed in this Chapter’s Specifications.
8The remaining steps are the reverse of
removal.
16 Engine mounts-
check and renewal
3
1Engine mounts seldom require attention,
but broken or deteriorated mounts should be
renewed immediately or the added strain
placed on the driveline components may
cause damage or wear.
Check
2During the check, the engine must be
raised to remove the weight from the mounts.3Raise the car and support it securely on
axle stands, then position a jack under the
engine sump. Place a large wood block
between the jack head and the sump, then
carefully raise the engine just enough to take
the weight off the mounts. Do not position the
wood block under the drain plug.
Warning: DO NOT place any part
of your body under the engine
when it’s supported by a jack!
4Check the front mounts to see if the rubber
is cracked, hardened or separated from the
metal plates. Sometimes the rubber will split
down the centre.
5Check for relative movement between the
mount plates and the engine or frame (use a
large screwdriver or pry bar to attempt to
move the mounts). If movement is noted,
lower the engine and tighten the mount
fasteners.
6Rubber preservative should be applied to
the mounts to slow deterioration.
Renewal
7Disconnect 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.
8Raise the car and support it securely on
axle stands. Support the engine as described
in paragraph 3.
Caution: Ensure the cooling fan doesn’t hit
the shroud as the engine is raised.
9To remove either engine mount, remove the
nut from the engine bracket, then raise the
engine (see illustration).
10From underneath the car, lower the
steering gear (see Chapter 10) for access to
the nut retaining the insulator to the chassis
bracket.
11Refitting is the reverse of removal. Use
thread-locking compound on the mount
bolts/nuts and be sure to tighten them
securely.
12See Chapter 7 for transmission mount
renewal.
2A•18 Engine in-car repair procedures
3261 Jaguar XJ6 15.6 Refit the retainer and oil seal onto the crankshaft
16.9 Front engine mount (A)
and retaining nut to engine bracket (B)

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

6Refit the compression gauge in the spark
plug hole (see illustration).
7Crank the engine over at least seven
compression strokes and watch the gauge.
The compression should build up quickly in a
healthy engine. Low compression on the first
stroke, followed by gradually increasing
pressure on successive strokes, indicates
worn piston rings. A low compression reading
on the first stroke, which doesn’t build up
during successive strokes, indicates leaking
valves or a blown cylinder head gasket (a
cracked cylinder head could also be the
cause). Deposits on the undersides of the
valve heads can also cause low compression.
Record the highest gauge reading obtained.
8Repeat the procedure for the remaining
cylinders and compare the results to this
Chapter’s Specifications.
9Add some engine oil (about three squirts
from a plunger-type oil can) to each cylinder,
through the spark plug hole, and repeat the
test.
10If the compression increases after the oil
is added, the piston rings are definitely worn.
If the compression doesn’t increase
significantly, the leakage is occurring at the
valves or cylinder head gasket. Leakage past
the valves may be caused by burned valve
seats and/or faces or warped, cracked or bent
valves.
11If two adjacent cylinders have equally low
compression, there’s a strong possibility that
the cylinder head gasket between them is
blown. The appearance of coolant in the
combustion chambers or the crankcase
would verify this condition.
12If one cylinder is 20 percent lower than the
others, and the engine has a slightly rough
idle, a worn exhaust lobe on the camshaft
could be the cause.
13If the compression is unusually high, the
combustion chambers are probably coated
with carbon deposits. If that’s the case, the
cylinder head(s) should be removed and
decarbonised.
14If compression is way down or varies
greatly between cylinders, it would be a goodidea to have a leak-down test performed by
an automotive repair workshop. This test will
pinpoint exactly where the leakage is
occurring and how severe it is.
5 Engine removal-
methods and precautions
If you’ve decided that an engine must be
removed for overhaul or major repair work,
several preliminary steps should be taken.
Locating a suitable place to work is
extremely important. Adequate work space,
along with storage space for the vehicle, will
be needed. If a workshop or garage isn’t
available, at the very least a flat, level, clean
work surface made of concrete or asphalt is
required.
Cleaning the engine compartment and
engine before beginning the removal
procedure will help keep tools clean and
organised.
An engine hoist or A-frame will also be
necessary. Make sure the equipment is rated
in excess of the combined weight of the
engine and transmission. Safety is of primary
importance, considering the potential hazards
involved in lifting the engine out of the vehicle.
If the engine is being removed by a novice,
a helper should be available. Advice and aid
from someone more experienced would also
be helpful. There are many instances when
one person cannot simultaneously perform all
of the operations required when lifting the
engine out of the vehicle.
Plan the operation ahead of time. Arrange
for or obtain all of the tools and equipment
you’ll need prior to beginning the job. Some of
the equipment necessary to perform engine
removal and refitting safely and with relative
ease are (in addition to an engine hoist) a
heavy duty trolley jack, complete sets of
spanners and sockets as described in the
front of this manual, wooden blocks and
plenty of rags and cleaning solvent for
mopping up spilled oil, coolant and petrol. If
the hoist must be rented, make sure that you
arrange for it in advance and perform all of the
operations possible without it beforehand.
This will save you money and time.
Plan for the vehicle to be out of use for
quite a while. A machine workshop will be
required to perform some of the work which
the do-it-yourselfer can’t accomplish without
special equipment. These shops often have a
busy schedule, so it would be a good idea to
consult them before removing the engine in
order to accurately estimate the amount of
time required to rebuild or repair components
that may need work.
Always be extremely careful when removing
and refitting the engine. Serious injury can
result from careless actions. Plan ahead, take
your time and a job of this nature, although
major, can be accomplished successfully.
6 Engine- removal and refitting
3
Note:Read through the entire Section before
beginning this procedure. It is recommended
to remove the engine and transmission from
the top as a unit, then separate the engine
from the transmission on the workshop floor. If
the transmission is not being serviced, it is
possible to leave the transmission in the
vehicle and remove the engine from the top by
itself, by removing the crankshaft damper and
tilting up the front end of the engine for
clearance,but access to the upper
bellhousing bolts is only practical when the
rear transmission mount and driveshaft have
been removed and the transmission is angled
down with a trolley jack.
Removal
1Relieve the fuel system pressure (see
Chapter 4).
2Disconnect 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.
3Place protective covers on the wings and
cowl and remove the bonnet (see Chapter 11).
4Remove the battery and battery tray.
5Remove the air cleaner assembly (see
Chapter 4).
6Raise the vehicle and support it securely on
axle stands. Drain the cooling system and
engine oil and remove the drivebelts (see
Chapter 1).
7Clearly label, then disconnect all vacuum
lines, coolant and emissions hoses, wiring
harness connectors and earth straps.
Masking tape and/or a touch up paint
applicator work well for marking items (see
illustration). Take instant photos or sketch
the locations of components and brackets.
8Remove the cooling fan(s) and radiator (see
Chapter 3).
9Disconnect the heater hoses.
10Release the residual fuel pressure in the
tank by removing the petrol cap, then detach
the fuel lines connecting the engine to the
chassis (see Chapter 4). Plug or cap all open
fittings.
2B•4 Engine removal and overhaul procedures
4.6 A compression gauge with a threaded
fitting for the spark plug hole is preferred
over the type that requires hand pressure
to maintain the seal - be sure to block
open the throttle valve as far as possible
during the compression check!
6.7 Label both ends of each wire and hose
before disconnecting it
3261 Jaguar XJ6