1997 JAGUAR XJ6 oil level

5 Power hydraulic system
fluid level check
1
Caution: Use only Castrol or Jaguar
hydraulic system mineral oil (HSMO) in the
power hydraulic system (available at
Jaguar dealer service departments).
1The power hydraulic system controls the ride
levelling and the brake servo systems. The
fluid reservoir also supplies the power
steering system on some models. The level
of the fluid should be carefully maintained. Low
fluid levels can adversely affect the riding and
braking capabilities of your vehicle. The power
hydraulic system fluid reservoir is located on
the right inner wing of the engine compartment.
1988 and 1989 models
2The fluid level can easily be checked by
viewing the reservoir sight glass. A green
indicator in the sight glass indicates an OK
condition, while a red indicator in the sight glass
requires fluid to be added (see illustration).
3If additional fluid is required, pop open the
plastic tab located on top of the reservoir cap
(see illustration).
4Insert the mineral oil dispensing tube into
the reservoir filler hole. Push down and turn
until the dispensing tube is locked in place.
5Add fluid until the green indicator in the
sight glass appears, then release the
dispensing tube by pushing downward and
turning the opposite direction of refitting.
1990 to 1994 models
6The fluid level can be checked by removing
the cap and observing the level of fluid on the
dipstick.
7Wipe off the fluid with a clean rag, reinsert
it, then withdraw it and read the fluid level
(see illustration). The dipstick is marked so
the fluid can be checked either cold or hot.
The level should be at the HOT mark if the
fluid was hot to the touch. It should be at the
COLD mark if the fluid was cool to the touch.
At no time should the fluid level drop below
the add mark.8If additional fluid is required, pour the
specified type directly into the reservoir, using
a funnel to prevent spills.
6 Battery check
and general information
1
Warning: Certain precautions
must be followed when working
with the battery. Hydrogen gas,
which is highly flammable, is
always present in the battery cells, so don’t
smoke, and keep naked flames and sparks
away from the battery. The electrolyte in
the battery is actually dilute sulphuric acid,
which will cause injury if splashed on your
skin or in your eyes. It will also ruin clothes
and painted surfaces. When removing the
battery cables, always detach the negative
cable first and hook it up last!1A routine preventive maintenance program
for the battery in your vehicle is the only way
to ensure quick and reliable starts. But before
performing any battery maintenance, make
sure that you have the proper equipment
necessary to work safely around the battery
(see illustration).
2There are also several precautions that
should be taken whenever battery
maintenance is performed. Before servicing
the battery, always turn the engine and all
accessories off and disconnect the cable from
the negative terminal of the battery.
3The battery produces hydrogen gas, which
is both flammable and explosive. Never create
a spark, smoke or light a match around the
battery. Always charge the battery in a
ventilated area.
4Electrolyte contains poisonous and corrosive
sulphuric acid. Do not allow it to get in your
eyes, on your skin or on your clothes, and
Every 7500 miles or 6 months 1•9
1
5.2 The power hydraulic system reservoir
is located on the right-hand inner wing -
to check the fluid level on 1988 and 1989
models simply look through the sight glass
and note the colour of the indicator5.3 To add fluid, remove the filler hole
dust cap (arrowed)5.7 On 1990 and later models remove the
cap and check the fluid level on the dipstick
6.1 Tools and materials required for
battery maintenance
1 Face shield/safety goggles - When
removing corrosion with a brush, the
acidic particles can fly up into your eyes
2 Baking soda - A solution of baking soda
and water can be used to neutralise
corrosion
3 Petroleum jelly - A layer of this on the
battery posts will help prevent corrosion
4 Battery post/cable cleaner - This wire
brush cleaning tool will remove all traces
of corrosion from the battery posts and
cable clamps
5 Treated felt washers - Placing one of
these on each post, directly under the
cable clamps, will help prevent corrosion
6 Puller - Sometimes the cable clamps are
difficult to pull off the posts, even after the
nut/bolt has been completely loosened.
This tool pulls the clamp straight up and
off the post without damage
7 Battery post/cable cleaner - Here is
another cleaning tool which is a slightly
different version of number 4 above, but
it does the same thing
8 Rubber gloves - Another safety item to
consider when servicing the battery;
remember that’s acid inside the battery!
3261 Jaguar XJ6

leak be found, renew the offending gasket or
oil seal by referring to the appropriate
Chapters in this manual.
2Also check the security and condition of all
the engine-related pipes and hoses. Ensure
that all cable ties or securing clips are in place
and in good condition. Clips which are broken
or missing can lead to chafing of the hoses,
pipes or wiring, which could cause more
serious problems in the future.
3Carefully check the radiator hoses and
heater hoses along their entire length. Renew
any hose which is cracked, swollen or
deteriorated. Cracks will show up better if
the hose is squeezed. Pay close attention
to the hose clips that secure the hoses to the
cooling system components. Hose clips can
pinch and puncture hoses, resulting in cooling
system leaks.
4Inspect all the cooling system components
(hoses, joint faces etc.) for leaks. A leak in the
cooling system will usually show up as white-
or rust-coloured deposits on the area
adjoining the leak. Where any problems of this
nature are found on system components,
renew the component or gasket with
reference to Chapter 3.
5From within the engine compartment,
check the security of all fuel hose attachments
and pipe unions, and inspect the fuel hoses
and vacuum hoses for kinks, chafing and
deterioration.
6Also check the condition of the power
steering fluid hoses and pipes.
8 Automatic transmission
fluid level check
1
1The level of the automatic transmission fluid
should be carefully maintained. Low fluid level
can lead to slipping or loss of drive, while
overfilling can cause foaming, loss of fluid and
transmission damage.
2The transmission fluid level should only be
checked when the transmission is at its
normal operating temperature.
Caution: If the vehicle has just been driven
for a long time at high speed or in city
traffic in hot weather, or if it has been
pulling a trailer, an accurate fluid level
reading cannot be obtained. Allow the fluid
to cool down for about 30 minutes.
3If the vehicle has not been driven, park the
vehicle on level ground, set the handbrake,
then start the engine and bring it to operating
temperature. While the engine is idling,
depress the brake pedal and move the
selector lever through all the gear ranges,
beginning and ending in Park.
4With the engine still idling, remove the
dipstick from its tube (see illustration). Check
the level of the fluid on the dipstick (see
illustration)and note its condition.
5Wipe the fluid from the dipstick with a clean
rag and reinsert it back into the filler tube until
the cap seats.6Pull the dipstick out again and note the fluid
level. If the transmission is cold, the level
should be in the COLD or COOL range on the
dipstick. If it is hot, the fluid level should be in
the HOT range. If the level is at the low side of
either range, add the specified transmission
fluid through the dipstick tube with a funnel.
7Add just enough of the recommended fluid
to fill the transmission to the proper level. It
takes about one pint to raise the level from the
low mark to the high mark when the fluid is
hot, so add the fluid a little at a time and keep
checking the level until it is correct.
8The condition of the fluid should also be
checked along with the level. If the fluid at the
end of the dipstick is black or a dark reddish
brown colour, or if it emits a burned smell, the
fluid should be changed (see Section 26). If
you are in doubt about the condition of the
fluid, purchase some new fluid and compare
the two for colour and smell.9 Differential oil level check
1
1The differential has a check/fill plug which
must be removed to check the lubricant level.
If the vehicle is raised to gain access to the
plug, be sure to support it safely on axle
stands - DO NOT crawl under the vehicle
when it’s supported only by the jack!2Remove the lubricant check/fill plug from
the differential (see illustration).Use a
3/8-inch drive ratchet and a short extension to
unscrew the plug.
3Use your little finger as a dipstick to make
sure the lubricant level is even with the
bottom of the plug hole. If not, use a syringe
or squeeze bottle to add the recommended
lubricant until it just starts to run out of the
opening.
4Refit the plug and tighten it securely.
10 Exhaust system check
1
1With the engine cold (at least three hours
after the vehicle has been driven), check the
complete exhaust system from its starting
point at the engine to the end of the tailpipe.
This should be done on a hoist where
unrestricted access is available.
2Check the pipes and connections for
evidence of leaks, severe corrosion or
damage. Make sure that all brackets and
hangers are in good condition and tight (see
illustration).
3At the same time, inspect the underside of
the body for holes, corrosion, open seams,
etc. which may allow exhaust gases to enter
the passenger compartment. Seal all body
openings with silicone or body putty.
4Rattles and other noises can often be
traced to the exhaust system, especially the
mounts and hangers. Try to move the pipes,
Every 7500 miles or 6 months 1•11
1
9.2 The differential check/fill plug is
located on the rear of the differential
housing - place your finger in the filler plug
hole to make sure the lubricant level is
even with the bottom of the hole
10.2 Check the exhaust system hangers
(arrowed) for damage and cracks
3261 Jaguar XJ6
8.4a The automatic transmission dipstick
(arrowed) is located in a tube which
extends forward from the transmission
8.4b Check the automatic transmission
fluid with the engine idling at operating
temperature and the gear selector in Park,
then add fluid to bring the level to the
upper mark

damage the crankshaft in the process (if the
crankshaft is damaged, the new seal will end
up leaking).
9The crankshaft seal rides on a spacer that
slips over the front of the crankshaft. Slip the
spacer off and clean the varnish off the seal
surface (see illustration).
10Clean the bore in the cover and coat the
outer edge of the new seal with engine oil or
multi-purpose grease. Apply moly-base
grease to the seal lip.
11Lubricate the spacer with clean engine oil
and refit it onto the crankshaft. Using a socket
with an outside diameter slightly smaller than
the outside diameter of the seal, carefully
drive the new seal into place with a hammer
(see illustration). Make sure it’s installed
squarely and driven in to the same depth as
the original. If a socket isn’t available, a short
section of large-diameter pipe will also work.
Note:The new seal comes with a plastic
installer guide. Do not remove this guide until
refitting is completed. The guide keeps the
seal lip properly oriented over the crankshaft.
12Refit the Woodruff key, then refit the
damper. Tighten the damper bolt to the
torque listed in this Chapter’s Specifications.
Note:The damper bolt can be used to pull the
damper back onto the crankshaft, but make
sure the damper is perfectly aligned with the
Woodruff key.
13The rest of the assembly is the reverse of
the removal procedure.
14Run the engine and check for oil leaks at
the front seal.
8 Timing chains
and sprockets- removal,
inspection and refitting
3
Caution: If the timing chain broke during
engine operation, the valves may have
come in contact with the pistons, causingdamage. Check the valve clearance (see
Section 10) before removal of the cylinder
head - bent valves usually will have
excessive clearance, indicating damage
that will require machine workshop work to
repair.
Note 1:This procedure requires that the sump
be removed (see Section 12).In a professional
workshop, this would be performed as an in-
car procedure with specialised tools to
remove the front suspension. Given the
equipment available to the average home
mechanic, this alternate procedure requires
removal of the engine from the car.
Note 2:If your engine is a 4.0 litre, built after
serial number 9J160552, and you’re
experiencing an engine rattle on cold starts
that disappears after the engine is warmed up,
the problem could be a defective upper
tensioner. A newly designed replacement
upper tensioner is available from the dealer
and should solve the problem. It can be
installed easily without pulling the cylinder
head or front cover, or can be installed during
a chain removal procedure.
Removal
1Disconnect the negative cable from the
battery.
Caution: If the stereo in your vehicle is
equipped with an anti-theft system, make
sure you have the correct activation code
before disconnecting the battery.
2Block the rear wheels and set the
handbrake.
3Refer to Part B of this Chapter for engine
removal procedures.
4Refer to Section 4 and remove the valve
cover.
5Refer to Section 3 and position the engine
at TDC for cylinder number 1, then mark and
remove the distributor (see Chapter 5).
6Refer to Section 11 and remove the cylinder
head. After cylinder head removal, the uppertiming chain will be loosely retained by the
two upper chain guides, which are retained by
refitting a large rubber band (see Section 10).
Caution: Do not rotate the crankshaft with
the upper timing chain disconnected and
the cylinder head and camshafts in place,
or damage could result from piston-to-
valve contact.
7Some models may be equipped with a
hydraulic pump used for the brake
servo/hydraulic self-levelling suspension
system. If equipped, it will be mounted to the
front cover. Models not equipped with this
option will have a flat block-off plate over the
hole. If equipped with the pump, refer to
Chapters 9 and 10 for procedures to reduce
the high pressure in the brake servo system
and to depressurise the self-levelling system.
Before removing the engine, unbolt the pump
from the front cover and set it aside without
disconnecting the hoses (see illustration).
8Refer to Section 7 and remove the
crankshaft pulley and damper. Refer to
Section 12 for removal of the sump.
9If equipped with the hydraulic pump,
remove the coupling disc and unbolt the drive
coupling from the intermediate shaft (see
illustrations).
2A•6 Engine in-car repair procedures
8.7 Unbolt the hydraulic pump (arrowed)
from the front cover, without
disconnecting the hoses
3261 Jaguar XJ6 7.9 Remove the spacer from the end of the crankshaft
and clean it thoroughly
7.11 Drive the new seal squarely into the front cover with a large
socket or section of pipe - do not remove the plastic refitting
guide (arrowed) until the seal is installed

23Clean and lubricate the lower tensioner.
Fill the lower tensioner oil reservoir with engine
oil and refit it on the engine block, aligning the
notch in the tensioner with the lug on the back
of the guide (see illustrations). This should
remove all slack from the lower timing chain. If
not, push the lower tensioner guide back and
forth a few times to prime the tensioner.
24Refit the upper chain tensioner guide and
mounting bracket to the engine block.
Caution: Before fully tightening the
mounting bracket to the engine block,
make sure the mount and chain guide are
clear of the lower chain, auxiliary sprocket
and intermediate sprocket. If necessary,
position the mount for clearance before
tightening the mounting bolts.
25Refit the oil pump drive chain and
sprocket to the crankshaft (see Section 13).
26Refit the upper chain fixed guide to the
engine block and place the upper timing chain
over the intermediate sprocket and auxiliary
shaft sprocket, draping the excess chain over
the top of the fixed guide. Lubricate the chain
and sprockets with clean engine oil.27Gather the loose portion of the upper
timing chain and place it between the upper
guides. Use a large rubber band to hold the
two guides snugly around the chain (see
Section 11).
28If necessary, renew the intermediate shaft
seal (see illustrations).
29Apply a thin coat of RTV sealant to the
engine side of the front cover and RTV sealant
to the oil-pan mating surface (bottom of the
front cover), then refit the front cover. Note:
Make sure the top surface of the cover aligns
with the top surface of the engine block, by
checking with a straightedge(see illustration).
30Refer to Section 11 for refitting of the
cylinder head and Section 10 for refitting of
the camshafts and connection of the upper
timing chain to the two camshaft sprockets.
31The remainder of the refitting is the
reverse of the removal procedure. If your car
is equipped with the hydraulic/self-levelling
suspension, refit the drive coupling and
coupling disc to the intermediate shaft (see
illustrations 8.9a and 8.9b). Coat the
mounting surface of the pump with RTVsealant and make sure the tang on the pump
aligns with the slot in the intermediate shaft
before bolting the pump to the front cover.
Refer to Section 7 for refitting of the
crankshaft spacer, damper and puller.
Caution: DO NOT start the engine until
you’re absolutely certain that the timing
chains are installed correctly. Serious and
costly engine damage could occur if the
chains are installed wrong.
32Run the engine and check for proper
operation.
9 Auxiliary shaft- renewal
3
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.
1Refer to Chapter 10 and remove the power
steering pump, without disconnecting the
hoses. Remove the plastic power steering
pump drive coupling disc.
2A•8 Engine in-car repair procedures
8.28a Drill a small hole in the intermediate
shaft seal, thread a sheet metal screw into
it and use a small slide-hammer pull the
seal out of the cover8.28b Drive the new seal in with a seal-
driver or socket, to the same depth as the
original seal8.29 Bolt the front cover on hand tight, use
a straightedge to make sure the cover’s
top surface is level with the top of the
engine block, then tighten the cover bolts
3261 Jaguar XJ6 8.23a Add oil to the reservoir in the lower tensioner . . .
8.23b . . . and refit the tensioner against the guide -
after it’s installed, push the tensioner guide back and forth
a few times to prime the tensioner

Inspection
8Clean and dry the pump body and both
rotors. Measure the outside diameter of the
outer rotor and thickness of both rotors.
9Place the outer rotor into the pump body
and use feeler gauges to measure the
clearance between the outer rotor and the
body (see illustration).
10Place a straightedge across the pump
body and measure between the straightedge
and the rotors to check the over-the-rotor
clearance (see illustration). Compare your
measurements to this Chapter’s Specifications
and renew the oil pump if any are beyond the
maximum allowable.
11Remove the oil pressure relief valve cap.
Remove and clean the relief valve components
(see illustration).
12Clean all components with solvent and
inspect them for wear and damage. If
excessive wear, damage or if any clearance is
beyond the Specifications, renew the entire
pump as an assembly.
13Check the oil pressure relief valve piston
sliding surface and valve spring. If either the
spring or the valve is damaged, they must be
renewed as a set.
Refitting
14Lubricate the drive and driven rotors with
clean engine oil and place them in the casewith the marks facing out. Apply a thin coat
of anaerobic sealant (Loctite 510 or 518) to
the gasket flange and refit the cover (see
illustration).
15Lubricate the oil pressure relief valve
piston with clean engine oil and refit the valve
components into the oil pump body (see
illustration 13.11).
16Apply a thin coat of anaerobic sealant
(Loctite 510 or 518) to the oil pump-to-engine
block-mounting surface, position the oil pump
body against the engine block and refit the
mounting bolts, tightening the bolts to the
torque listed in this Chapter’s Specifications.
Follow a criss-cross pattern when tightening
the bolts to avoid warping the oil pump body.
17If using the original oil pump, refit the
original sprocket shim pack (see illustration).
If a new pump is installed, start off with a
0.38 mm (0.015-inch) thick shim pack, refit the
drive sprocket and align the sprocket as
follows.
18Use a straightedge to check the alignment
of the oil pump sprocket with the crankshaft
sprocket (see illustration). If they are not
aligned, increase or decrease the shim pack at
the oil pump sprocket until alignment is correct,
then secure the oil pump sprocket bolts by
bending up the sheetmetal tabs. Note:You
may be able to use all or part of the original
shim pack from the original oil pump (if a new
pump is being fitted). If required, shims areavailable in 0.127 mm (0.005 inch), 0.254 mm
(0.010 inch) and 0.508 mm (0.020 inch) sizes.
19Fit new O-rings to each end of the transfer
tubes and refit the tubes into the transfer
housing. Note:Use petroleum jelly to lubricate
the O-rings.
20Apply a thin coat of RTV sealant to the
engine block-mounting surface of the transfer
housing. Lift the transfer housing and tubes
into place and push the front of the tubes
in the back of the oil pump, until you can start
the transfer housing-to-engine block bolts.
Tighten the bolts to the torque listed in this
Chapter’s Specifications.
21Refit the remaining parts in the reverse
order of removal.
22Add oil, start the engine and check for oil
pressure and leaks.
23Recheck the engine oil level.
14 Driveplate-
removal and refitting
4
Removal
1Raise the car and support it securely on
axle stands, then refer to Chapter 7 and
remove the transmission. If it’s leaking, now
would be a very good time to renew the front
pump seal/O-ring.
2A•16 Engine in-car repair procedures
13.9 Measure the outer rotor-to-body
clearance with feeler gauges (arrowed)13.10 With a straightedge held tight to the
pump surface, measure the clearance over
the rotors with feeler gauges13.11 Oil pressure relief valve components
A Relief valve cap
B TubeC Spring
D Valve
13.14 Apply a thin coat anaerobic sealant
(Loctite 510 or 518) to the pump cover
sealing surface
13.17 Refit the original shim pack
(arrowed) if the original pump is being
used - if a new pump is being installed,
refit a 0.38 mm (0.015-inch) shim pack
3261 Jaguar XJ6
13.18 Check the oil pump and crankshaft
sprocket alignment with a straightedge -
add or subtract shims until the sprockets
are aligned for smooth chain operation

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

11Disconnect the throttle linkage,
transmission linkage (and dipstick tube) and
speed control cable, if equipped, from the
engine (see Chapters 4 and 7).
12Refer to Part A of this Chapter and
remove the intake and exhaust manifolds.
13Unbolt the power steering pump (see
Chapter 10). Tie the pump aside without
disconnecting the hoses. Refer to Part A for
removal of the hydraulic pump (if equipped)
from the timing chain cover.
14On air-conditioned models, unbolt the
compressor and set it aside. Do not
disconnect the refrigerant hoses. Note:Wire
the compressor out of the way with a coat
hanger, don’t let the compressor hang on the
hoses.
15Refer to Part A of this Chapter and
remove the drivebelts, water pump pulley and
crankshaft pulley.
16Attach a lifting sling to the engine.
Position a hoist and connect the sling to it.
Take up the slack until there is slight tension
on the hoist.
17With a trolley jack and piece of wood
supporting the bottom of the transmission
sump, refer to Chapter 8 and remove the
driveshaft and rear transmission mount.
Warning: Do not place any part
of your body under the
engine/transmission when it’s
supported only by a hoist or
other lifting device.
18With the hoist taking the weight of the
engine, unbolt the engine mounts (see Part A
of this Chapter).
19Recheck to be sure nothing is still
connecting the engine or transmission to the
vehicle. Disconnect and label anything still
remaining.
20Slowly lift the engine/transmission out of
the vehicle (see illustration). It may be
necessary to pry the mounts away from the
frame brackets.21Move the engine away from the vehicle
and carefully lower the hoist until the
engine/transmission can be set on the floor.
Refer to Chapter 7 and remove the
transmission and converter. Refer to Part A of
this Chapter for removal of the flywheel. With
the flywheel removed, remove the four large
bolts and the transmission adapter plate from
the engine (see illustration).
22Refer to Part A of this Chapter for removal
of the rear main seal retainer plate from the
back of the engine, then lift the engine to a
position where it can be attached to a sturdy
engine stand.
Refitting
23Check the engine/transmission mounts. If
they’re worn or damaged, renew them.
24Attach the hoist and remove the engine
from the stand. Refer to Part A of this Chapter
and renew the rear main seal and retainer
plate, then reattach the transmission adapter
plate and refer to Chapter 7 for mounting the
converter and transmission.
25Carefully lower the engine into the vehicle
with the hoist. An assistant is helpful to guide
the engine clear of accessories in the engine
compartment as the engine is lowered into
place.
26Refit the engine mount bolts and tighten
them securely. Raise the back of the
transmission with the trolley jack and reattach
the transmission mount, driveshaft and shift
linkage.
27Refit the remaining components and
fasteners in the reverse order of removal.
28Add coolant, oil, power steering and
transmission fluids as needed (see Chapter 1).
29Run the engine and check for proper
operation and leaks. Shut off the engine and
recheck the fluid levels.
7 Engine rebuilding
alternatives
The do-it-yourselfer is faced with a number
of options when performing an engine
overhaul. The decision to renew the engine
block, piston/connecting rod assemblies and
crankshaft depends on a number of factors,
with the number one consideration being the
condition of the engine block. Other
considerations are cost, access to machine
workshop facilities, parts availability, time
required to complete the project and the
extent of prior mechanical experience on the
part of the do-it-yourselfer.
Some of the rebuilding alternatives include:
Individual parts- If the inspection
procedures reveal that the engine block and
most engine components are in reusable
condition, purchasing individual parts may be
the most economical alternative. The engine
block, cylinder head, crankshaft, and
piston/connecting rod assemblies should all
be inspected carefully. Even if the engine
block shows little wear, the cylinder bores
should be surface honed.
Short block- A short block consists of an
engine block with a crankshaft and
piston/connecting rod assemblies already
installed. All new bearings are incorporated
and all clearances will be correct. The existing
camshafts, valve train components, cylinder
head and external parts can be bolted to the
short block with little or no machine workshop
work necessary.
Long block- A long block consists of a
short block plus an oil pump, sump, cylinder
head, valve cover, camshaft and valve train
components, timing sprockets and chain or
gears and timing cover. All components are
installed with new bearings, seals and gaskets
Engine removal and overhaul procedures 2B•5
2B
3261 Jaguar XJ6 6.20 Lift the engine high enough to clear the vehicle, tilting it up
at the front to clear the front crossmember, then move it away
and lower the hoist
6.21 With the engine on the floor but still supported by the hoist,
remove the four large bolts (arrowed) and pull off the
transmission adapter plate