VIN JAGUAR XJ6 1997 2.G Owner's Guide

incorporated throughout. The refitting of
manifolds and external parts is all that’s
necessary. Engines in this rebuilt form are
available from Jaguar dealers, and some
independent rebuilders.
Give careful thought to which alternative is
best for you and discuss the situation with
local automotive machine shops, auto parts
dealers and experienced rebuilders before
ordering or purchasing replacement parts.
8 Engine overhaul-
dismantling sequence
1It’s much easier to dismantle and work on
the engine if it’s mounted on a portable
engine stand. A stand can often be rented
quite cheaply from an equipment rental yard.
Before the engine is mounted on a stand, the
driveplate and rear oil seal retainer should be
removed from the engine.
2If a stand isn’t available, it’s possible to
dismantle the engine with it blocked up on the
floor. Be extra careful not to tip or drop the
engine when working without a stand.
3If you’re going to obtain a rebuilt engine, all
external components must come off first, to
be transferred to the replacement engine, just
as they will if you’re doing a complete engine
overhaul yourself. These include:
Alternator and brackets
Emissions control components
Distributor, spark plug leads and spark
plugs
Thermostat and housing cover
Water pump
EFI components
Intake/exhaust manifolds
Oil filter
Engine mounts
Driveplate
Transmission adapter plate
Note:When removing the external
components from the engine, pay close
attention to details that may be helpful or
important during refitting. Note the installed
position of gaskets, seals, spacers, pins,
brackets, washers, bolts and other small items.
4If you’re obtaining a short block, which
consists of the engine block, crankshaft,
pistons and connecting rods all assembled,
then the cylinder head, sump and oil pump will
have to be removed as well from your engine
so that your short-block can be turned in to
the rebuilder as a core. See Engine rebuilding
alternativesfor additional information
regarding the different possibilities to be
considered.
5If you’re planning a complete overhaul, the
engine must be dismantled and the internal
components removed in the following order:
Intake and exhaust manifolds
Valve cover
Upper timing chain and camshaft
sprocketsCamshafts
Timing chain cover
Cylinder head
Sump
Oil pump
Piston/connecting rod assemblies
Crankshaft rear oil seal retainer
Crankshaft and main bearings
6Before beginning the dismantling and
overhaul procedures, make sure the following
items are available. Also, refer to Section 21
for a list of tools and materials needed for
engine reassembly.
Common hand tools
Small cardboard boxes or plastic bags for
storing parts
Gasket scraper
Ridge reamer
Micrometers
Telescoping gauges
Dial indicator set
Valve spring compressor
Cylinder surfacing hone
Piston ring groove-cleaning tool
Electric drill motor
Tap and die set
Wire brushes
Oil gallery brushes
Cleaning solvent
Special Jaguar tools
Engine lifting brackets (18G 1465)
Timing damper simulator (18E 1436)
Camshaft TDC tool (18G 1433)
9 Cylinder head- dismantling
2
Note: New and rebuilt cylinder heads are
available from Jaguar and some independent
rebuilders. Due to the fact that some
specialised tools are necessary for the
dismantling and inspection procedures, and
replacement parts may not be readily
available, it may be more practical and
economical for the home mechanic to
purchase a replacement cylinder head rather
than taking the time to dismantle, inspect and
recondition the original.1Cylinder head dismantling involves removal
of the intake and exhaust valves and related
components. It’s assumed that the lifters and
camshafts have already been removed (see
Part A as needed).
2Before the valves are removed, arrange to
label and store them, along with their related
components, so they can be kept separate
and reinstalled in the same valve guides they
are removed from (see illustration).
3Compress the springs on the first valve with
a spring compressor and remove the keepers
(see illustration). Carefully release the valve
spring compressor and remove the retainer,
the spring and the spring seat (if used). Note:
If your spring compressor does not have an
end (such as the one shown) with cut-outs on
the side, an adapter is available to use with a
standard spring compressor.
Caution: Be very careful not to nick or
otherwise damage the lifter bores when
compressing the valve springs.
4Pull the valve out of the cylinder head, then
remove the oil seal from the guide. If the valve
binds in the guide (won’t pull through), push it
back into the cylinder head and deburr the
area around the keeper groove with a fine file
or whetstone.
5Repeat the procedure for the remaining
valves. Remember to keep all the parts for
each valve together so they can be reinstalled
in the same locations.
6Once the valves and related components
have been removed and stored in an
organised manner, the cylinder head should
be thoroughly cleaned and inspected. If a
complete engine overhaul is being done,
finish the engine dismantling procedures
before beginning the cylinder head cleaning
and inspection process.
10 Cylinder head-
cleaning and inspection
2
1Thorough cleaning of the cylinder head(s)
and related valve train components, followed
by a detailed inspection, will enable you to
decide how much valve service work must be
2B•6 Engine removal and overhaul procedures
9.2 A small plastic bag, with an appropriate
label, can be used to store the valve train
components so they can be kept together
and reinstalled in the correct guide
3261 Jaguar XJ6
9.3 Compress the spring until the keepers
can be removed with a small magnetic
screwdriver or needle-nose pliers - use a
valve spring compressor with an adapter
(arrowed) to remove the keepers

15Check the valve stem-to-guide clearance
with a small hole gauge and micrometer, or a
small dial bore gauge (see illustration). Also,
check the valve stem deflection with a dial
indicator attached securely to the cylinder
head. The valve must be in the guide and
approximately 1/16-inch off the seat. The total
valve stem movement indicated by the gauge
needle must be noted, then divided by two to
obtain the actual clearance value. If it exceeds
the stem-to-guide clearance limit found in this
Chapter’s Specifications, the valve guides
should be renewed. After this is done, if
there’s still some doubt regarding the
condition of the valve guides they should be
checked by an automotive machine workshop
(the cost should be minimal).
Valves
16Carefully inspect each valve face for
uneven wear, deformation, cracks, pits and
burned areas. Check the valve stem for
scuffing and galling and the neck for cracks.
Rotate the valve and check for any obvious
indication that it’s bent. Look for pits and
excessive wear on the end of the stem. The
presence of any of these conditions indicates
the need for valve service by an automotive
machine workshop.
17Measure the margin width on each valve
(see illustration). Any valve with a margin
narrower than 1/32-inch will have to be
replaced with a new valve.
Valve components
18Check each valve spring for wear (on the
ends) and pits. Measure the free length and
compare it to this Chapter’s Specifications
(see illustration). Any springs that are shorter
than specified have sagged and should not be
re-used. The tension of all springs should be
pressure checked with a special fixture before
deciding that they’re suitable for use in a
rebuilt engine (take the springs to an
automotive machine workshop for this check).
Note:If any valve springs are found broken on
1988 or 1989 engines, all springs should be
replaced with the improved springs used in
1990 (after VIN 9EPCLA120245) and later
engines. They are identified with a white
stripe. If your engine has springs with white-
stripes, they have already been replaced, and
only broken ones need be replaced.
19Stand each spring on a flat surface and
check it for squareness (see illustration). If
any of the springs are distorted or sagged,
renew all of the springs.
20Check the spring retainers and keepers
for obvious wear and cracks. Any
questionable parts should be renewed, as
extensive damage will occur if they fail during
engine operation.
21If the inspection process indicates that the
valve components are in generally poor
condition and worn beyond the limits specified,
which is usually the case in an engine that’s
being overhauled, reassemble the valves in the
cylinder head and refer to Section 11 for valve
servicing recommendations.
11 Valves- servicing
5
1Because of the complex nature of the job
and the special tools and equipment needed,
servicing of the valves, the valve seats and the
valve guides, commonly known as a valve job,
should be done by a professional.
2The home mechanic can remove and
dismantle the cylinder head(s), do the initial
cleaning and inspection, then reassemble and
deliver them to a dealer service department or
an automotive machine workshop for the
actual service work. Doing the inspection will
enable you to see what condition the cylinder
head(s) and valvetrain components are in and
will ensure that you know what work and new
parts are required when dealing with an
automotive machine workshop.
3The dealer service department, or
automotive machine workshop, will remove
the valves and springs, will recondition or
renew the valves and valve seats, recondition
the valve guides, check and renew the valve
springs, spring retainers and keepers (as
necessary), replace the valve seals with new
ones, reassemble the valve components and
make sure the installed spring height is
correct. The cylinder head gasket surface will
also be resurfaced if it’s warped.
4After the valve job has been performed by a
professional, the cylinder head(s) will be in like
new condition. When the cylinder heads are
returned, be sure to clean them again before
refitting on the engine to remove any metal
particles and abrasive grit that may still be
present from the valve service or cylinder
head resurfacing operations. Use compressed
air, if available, to blow out all the oil holes and
passages.
12 Cylinder head- reassembly
2
1Regardless of whether or not the cylinder
head was sent to an automotive machine
workshop for valve servicing, make sure it’s
clean before beginning reassembly. Renew
the cylinder head rear plate gasket any time
that the engine is overhauled or the cylinder
head is reconditioned (see Part A of this
Chapter for renewal procedure).
2If the cylinder head was sent out for valve
servicing, the valves and related components
will already be in place. Begin the reassembly
procedure with paragraph 8.
3Refit new seals on each of the valve guides.
Gently push each valve seal into place until
it’s seated on the guide.
Caution: Don’t hammer on the valve seals
once they’re seated or you may damage
them. Don’t twist or cock the seals during
refitting or they won’t seat properly on the
valve stems.
2B•8 Engine removal and overhaul procedures
10.15 Use a small dial bore gauge to
determine the inside diameter of the valve
guides - subtract the valve stem diameter
to determine the stem-to-guide clearance10.17 The margin width on each valve
must be as specified (if no margin exists,
the valve cannot be re-used)
10.18 Measure the free length of each
valve spring with a dial or vernier caliper10.19 Check each valve spring for
squareness
3261 Jaguar XJ6

4Beginning at one end of the cylinder head,
lubricate and refit the first valve. Apply moly-
base grease or clean engine oil to the valve
stem.
5Place the spring seat or shim(s) over the
valve guide and set the valve spring and
retainer in place.
6Compress the springs with a valve spring
compressor and carefully refit the keepers in
the upper groove, then slowly release the
compressor and make sure the keepers seat
properly. Apply a small dab of grease to each
keeper to hold it in place if necessary (see
Haynes Hint).
7Repeat the procedure for the remaining
valves. Be sure to return the components to
their original locations - don’t mix them up!
13 Pistons/connecting rods-
removal
4
Note :Prior to removing the piston/connecting
rod assemblies, remove the cylinder head(s),
the sump and the oil pump transfer tubes by
referring to Chapter 2A.
1Use your fingernail to feel if a ridge has
formed at the upper limit of ring travel (about
1/4-inch down from the top of each cylinder).
If carbon deposits or cylinder wear have
produced ridges, they must be completely
removed with a special tool (see illustration).
Follow the manufacturer’s instructions
provided with the tool. Failure to remove the
ridges before attempting to remove the
piston/connecting rod assemblies may result
in piston damage.
2After the cylinder ridges have been
removed, turn the engine upside-down so the
crankshaft is facing up. Remove the screws
and the front and rear baffle plates from the
bottom of the engine block (see illustration).
3Before the connecting rods are removed,
check the endplay with a feeler gauge. Slide
the blade between the first connecting rod
and the crankshaft throw until the play is
removed (see illustration). The endplay is
equal to the thickness of the feeler gauge(s). If
the endplay exceeds the specified service
limit, new connecting rods will be required. Ifnew rods (or a new crankshaft) are installed,
the endplay may fall under the service limit (if
it does, the rods will have to be machined to
restore it - consult an automotive machine
workshop for advice if necessary). Repeat the
procedure for the remaining connecting rods.
4Check the connecting rods and caps for
identification marks. If they aren’t plainly
marked, use a small centre punch to make the
appropriate number of indentations on each rod
and cap (1, 2, 3, etc, depending on the cylinder
they’re associated with) (see illustration).
5Loosen each of the connecting rod cap nuts
1/2-turn at a time until they can be removed by
hand. Remove the number one connecting rod
cap and bearing insert. Don’t drop the bearing
insert out of the cap. Note:These engines use
special connecting rod and main bearing cap
bolts that are designed to be used one time
only. They can be used during Plastigage
checks, but must be replaced with new bolts
when the engine is finally reassembled.
6Slip a short length of plastic or rubber hose
over each connecting rod cap bolt to protect
the crankshaft journal and cylinder wall as the
piston is removed (see illustration).
7Remove the bearing insert and push the
connecting rod/piston assembly out through
the top of the engine. Use a wooden hammer
handle to push on the upper bearing surface
in the connecting rod. If resistance is felt,
double-check to make sure that all of the
ridge was removed from the cylinder.
Engine removal and overhaul procedures 2B•9
2B
13.2 Remove the screws (arrowed) and
remove the front and rear baffle plates13.3 Check the connecting rod side
clearance with a feeler gauge as shown
13.4 The connecting rods and caps should
be marked by cylinder number - if they
aren’t, mark them with a centre punch to
avoid confusion during reassembly13.6 To prevent damage to the crankshaft
journals and cylinder walls, slip sections of
hose over the connecting rod bolts before
removing the pistons
3261 Jaguar XJ6 13.1 A ridge reamer is required to remove
the ridge from the top of each cylinder -
do this before removing the pistons!
The keepers are easier to fit if a small
amount of grease is applied to keep
them in place

8Repeat the procedure for the remaining
cylinders. Note:Turn the crankshaft as
needed to position the piston/connecting rod
assembly to be removed close to parallel with
the cylinder bore - i.e. don’t try to drive it out
while at a large angle to the bore.
9After removal, reassemble the connecting
rod caps and bearing inserts in their
respective connecting rods and refit the cap
nuts/bolts finger tight. Leaving the old bearing
inserts in place until reassembly will help
prevent the big-end bearing surfaces from
being accidentally nicked or gouged.
10Don’t separate the pistons from the
connecting rods (see Section 18 for additional
information).
14 Crankshaft- removal
3
Note:The rear main oil seal and retainer must
be removed from the engine block before
proceeding with crankshaft removal (see Part
A of this Chapter).
1Before the crankshaft is removed, check
the endplay. Mount a dial indicator to the front
of the engine with the stem in line with, and
just touching, the end of the crankshaft (see
illustration).2Push the crankshaft all the way to the rear
and zero the dial indicator. Next, pry the
crankshaft to the front as far as possible and
check the reading on the dial indicator. The
distance that it moves is the endplay. If it’s
greater than that specified in this Chapter’s
Specifications, check the crankshaft thrust
surfaces for wear. If no wear is evident, new
thrust washers should correct the endplay.
3If a dial indicator isn’t available, feeler
gauges can be used. Gently pry or push the
crankshaft all the way to the front of the
engine. Slip feeler gauges between the
crankshaft and the front face of the number 4
(thrust) main bearing to determine the
clearance (see illustration).
4Check the main bearing caps to see if
they’re marked to indicate their locations.
They should be numbered consecutively from
the front of the engine to the rear. If they
aren’t, mark them with number stamping dies
or a centre punch. Main bearing caps
generally have a cast-in arrow, which points
to the front of the engine. Loosen the main
bearing cap bolts 1/4-turn at a time each,
stating at the ends and working toward the
centre, until they can be removed by hand.
5The main bearing caps are numbered on
the right side with corresponding numbers
stamped into the sump rail on the same side
(see illustration). Gently tap the caps with asoft-face hammer, then separate them from
the engine block. If necessary, use the bolts
as levers to remove the main bearing caps.
Try not to drop the bearing inserts if they
come out with the caps. Note:The number
four main bearing is the thrust bearing and is
not numbered.
6Carefully lift the crankshaft out of the
engine. It may be a good idea to have an
assistant available, since the crankshaft is
quite heavy. With the bearing inserts in place
in the engine block and main bearing caps,
return the main bearing caps to their
respective locations on the engine block and
tighten the bolts finger tight.
15 Engine block- cleaning
2
Caution: The core plugs (also known as
freeze or soft plugs) may be difficult or
impossible to retrieve if they’re driven
completely into the engine block coolant
passages.
1Using the blunt end of a punch, tap in on
the outer edge of the core plug to turn the
plug sideways in the bore. Then using pliers,
pull the core plug from the engine block (see
illustrations).
2B•10 Engine removal and overhaul procedures
14.5 The right side of each main bearing
cap is stamped with a number (left arrow)
that corresponds to the stamped number
on the pan rail (right arrow)15.1a A hammer and a large punch can be
used to knock the core plugs sideways in
their bores15.1b Pull the core plugs from the engine
block with pliers
3261 Jaguar XJ6 14.1 Checking crankshaft endplay with a dial indicator
14.3 Checking crankshaft endplay with a feeler gauge

is the difference between the parallel and
perpendicular readings. Compare your results
to this Chapter’s Specifications.
8If the cylinder walls are badly scuffed or
scored, or if they’re out-of-round or tapered
beyond the limits given in this Chapter’s
Specifications, have the engine block rebored
and honed at an automotive machine
workshop. If a rebore is done, oversize
pistons and rings will be required.
9Using a precision straightedge and feeler
gauge, check the engine block deck (the
surface that mates with the cylinder head) for
distortion (see illustration 10.13). If it’s
distorted beyond the specified limit, it can be
resurfaced by an automotive machine
workshop.
10If the cylinders are in reasonably good
condition and not worn to the outside of the
limits, and if the piston-to-cylinder clearances
can be maintained properly, then they don’t
have to be rebored. Honing is all that’s
necessary (refer to Section 17).
17 Cylinder honing
3
1Prior to engine reassembly, the cylinder
bores must be honed so the new piston rings
will seat correctly and provide the best
possible combustion chamber seal. Note:If
you don’t have the tools or don’t want to
tackle the honing operation, most automotive
machine shops will do it for a reasonable fee.
2Before honing the cylinders, refit the main
bearing caps (without bearing inserts) and
tighten the bolts to the specified torque.
3Two types of cylinder hones are commonly
available - the flex hone or “bottle brush” type
and the more traditional surfacing hone with
spring-loaded stones. Both will do the job, but
for the less-experienced mechanic the “bottle
brush” hone will probably be easier to use.
You’ll also need some paraffin or honing oil,
rags and a variable-speed electric drill motor.
The drill motor should be operated at a
steady, slow speed. Proceed as follows:
a) Mount the hone in the drill motor,
compress the stones and slip it into the
first cylinder (see illustration).
Warning: Be sure to wear safety
goggles or a face shield!
b) Lubricate the cylinder with plenty of
honing oil, turn on the drill and move the
hone up-and-down in the cylinder at a
pace that will produce a fine crosshatch
pattern on the cylinder walls. Ideally, the
crosshatch lines should intersect at
approximately a 60° angle (see
illustration). Be sure to use plenty of
lubricant and don’t take off any more
material than is absolutely necessary to
produce the desired finish. Note:Piston
ring manufacturers may specify a smallercrosshatch angle than the traditional 60° -
read and follow any instructions included
with the new rings.
c) Don’t withdraw the hone from the cylinder
while it’s running. Instead, shut off the drill
and continue moving the hone up-and-
down in the cylinder until it comes to a
complete stop, then compress the stones
and withdraw the hone. If you’re using a
“bottle brush” type hone, stop the drill
motor, then turn the chuck in the normal
direction of rotation while withdrawing the
hone from the cylinder.
d) Wipe the oil out of the cylinder and repeat
the procedure for the remaining cylinders.
4After the honing job is complete, chamfer
the top edges of the cylinder bores with a
small file so the rings won’t catch when the
pistons are installed. Be very careful not to
nick the cylinder walls with the end of the file.
5The entire engine block must be washed
again very thoroughly with warm, soapy water
to remove all traces of the abrasive grit
produced during the honing operation. Note:
The bores can be considered clean when a
lint-free white cloth - dampened with clean
engine oil - used to wipe them out doesn’t
pick up any more honing residue, which will
show up as grey areas on the cloth. Be sure to
run a brush through all oil holes and galleries
and flush them with running water.
6After rinsing, dry the engine block and
apply a coat of light rust preventive oil to all
machined surfaces. Wrap the engine block in
a plastic bag to keep it clean and set it aside
until reassembly.
18 Pistons/connecting rods-
inspection
2
1Before the inspection process can be
carried out, the piston/connecting rod
assemblies must be cleaned and the original
piston rings removed from the pistons. Note:
Always use new piston rings when the engine
is reassembled.
2Using a piston ring refitting tool, carefully
remove the rings from the pistons. Be careful
not to nick or gouge the pistons in the
process.
3Scrape all traces of carbon from the top of
the piston. A hand-held wire brush or a piece
of fine emery cloth can be used once the
majority of the deposits have been scraped
away. Do not, under any circumstances, use a
wire brush mounted in a drill motor to remove
deposits from the pistons. The piston material
is soft and may be eroded away by the wire
brush.
4Use a piston ring groove-cleaning tool to
remove carbon deposits from the ring
grooves. If a tool isn’t available, a piece
broken off the old ring will do the job. Be very
careful to remove only the carbon deposits -
don’t remove any metal and do not nick or
scratch the sides of the ring grooves (see
illustrations).
5Once the deposits have been removed,
clean the piston/connecting rod assemblies
with solvent and dry them with compressed
air (if available). Make sure the oil return holes
2B•12 Engine removal and overhaul procedures
17.3a A “bottle brush” hone will produce
better results if you have never done
cylinder honing before17.3b The cylinder hone should leave a
smooth, crosshatch pattern with the lines
intersecting at approximately a 60° angle
18.4a The piston ring grooves can be
cleaned with a special tool, as shown . . .18.4b . . . or a section of a broken ring
3261 Jaguar XJ6

reveal valuable information about the condition
of the engine (see illustration).
2Bearing failure occurs because of lack of
lubrication, the presence of dirt or other foreign
particles, overloading the engine and corrosion.
Regardless of the cause of failure, it must be
corrected before the engine is reassembled to
prevent it from happening again.
3When examining the bearings, remove
them from the engine block, the main bearing
caps, the connecting rods and the rod caps
and lay them out on a clean surface in the
same general position as their location in the
engine. This will enable you to match any
bearing problems with the corresponding
crankshaft journal.
4Dirt and other foreign particles get into the
engine in a variety of ways. It may be left in
the engine during assembly, or it may pass
through filters or the PCV system. It may get
into the oil, and from there into the bearings.
Metal chips from machining operations and
normal engine wear are often present.
Abrasives are sometimes left in engine
components after reconditioning, especially
when parts are not thoroughly cleaned using
the proper cleaning methods. Whatever the
source, these foreign objects often end up
embedded in the soft bearing material and are
easily recognised. Large particles will not
embed in the bearing and will score or gouge
the bearing and journal. The best prevention
for this cause of bearing failure is to clean all
parts thoroughly and keep everything
spotlessly clean during engine assembly.
Frequent and regular engine oil and filter
changes are also recommended.5Lack of lubrication (or lubrication
breakdown) has a number of interrelated
causes. Excessive heat (which thins the oil),
overloading (which squeezes the oil from the
bearing face) and oil leakage or throw off
(from excessive bearing clearances, worn oil
pump or high engine speeds) all contribute to
lubrication breakdown. Blocked oil passages,
which usually are the result of misaligned oil
holes in a bearing shell, will also oil starve a
bearing and destroy it. When lack of
lubrication is the cause of bearing failure, the
bearing material is wiped or extruded from the
steel backing of the bearing. Temperatures
may increase to the point where the steel
backing turns blue from overheating.
6Driving habits can have a definite effect on
bearing life. Low speed operation in too high a
gear (labouring the engine) puts extremely
high loads on bearings, which tends to
squeeze out the oil film. These loads cause
the bearings to flex, which produces fine
cracks in the bearing face (fatigue failure).
Eventually the bearing material will loosen in
pieces and tear away from the steel backing.
Short trip driving leads to corrosion of
bearings because insufficient engine heat is
produced to drive off the condensed water
and corrosive gases. These products collect
in the engine oil, forming acid and sludge. As
the oil is carried to the engine bearings, the
acid attacks and corrodes the bearing
material.
7Incorrect bearing refitting during engine
assembly will lead to bearing failure as well.
Tight-fitting bearings leave insufficient bearing
oil clearance, and this will lead to oilstarvation. Dirt or foreign particles trapped
behind a bearing insert result in high spots on
the bearing which lead to failure.
Selection
8If the original bearings are worn or
damaged, or if the oil clearances are incorrect
(see Sections 23 or 25), the following
procedures should be used to select the
correct new bearings for engine reassembly.
However, if the crankshaft has been reground,
new undersize bearings must be installed -
the following procedure should not be used if
undersize bearings are required! The
automotive machine workshop that
reconditions the crankshaft will provide or
help you select the correct-size bearings.
Regardless of how the bearing sizes are
determined, use the oil clearance, measured
with Plastigage, as a guide to ensure the
bearings are the right size.
9If you need to use a STANDARD size main
or big-end bearing, refit one that has the same
number as the original bearing. Note:4.0 litre
engines after #164637 have sized crankshafts
and bearings in three grades, indicated by
colour and letter. The codes are stamped into
the front throw of the crankshaft(see
illustration). Match replacement bearings by
the colour codes: pink (P), white (W) or
green (G) for main bearings; red (R), yellow (Y)
or blue (B) for the three grades of big-end
bearings.
10Remember, the oil clearance is the final
judge when selecting new bearing sizes. If you
have any questions or are unsure which
bearings to use, get help from a dealer parts
or service department.
2B•14 Engine removal and overhaul procedures
3261 Jaguar XJ6 20.1 When inspecting the main and big-end bearings, look for
these problems
20.9 Later model 4.0 litre engines have graded journals and
bearings, with the markings indicated on the front throw of the
crankshaft - “A” indicates the front of the engine, “B” indicates
the codes for the main journals/bearings, and “C” indicates the
connecting rod journal grades

pull loose, tap it with a soft-faced hammer. Do
not use a screwdriver between the cover and
the thermostat housing.
8Remove the thermostat, noting the
direction in which it was installed in the
housing, and thoroughly clean the sealing
surfaces.
9Refit a new O-ring onto the thermostat (see
illustration). Make sure it is evenly fitted all
the way around.
10Apply a bead of RTV sealant to the
thermostat housing. Refit the thermostat and
housing, positioning the jiggle pin at the
highest point. Note:The thermostat is usually
marked TOP on the radiator side for proper
orientation.
11Tighten the cover fasteners to the torque
listed in this Chapter’s Specifications.
12Refill the cooling system, run the engine
and check for leaks and proper operation.
4 Engine cooling fans-
check and renewal
3
Mechanical fan
(1988 to 1992 models)
Warning: Keep hands, hair, tools
and clothing away from the fan
when the engine is running. Toavoid injury or damage DO NOT operate
the engine with a damaged fan. Do not
attempt to repair fan blades - renew a
damaged fan .
Check
Warning: In order to check the
fan clutch, the engine will need
to be at operating temperature,
so while going through checks
prior to Step 6 be careful that the ignition is
NOT switched on. Severe personal injury
can result!
1Symptoms of failure of the fan clutch are
continuous noisy operation, looseness,
vibration and evidence of silicone fluid leaks.
2Rock the fan back and forth by hand to
check for excessive bearing play.
3With the engine cold, turn the blades by
hand. The fan should turn freely.
4Visually inspect for substantial fluid leakage
from the fan clutch assembly, a deformed bi-
metal spring or grease leakage from the
cooling fan bearing. If any of these conditions
exist, renew the fan clutch.
5When the engine is fully warmed up, turn off
the ignition switch and disconnect the cable
from the negative battery terminal. Turn the
fan by hand. Some resistance should be felt. If
the fan turns easily, renew the fan clutch.
Caution: If the stereo in your vehicle is
equipped with an anti-theft system, makesure you have the correct activation code
before disconnecting the battery.
Removal and refitting
6Leave the battery cable disconnected (see
the Caution in Step 5).
7Remove the fan’s drivebelt (see Chapter 1).
8Remove the nuts holding the fan assembly
to the water pump (see illustration). Note:
You’ll have to “walk” the fan assembly forward
as you loosen the nuts. There is not enough
room to remove them all the way at one time.
9The fan can be removed without removing
the shroud, if you are only renewing the fan or
clutch (see illustration). Be careful not to
allow the blades contact the radiator fins.
10Remove the two fan shroud mounting
clips at the top of the shroud (see illustration).
11Lift the shroud up and out of the engine
compartment. The bottom of the fan shroud
does not have any fasteners. It has two tangs
on the bottom that slip out of slots in the body
when pulled up.
12The fan clutch can be unbolted from the
fan blade assembly for renewal (see
illustration).
Caution: To prevent silicone fluid from
draining from the clutch assembly into the
fan drive bearing and ruining the lubricant,
DON’T place the clutch in a position with
the rear pointing down. Store the clutch in
its upright position if possible.
Cooling, heating and air conditioning systems 3•3
3
4.9 The fan can be removed with the
shroud in place by angling it out of
the shroud4.10 Pry out the two clips (arrow indicates
the left one) at the top of the fan shroud
and lift out the shroud
3261 Jaguar XJ6 3.9 The thermostat is fitted with the spring end towards the
cylinder head - use a new O-ring (A) and position jiggle pin (B) up
4.8 Remove the four nuts (arrows indicate three shown here)
holding the fan/clutch assembly to the front of the water pump
4.12 Separate the fan clutch from the fan
by removing the four bolts (arrowed)

4Remove the water pump mounting bolts
(see illustration).
Note 1:The water pump is sold as a complete
assembly, including the rear housing with the
hose connections. Unless the rear housing is
corroded or cracked, many Jaguar mechanics
only refit the pump assembly itself, using the
original rear housing with all its hoses intact.
However, if the engine has a great deal of
years or mileage on it, it would be a good idea
to renew those hoses as well, in which case
the new rear housing can be installed.
Note 2:There are three different lengths of
water pump bolts. The longer bolts retain the
pump and rear housing to the engine(see
illustration 7.3).
5If the pump doesn’t come loose right away,
tap it with a soft-faced hammer to break the
gasket seal. Be careful not to hit the radiator
fins with the pump during removal.
6Thoroughly clean all sealing surfaces,
removing all traces of gasket or sealant from
the back of the pump and the face of the
housing.
7Apply a bead of RTV sealant to the sealing
surface on the back of the pump. Refit the
pump and bolts, tightening the bolts to the
torque listed in this Chapter’s Specifications.
8Refit the remaining parts in the reverse
order of removal. Note:If the pump has been
renewed after many miles of usage, it’s a good
idea to also renew the hoses connected to the
water pump housing(see illustrations). Refer
to Chapter 2A for intake manifold removal to
access the coolant pipes and hoses. If you
have noticed water leaks or stains on the left
side of the engine, the leaks may be coming
from these pipes and hoses.
9Refill the cooling system (see Chapter 1),
run the engine and check for leaks and proper
operation.
9 Coolant temperature
sender unit- check and
renewal
2
Warning: Do not start this
procedure until the engine is
completely cool.
Check
1If the coolant temperature gauge is
inoperative, check the fuses first (Chapter 12).
2If the temperature gauge indicates
excessive temperature after running awhile,
see the Fault finding section at the rear of the
manual.
3If the temperature gauge indicates Hot as
soon as the engine is started cold, disconnect
the wire at the coolant temperature sender
(see illustration). If the gauge reading drops,
renew the sender unit. If the reading remains
high, the wire to the gauge may be shorted to
ground, or the gauge is faulty.
4If the coolant temperature gauge fails to
show any indication after the engine has been
warmed up, (approx. 10 minutes) and the
fuses checked out OK, shut off the engine.
Disconnect the wire at the sender unit and,
using a jumper wire, connect the wire to a
clean ground on the engine. Briefly turn on the
ignition without starting the engine. If the
gauge now indicates Hot, renew the sender
unit.
5If the gauge fails to respond, the circuit may
be open or the gauge may be faulty - see
Chapter 12 for additional information.
Renewal
6Drain the coolant (see Chapter 1).
7Disconnect the electrical connector from
the sender unit.8Using a deep socket or a spanner, remove
the sender unit.
9Refit the new unit and tighten it securely.
Do not use thread sealant as it may
electrically insulate the sender unit.
10Reconnect the wiring connector, refill the
cooling system and check for coolant leakage
and proper gauge function.
10 Heating and air conditioning
blower motors- circuit check
and component renewal
3
Warning: Later models are
equipped with airbags. To
prevent accidental deployment
of the airbag, which could cause
personal injury or damage to the airbag
system, DO NOT work in the vicinity of the
steering wheel or instrument panel. Jaguar
recommends that, on airbag-equipped
models, the following procedure should be
left to a dealer service department or other
repair workshop because of the special
tools and techniques required to disable
the airbag system.
1Disconnect 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.
2There are two blower motors, one under the
left side of the dash and one behind the glove
compartment (see illustration). If the blower
doesn’t work, check the fuse and all
connections in the circuit for looseness and
corrosion. Make sure the battery is fully
charged. To access the right blower, remove
the glove compartment liner, the glove
compartment door and the right lower dash
panel (see Chapter 11).
Warning: When working around
the area behind the glove box,
watch out for a strip of sheet
metal bracing that has a very
sharp edge (see illustration). Apply some
heavy duct tape to the edge of the brace
before beginning work in this area, or you
could injure your hands.
Cooling, heating and air conditioning systems 3•7
3
8.4 Remove the water pump mounting
bolts (arrows indicate five visible here)8.8a Once the water pump is removed, the
rear housing (arrowed) is held in place only
by the hoses - check them for leakage and
condition whenever the pump is disturbed8.8b The water pipe (arrowed) may need
new gaskets where it meets the block - the
pipe is best accessed from below or with
the intake manifold unbolted
9.3 The coolant temperature sender unit
(arrowed) is located in the top of the
thermostat housing - it is the sender unit
with the single wire
3261 Jaguar XJ6

cushions fit on the mounting points and that
any foam insulator strips are still in place or
transferred to the new condenser.
6Reconnect the refrigerant lines, using new
O-rings. If a new condenser has been
installed, add 84 cc (3 fluid ounces) of new
refrigerant oil. Note:The oil and O-rings must
be compatible with the type of refrigerant you
are using.
7Refit the remaining parts in the reverse
order of removal.
8Have the system evacuated, charged and
leak tested by the workshop that discharged
it.
17 Air conditioning evaporator
and expansion valve-
removal and refitting
4
Warning 1: The air conditioning
system is under high pressure.
Do not loosen any hose fittings
or remove any components until
the system has been discharged. Air
conditioning refrigerant should be properly
discharged into an EPA-approved
recovery/recycling unit by a dealer service
department or an automotive airconditioning repair facility. Always wear
eye protection when disconnecting air
conditioning system fittings.
Warning 2: Later model vehicles
are equipped with airbags. To
prevent the accidental
deployment of the airbag, which
could cause personal injury or damage to
the airbag system, DO NOT work in the
vicinity of the steering wheel or instrument
panel. The manufacturer recommends
that, on airbag-equipped models, the
following procedure should be left to a
dealer service department or other repair
workshop because of the special tools and
techniques required to disable the airbag
system.
1Refer to Chapter 11 for removal of the glove
compartment, under-dash panels and
console. Note:The removal of the
heater/evaporator housing is difficult and
time-consuming, much more so than the
removal of the heater core (see Section 11).
For some home mechanics, the job is better
left to a Jaguar dealership or other qualified
repair workshop.
2Disconnect the air conditioning lines from
the backside of the expansion valve (at the
bulkhead, just to the right of the engine), usingtwo spanners (see illustration). Cap the open
fittings and expansion valve after dismantling
to prevent the entry of air or dirt.
3Refer to Section 11 for moving the climate-
control computer aside and disconnecting the
heater core pipes.
4From the engine side of the bulkhead, near
the expansion valve, remove the nut retaining
the heat/air conditioning assembly housing
(see illustration). Another mounting nut is on
the left side, under the wiper motor (see
illustration 11.2).
5Disconnect the defroster ducts on the left
and right side of the evaporator housing (see
illustration).
6Identify all of the vacuum motor lines with
masking tape and a felt pen, then disconnect
the lines. Note:Most vacuum lines are colour-
coded. Make notes on which ones go to
which devices.
7Tag and disconnect the wiring plugs
connected to the heating/air conditioning
housing.
8At the bottom left and bottom right of the
housing, pull off the rubber drain tubes that go
into the flooring.
9Remove the four rod-type support braces.
Two support the dash, and two connect the
case to the floor of the car (see illustrations).
3•14 Cooling, heating and air conditioning systems
17.5 Left duct (large arrow) can be removed
by pulling off the clip (small arrow) - right
duct pulls out without a clip17.9a Unbolt the four support braces
(small arrows) from the case (large arrow)
and floor17.9b Black case-support rods are held
with nuts (arrowed), the gold dash-support
rods are retained by a bolt/nut to the dash
3261 Jaguar XJ6 17.2 Use two spanners when disconnecting the air conditioning
lines (arrowed) at the bulkhead, on the backside of the expansion
valve - one spanner holds the body of the expansion valve
17.4 Remove the housing retaining nut (arrowed) on the engine
side of the bulkhead, near the expansion valve - another nut is on
the right, near the heater core pipes

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