torque JAGUAR XJ6 1997 2.G Owner's Manual

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)

Engine block
Deck warpage limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.076 mm (0.003 inch)
Cylinder bore diameter
Standard
Size group A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90.990 to 91.003 mm (3.5823 to 3.5828 inches)
Size group B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91.005 to 91.018 mm (3.5829 to 3.5834 inches)
Oversize
0.25 mm (0.010 inch) OS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91.259 to 91.272 mm (3.5929 to 3.5934 inches)
0.50 mm (0.020 inch) OS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91.513 to 91.526 mm (3.6029 to 3.6034 inches)
Pistons and rings
Piston-to-bore clearance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.017 to 0.043 mm (0.0007 to 0.0017 inch)
Piston ring end gap
No.1 (top) compression ring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.40 to 0.66 mm (0.016 to 0.026 inch)
No.2 (middle) compression ring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.40 to 0.66 mm (0.016 to 0.026 inch)
Oil ring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.30 to 0.55 mm (0.012 to 0.022 inch)
Piston ring groove clearance
No. 1 (top) compression ring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.040 to 0.076 mm (0.0016 to 0.0030 inch)
No. 2 (middle) compression ring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.040 to 0.076 mm (0.0016 to 0.0030 inch)
Torque wrench settingsNm lbf ft
Main bearing cap bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136 to 142 100 to 105
Connecting rod cap nuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 to 60 37 to 44
* Note:Refer to Part A for additional torque specifications.
2B•2 Engine removal and overhaul procedures
3261 Jaguar XJ6
1 General information
Included in this portion of Chapter 2 are the
general overhaul procedures for the cylinder
head and internal engine components.
The information ranges from advice
concerning preparation for an overhaul and
the purchase of replacement parts to detailed,
step-by-step procedures covering removal
and refitting of internal engine components
and the inspection of parts.
The following Sections have been written
based on the assumption that the engine has
been removed from the vehicle. For
information concerning in-vehicle engine
repair, as well as removal and refitting of the
external components necessary for the
overhaul, see Part A of this Chapter.
The Specifications included in this Part are
only those necessary for the inspection and
overhaul procedures which follow. Refer to
Part A for additional Specifications.
2 Engine overhaul-
general information
It’s not always easy to determine when, or if,
an engine should be completely overhauled,
as a number of factors must be considered.
High mileage is not necessarily an indication
that an overhaul is needed, while low mileage
doesn’t preclude the need for an overhaul.
Frequency of servicing is probably the most
important consideration. An engine that’s had
regular and frequent oil and filter changes, as
well as other required maintenance, will most
likely give many thousands of miles of reliableservice. Conversely, a neglected engine may
require an overhaul very early in its life.
Excessive oil consumption is an indication
that piston rings, valve seals and/or valve
guides are in need of attention. Make sure that
oil leaks aren’t responsible before deciding
that the rings and/or guides are bad. Perform a
cylinder compression check to determine the
extent of the work required (see Section 4).
Also check the vacuum readings under various
conditions (see Section 3).
Check the oil pressure with a gauge
installed in place of the oil pressure sender
unit (see illustrations)and compare it to this
Chapter’s Specifications. If it’s extremely low,
the bearings and/or oil pump are probably
worn out.
Loss of power, rough running, knocking or
metallic engine noises, excessive valve train
noise and high fuel consumption rates may
also point to the need for an overhaul,
especially if they’re all present at the same
time. If a complete tune-up doesn’t remedy
the situation, major mechanical work is the
only solution.An engine overhaul involves restoring the
internal parts to the specifications of a new
engine. During an overhaul, the piston rings
are replaced and the cylinder walls are
reconditioned (rebored and/or honed). If a
rebore is done by an automotive machine
workshop, new oversize pistons will also be
installed. The main bearings, big-end bearings
and camshaft bearings are generally replaced
with new ones and, if necessary, the
crankshaft may be reground to restore the
journals. Generally, the valves are serviced as
well, since they’re usually in less-than-perfect
condition at this point. While the engine is
being overhauled, other components, such as
the distributor, starter and alternator, can be
rebuilt as well. The end result should be a like
new engine that will give many trouble free
miles. Note:Critical cooling system
components such as the hoses, drivebelts,
thermostat and water pump should be
replaced with new parts when an engine is
overhauled. The radiator should be checked
carefully to ensure that it isn’t clogged or
leaking (see Chapter 3).If you purchase a
2.4a The oil pressure sender unit (arrowed)
is located in the right front corner of the
engine block, near the oil filter2.4b The oil pressure can be checked by
removing the sender unit and refitting a
pressure gauge in its place

2Using a gasket scraper, remove all traces of
gasket material from the engine block. Be very
careful not to nick or gouge the gasket sealing
surfaces.
3Remove the main bearing caps and
separate the bearing inserts from the caps
and the engine block. Tag the bearings,
indicating which cylinder they were removed
from and whether they were in the cap or the
engine block, then set them aside.
4Remove all of the threaded oil gallery plugs
from the engine block. The plugs are usually
very tight - they may have to be drilled out and
the holes retapped. Use new plugs when the
engine is reassembled.
5If the engine is extremely dirty, it should be
taken to an automotive machine workshop to
be steam cleaned or hot tanked.
6After the engine block is returned, clean all
oil holes and oil galleries one more time.
Brushes specifically designed for this purpose
are available at most car accessory outlets.
Flush the passages with warm water until the
water runs clear, dry the engine block
thoroughly and wipe all machined surfaces
with a light, rust preventive oil. If you have
access to compressed air, use it to speed the
drying process and to blow out all the oil
holes and galleries. Warning: Wear eye protection
when using compressed air!
7If the engine block isn’t extremely dirty or
sludged up, you can do an adequate cleaning
job with hot soapy water and a stiff brush.
Take plenty of time and do a thorough job.
Regardless of the cleaning method used, be
sure to clean all oil holes and galleries very
thoroughly, dry the engine block completely
and coat all machined surfaces with light oil.
8The threaded holes in the engine block
must be clean to ensure accurate torque
readings during reassembly. Run the proper
size tap into each of the holes to remove rust,
corrosion, thread sealant or sludge and
restore damaged threads (see illustration). If
possible, use compressed air to clear the
holes of debris produced by this operation.
9Refit the main bearing caps and tighten the
bolts finger tight.
10After coating the sealing surfaces of the
new core plugs with suitable sealant, refit
them in the engine block (see illustration).
Make sure they’re driven in straight and
seated properly or leakage could result.
Special tools are available for this purpose,
but a large socket, with an outside diameter
that will just slip into the core plug, a 1/2-inchdrive extension and a hammer will work just
as well.
11Apply non-hardening sealant (such as
Permatex no. 2 or Teflon pipe sealant) to the
new oil gallery plugs and thread them into the
holes in the engine block. Make sure they’re
tightened securely.
12If the engine isn’t going to be
reassembled right away, cover it with a large
plastic trash bag to keep it clean.
16 Engine block- inspection
2
1Before the engine block is inspected, it
should be cleaned as described in Section 15.
2Visually check the engine block for cracks,
rust and corrosion (see illustration 10.12).
Look for stripped threads in the threaded
holes. It’s also a good idea to have the engine
block checked for hidden cracks by an
automotive machine workshop that has the
special equipment to do this type of work,
especially if the vehicle had a history of
overheating or using coolant. If defects are
found, have the engine block repaired, if
possible, or renewed. If the top of the engine
block has been eroded by coolant leakage
and the erosion is near the cylinder bores, the
engine block must be renewed.
3Check the cylinder bores for scuffing and
scoring.
4Check the cylinders for taper and out-of-
round conditions as follows (see illustrations):
5Measure the diameter of each cylinder at
the top (just under the ridge area), centre and
bottom of the cylinder bore, parallel to the
crankshaft axis.
6Next, measure each cylinder’s diameter at
the same three locations perpendicular to the
crankshaft axis.
7The taper of each cylinder is the difference
between the bore diameter at the top of the
cylinder and the diameter at the bottom. The
out-of-round specification of the cylinder bore
Engine removal and overhaul procedures 2B•11
2B
16.4a Measure the diameter of each
cylinder at 90° to engine centreline (A), and
parallel to engine centreline (B) - out-of-
round is the difference between A and B;
taper is the difference between A and B at
the top of the cylinder and A and B at the
bottom of the cylinder16.4b The ability to “feel” when the
telescoping gauge is at the correct point
will be developed over time, so work
slowly and repeat the check until you’re
satisfied that the bore measurement is
accurate
3261 Jaguar XJ6
15.8 All bolt holes in the engine block -
particularly the main bearing cap and
cylinder head bolt holes - should be
cleaned and restored with a tap (remove
debris from holes after this is done)15.10 A large socket on an extension can
be used to drive the new core plugs into
the bores
16.4c The gauge is then measured with a
micrometer to determine the bore size

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

21 Engine overhaul-
reassembly sequence
1Before beginning engine reassembly, make
sure you have all the necessary new parts,
gaskets and seals as well as the following
items on hand:
Common hand tools
A 1/2-inch drive torque wrench
Piston ring refitting tool
Piston ring compressor
Short lengths of rubber or plastic hose to
fit over connecting rod bolts
Plastigauge
Feeler gauges
A fine-tooth file
New engine oil
Engine assembly lube or moly-base
grease
Gasket sealer
Thread locking compound
Special Jaguar tools:
Engine lifting brackets (18G 1465)
Timing damper simulator (18E 1436)
Camshaft TDC tool (18G 1433)
2In order to save time and avoid problems,
engine reassembly must be done in the
following general order:
Piston rings (Part B)
Crankshaft and main bearings (Part B)
Piston/connecting rod assemblies (Part B)
Rear main (crankshaft) oil seal (Part B)
Auxiliary shaft (Part A)
Timing chains and sprockets (Part A)
Oil pump (Part A)
Timing chain cover (Part A)
Cylinder head and lifters (Part A)
Camshafts (Part A)
Oil pick-up (Part A)
Sump (Part A)
Intake and exhaust manifolds (Part A)
Valve cover (Part A)
Flywheel/driveplate (Part A)
22 Piston rings- refitting
3
1Before refitting the new piston rings, the ring
end gaps must be checked. It’s assumed that
the piston ring groove clearance has been
checked and verified correct (see Section 18).
2Lay out the piston/connecting rod
assemblies and the new ring sets so the ring
sets will be matched with the same piston and
cylinder during the end gap measurement and
engine assembly.
3Insert the top (number one) ring into the first
cylinder and square it up with the cylinder
walls by pushing it in with the top of the piston
(see illustration). The ring should be near the
bottom of the cylinder, at the lower limit of
ring travel.
4To measure the end gap, slip feeler gauges
between the ends of the ring until a gauge
equal to the gap width is found (see
illustration). The feeler gauge should slide
between the ring ends with a slight amount of
drag. Compare the measurement to that
found in this Chapter’s Specifications. If the
gap is larger or smaller than specified,
double-check to make sure you have the
correct rings before proceeding.
5If the gap is too small, it must be enlarged
or the ring ends may come in contact with
each other during engine operation, which
can cause serious damage to the engine. The
end gap can be increased by filing the ring
ends very carefully with a fine file. Mount thefile in a vice equipped with soft jaws, slip the
ring over the file with the ends contacting the
file face and slowly move the ring to remove
material from the ends(see illustration).
Caution: When performing this operation,
file only from the outside in, and after the
correct gap is achieved, deburr the filed
ends of the rings with a fine whetstone.
6Excess end gap isn’t critical unless it’s
greater than Specifications. Again, double-
check to make sure you have the correct rings
for your engine.
7Repeat the procedure for each ring that will
be installed in the first cylinder and for each
ring in the remaining cylinders. Remember to
keep rings, pistons and cylinders matched.
8Once the ring end gaps have been
checked/corrected, the rings can be installed
on the pistons.
9The oil control ring (lowest one on the
piston) is usually installed first. It’s composed
of three separate components. Slip the
spacer/expander into the groove (see
illustration). If an anti-rotation tang is used,
make sure it’s inserted into the drilled hole in
the ring groove. Next, refit the lower side rail.
Don’t use a piston ring refitting tool on the oil
ring side rails, as they may be damaged.
Instead, place one end of the side rail into the
groove between the spacer/expander and the
ring land, hold it firmly in place and slide a
finger around the piston while pushing the rail
into the groove (see illustrations). Next, refit
the upper side rail in the same manner.
10After the three oil ring components have
been installed, check to make sure that both
Engine removal and overhaul procedures 2B•15
2B
22.3 When checking piston ring end gap,
the ring must be square in the cylinder
bore (this is done by pushing the ring down
with the top of a piston as shown)22.4 With the ring square in the cylinder,
measure the end gap with a feeler gauge22.5 If the end gap is too small, clamp a
file in a vice and file the ring ends (from the
outside in only) to enlarge the gap slightly
22.9a Refit the spacer/expander in the oil
control ring groove22.9b DO NOT use a piston ring refitting
tool when refitting the oil ring side rails
3261 Jaguar XJ6

the upper and lower side rails can be turned
smoothly in the ring groove.
11The number two (middle) ring is installed
next. It’s usually stamped with a mark which
must face up, toward the top of the piston.
Note:Always follow the instructions on the
ring package or box - different manufacturers
may require different approaches. Do not mix
up the top and middle rings, as they have
different cross sections.
12Use a piston ring refitting tool and make
sure the ring’s identification mark is facing the
top of the piston, then slip the ring into the
middle groove on the piston (see illustration).
Don’t expand the ring any more than
necessary to slide it over the piston.
13Refit the number one (top) ring in the
same manner. Make sure the mark is facing
up. Be careful not to confuse the number one
and number two rings.
14Repeat the procedure for the remaining
pistons and rings.
23 Crankshaft- refitting and
main bearing oil clearance
check
3
1Crankshaft refitting is the first major step in
engine reassembly. It’s assumed at this point
that the engine block and crankshaft have
been cleaned, inspected and repaired or
reconditioned.
2Position the engine with the bottom facing
up.
3Remove the main bearing cap bolts and lift
out the caps. Lay the caps out in the proper
order.
4If they’re still in place, remove the old
bearing inserts from the engine block and the
main bearing caps. Wipe the main bearing
surfaces of the engine block and caps with a
clean, lint free cloth. They must be kept
spotlessly clean!
Main bearing
oil clearance check
5Clean the back sides of the new main
bearing inserts and lay the bearing half with
the oil groove in each main bearing saddle inthe engine block. Lay the other bearing half
from each bearing set in the corresponding
main bearing cap. Make sure the tab on each
bearing insert fits into the recess in the engine
block or cap. Also, the oil holes in the block
must line up with the oil holes in the bearing
insert.
Caution: Do not hammer the bearings into
place and don’t nick or gouge the bearing
faces. No lubrication should be used at this
time.
6The thrust bearings (washers) must be
installed in the number four main bearing cap
and saddle.
7Clean the faces of the bearings in the
engine block and the crankshaft main bearing
journals with a clean, lint free cloth. Check or
clean the oil holes in the crankshaft, as any
dirt here can go only one way - straight
through the new bearings.
8Once you’re certain the crankshaft is clean,
carefully lay it in position in the main bearings.
9Before the crankshaft can be permanently
installed, the main bearing oil clearance must
be checked.
10Trim several pieces of the appropriate size
Plastigauge (they must be slightly shorter than
the width of the main bearings) and place one
piece on each crankshaft main bearing
journal, parallel with the journal axis (see
illustration).
11Clean the faces of the bearings in the
caps and refit the caps in their respective
positions (don’t mix them up) with the arrows
pointing toward the front of the engine. Don’t
disturb the Plastigauge. Apply a light coat of
oil to the bolt threads and the undersides of
the bolt heads, then refit them. Note:Use the
old bolts for this step (save the new bolts for
final refitting).
12Tighten the main bearing cap bolts, in
three steps, to the torque listed in this
Chapter’s Specifications. Don’t rotate the
crankshaft at any time during this operation!
13Remove the bolts and carefully lift off the
main bearing caps or cap assembly. Keep
them in order. Don’t disturb the Plastigauge or
rotate the crankshaft. If any of the main
bearing caps are difficult to remove, tap them
gently from side-to-side with a soft-face
hammer to loosen them.14Compare the width of the crushed
Plastigauge on each journal to the scale printed
on the Plastigauge envelope to obtain the main
bearing oil clearance (see illustration). Check
the Specifications to make sure it’s correct.
15If the clearance is not as specified, the
bearing inserts may be the wrong size (which
means different ones will be required - see
Section 20). Before deciding that different
inserts are needed, make sure that no dirt or
oil was between the bearing inserts and the
caps or engine block when the clearance was
measured. If the Plastigauge is noticeably
wider at one end than the other, the journal
may be tapered (see Section 19).
16Carefully scrape all traces of the
Plastigauge material off the main bearing
journals and/or the bearing faces. Don’t nick
or scratch the bearing faces.
Final crankshaft refitting
17Carefully lift the crankshaft out of the
engine. Clean the bearing faces in the engine
block, then apply a thin, uniform layer of clean
moly-base grease or engine assembly lube to
each of the bearing surfaces. Coat the thrust
washers as well.
18Lubricate the crankshaft surfaces that
contact the oil seals with moly-base grease,
engine assembly lube or clean engine oil.
19Make sure the crankshaft journals are
clean, then lay the crankshaft back in place in
the engine block. Clean the faces of the
bearings in the main bearing caps, then apply
lubricant to them. Refit the main bearing caps
in their respective positions with the arrows
pointing toward the front of the engine. Note:
Be sure to refit the thrust washers (lubricated)
with the number 4 main journal.The upper
(block side) thrust washers can be rotated into
position around the crankshaft with the
crankshaft installed in the engine block, with
the thrust washer grooves facing OUT. The
lower thrust washers should be placed on the
main bearing caps with their grooves OUT.
20For the final assembly, use only new
bolts, for both the main bearings and the
2B•16 Engine removal and overhaul procedures
23.10 Lay the Plastigauge strips on the
main bearing journals, parallel to the
crankshaft centreline
23.14 Compare the width of the crushed
Plastigauge to the scale on the envelope to
determine the main bearing oil clearance
(always take the measurement at the
widest point of the Plastigauge). Be sure to
use the correct scale - imperial and metric
scales are included
3261 Jaguar XJ6
22.12 Refit the compression rings with a
ring expander - the mark must face up

connecting rods. Apply a light coat of oil to
the bolt threads and the under sides of the
bolt heads, then refit them. Tighten all main
bearing cap bolts to the torque listed in this
Chapter’s Specifications, starting in the centre
and working out to the ends.
21Rotate the crankshaft a number of times
by hand to check for any obvious binding.
22Check the crankshaft endplay with a
feeler gauge or a dial indicator as described in
Section 14. The endplay should be correct if
the crankshaft thrust faces aren’t worn or
damaged and new thrust washers have been
installed. Note:If the end-play is too great,
even with the new thrust bearings, oversized
thrust bearings are available. There are two
sizes, 0.005-inch and 0.010-inch oversize.
23Refit a new rear main oil seal, then bolt the
retainer to the engine block (see Section 24).
24 Rear main oil seal refitting
2
1The crankshaft must be installed first and
the main bearing caps bolted in place, then
the new seal should be installed in the retainer
and the retainer bolted to the engine block.
2Check the seal contact surface on the
crankshaft very carefully for scratches and
nicks that could damage the new seal lip and
cause oil leaks. If the crankshaft is damaged,
the only alternative is a new or different
crankshaft.
3Refer to Part A of this Chapter for refitting
of the new rear seal, using the plastic
alignment tool supplied with the engine
overhaul gasket set.
25 Pistons/connecting rods-
refitting and big-end bearing
oil clearance check
3
1Before refitting the piston/connecting rod
assemblies, the cylinder walls must be
perfectly clean, the top edge of each cylinder
must be chamfered, and the crankshaft must
be in place.
2Remove the cap from the end of the
number one connecting rod (refer to the
marks made during removal). Remove the
original bearing inserts and wipe the bearing
surfaces of the connecting rod and cap with a
clean, lint-free cloth. They must be kept
spotlessly clean.
Big-end bearing
oil clearance check
3Clean the back side of the new upper
bearing insert, then lay it in place in the
connecting rod. Make sure the tab on the
bearing fits into the recess in the rod so the oil
holes line up. Don’t hammer the bearing insert
into place and be very careful not to nick or
gouge the bearing face. Don’t lubricate the
bearing at this time.4Clean the back side of the other bearing
insert and refit it in the rod cap. Again, make
sure the tab on the bearing fits into the recess
in the cap, and don’t apply any lubricant. It’s
critically important that the mating surfaces of
the bearing and connecting rod are perfectly
clean and oil free when they’re assembled.
5Position the piston ring gaps at staggered
intervals around the piston (see illustration).
6Slip a section of plastic or rubber hose over
each connecting rod cap bolt.
7Lubricate the piston and rings with clean
engine oil and attach a piston ring compressor
to the piston. Leave the skirt protruding about
1/4-inch to guide the piston into the cylinder.
The rings must be compressed until they’re
flush with the piston.
8Rotate the crankshaft until the number one
connecting rod journal is at BDC (bottom
dead centre) and apply a coat of engine oil to
the cylinder wall.
9With the word FRONT (or the arrow) on top
of the piston facing the front of the engine
(see illustration), gently insert the piston/
connecting rod assembly into the number one
cylinder bore and rest the bottom edge of the
ring compressor on the engine block.
10Tap the top edge of the ring compressor
to make sure it’s contacting the engine block
around its entire circumference.11Gently tap on the top of the piston with
the end of a wooden hammer handle (see
illustration) while guiding the end of the
connecting rod into place on the crankshaft
journal. The piston rings may try to pop out of
the ring compressor just before entering the
cylinder bore, so keep some downward
pressure on the ring compressor. Work
slowly, and if any resistance is felt as the
piston enters the cylinder, stop immediately.
Find out what’s hanging up and fix it before
proceeding.
Caution: Do not, for any reason, force the
piston into the cylinder - you might break a
ring and/or the piston.
12Once the piston/connecting rod assembly
is installed, the big-end bearing oil clearance
must be checked before the rod cap is
permanently bolted in place.
13Cut a piece of the appropriate size
Plastigauge slightly shorter than the width of
the big-end bearing and lay it in place on the
number one connecting rod journal, parallel
with the journal axis (see illustration).
14Clean the connecting rod cap bearing
face, remove the protective hoses from the
connecting rod bolts and refit the rod cap.
Make sure the mating mark on the cap is on
the same side as the mark on the connecting
rod. Check the cap to make sure the front
mark is facing the timing chain of the engine.
15Apply a light coat of oil to the under sides
of the nuts, then refit and tighten them to the
torque listed in this Chapter’s Specifications,
Engine removal and overhaul procedures 2B•17
2B
25.13 Lay the Plastigauge strips on each
big-end bearing journal, parallel to the
crankshaft centreline
3261 Jaguar XJ6
25.5 Stagger the ring end gaps around the
piston as shown25.9 Pistons must be installed with the
arrow (right arrow) or FRONT facing the
front of the engine - left arrow indicates
piston size letter
25.11 The piston can be driven (gently)
into the cylinder bore with the end of a
wooden or plastic hammer handle
A Oil ring rail gaps
B Second compression ring gap
C Oil ring spacer gap
D Top compression ring gap

working up to it in three steps. Note:Use the
old bolts for this step (save the new bolts for
final refitting).Use a thin-wall socket to avoid
erroneous torque readings that can result if
the socket is wedged between the rod cap
and nut. If the socket tends to wedge itself
between the nut and the cap, lift up on it
slightly until it no longer contacts the cap. Do
not rotate the crankshaft at any time during
this operation.
16Remove the nuts and detach the rod cap,
being careful not to disturb the Plastigauge.
17Compare the width of the crushed
Plastigauge to the scale printed on the
envelope to obtain the oil clearance (see
illustration). Compare it to this Chapter’s
Specifications to make sure the clearance is
correct.
18If the clearance is not as specified, the
bearing inserts may be the wrong size (which
means different ones will be required). Before
deciding that different inserts are needed,
make sure that no dirt or oil was between the
bearing inserts and the connecting rod or cap
when the clearance was measured. Also,
recheck the journal diameter. If the Plastigauge
was wider at one end than the other, the journal
may be tapered (refer to Section 19).
Final connecting rod refitting
19Carefully scrape all traces of the
Plastigauge material off the rod journal and/or
bearing face. Be very careful not to scratchthe bearing, use your fingernail or the edge of
a credit card to remove the Plastigauge.
20Make sure the bearing faces are perfectly
clean, then apply a uniform layer of clean
moly-base grease or engine assembly lube to
both of them. You’ll have to push the piston
higher into the cylinder to expose the face of
the bearing insert in the connecting rod, be
sure to slip the protective hoses over the
connecting rod bolts first.
21At this time, remove the original
connecting rod bolts/nuts and replace them
with new bolts/nuts. They are of a design
which requires they be used only once. The
old ones are OK for Plastigauge checking, but
for final assembly use only new connecting
rod bolts/nuts. Refit the rod cap and tighten
the nuts to the torque listed in this Chapter’s
Specifications. Again, work up to the torque in
three steps.
22Repeat the entire procedure for the
remaining pistons/connecting rod assemblies.
23The important points to remember are:
a) Keep the back sides of the bearing inserts
and the insides of the connecting rods and
caps perfectly clean during assembly..
b) Make sure you have the correct piston/
connecting rod assembly for each
cylinder.
c) The dimple on the piston must face the
front of the engine.
d) Lubricate the cylinder walls with clean oil.
e) Lubricate the bearing faces when refitting
the rod caps after the oil clearance has
been checked.
24After all the piston/connecting rod
assemblies have been properly installed,
rotate the crankshaft a number of times by
hand to check for any obvious binding.
25As a final step, the connecting rod
endplay must be checked. Refer to Section 13
for this procedure.
26Compare the measured endplay to this
Chapter’s Specifications to make sure it’s
correct. If it was correct before dismantling
and the original crankshaft and connecting
rods were reinstalled, it should still be right.
However, if new connecting rods or a new
crankshaft were installed, the endplay may beinadequate. If so, the connecting rods will
have to be removed and taken to an
automotive machine workshop for resizing.
26 Initial start-up
and running-in after overhaul
1
Warning: Have a suitable fire
extinguisher handy when starting
the engine for the first time.
1Once the engine has been installed in the
vehicle, double-check the engine oil and
coolant levels.
2With the spark plugs out of the engine and
the ignition system and fuel pump disabled,
crank the engine until oil pressure registers on
the gauge or the light goes out.
3Refit the spark plugs, hook up the plug
leads and restore the ignition system and fuel
pump functions.
4Start the engine. It may take a few
moments for the fuel system to build up
pressure, but the engine should start without
a great deal of effort.
5After the engine starts, it should be allowed
to warm up to normal operating temperature.
While the engine is warming up, make a
thorough check for fuel, oil and coolant leaks.
6Shut the engine off and recheck the engine
oil and coolant levels.
7Drive the vehicle to an area with no traffic,
accelerate from 30 to 50 mph, then allow the
vehicle to slow to 30 mph with the throttle
closed. Repeat the procedure 10 or 12 times.
This will load the piston rings and cause them
to seat properly against the cylinder walls.
Check again for oil and coolant leaks.
8Drive the vehicle gently for the first
500 miles (no sustained high speeds) and
keep a constant check on the oil level. It is not
unusual for an engine to use oil during the
running-in period.
9At approximately 500 to 600 miles, change
the oil and filter.
10For the next few hundred miles, drive the
vehicle normally. Do not pamper it or abuse it.
11After 2000 miles, change the oil and filter
again and consider the engine run-in.
2B•18 Engine removal and overhaul procedures
25.17 Measure the width of the crushed
Plastigauge to determine the big-end
bearing oil clearance
3261 Jaguar XJ6

3261 Jaguar XJ6
3
Chapter 3
Cooling, heating and air conditioning systems
General
Radiator cap pressure rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13.5 to 117.5 psi
Thermostat rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180 to 207° F
Torque wrench settingsNm lbf ft
Coolant pipe to block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 to 28 16 to 21
Fan assembly-to-drive hub nuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 to 28 16 to 21
Fan clutch-to-fan blade bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 to 28 16 to 21
Thermostat cover bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 to 28 16 to 21
Thermostat housing-to-block bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 to 28 16 to 21
Water pump bolts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 to 28 16 to 21 Air conditioning and heating system - check and maintenance . . . . 13
Air conditioning compressor - removal and refitting . . . . . . . . . . . . . 15
Air conditioning condenser - removal and refitting . . . . . . . . . . . . . . 16
Air conditioning evaporator and expansion valve - removal
and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Air conditioning receiver/drier - removal and refitting . . . . . . . . . . . . 14
Antifreeze/coolant - general information . . . . . . . . . . . . . . . . . . . . . . 2
Coolant level check . . . . . . . . . . . . . . . . . . . . . . . . . . . . See Chapter 1
Coolant temperature sender unit - check and renewal . . . . . . . . . . . .9
Cooling system check . . . . . . . . . . . . . . . . . . . . . . . . . . See Chapter 1
Cooling system draining, flushing and refilling . . . . . . . . See Chapter 1
Drivebelt check, adjustment and renewal . . . . . . . . . . . See Chapter 1
Engine cooling fans - check and renewal . . . . . . . . . . . . . . . . . . . . . 4Engine oil cooler - renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
General information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Heater and air conditioning blower motors -circuit check
and component renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Heater and air conditioning control assembly -
check, removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Heater core - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Radiator, expansion tank and coolant reservoir -
removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Thermostat - check and renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Underbonnet hose check and renewal . . . . . . . . . . . . . . See Chapter 1
Water pump - check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Water pump and pipes - renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3•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
Engine cooling system
All vehicles covered by this manual employ a
pressurised engine cooling system with
thermostatically-controlled coolant circulation.
An impeller type water pump mounted on the
front of the block pumps coolant through the
engine. The coolant flows around each cylinder
and toward the rear of the engine. Cast-in
coolant passages direct coolant around the
intake and exhaust ports, near the spark plug
areas and in proximity to the exhaust valve
guides.A wax-pellet type thermostat is located in
the thermostat housing at the front of the
engine. During warm up, the closed
thermostat prevents coolant from circulating
through the radiator. When the engine
reaches normal operating temperature, the
thermostat opens and allows hot coolant to
travel through the radiator, where it is cooled
before returning to the engine.
The cooling system is sealed by a pressure-
type radiator cap. This raises the boiling point
of the coolant, and the higher boiling point of
the coolant increases the cooling efficiency
of the radiator. If the system pressure exceeds
the cap pressure-relief value, the excess
pressure in the system forces the spring-
loaded valve inside the cap off its seat and
allows the coolant to escape through the
overflow tube into a coolant reservoir. Whenthe system cools, the excess coolant is
automatically drawn from the reservoir back
into the radiator. This type of cooling system is
known as a closed design because coolant
that escapes past the pressure cap is saved
and reused.
The Jaguar cooling system on 1988 and
1989 models has both a manifold tank and a
coolant recovery tank. The manifold tank is the
highest point in the cooling system and is the
location of the “radiator” cap (the cap is not on
the radiator). The recovery tank down in the
passenger’s footwell collects heated coolant
as described above. Models from 1990 to
1994 do not have a coolant recovery tank, but
have an enlarged manifold tank. In all models,
the recovery tank has a sensor in it to detect a
low coolant level, and the instrument panel has
a warning light to that effect.

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)