1997 JAGUAR XJ6 check engine

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.

Heating system
The heating system consists of two blower
fans, one under the dash on the right and one
on the left, and a heater core located within
the heater/air conditioning assembly which is
under the dash and behind the console.
Hoses connect the heater core to the engine
cooling system. Heater function is controlled
by the heater/air conditioning control head on
the dashboard. Hot engine coolant is
circulated through the heater core. When the
heater mode is activated, a flap door opens to
expose the heater box to the passenger
compartment. A fan switch on the control
head activates the blower motor, which forces
air through the core, heating the air.
Air conditioning system
The air conditioning system consists of a
condenser mounted in front of the radiator, an
evaporator mounted in the heat/air
conditioning assembly behind the console and
under the centre of the dash, a compressor
mounted on the engine, a filter-drier which
contains a high pressure relief valve and the
plumbing connecting all of the above.
A blower fan forces the warmer air of the
passenger compartment through the
evaporator core (sort of a radiator-in-reverse),
transferring the heat from the air to the
refrigerant. The liquid refrigerant boils off into
low pressure vapour, taking the heat with it
when it leaves the evaporator. The
compressor keeps refrigerant circulating
through the system, pumping the warmed
coolant through the condenser where it is
cooled and then circulated back to the
evaporator.
2 Antifreeze/coolant-
general information
Warning: Do not allow antifreeze
to come in contact with your
skin or painted surfaces of the
vehicle. Rinse off spills immediately withplenty of water. Antifreeze is highly toxic if
ingested. Never leave antifreeze lying
around in an open container or in puddles
on the floor; children and pets are
attracted by it’s sweet smell and may drink
it. Check with local authorities about
disposing of used antifreeze. Many
communities have collection centres which
will see that antifreeze is disposed of
safely. Never dump used antifreeze on the
ground or into drains.
Note:Non-toxic antifreeze is now
manufactured and available at local car
accessory outlets, but even these types
should be disposed of properly.
The cooling system should be filled with a
water/ethylene-glycol based antifreeze
solution, which will prevent freezing down to
at least -20° F, or lower if local climate
requires it. It also provides protection against
corrosion and increases the coolant boiling
point.
The cooling system should be drained,
flushed and refilled every 24,000 miles or
every two years (see Chapter 1). The use of
antifreeze solutions for periods of longer than
two years is likely to cause damage and
encourage the formation of rust and scale in
the system. If your tap water is “hard”, i.e.
contains a lot of dissolved minerals, use
distilled water with the antifreeze.
Before adding antifreeze to the system,
check all hose connections, because
antifreeze tends to leak through very minute
openings. Engines do not normally consume
coolant. Therefore, if the level goes down, find
the cause and correct it.
The exact mixture of antifreeze-to-water
you should use depends on the relative
weather conditions. The mixture should
contain at least 50-percent antifreeze, but
should never contain more than 70-percent
antifreeze. Consult the mixture ratio chart on
the antifreeze container before adding
coolant. Hydrometers are available at most
car accessory outlets to test the ratio
of antifreeze to water (see illustration). Use
antifreeze which meets the vehicle
manufacturer’s specifications.
3 Thermostat-
check and renewal
2
Warning: Do not attempt to
remove the radiator cap, coolant
or thermostat until the engine
has cooled completely.
Check
1Before assuming the thermostat is
responsible for a cooling system problem,
check the coolant level (Chapter 1), drivebelt
tension (Chapter 1) and temperature gauge (or
light) operation.
2If the engine takes a long time to warm up
(as indicated by the temperature gauge or
heater operation), the thermostat is probably
stuck open. Renew the thermostat.
3If the engine runs hot, use your hand to
check the temperature of the lower radiator
hose.
Warning: Do this check with the
engine off. Do not get your
hands near the fan blades. If the
hose is not hot, but the engine
is, the thermostat is probably stuck in the
closed position, preventing the coolant
inside the engine from travelling through
the radiator. Renew the thermostat. Do not
drive the vehicle without a thermostat. The
computer may stay in open loop and
emissions and fuel economy will suffer.
4If the lower radiator hose is hot, it means
that the coolant is flowing and the thermostat
is open. Consult the Troubleshootingsection
at the front of this manual for further diagnosis.
Renewal
5Disconnect 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.
6Drain the coolant from the radiator (see
Chapter 1).
7Remove the bolts from the thermostat
cover (see illustration). If the cover doesn’t
3•2 Cooling, heating and air conditioning systems
3261 Jaguar XJ6 2.4 An inexpensive hydrometer can be
used to test the condition of your coolant
3.7 Remove the two bolts (small arrows)
holding the thermostat cover to the
housing (large arrow)

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)

13Refitting is the reverse of removal. Tighten
the fan clutch-to-fan blade bolts and the fan
assembly-to-drive hub nut to the torque listed
in this Chapter’s Specifications.
Electric fans
Check
Warning: Keep your hands or
clothing away from the fan
blades at all times.
14On 1988 through 1992 models, a single
electric fan is mounted in front of the radiator,
controlled by a thermostatic switch. Access to
the fan is with the grille removed. The 1993
and 1994 models have a fan shroud assembly
that includes two electric fans, and a “twin”
thermostatic switch, with the assembly
mounted on the engine side of the radiator.
15If the electric fan does not come on at any
time, bypass the thermostatic switch by
disconnecting the electrical connector at the
switch and connecting the two pins with a
jumper wire (see illustration). If the fan now
operates, renew the thermostatic switch. If the
fan doesn’t operate, the problem is either the
fan relay or the fan motor. On 1993 and 1994
models with twin electric fans, jumpering one
set of connections in the plug from the switch
should make both fans operate at slow speed
(fans in series) and jumpering the other two
should run both fans at higher speed (fans in
parallel). In normal operation, the fans operate
at the higher-speed only when the air
conditioning is on, or when coolant
temperature exceeds 212° F. When the
coolant cools down to below 200° F, the fans
revert to the normal speed.
16To renew a defective thermostatic switch,
allow the vehicle to cool off and drain the
coolant (see Chapter 1). Remove the switch
from the radiator and refit the new switch.
Connect the electrical connector and test
again for proper fan operation.17To test an inoperative fan motor (one that
doesn’t come on when the engine gets hot or
when the air conditioner is on), first check the
fuses and/or fusible links (see Chapter 12).
Then disconnect the electrical connector at
the motor (refer to Chapter 11 for removal of
the grille for access on front-mounted-fan
models) and use fused jumper wires to
connect the fan directly to the battery and to
chassis ground (see illustration). If the fan
still does not work, renew the fan motor.
Warning: Do not allow the test
clips to contact each other or
any metallic part of the vehicle.
18If the motor tested OK in the previous test
but is still inoperative, then the fault lies in the
relay, fuse, or wiring. The fan relay can be
tested for continuity (see Chapter 12).
Renewal
19Disconnect the negative battery 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.20Access the 1988 through 1992 single
electric fan with the grille removed (see
Chapter 11 for grille removal). Disconnect the
electrical connector and remove the bolts
holding the fan assembly to the body (see
illustration).
21On 1993 and 1994 models, remove the
two bolts holding the fan shroud to the top of
the radiator and lift the shroud/fans assembly
from the vehicle.
22If the fan on 1988 to 1992 models must be
renewed, renew the fan, motor and shroud as
a unit. The fan is separate from the shroud on
later models.
23Refitting is the reverse of removal. If the
thermostatic switch was renewed, refill the
cooling system.5 Radiator, expansion tank
and coolant reservoir-
removal and refitting
3
Warning: Do not start this
procedure until the engine is
completely cool.
Radiator
Removal
1Disconnect the negative battery 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.
2Drain the coolant into a container (see
Chapter 1).
3Remove both the upper and lower radiator
hoses, and the small expansion tank hose from
the top left of the radiator (see illustration).
4Remove the cooling fan and shroud (see
Section 4).
3•4 Cooling, heating and air conditioning systems
4.20 Disconnect the fan’s electrical
connector (large arrow) and remove the
bolts (small arrows) on single-fan models -
grille is removed here
3261 Jaguar XJ6 4.15 Disconnect the electrical connector (A) from the
thermostatic switch (B) in the radiator and bypass it with a
jumper wire (C) - the fan should operate now with the ignition on
4.17 Disconnect the fan wiring connector and connect jumper
wires from there directly to the positive and negative terminals of
the battery - the purple wire’s terminal should receive the battery
power and the black wire’s terminal should be earthed

5If equipped with an automatic transmission,
disconnect the cooler lines from the radiator
(see illustrations). Disconnect the cooling fan
switch connector (see illustration 4.15).
Place a drip pan to catch the fluid and cap the
fittings. Note:The transmission oil cooler lines
enter the radiator on the left, while the power
steering cooler lines attach on the right side of
the radiator. On 1993 and 1994 models, the
cooler fittings require a spring-lock coupling
tool, normally used on fuel lines or air
conditioning lines.
6Remove the four bolts from the radiator
cowl panel and take off the panel (see
illustration).
7Lift out the radiator. Be aware of dripping
fluids and the sharp fins. Take care not to
damage the radiator fins by contact with other
parts.
8With the radiator removed, it can be
inspected for leaks, damage and internal
blockage. If repairs are necessary, have a
radiator specialist or dealer service department
perform the work, as special techniques are
required. Check the rubber mounting pads on
the bottom of the radiator (see illustration). If
they’re cracked or damaged, get new ones
before refitting the radiator.
9Bugs and dirt can be cleaned from the
radiator with compressed air and a soft brush.
Don’t bend the cooling fins as this is done.
Warning: Wear eye protection.
Refitting
10Refitting is the reverse of the removal
procedure. Be sure the rubber mounts are in
place on the bottom of the radiator.
11After refitting, fill the cooling system with
the proper mixture of antifreeze and water.
Refer to Chapter 1 if necessary.
12Start the engine and check for leaks.
Allow the engine to reach normal operating
temperature, indicated by both radiator hoses
becoming hot. Recheck the coolant level and
add more if required.
13On automatic transmission equipped
models, check and add fluid as needed and
check the power steering fluid level as well.
Expansion tank and coolant
reservoir, removal and refitting
14The expansion tank is located at the top
of the left-hand side inner wing. With the
cooling system drained below the level of the
expansion tank, remove the hoses, the
coolant level probe and the two screws
mounting it to the body (see illustration).
15Wash out and inspect the reservoir for
cracks and chafing. Renew it if damaged.16If the low-coolant level light has been
showing on the instrument panel, even when
the coolant level is correct, disconnect the
sensor’s connector and test it with an
ohmmeter (see illustration). The sensor
should be renewed if the resistance at the
connections is over 150 ohms.
Caution: Using a long-necked funnel to
add coolant can damage the sensor, which
is just below the expansion tank filler neck.
Cooling, heating and air conditioning systems 3•5
3
5.5a At the left side of the radiator,
disconnect the automatic transmission
cooler lines (small arrows) and the lower
radiator hose (larger arrow)5.5b Disconnect the power steering cooler
lines (small arrows) at the right side of the
radiator, and the upper radiator hose
(large arrow)
3261 Jaguar XJ6 5.3 Remove the clamp and the hose going
to the expansion tank
5.6 Remove the bolts (arrowed) and take
off the radiator cowl panel
5.14 The expansion tank is located on the
left inner wing
A Hose to recovery tank (where applicable)
B Hose to radiator
C Hose to thermostat housing
D Hose to water pump housing
E Mounting screws
F Low-coolant-level sensor
5.8 There are rubber mounts (arrowed)
for the radiator and the condenser -
they must be in place when these
components are reinstalled
5.16 The low-coolant-level sensor can be
tested with an ohmmeter - resistance
should be below 150 ohms - gently use a
pair of long-neck pliers to move the sensor
up and down in the tank to get a reading