1998 JAGUAR X308 Radiator

combin
ed with the outlet duct and consequently, there is no separate housin
g assembly fitted above the water pump, as used
on the normally aspirated engine. The illustration shows the outlet duct viewed from the engine.
Thermostat Housing

The plastic housing for the thermostat is fitted between th e two cylinder banks immediately above the coolant pump.
Controlling the coolant flow through the radiator, the thermostat starts to open at 80 ° to 84 °C and is fully open at 96 °C.
A duct in the cylinder block connects the thermostat housing outlet to the coolant pump inlet. The joint between the
thermostat housing and the cylinder block is via an in-groove seal.
An air bleed outlet vents an y air in the system into the expansion reservoir, durin
g normal operation. A removable cap (usin g
a hex key) allows air to vent from the system when filling from empty.
On supercharged engines, the thermostat housin g is combined with the coolant outlet duct.
Radiator

The cooling
pack incorporates the radiator a
ssembly with integral transmission oil cool er (located in the radiator outlet tank),
an air conditioning condenser, and the cooling fans and cowl assembly.
The cooling pack on supercharged vehicles is the same as described above, but with the addition of a charge air cooler
coolant radiator located in front of the condenser.
Radiator Mounti
ng/Retention
T
he radiator is mounted on four rubber mounts, one on each
end of the upper and lower horizontal face. The two lower
mountings are supported on two isolated brackets mounted on the body; the lower cradle assembly has subsequently been
deleted.
A closing panel made from polypropylene, which retains the radiat or assembly, fits over the top of the radiator and is bolted
to the vehicle top panel.
Coolant Hoses - Engine

s
ystem (pressure).
Outputs from the ECM control the radiator fans control module, located behind the left hand side of the bumper, to operate
the fans in the series mode (slow), paralle l mode (Fast) or Off modes. Hysteresis in the temperature and pressure switching
values prevents 'hun ting' between modes.
Under hot operating conditions, the fans may continue to operat e for some time after the engine has been switched off, but
will stop automatically when the coolant te mperature has been sufficiently reduced.
Engine Coolant Temperature Sensor (ECT) and ECM

The engine coolant temperature (ECT) sensor is located in the coolant outlet pipe and reacts to engine coolant temperature
changes, providing an input to the Engine Control Module (ECM). The sensor has a negative te mperature coefficient so that
the sensor resistance decrea ses as temperature rises.
Temperature / Resistance Relationship Graph

T
emperature / Resistance
Relationship Table

Engine Cooling - Cooling System Draining,
Filling and Bleeding4.0L NA V8
- AJ27/3.2L NA V8 - AJ26
Gen
eral Procedures
Drain
Refill
1. O
pen the engine compartment and fit paintwork protection
sheets.
2. Ensure that the cooling system is cool and very carefully,
remove the pressure cap from the header tank.
3. Raise the vehicle.

4. Drain th
e coolant.
Pla

ce a coolant drain tray on
the floor, below the radiator
drain plug.
1. Remove the radiator drain plug. and allow the coolant to drain.

5. Fit a new seal to the
drain plug.
1. Remove the seal from the drain plug. and clean the plug face.
Fit a new seal.

6. Re
fit the radiator drain plug.
Cl

ean any coolant from the
underside of the vehicle.
Remove the drain tray.
7. Lower the vehicle.
1. Refill the cooling system with a 50% solution of water and
Jaguar Antifreeze / Corrosion Inhibitor ESD-M97B49-A.
1. Fill the cooling system at the header tank until the level stabilises at the top of the breather neck.

Engine Cooling - Cooling System Draining, Filling and Bleeding4.0L SC V8 -
AJ26

Gen
eral Procedures
Drain
Refill
1. O
pen the engine compartment and fit paintwork protection
sheets.
2. Ensure that the cooling system is cool and very carefully,
remove the pressure cap from the header tank.
3. Raise the vehicle.

4. Drain th
e coolant.
Pla

ce a coolant drain tray on
the floor, below the radiator
drain plug.
1. Remove the radiator drain plug. and allow the coolant to drain.

5. Fit a new seal to the
drain plug.
1. Remove the seal from the drain plug. and clean the plug face.
Fit a new seal.

6. Re
fit the radiator drain plug.
Cl

ean any coolant from the
underside of the vehicle.
Remove the drain tray.
7. Lower the vehicle.
1. Refill the cooling system with a 50% solution of water and
Jaguar Antifreeze / Corrosion Inhibitor ESD-M97B49-A.
1. Remove the threaded plug and Dowty washer from the charge air cooler fill point.

• NOTE
: To ensure that
air is not drawn into the system during the following operations:
Do
not remove the cap from the header tank whilst the
charge air cooling system is open to atmosphere.
Do
not switch on the ignition when th
e charge air cooling system is open to atmosphere because the electrical
cooling pump may draw air into the system.
2. Fi
ll the cooling system at the header tank until the
level stabilises near the to p of the charge air cooler
fill point. This will take some time, as air is being
purged from the system.
Ensure that the head
er tank is full.
2. Fit the pressure cap to the header tank.

3. Pour coolant careful l
y into the charge air cooler fill point until
the system is full.
Fi t t
he plug and washer to the fill point.
4. Remove the pressure cap from the header tank.
5. Switch on the ignition and switch off the climate control
system.
Le ave
the ignition switched on (do not start the engine)
for at least 2 minutes to allow the air charge cooler
electric water pump to oper ate and to purge any air from
the air charge cooler radiator to the header tank. (This
operation will be repeated later)
6. Switch off the ignition for at least 1 minute.
7. Leave the ignition switched on (do not start the engine) for at
least 2 minutes to allow the air charge cooler electric water
pump to operate and to purg e any air from the air charge
cooler radiator to the header tank.
8. Top up the cooling system.
1. Top up the header tank and fit the pressure cap.
2. Remove the plug from the air charge cooler fill point. Pour coolant carefully into the air charge cooler fill
point until the system is full.
3. Fit the plug and washer to the fill point.

Engine Cooling - Cooling System Draining and Vacuum Filling
Gene
ral Procedures
WARNING: To avoid having scalding ho t coolant or steam blowing out of the cooling system, use extreme care when
removing the coolant pressure cap from a hot cooling system. Wait until the engine has cooled, then wrap a thick cloth
around the coolant pressure cap and turn it slowly until the pressure begins to release. Step ba ck while the pressure is
released from the system. When certain al l the pressure has been released (still with a cloth) turn and remove the coolant
pressure cap from the coolant expansion tank. Failure to fo llow these instructions may result in personal injury.
• CAUTIONS:
The engine cooling syst em must be maintained with the correct concentration and type of anti-freeze solution to
prevent corrosion and frost damage. Failure to follow th is instruction may result in damage to the vehicle.
Engine coolant will damage the paint finished surfaces. If spilt, immediately remove the coolant and clean the area
with water.
• NOTE: Vehicles fitted with supercharged engines shown, V8 NA engines similar.
All vehicles
1. Set
the heater controls to maximum HOT.

2. WARN
ING: Relieve the cooling system pressure by
unscrewing the coolant pressure cap. Failure to follow this
instruction may result in personal injury.
Remove the coolant expans ion tank pressure cap.
3. Raise a
nd support the vehicle.

4. NOTE : Remov
e and discard the
radiator drain plug seal.
Drain the coolant into a suitable container.
Remove the radiato
r drain plug.
5. CAUTION: Do not over tighten the drain plug. Failure to
follow this instruction may result in damage to the vehicle.
• NOTE: Install a new radiator drain plug seal.
Install the coolant drain plug.

All vehicles


21.
N
OTE: Install a new sealing washer.
• NOTE: Clean off any spillages.
Install the supercharger coolant fill plug.
Tighte
n to 45 Nm.
22. Remove the coolant expans ion tank pressure cap.
23. Switch ignition on.
24. CAUTION: Do not allow the supercharger water pump to
run dry. Failure to follow this instruction may result in damage to
the vehicle.
• NOTE: Leave the ignition switched on (do not start the engine)
for at least 2 minutes to allow the air charge cooler electric water
pump to operate and to purge an y air from the air charge cooler
radiator to the header tank.
Allow the supercharger pump to run and top up the system
through the coolant expansion tank.
25 . Swit
ch the ignition off.
26. Install the coolant expansion tank pressure cap.
27. START and RUN the engine.
28. CAUTION: Observe the engine temperature gauge. If
the engine starts to over-heat switch off immediately and allow to
cool. Failure to follow this inst ruction may cause damage to the
vehicle.
Run the engine at between 1500 and 2000 rpm until the cooling
fan operates.
29 .
Swi
tch off the engine.
30. Allow the engine to cool.
31. Check and top-up the coolant if required.