1994 JAGUAR XJ6 cooling

Cooling System (VI 2)
0
4.2.2 COOLING SYSTEM CONFIGURATION
Theconfigurationofthecooling system isshown in Fig. 1. Themaincoolantflows,withthesystem at normaloperating
temperature (i.e. with the engine thermostats open), are indicated
by arrows.
6 rr
1
2
1. Header Tank 3. Water Pump 5. Engine 7. Heater Pump
2. Radiator 4. Thermostat 6. Heater 8. Heater Valve
Fig.
1 Cooling System Layout
Issue 1 August 1994 2 X300 VSM

WARNING: DO NOT REMOVE THE HEADER TANK PRESSURE CAP WHILE THE ENGINE IS HOT. IF THE CAP MUST
BE REMOVED, PROTECT THE HANDS AGAINST ESCAPING STEAM AND SLOWLY TURN THE CAP ANTI- CLOCKWISE UNTIL THE EXCESS PRESSURE CAN ESCAPE. LEAVE THE CAP IN THIS POSITION UNTIL
ALL THE STEAM AND PRESSURE HAS ESCAPED AND THEN REMOVE THE CAP COMPLETELY.
WARNING: WHEN DRAINING THE COOLANT WITH THE ENGINE HOT, PROTECT THE HANDS AGAINST CONTACT
WITH HOT COOLANT.
WARNING
: WHEN WORKING WITHIN THE ENGINE COMPARTMENT, KEEP CLEAR OF THE ENGINE DRIVEN RADI- ATOR COOLING FAN WHEN THE ENGINE IS RUNNING.
4.2.3.2 Working Practices
Whenfilling thesystem with coolant,ensurethatthevehicle isstanding on a level surfaceand thatthecoolant is poured
in slowly so that airlocks are not introduced into the system. Airlocks can seriously affect the operation of the climate
control system and can cause damage to the heater circuit pump.
Hose clips should always be positioned
so that there is proper access for tightening and that the clip does not foul or
interfere with the operation of any components.
4.2.3 SERVICE PROCEDURES
4.2.3.1 Safety Precautions
The anti-freeze specified in Appendix A1 must be used wherever possible. It is designed to afford the maximum cor- rosion protection to all metals found in the engine cooling system, as well as having the frost protection properties
necessary during the winter months. Should it not be available, then anti-freeze conforming to Ford Motor Company
specification
ESBM97B49-A may be used. To provide optimum temperature and corrosion protection, the specified
anti-freeze concentration must always be used. Once coolant has been drained from the system, it must be discarded
and not reused. Anti-freeze is harmful to the environment. Always dispose of used coolant safely and never pour it down a drain connected to the public sewer.
CAUTION: Never fill or topup the system with water only.
CAUTION
: Anti-freeze is harmful to paintwork. Coolant spillages must be wiped up immediately and the affected
area washed to remove all traces of coolant.
CAUTION: To prevent the possibility of damage to the heater circuit
pump, the pump should be electrically isolated if the ignition has to be turned ON while the cooling system is drained.
The drive belt must always be tensioned to the specified value and the tension checked at the correct point on the belt.
This information is given in Sub-section IV in the preliminary pages.
When tightening components, the torque figures given in Sub
-section II in the preliminary pages should always be
used for the fastenings listed.
When fitting a replacement thermostat, ensure that the jiggle-pin is to the top of the thermostat housing.
4.2.3.3 Coolant Change
The coolant must be changed at intervals of four years. The system should be drained from the radiator drain plug,
flushed and filled with fresh coolant. Flushing should be carried out thoroughly to remove all the old coolant from the
engine and heater matrix. (The heatervalve isopen with the ignition OFF). AfterfilIing,checkthecoolant concentration
with a hydrometer. For specified anti-freeze and coolant concentration, see in Appendix Al.
X300 VSM 3 Issue 1 August 1994

€3 Cooling System (V12)
4.2.4 DRAIN AND FILL PROCEDURES
4.2.4.1 Radiator, Drain
. Place a drain tray in position under the radiator drain plug
. Remove the headertank pressure cap. Release thecaptive
Tighten the radiator drain plug.
(Fig.
1).
radiator drain
plug and drain the coolant.
CAUTION: This procedure does not drain the heater cir- cuit.
m: DO NOT REMOVE THE HEADER TANK PRES- SURE CAP WHILE THE ENGINE IS HOT. IF THE
CAP MUST BE REMOVED, PROTECT THE
HANDS AGAINST ESCAPING STEAM AND
SLOWLY TURN THE CAP
ANTI-CLOCKWISE UNTIL THE EXCESS PRESSURE CAN ESCAPE.
LEAVE THE CAP IN THIS POSITION UNTIL ALL
THE STEAM AND PRESSURE HAS ESCAPED
AND THEN REMOVE THE CAP COMPLETELY.
WARNING: WHEN DRAINING THE COOLANT
WITH THE
ENGINE HOT, PROTECT ME HANDS AGAINST
CONTACT WITH HOT COOLANT.
Fig. 1
4.2.4.2 Radiator, Fill
. Add coolant until the level in the header tank is steady at MAX. (Do not fit the header tank cap).
. Switch on the ignition. (The climate control system must be OFF).
. Start the engine and add coolant to the header tank if required to ensure that it does not empty.
. Run the engine until thetemperature gauge reads normal. (The enginespeed may be raised to reduce warm uptime).
. Switch off the ignition and wait for one minute.
Check that the coolant level in the header tank is between MAX and
10 mm above MAX. Add coolant as necessary.
. Fit the header tank cap.
4.2.4.3 Complete System, Fill
. Add coolant until the level in the header tank is steady at MAX. (Do not fit the header tank cap).
= Switch on the ignition. (The climate control system must be OFF).
. Start the engine and add coolant to the header tank if required to ensure that it does not empty.
. Run the engine until the temperature gauge reads normal, (The engine speed may be raised to reduce the warm up
. Turn the climate control system ON. Set the temperature to HI. Manually select a fan speed of approximately 50%.
. Run the engine for four minutes. Ensure that the climate control system outlet air temperature is hot to very hot and
that there is no noise from the heater coolant circulating pump. (The engine speed may be raised to assist with heat- ing).
time).
8 Switch
off the ignition and wait for one minute.
. Check that the coolant level in the header tank is between MAX and 10 mm above MAX. Add coolant as necessary.
. Fit the header tank cap.
4.2.4.4 System, Air Bleeding
After filling the system with coolant, any air present must be purged before effective cooling is possible. Provided the
correct fill procedure has been followed, purging of the system takes place automatically as follows:
The air entrained by the coolant, rises to the top of the radiator and to the highest point on each side of the engine (the
thermostat housings). While the thermostats are closed, the radiator is under reduced pressure due to the pump suc
- tion and air is bled through the jiggle-pins in each thermostat. Purged air is returnedvia the bleed system to the header
tank. When normal operating temperature is reached, the thermostats open and the system operates normally. ~~
Issue 1 August 1994 4 X300 VSM

4.2.5.2 Diagnostic Procedures
1
I Symptom ..
Overheating
herheating at
dle
roo cold ~~~
Possible Cause
Thermostat(s) stuck
closed
Incorrect thermostat rating
Faulty temperature gauge
Faulty temperature transmitter
Radiator core blocked
Radiator grille obstructed
Concentration of anti
-freeze
too high
Drive belt slack
Drive belt broken
Water pump seized
lnsuff icient coolant
Internally collapsed hoses
Incorrect ignition timing
Fuel
/ air mixture too weak
Incorrect valve timing
Cylinder head
gasket(s) leak-
ing
Brakes binding
Electric cooling
fan(s) not op- erating
Thermostat(s) stuck open
Incorrect thermostat rating
Thermostatb) not fitted
Electric cooling
fan(s) operat-
ing continuously
Faulty temperature gauge
Faulty temperature transmitter
Check
Cooling System (V12)
4.2.5 FAULT DIAGNOSIS
4.2.5.1 Introduction
The following diagnostic procedures are provided to assist properly qualified persons to identify and rectify the faults in the system which are most likely to be encountered. Reference is made to the Electrical Diagnostic Manual (EDM), which should be consulted for all electrical faults. When investigating faults relating to temperature, the prevailing
ambient temperature conditions should be taken into account. The climate control system is dealt with in Section 14.
Test thermostat(s)
Check thermostat operating
temperature
Refer to EDM
Refer to EDM
Check for
hotspots in radiator
Check grille for obstruction
Check strength of coolant
Check belt tension
Visual check Slacken drive belt and turn
water pump pulley by hand.
Check belt for damage
Check coolant level
Pressure test system and
check for deformation of hoses
Refer to EDM
Refer to EDM
Check valve timing
Pressure
-test system. (Check
for contamination of coolant in
header tank)
Check brake calipers for stick
- ing pistons and seized brake
pad pins
..
Refer to EDM
Test
thermostat(4
Check thermostat operating
temperature
Remove thermostat housing
and inspect
Refer to EDM
Refer to EDM
Refer to EDM
Remedy
Renew thermostat(s)
Renew thermostat(s1
Renew gauge
Renew transmitter
Flush or renew radiator
Remove obstruction from
grille
Drain and
fill with coolant of
correct concentration
Adjust belt to correct tension
or renew belt
if worn
Renew belt
Renew water pump. Renew
drive belt
if required
Top
-up coolant
Renew hoses as required
Rectify as required
Rectify as required
Correct valve timing
Renew head
gasket(s)
Rectify as required
Rectify as required
Renew
thermostat(s1
Renew thermostatb)
Fit thermostat(s)
Rectify as required
Renew gauge
Renew transmitter
Issue 1 August 1994 X300 VSM 5

rn Cooling System (VI 2)
Diagnostic Procedures (continued)
Symptom
-0ss of cool-
ant
Possible Cause
Loose clips on hoses
Hoses perished
Radiator core leaking
Water pump seal leaking
Thermostat
gasket(s) leaking
Header tank cap defective
Porosity in castings
Corrosion caused by con
- centration of anti-freeze being
too low
Cylinder head
gasket(4 leak- ing
Cracked or damaged internal
engine component
Check
Check clips for correct tight-
ness
Visual check
Pressure
-test system
Pressure
-test system
Pressure
-test system. (Check
for distortion of thermostat
housing(s))
Inspect cap or test cap spring
pressure
Pressure
-test system
Pressure
-test system. Check
strength of coolant
Pressure
-test system. Check
for contamination of coolant
and engine lubrication system
Identify
component(s) affected. (Check for
contamination of engine
lubrication system)
Remedy
Tighten clips as required
Renew hoses as required
Repair or renew radiator
Renew water pump
Renew gasket. Renew
hous-
ing(s) if required
Renew cap Rectify as required
Rectify as required. Drain and
fill with coolant of correct con
-
centration
Renew head
gasket(s)
Rectify as required
Issue 1 August 1994 6 X300 VSM

Fuel, Emission Control & Engine Management (AJ16)
5.1.6 THROTTLE ASSEMBLY (SUPERCHARGED), RENEW
SRO 18.30.17 THROTTLE POTENTIOMETER
SRO 19.70.07 THROTTLE HOUSING GASKET
SRO 19.70.04 THROTTLE HOUSING
J 12-62 2
Fig. 1
Remove
. Disconnect battery.
. Remove the intercooler intake elbow.
. Raise vehicle on a four-post ramp.
. Remove the rear air duct to throttle body connecting hose.
Undo and remove bolts securing EGR supply pipe to manifold.
Remove EGR supply pipe gasket.
Reposition EGR sensor harness multi-plug from mounting bracket.
. Release throttle outer cable abutment from abutment bracket.
. Disconnect throttle inner cable from throttle linkage.
. Disconnect and remove return spring.
. Disconnect speed control actuator vacuum hose.
. Release cooling system pressure by slowly undoing the tank cap.
Tighten cap after pressure release.
. Remove abutment bracket assembly.
Disconnect idle speed actuator harness multi
-plug.
. Disconnect throttle potentiometer harness multi-plug.
. Fit pipe clamps to throttle housing cooling hoses and disconnect hoses from throttle housing.
Remove
the oil filter cartridge and gasket.
Remove speed control speed control bracket to throttle lever clevis pin and pin
circlip.
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Issue 1 August 1994 10 X300 VSM

Climate Control Systems
CL /MATE CONTROL SYSTEM 0 14*2 14.2.1 Description
The climate control system in the 1995 model year saloon has a centre mounted heater / cooler unit with separate
blower assemblies, one LH and one RH. Heating temperature control is effected by means of a coolant flow valve and
circulation pump.
For models fitted with air conditioning, cooling is provide by passing air through the evaporator, which is situated im
- mediately behind the heater / cooler case inlet ducts.
Electric motors with integral potentiometers are used to position
all flaps.
W: There are no vacuum operated components in the system.
14.2.2 Features
o Self diagnostic control system with error codes.
0 Actuator 'self check'.
0 Display element check.
m: These features will be helpful for initial trouble shooting and where Jaguar Diagnostic Equipment (JDE) is not
available.
0 'Soft touch' logic controls. 0
0 Serial link from panel to control module (NCCM).
0 LCD display for temperature, status and fan speed.
0 Variable fan speed, whether in automatic or manual mode.
0 Manual air flow distribution over-rides.
0 Compensated air flow with regard to vehicle speed.
0 Rear footwell outlets.
0 Rear face outlets.
0 Scavenge system closed circuit temperature control.
0 Heated front screen (where fitted).
x300 VSM 3

Climate Control Systems
8. AUTO selection display.
9. EXTERIOR temperature selection button. There are two modes:
a) Press and immediate release; provides timed display of four (4) seconds.
b) Press and hold for two (2) seconds; 'latches' the mode until operator over-ride.
10. A/C push-on / push-off button will either engage or disengage (as indicated by the state lamp) the refrigeration
system compressor. The state lamp is also used as a compressor speed fault indicator,see System protection, this
section.
11. AUTO push-on button and state lamp. When selected and the state lamp lit, the A/C mode is selected and control
of demand temperature, fans speed, and air distribution is automatic. AUTO is cancelled by selection of any 'dis- tribution' button, A/C off, or manual FANS SPEED.
12. DEFROST push
-on / push-off button and state lamp. When engaged, air is distributed to the screen at maximum
fans speed and the heated front screen elements (where fitted) are ener ized. The heated front screen is automati- cally timed for a six (6) minute cycle but may be cancelled by pressing tfe HEATED FRONT SCREEN button. Auto- matic temperature control is retained and the fans speed may be manually reduced. Deselection will return the
system to the previous state and selection of AUTO will resume automatic system control.
13. The push
-on / push-off (F) button with state lamp manually controls the HEATED FRONT SCREEN (where fitted).
This facility allows rapid screen de-icing using laminated electrical heating elements to supplement the hot air
defrost.
14. The push-on / push-off (R) button with state lamp manually controls the HEATED REAR SCREEN and door mirror
glass heating elements for a timed cycle of; screen twenty (20) minutes and mirrors eleven (1 1) minutes.
m: The state lamp will remain lit after the mirror timer has gone through its 11 minute cycle and will not go out
until either completion of the 20 minute screen cycle or manual override.
15. TEMPERATURE decrease button
in IoC or I0F steps.
16. TEMPERATURE increase button in
IoC or I0F steps.
w: Automatic temperature control operates over the range 17OC to 31OC (61OF to 90OF). Extreme limits selected
by items 15 and 16 ('Lo' and 'Hi') provide maximum cooling or heating at maximum fans speed.
17. FACE level manual distribution over
-ride push-on / push-off button and state lamp.
0 18. Bi LEVEL (foot and face) manual distribution over-ride push-on / push-off button and state lamp.
19. FOOT level manual distribution over
-ride push-on / push-off button and state lamp.
20. DEMIST (screen and foot) level manual distribution over
-ride push-on / push-off button and state lamp.
!Y&Q: Selection of AUTO will over-ride any manual setting and deselection of any manual distribution will revertthe
system to AUTO distribution.
21. FACE VENTTEMPERATURE CONTROL thumb
-wheel. Situated between dash centre face level vents to reduce face
air outlet temperature relative to that of the foot-well.
Issue 1 August 1994 X300 VSM 5