1994 JAGUAR XJ6 engine coolant

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

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 (V12) ~~ ~
5.2.5
SRO
18.30.74 VEHICLE SET
IDLE SPEED CONTROL VALVE/ GASKETS, RENEW
SRO
18.30.73 VALVE- RIGHT HAND
SRO 18.30.76 GASKET
- RIGHT HAND
SRO
SRO 18.30.75 GASKET- LEFT HAND
18.30.72
VALVE
- LEFT HAND
Remove
. Disconnect battery.
. Drain coolant from radiator, see Section 4.2.
. Disconnect idle speed control valve multi-plug.
Disconnect all hoses linked to the idle speed control valve.
. Remove valve.
. Remove gasket.
Refit in the reverse order of the removal procedure.
5.2.6 FUEL CUT-OFF INERTIA SWITCH, RENEW
SRO
18.30.35
Remove
. Disconnect battery.
. Remove the 'A' post lower trim pad.
= Remove the EMS control module, see Section 15.
. Disconnect vehicle harness through-panel connector.
. Disconnect inertia switch multi-plug (Fig. 2).
9 Remove switch.
Refit in the reverse order
of the removal procedure. Fig.
1
Fig. 2
X300 VSM 9 Issue 1 August 1994

@ Steering
10.1.3 Steering Hydraulic System Major Components
Engine driven rotary vane pump (belt driven 12 cylinder; direct drive from timing gear 6 cylinder) with falling
flow characteristic (as
pump speed increases fluid flow decreases) and integral pressure relief valve.
Remote fluid reservoir with integral 'return' side filter.
Steering rack (incorporating speed sensitive transducer).
Steering control module
(SCM).
Fluid cooler integral with engine coolant radiator and associated pipe-work.
10.1.4 Hydraulic System Features
The 'Servotronic' system reduces steering input loads during parking and low speed manoeuvres and progressively
increases input loads as vehicle speed rises. This feature enhances steering feel.
10.1.5
Rotary motion of the steering wheel is converted, via the steering gear pinion to lateral motion of the rack. Hydraulic
assistance is provided by pressurized fluid being directed against the rack bar piston in the rack cylinder. The pressure
applied to each side of the rack piston is controlled by the pinion valve which varies the restriction through which the
flow for each side of the rack piston must pass.
Hydraulic System Operating Principle (see illustrations on next three pages)
Section on X X
J57-277
A. Steering rack F. Torsion bar 0 Radial groove B. Driving pinion G. Oil pump 1 Speedometer
C. Power cylinder H Pressure & flow 2 SCM D. Rotary disc valve limiting valve 3 Transducer
E. Control sleeve N Radial groove
Fig.
1 Major components & hydraulic flow - Neutral position ~
Issue 1 August 1994 X300 VSM 2

@ Steering
10.4.4 Diagnostic chart 3
Trouble
Hydraulic noise when
turning lock to lock
Continuous pressure
relief valve operation
Continuous noise
Cause
Fluid level low?
Air ingress at connections
Air ingress through feed hose lining
or
skin
Air ingress at pump front seal
Water contamination caused by fractured
cooler pipe within engine coolant radi
-
ator
Pump starvation or cavitation caused by
twisted or trapped feed hose
Pump starvation caused by blocked filter
Worn
pump
High pressure hose (pump to rack) dam-
aged or restricted
Fluid level low?
Drive belt loose
(12 cyl only)
Drive pulley loose
Steering pump mounting
(4 loose
Drive 'dog' loose, slipping or incorrectly
fitted
(6 cyl only)-
Hose or pipe fretting on body or chassis
structure
Hose twisted or restricted
Remedy
Rectify fluid loss and or top up
Check and tighten all connections to spec
-
ification
Renew faulty
'0' rings or Dowty washers
Renew porous
1 damaged hoses
Renew
pump
Renew radiator. Flush and drain steering
system twice
minimum, check for noise
and system performance (Pump is most
susceptible to damage due to
loss of lu-
brication and may have to be renewed)
Reroute or relieve pressure
Renew reservoir
Renew pump
Renew hose
Rectify
fluid loss and or top up
Inspect for damage and renew as required
Tighten pulley to specification
Tighten to specification
Investigate
& rectify as required
Rectify routing
Rectify routing
Issue 1 August 1994 8 X300 VSM

Climate Control Systems
14.4 TEMPERATURE CONTROL
14.4.1 Coolant Circuit
The main coolant system supplies liquid at engine temperature to the heater matrix to provide heat to the vehicle
interior. Unlike previous air blend / constant matrix temperature systems, in-car temperature is now controlled by
mixing recirculated coolant in the heater circuit with engine-temperature coolant. Matrix temperature is controlled
by a valve which opens to raise temperature (admit engine coolant) and closes to reduce it (recirculates coolant within
the circuit). The coolant flow valve operates on a six (6) second 'duty cycle', during which it may be open for whatever
period thecontrol system dictates. FACEvent airtemperature of howeveriscontrolled bythe'cool air by-passdamper'
which allows incoming air to flow around the top of the the heater matrix and thus remain unheated.
Because the engine coolant pump is driven proportionally to engine speed, the coolant delivery rate changes with
engine revolutions thus causing temperature variations. To stabilize the flow through the matrix, and thus the
temperature, an electrically driven circulation pump has been introduced into the system.
1
1. Engine 2. Coolant flow valve 3. Circulation pump
4. Heater matrix
5. Bottom hose
6. Engine cooling system radiator
Fig.
1 Coolant circuit, schematic view
Issue 1 August 1994 6 X300 VSM