1998 JAGUAR X308 coolant temperature

E
ngine - Cylinder Head RH
In-ve
hicle Repair
Remova

l
CAU
TION: If a replacement cylinder head is to be installed to a
vehicle with variable camshaft timing (VCT) the cylinder head m ust have the
oil gallery blind rivet removed before installation.
Spe
cial Tool(s)

Cams

haft setting
303-530

Ti
ming chain tensioning
303-532

Wedges, prim
ary chain
303-533

Cr
ankshaft setting
303-531
1.
Open the engine compartment and install paintwork protection sheets.
2. Set the engine compartment cover to the service access position.

3.
Disconnect the battery ground cable.
Re

move the battery cover.
4. Remove the engine front cover.For additional information, refer to: Engine
Front Cover (303-01 Engi
ne, In-vehicle Repair).
5. Remove the Inlet Manifold. Refer to Operation 30.15.01 in this Section. This operation includes depressurising the fuel system and removing the throttle
housing.
6. Disconnect the hoses and multi-plug from the coolant outlet pipe.
1. Release and reposition the hose clip, and disconnect the heater hose.
2. Disconnect the multi-plug from the temperature sensor.
3. Release and reposition the hose clip along the bypass hose.

23.
Install the supercharger driv e belt tensioner. Refer to
Operation 18.50.24.

24. Install the supercharger idle r pulley mounting bracket.
1. Position the mounting bracket to the timing cover.
2. Install the three bolts which secure the mounting bracket. Tighten to 8-10 Nm.
25. Install the supercharger drive belt idler pulley. Refer to
Operation 18.50.09. (34-46 Nm).
26. Install the supercharger driv e belt. Refer to Operation
18.50.08.
27. Install the coolant outlet pipe. Refer to Operation 26.31.08.
28. Install the twin fan and motor assembly. Refer to Operation
26.25.12.
29. Refill the cooling system. Refer to Operation 26.10.01 in
General Procedures section of the cooling system.
30. NOTE: When the engine is star ted from cold and run for a
short period only, before being swit ched off, a quantity of oil will
be 'hung up' within the engine because it is not up to operating
temperature.
Should the oil level subsequently be topped-up, the level could
become too high, causing oil burning.
Typically, 0.875 L is hung up.
Refill the engine with the correct specification engine oil.
31. Connect the battery and in stall the battery cover.
Refer to the Battery Reconnection Procedure 86.15.15.
32. Check the oil level and start th e engine. Check for leaks and
that the engine runs correctly.
33. Install the engine compartmen t cover. Refer to Operation
76.16.01.
34. Remove the paintwork protection sheets and close the engine
compartment cover.

Engine Cooling
- Engine Cooling
Descr
i
ption and Operation
Engine Cooling Comp onents - Normally Aspirated Vehicles

Engine cooling is via a low volume, high velocity system which achieves a very fast warm up. The temperature of the
combustion chambers is reduced along with a more even temperature distribution. The temperature of the bores is increased.

F r
om the pump, coolant flows into each bank of the cylinder bl
ock. In each bank, approximately 50% of the coolant cools the
cylinder bores and the remainder is diverted th rough the bypass gallery to the cylinder head.
With the thermostat closed, coolant returns directly to the pump through the bypass on the thermostat housing.
With the thermostat open, coolant returns to the pump via the radiator.
The cooling system uses a mixture of water and Jaguar Anti-Freeze/Inhibitor (Dow 542).
The cooling system on a supercharged engine is similar, but has additional components for cooling the intake air.
Engine Cooling Co mponents - Supercharged Vehicles
ItemDescrip
tion
1Thr
ottle B
ody
2Hea
ter Return
3Coolant Pum p
4Ther
mostat Housing
5Vehicle Radia
t
or
6Hea
ter Su
pply
7Bleed
Outl
et (to expansion tank)
8EGR V
a
lve (when fitted)
9Bleed
Outl
et (to expansion tank)

A coola
nt outlet plastic pipe connects to the outlet port of ea
ch cylinder head to provide a common connection point for the
radiator top hose. It also incorporates the Engine Coolant Te mperature (ECT) sensor which provides a signal representing
coolant temperature at the cylinder heads. The outlet pipe has connections to supply the heater matrix and the bypass flow
to the thermostat housing. An in-groove ga sket, seals each of the outlet-to-cylinder head joints. An aluminium gasket seals
the ECT sensor to duct joint.
Coolant Outlet Duct - Supercharged

The coolant outlet duct on the supercharged engine performs exactly the same function as on the normally aspirated engine
and connects to the same ports on the engine. The main physical difference is that the thermostat housing has been
ItemDe
scription
1Bottom

Hose Connection
2The

rmostat Cover
3The

rmostat
4Coolan

t Outlet Duct
5B

reather Connection
6ECT Se

nsor
7Top Hose Conn

ection
8Bypa

ss to Water Pump
9Hea

ter Hose Connection

Whe r
e considered necessary, some hose conn
ections have an indication mark to ensure correct orientation of the hose when
being fitted.
All joints use spring-band clips, except small pipes on the bleed system joints - which use cobra clips. The heater feed and
return hoses use quick-connection unions.
Supply and return hoses for the heater are located between the cylinder banks.
A connection on the rear of the A-bank provides coolant supply for the electronic throttle and the EGR valve (where fitted).
The outlet from the electronic throttle connects to the return hose from the heater.
Cool
ant Header and Recovery Tanks
A recovery system comp
rising the header tank
and a recovery tank is fitted. The recove ry tank is located in front of the left
hand front wheel arch liner.
The header tank provides the cooling system filling point and carries the coolant level sensor. The pressure cap allows
controlled release of coolant to the re covery tank during normal operation.
The recovery tank accommodates the expansion of the system coolant during normal operation. On engine cool-down, the
coolant contracts and is returned to the main system.
Coo lin
g Fans
The two
rad
iator cooling fans are mounted in
a cowl assembly within the cooling module.
The fans are controlled by the ECM dependent on the demand fr om the cooling system (temperature) or the air conditioning
ItemDescrip
tion
1EGR
E
ngines
2Non
-
EGR Engines
3Hea
ter Connections

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

Engi
ne Coolant Temperature Sensor (ECT) - Circuit Diagram

Intercooler Pump Relay - Circuit Diagram
T emper
ature (°C)
No
mi
nal Resistance (kOHM)
-2
015 .0
4
05.7
4
202.45
401.15
600.
584
800.3
2
1000.
184
ItemPar
t
Number
De
scrip
tion
1—Eng
i
ne Coolant Temperature (ECT) Sensor
2—Eng
i
ne to EMS Harness Connector
3—EMS Con
trol Modu
le

Engine Cooling - Engine Cooling
Diagn
osis and Testing
Related Faults / Codes

Adaptive
Fue
ling
Sym
p
tom Chart
Sy
m
ptom Chart
S
p
ecial Tool(s)

D
i
gital multimeter

Generi
c scan tool
Conditi
on
Possib
l
e Source
Acti
o
n
D
T
C P0171 System too lean bank
1 (A)
D T
C P0174 System too lean bank
2 (B)
Fuel delivery blockage Fu
el delivery pressure (low)
F
a
ulty injector (blocked)
Ai
r i
ntake system leak
F
u
el injector electrical fault
ECT sensor
faul
t
MAFM sensor fault IAT se
nsor fault

Thro
tt
le position sensor
fault
Mec hanica
l check
Mec
hanica
l check
Mec
hanica
l check
Mec
hanica
l check
Go t
o DTC P020
1 to 0208
Go t
o
DTC P0116 to 0118, P0125
Go t
o
DTC P0101 to 0103, P1104
Go t
o DTC P011
1 to 0113
Go t
o
DTC P0121 to 0123, P0222,
P0223
D T
C P0172 System too rich bank
1 (A)
D T
C P0175 System too rich bank
2 (B)
F u
el delivery pressure
(high)
F a
ulty injector (leaking)
F
u
el injector continuously
open
Ai r i
ntake system restricted

Fu
el injector electrical fault
ECT sensor
faul
t
MAFM sensor fault IAT sensor fault


Thrott

le position sensor
fault
Mec hanica
l check
Mec
hanica
l check
Mec
hanica
l check
Mec
hanica
l check
Go t
o DTC P020
1 to P0208
Go t
o
DTC P0116 to P0118, P0125
Go t
o
DTC P0101 to P0103, P1104
Go t
o DTC P011
1 to P0113
Go t
o
DTC P0121 to P0123, P0222,
P0223
Sy m
ptom
Possib
l
e Sources
Acti
o
n
D
T
C P0116 ECT circuit range / performance problem
Thermostat
Coo
l
ant level / contamination
Sensor out of range
Harness open circuit
Connector loose or corroded
*
*
*
*
*
GO to Pinpoint

Test A

*
D
T
C P0125 Insufficient coolant temperature for closed
loop fuel control
Thermostat
Coo l
ant level / contamination
Sensor out of range
Harness open circuit
Connector loose or corroded
*
*
*
*
*
GO to Pinpoint

Test A

*
D
T
C P0117 ECT circuit low input
Sensor o
p
en circuit
Harness open circuit
Harness short
*
*
*
GO to Pinpoint

Test B

*