coolant JAGUAR X308 1998 2.G Repair Manual

A coola n
t drain plug is located at the rear of the cylinder block.
Coolant may be drained from the A-bank, by removing the coolant pipe from behind the starter motor.
For vehicles fitted with the cold climate package, a cylinder block heater (shown) replaces the drain plug located on the B-
bank.
Coolant Pump and Flow Control

The coolant pump is fitted between the two cylinder banks, on the front face of the cylinder block.
The pump consists of a housing containing a shaft, with a sh rouded plastic impeller on one end and a drive pulley on the
other.
A pair of roller bearings support the shaft in the housing. A seal behind the impeller prevents coolant from contaminating the
bearings. Should this seal fail, coolant escapes from a witness hole in the housin g indicating that immediate action is
required.
An O-ring and an aluminum-alloy gasket, seal the ports between the pump and the cylinder banks.
Coolant Outlet Duct

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

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

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

*

Pinpoint test
A: P0116, P0125
Connector
loose or corroded
*
D
TC P0118 ECT circuit high input
Sensor short
Harness open circui

t
Harness short
Connector loose or corroded
*
*
*
*
GO to Pinpoint

Test C
*
D
TC P1474 Intercooler coolant pump relay malfunction
Intercooler pump relay
failure
Intercooler pump relay to ECM drive circuit
fault Intercooler pump relay coil ground circuit
fault Harness fault
Connector loose or corroded
Connector pins(s) bent or tracking between
connections ECM power supply fault
*
*
*
*
*
*
*
GO to Pinpoint

Test D
*
P
INPOINT TEST A : P0116, P0125
T
EST CONDITIONS
D
ETAILS/RESULTS/ACTIONS
A1

: RETRIEVE DTCS
•

NOTE: Battery and or ECM disconnection prior to scanning wi
ll erase all data, ensure that the correct DTC is present.
Conne
ct the scan tool
1
Have the DTC(s) and fr

eeze
frame data been recorded?
Yes GO to A2
A2: ENGINE
COOLANT SYSTEM CHECK
•

NOTE: Do not use the instrument display, if th
e ECT has failed this will not operate correctly.
Chec
k engine temperature rise using a thermocouple or
similar device.
1
Engine
temperature increasing?
Yes GO to A3
No Check coolant level
Check coolant for contamination
Check/test thermostat

Ig
nition switch to position 0
1
R
e
move intercooler
coolant pump relay
Inside EC
M housing
2
Ignition switc
h
to position II
3
Ch
e
ck for battery voltage at relay socket between pins 3
and 2.
4
B+ ?
Yes
GO to D6

No GO to D4
D4: C H
ECK RELAY SOCKET SUPPLY CONTINUITY
•

NOTE: Install fuse F2.
Do not replace relay.