coolant temperature JAGUAR S TYPE 1999 1.G Powertrain Manual

Glossary
2The following abbreviations are used in this document:
A Ab
bb
br
re
ev
vi
ia
at
ti
io
on
nD
De
es
sc
cr
ri
ip
pt
ti
io
on
n
AAC air assisted (injection) control valve
AAI air assisted injection
ABDC after bottom dead centre
A/C air conditioning
AH amp-hour
API American Petroleum Institute
APP accelerator pedal position (sensor)
ATDC after top dead centre
bank 1 A bank
bank 2 B bank
BBDC before bottom dead centre
BTDC before top dead centre
ûC degree Celsius
CHT cylinder head temperature (sensor)
CKP crankshaft position (sensor)
CMP camshaft position (sensor)
ECT engine coolant temperature (sensor)
EFT engine fuel temperature (sensor)
EGR exhaust gas recirculation
EMS engine management system
EOP engine oil pressure (sensor)
EOT engine oil temperature (sensor)
EVAP evaporative emission
ûF degrees Fahrenheit
HO2 heated oxygen (sensor)
Hz Hertz (cycles per second)
IAT intake air temperature (sensor)
IMT intake manifold tuning (valve)
IP injector pressure (sensor)
JTIS Jaguar Technical Information System
KS knock sensor (sensor)
LH lefthand
MAF mass air flow (sensor)
N/A normally aspirated
NAS North American specification
OBDII on-board diagnostics stage 2
PAS power assisted steering
PCM powertrain control module
PCV positive crankcase ventilation
PWM pulse width modulated
RH righthand
RPM revolutions per minute
SAE Society of Automotive Engineers (USA)
SCP standard corporate protocol
TAC throttle actuator control (module)
TP throttle position (sensor)
VVT variable valve timing
W watts
AJ-V6/AJ28

V6 EngineAJ-V6/AJ28
5
Engine Specifications
Configuration 60û V6
Displacement 2967 cc (181 cu. in)
Bore 89.0 mm (3.504 in)
Stroke 79.5 mm (3.130 in)
Compression ratio 10.5 :1
Cylinder head 2 overhead camshafts per bank, 4 valve per cylinder
Firing order 1-4-2-5-3-6
Maximum power DIN - 179 kW (240 BHP) at 6800 RPM
EEC - 175 kW (238 PS) at 6800 RPM
Maximum torque DIN - 300 Nm (221 lbft) at 4500 RPM
EEC - 293 Nm (216 lbft) at 4500 RPM
Oil specification see below
Oil volume 5.7 Litres (6 quarts)
Coolant specification see page 35
Coolant volume 10.4 Litres (11 quarts)
Weight 174 kg (384 lbs)
JOL.29550
50JOL.296
Oil Specification
All markets except the USA and Canada
Engine oil for all markets except the USA and
Canada must be to API specification SJ/ACEA A1
or A3.
The recommended SAE viscosity for different
ranges of ambient temperature are shown in
table 1.
USA/Canada
Engine oil for USA and Canada must be to API
specification SJ/ILSAC GF-2.
The recommended SAE viscosity for different
ranges of ambient temperature are shown in
table 2. For maximum economy and in most
climate conditions, SAE 5W/30 is to be preferred
but SAE 10W/30 or 15W/40 are acceptable in
moderate to hot climates.SAE/TEMPERATURE TABLE 2
SAE/TEMPERATURE TABLE 1

V6 EngineAJ-V6/AJ28
15
Oil Cooler and Filter Mounting
The oil filter and oil cooler are mounted slightly
away from the cylinder block on an aluminium
alloy adaptor which is an integral extension of the
LH engine mount. The oil filter is a replaceable
canister screw on type and the cooler is fixed by a
single through bolt to the adaptor. Both
components are connected to the cylinder block
through internal oilways in the adaptor casting
and via an interfacing filter mounting in the
block. A hollow bolt passes through the
adaptor/engine mount and screws into the centre
channel of the block filter mounting to provide
the oil return from the cooler to the cylinder
block.
The adaptor mounted oil cooler is an oil to water
heat exchanger and the coolant matrix is
connected via hoses into the main coolant system
at the radiator bottom hose (see Cooling System).
ENGINE OIL PRESSURE AND OIL TEMPERATURE SENSORS
D.303.1205
OIL COOLER AND FILTER ASSEMBLY
EOP Sensor
EOT Sensor
D.303.1205
D.303.1371
Engine Oil Pressure (EOP) and Oil
Temperature (EOT) Sensors
EOP and EOT sensors are fitted on the LH side of
the cylinder block in the return feed from the oil
cooler. The oil temperature is monitored to
provide data for the VVT system.
Oil Cooler
Hollow Bolt
Engine Mount/
Oil Cooler Adapter

V6 EngineAJ-V6/AJ28
17
Exhaust Gas Re-circulation (EGR)
Operation
The EGR system is only fitted to vehicles in NAS
markets and comprises the following
components:
¥ EGR vacuum regulator valve
¥ EGR valve
¥ differential pressure feedback EGR sensor
¥ exhaust gas feedback pipe with internal
orifice
Exhaust gas is re-circulated back to the engine
intake in proportion to a measured pressure
differential in the feedback pipe. The amount of
gas re-circulated varies primarily with engine
speed and load but is also modified by the EMS to
allow for other factors, eg coolant temperature,
and also to achieve optimum emissions and fuel
economy.
The re-circulated exhaust gas is taken from the A
bank exhaust manifold and fed into the engine via
the EGR valve. The feedback pipe contains an
internal tube with a small diameter orifice that
creates a pressure differential in the feedback
pipe. Two small pipes, connected to the feedbackpipe each side of the orifice, transmit the pressure
differential to the differential pressure feedback
EGR sensor.
The sensor consists of a transducer (a vacuum
operated variable capacitor) and a processing
circuit which convert the input pressure/vacuum
value to a corresponding analogue voltage which is
sent to the PCM. The differential pressure feedback
EGR sensor has a linear response and the
variations in exhaust pressure produce outputs in
the approximate range 1V- 3.5V dc.
The EGR vacuum regulator valve and the EGR
valve comprise the actuating components of the
control loop. The EGR vacuum regulator valve has
a vacuum input from the manifold distribution
pipes, a vacuum output to the EGR valve and
receives a pulse width modulated (PWM) signal
from the PCM. The PWM signal switches the
vacuum control output to the EGR valve according
to input demand from the differential pressure
feedback EGR sensor or in response to override
conditions determined by the engine management
system. The EGR valve is a vacuum operated
EGR SYSTEM
J.303.1282
Exhaust Gas
Feedback Pipe
Differential Pressure
Feedback EGR sensor
EGR Vacuum
Regulator Valve
EGR valve
Orifice

V6 Engine AJ-V6/AJ28
18diaphragm valve with no electrical connections
which opens the EGR feed pipe to the induction
manifold under the EGR vacuum regulator
control.
Where the EGR system is not fitted, a blanking
plate seals the manifold in place of the EGR valve.
Control Conditions
EGR operates over most of the engine speed/load
range but is disabled by the engine management
system under certain conditions:
¥ during engine cranking
¥ until normal operating temperature is
reached
¥ when the diagnostic system registers a failure
which affects the EGR system (eg a faulty
sensor)
¥ during idling to avoid unstable or erratic
running
¥ during wide open throttle operation
¥ when traction control is operative.
While the main control loop is based on feedback
from the differential pressure feedback EGR
sensor, the EGR rate is also modified by other
engine conditions; coolant, ambient and air
charge temperatures, barometric pressure, VVT
cam position and air charge mass. Note also that
the EGR rate increases gradually after it is enabled
on each drive cycle.

V6 Engine AJ-V6/AJ28
32(LHD vehicles) or rear right (RHD) of the engine
bay and in the LHD location has a bleed valve on
the return pipe running across the bulkhead. The
pipe layout is shown in the ÔS-TYPE IntroductionÕ
Technical Guide. A dip tube within the bottle
ensures that coolant is drawn back into the engine
when it cools down.
A subsidiary circuit provides a series coolant feed
through the lower throttle body and top of the
intake manifold inlet. This is necessary to prevent
ice forming at low ambient temperatures at the
base of the throttle body and also in the positive
crankcase ventilation (PCV) port.
Hoses and Connectors
Coolant ducting consists of flexible hoses,
aluminium tubing and plastic tubing with
injection moulded rubber to plastic joints. All
coolant hose clamps are of the spring band type
and are glued to the hose with a pull off clip for
D.303.1374
HOSE LAYOUT
Electronic throttle
D.303.1374
fitting. The thermostat is enclosed in an
aluminium casting which is a separate component
supported by hose connections.
Top Hose
Bottom Hose
Heater Control
Valve
Thermostat
Coolant Pump

V6 EngineAJ-V6/AJ28
35
J.303.1384
ENGINE BLOCK HEATER
D.303.1384
J.303.1377
FAN SPEED REGULATOR MODULE COOLING DUCT speed regulator module are fixed to the glass
filled nylon fan shroud assembly which is
mounted on the rear of the radiator end tanks via
two lower slots and pegs, two upper screws and
two clips at the bottom of the radiator. The A/C
system receiver drier bottle is also mounted on
the fan shroud assembly - see the
ÔS-TYPE IntroductionÕ Technical Guide.
The 500W fan motor drives a glass filled nylon
impeller over a continuously variable speed range
from 300RPM to 2900RPM and is controlled by a
regulator module mounted at the lower LH side of
the fan shroud. Since the fan speed regulator
module provides power drive to the fan, it has a
finned heat sink outer casing and is enclosed
within a cooling duct. The ducting extends
forwards below the cooling pack to receive an
inflow of air.
The radiator drain is located on the RH end tank.
Coolant
A new type of anti-freeze fluid is used for the
coolant mixture. This product is a conventional
ethylene glycol based fluid but with new organic
corrosion inhibitors instead of the silicate, nitrite
and other additives which are normally used.
These new corrosion inhibitors do not form a
deposit on the inner surfaces of the coolant
system and therefore provide improved heat
transfer (more efficient cooling), better
component protection and an extended coolant
life due to the low rate of depletion of the
additives. The recommended coolant change is
every five years or 250,000km (150,000miles).
Engine Block Heater
For markets subject to very low temperatures, an
engine coolant heater, for connection to an
external mains electrical supply, is screwed into
the RH side of the cylinder block adjacent to the
knock sensor. Two heaters are available, a 400W
115V unit with a two pin connector and a 600W
230V unit with flying lead.
J.303.1377

V6 Engine AJ-V6/AJ28
36
Fail Safe Cooling System
A unique feature of the V6 engine is the use of a fail safe cooling strategy, controlled by the EMS, in the
event of coolant loss leading to rising engine temperatures. The principle of the strategy involves
switching off one or more fuel injectors to inhibit combustion and reduce heat, thus allowing the flow of
ambient intake air to further cool the selected cylinders. By cycling the selected cylinders, ie switching
different injectors off for a period and in a sequence determined by EMS parameters, overall engine
temperature can be controlled sufficiently to allow the vehicle to be driven, at reduced power, for a
short distance. Throughout the malfunction period, instrument panel messages and warnings advise the
driver of the current status of the cooling system as described below.
Driver Indication and EMS Action
The fail safe strategy moves though different stages depending on engine temperature:
¥ Temperatures below 122û C (250û F) are within the normal range. At high temperatures below this
level the temperature gauge pointer enters the red zone.
¥ If the temperature rises to between 122û C - 127û C (250û F to 260û F) no action is taken by the EMS
which affects engine running but the following indications appear:
Temperature gauge pointer in red zone
Message Centre HIGH ENGINE TEMPERATURE
Warning light TEMP
Priority light red
Audible indicator single chime sounded
¥ If the temperature rises to 127û C (260û F) or above, the fail safe strategy operates. At 127û C (260û F),
the EMS will cut out one cylinder (the selected cylinder is varied) and as the temperature continues
to rise, this will increase to a maximum of three cylinders cut (with cylinder cycling). The following
indications are given:
Temperature gauge pointer in red zone
Message Centre ENGINE POWER REDUCED
Warning light TEMP
Priority light red
Audible indicator three chimes sounded
¥ At 166û C (300û F) or above, the fail safe strategy continues as described but the following
indications are given:
Temperature gauge pointer in red zone
Message Centre PULL OFF ROAD SAFELY alternates with TURN OFF IGNITION
Warning light TEMP flashes
Priority light red
Audible indicator five chimes sounded
¥ EMS shuts the engine down.

V6 Engine AJ-V6/AJ28
40
Engine Management Sensors
Key to illustration on page 41:
1. Throttle motor
2. TP sensor
3. IAT sensor
4. MAF sensor
5. Top IMT valve
6. Bottom IMT valve
7. EFT sensor
8. IP sensor
9. Fuel injectors
10. Coil-on-plug units
11. VVT shuttle valve
12. CMP sensor
13. CHT sensor
14. KS sensors
15. EOT sensor
16. CKP sensor
17. HO2 sensors
18. HO2 sensors (catalyst monitors)
Cylinder Head Temperature (CHT) Sensor
The single CHT sensor is located between the two
rear coil-on-plug units in the bank 2 cylinder
head. The sensor directly monitors the metal
temperature of the cylinder head. This method of
engine heat sensing is used in place of a
conventional coolant temperature sensor to
enable the fail safe cooling strategy to operate.
The use of a metal temperature sensor allows
cylinder head temperature to be measured even if
coolant has been lost unlike an ECT sensor which
would produce inaccurate temperature
indications, eg measuring steam temperature.
Crankshaft Position (CKP) Sensor
Crankshaft position and rotational speed are
sensed from a steel timing ring keyed to the front
end of the crankshaft immediately behind the
front cover. The timing ring has 36-1 teeth, ie one
missing tooth, which are angled slightly forward
and bent at rightangles to provide a sensing area
for the inductive sensor. The sensor is positioned
in the front cover, to the side of the crankshaft
damper, at approximately 20û to the plane of the
timing ring.
D.303.1342
J.303.1343
CHT SENSOR
CKP SENSOR
D.303-1342
J.303-1343
Engine management sensors and actuators (but
not off engine sensors) are summarised in the
illustration on page 41 and are also described
below or in the relevant section (VVT, fuel system,
throttle, tuned manifold).
The engine management system is described in a
separate section.