Page 20 of 75

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
Page 24 of 75

V6 EngineAJ-V6/AJ28
19
Variable Valve Timing (VVT)
A VVT system is used to allow the phasing of the
inlet valve opening to be changed relative to the
fixed timing of the exhaust valves. Two positions
are used, 30û apart, with the advanced position
occurring at 30û BTDC and overlapping with the
exhaust opening. The system is similar to that
previously used on the AJ26 V8 engine but uses
different components and a different oil feed
arrangement.
The operating regime is controlled by the engine
management system in conjunction with the
variable geometry induction system so as to
optimise torque characteristics over the engine
speed/load range. The engine torque curve with
VVT operating points is shown in the section on
the Variable Intake System. The VVT system also
provides increased amounts of ÔinternalÕ EGR
under certain speed/load operating conditions.
VVT Oil Feed
The VVT/sprocket unit is fixed on the nose of the
inlet camshaft via a locating pin and hollow bolt
and is driven directly by the timing chain. Unlike
the VVT systems on the V8 engines, the oil feed
J.303.1288
VVT OIL FEED
J.303.1288
VVT Unit
VVT Oil
Control Valve
D.303.1361
VVT TIMING DIAGRAM
D.303.1361
Inlet Camshaft RetardedInlet Camshaft Advanced
Inlet opens TDC
Exhaust closes
11.5û ATDCInlet opens
30û BTDCExhaust closes
11.5û ATDC
TDC
Inlet closes
36û ABDC
Exhaust
opens 57.5û
BBDC Inlet closes
66û ABDCExhaust opens
57.5û BBDC41.5û Overlap 11.5û Overlap
Inlet Camshaft
Valve Overlap
Exhaust Camshaft
Page 50 of 75

V8 EngineAJ-V6/AJ28
45
Introduction
The AJ28 engine is a variant of the 4.0L 90û V8 units fitted to the XJ and XK range of vehicles. The AJ28
shares some of the changes incorporated in the current AJ27 engine: both engines are derived from the
original AJ26 unit. A number of features are unique to the AJ28 or are shared with the AJ-V6 engine also
described in this publication.
Features of the AJ28 engine are:
¥ Continuously variable inlet valve timing over a 48û
+
-2û crank angle: as fitted to the AJ27 engine
¥ Full authority cable-less electronic throttle control: as fitted to the AJ-V6 engine
¥ Air assisted fuel injection: similar to system used on the AJ27 engine
¥ Unique induction manifold with centrally mounted throttle body
¥ Returnless fuel system: similar to AJ-V6 engine
¥ Twin wall exhaust manifold
¥ Engine management system as used on the AJ-V6
¥ New sensors
¥ Modified sump and oil cooler
¥ Modified front end ancillary drive and components
Engine Specification
Maximum power DIN - 209 kW (281 BHP) at 6100 RPM
EEC - 203 kW (276 PS) at 6100 RPM
Maximum torque DIN - 390 Nm (287 lbft) at 4300 RPM
EEC - 278 Nm (279 lbft) at 4300 RPM
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.
JOL.29550
50JOL.296
SAE/TEMPERATURE TABLE 2
SAE/TEMPERATURE TABLE 1
Page 51 of 75
V8 Engine AJ-V6/AJ28
46
Basic Engine
Bottom End
Changes to the cylinder block, connecting rods
and pistons which were introduced for the AJ27
N/A engine are also applicable to the AJ28 unit
and are described in the ÔXK and XJ series 1999
MY updateÕ Technical Guide.
Oil Sump Body and Pan
A revised oil sump body and sump pan are
necessary to accommodate the V8 engine in the
S-TYPE model but the sump capacity is
unchanged.
D.303.1184
OIL SUMP AND PAN
D.303-1184
J.303.1317
TRANSMISSION DRIVE PLATE
J.303.1317
Transmission Drive Plate
The transmission drive plate is similar to AJ27 but
is fixed with eight bolts to an adaptor plate on the
torque converter (see Transmission sections). The
crankshaft sensor ring is fitted to the engine side
of the drive plate as for the previous V8 engines.
Page 52 of 75

V8 EngineAJ-V6/AJ28
47
Cylinder Head
The cylinder head incorporates the modifications
first introduced for the AJ27 engine except for the
camshaft sensor ring and cam cover.
Camshaft Sensor Ring
Cam position sensing is similar to that used on the
AJ27 engine, except that the sensor ring fitted to
each inlet camshaft has five triggering teeth.
Camshaft Covers
To improve accessibility, an extension tube is
fitted to the oil filler hole on the bank 2 cam
cover. Due to the position of the throttle and air
intake ducting, the part load breather outlet is
taken from bank 1 cam cover and the full load
breather outlet from bank 2 (the reverse of AJ27).
Front Cover
The front cover is modified from the AJ27 to
include a mounting boss for a new idler pulley
(see Front End Accessories Drive).
Lubrication
The lubrication system includes the uprated oil
pump (for the linear VVT system) and the same oil
temperature sensor as fitted to the AJ27 engine.
The oil sump and pan are modified as described
on page 46.
The external oil system components are located
laterally across the front of the sump body and
consist of an oil filter, oil cooler and oil filter head
assembly. The oil cooler is an oil to water heat
exchanger similar to the V6 oil cooler and the
cooler matrix is also connected via hoses to a
circulator orifice in the radiator bottom hose (see
Cooling System). The oil filter screws on to the
cooler which connects to the sump body through
an adaptor, the oil filter head assembly.
J.303.1189
CAMSHAFT SENSOR RING
D.303.1189
D.303.1185
CAMSHAFT COVER/OIL FILLER
D.303.1185
D.303.1186
OIL FILTER, COOLER AND ADAPTOR
D.303.1185
Oil temperature sensor
Oil pressure switch
Oil Cooler
Page 59 of 75
V8 Engine AJ-V6/AJ28
54
Engine Management Sensors
The configuration of the AJ28 engine management sensors is changed from the previous V8 variants:
¥ New components unique to AJ28 engine are the MAF sensor and engine fuel temperature (EFT)
sensor.
¥ Components in common with the V6 engine are the IAT sensor, KS sensors, injector pressure (IP)
sensor, engine oil temperature (EOT) sensor and HO2 sensors.
¥ The crankshaft (CKP) and camshaft (CMP) sensors are the same as those fitted to the AJ27 engine.
Heated Oxygen (HO2) Sensors
Upstream and dowmstream HO2 sensors are
fitted and are of the type used on the V6 engine
(the linear type sensor is not used).
J.303.1387
HO2 SENSORS
J.303.1387
J.303.1281
COIL ON PLUG UNIT
J.303.1281
Ignition System
The coil-on-plug ignition modules are specific to
the AJ28 engine and are triggered directly from
the PCM. Double electrode platinum plugs are
fitted.
Page 66 of 75

Automatic TransmissionAJ-V6/AJ28
61
Introduction
The 5R55N type 5-speed automatic transmission is fitted to both the V6 and V8 engines. The
transmission is controlled electronically by the powertrain control module (PCM) without the use of a
dedicated control module. Normal P, R, N, D drive functions plus manual selection of 4th, 3th and 2nd
gears are provided by a Jaguar style ÔJÕ gate (not the same as XJ and XK Series - see ÔS-TYPE IntroductionÕ
Techical Guide). Sports mode and traction assistance are selected at the ÔJÕ gate.
Specification
Transmission weight with fluid: 90 kg (198 lbs)
Oil type: Mercon V semi-synthetic (not compatible with other fluids)
Oil capacity: 9 Litres (9.5 quarts) - new
5 Litres (5.3 quarts) - after draining
Oil Fill/change: Filled for life, no top up required (no dipstick)
Gear ratios: 1st 2nd 3rd 4th 5th Rev
3.24 : 1 2.44 : 1 1.55 : 1 1 : 1 0.75 : 1 3.07 : 1
D.307.313
5R55N AUTOMATIC TRANSMISSION
D.303.313
Vent Tube
Turbine Speed
Sensor
Intermediate
Speed Sensor
Output Speed
Sensor
Range Switch
Rear Mounting
BracketJ-gate Selector
Cable Lever
Page 69 of 75

Introduction
Manual Transmission AJ-V6/AJ28
64In Europeon markets only, manual transmission is fitted as standard on the V6 entry S-TYPE model and
as an option on the V6 high specification model. Manual transmission is not available for the V8 variant.
The manual transmission is a 5 speed Getrag 221 unit with the following features:
¥ direct gearing (1:1) on 5th gear (it is normally on 4th) reduces losses
¥ twin synchronising cones on 1st and 2nd gears provide a smoother change
¥ four plane shift gate (R-1-3-5) with Ôknock-overÕ protection on the Reverse position.
A reverse light switch and speed sensor are fitted on the LH side of the gearbox. The speed sensor
monitors output shaft speed to provide an input to the PCM in addition to the signals received from the
road wheel speed sensors.
Specification:
Gear ratios: 1st 2nd 3rd 4th 5th Reverse
4.23 : 1 2.52 : 1 1.67 : 1 1.22 : 1 1 : 1 4.14 : 1
Weight: 33 kg (72 lbs)
Oil specification: ESSOD21065
Oil change interval: 60,000 miles (96,000 km)
D.307.312
MANUAL TRANSMISSION, CLUTCH ASSEMBLY AND DUAL MASS FLYWHEEL
D.307.312
Reverse Light Switch
Speed Sensor