1999 JAGUAR S TYPE weight

IntroductionAJ-V6/AJ28
3 The new S-TYPE sports sedan has an in-line powertrain and rear wheel drive configuration and is
available with either a 3 Litre V6 or a 4 Litre V8 engine, both normally aspirated. The V6 engine,
designated AJ-V6 is new to the Jaguar range and provides expected Jaguar levels of performance with
smooth power delivery, economy and excellent torque characteristics across the engine speed/load
range. The engine is of a lightweight but rigid design with particular attention paid to minimising noise
and vibration. A major innovation is the use of a variable geometry air intake manifold, which is
controlled, via valves, by the engine management system and produces optimised volumetric efficiency
at all engine speeds. Two stage variable valve timing is also fitted and both systems are optimised
together to achieve the wide torque delivery at all engine speeds.
The V8 engine, designated AJ28, is a developement of the now established engine fitted to the
successfull XK Series sports and XJ Series sedan and incorporates the latest modifications fitted to the
AJ27 variant, in particular the continuously variable valve timing system and air assisted fuel injection.
Both the V6 and V8 engines are fitted with a new, common, electronic throttle which does not require a
mechanical cable. Another new feature, also common to both engines, is the use of a returnless fuel
system to reduce the formation of fuel vapour (evaporative emissions).
A new 5-speed automatic transmission is fitted (with slight differences) to both engines. In certain
markets only, an optional 5-speed manual transmission, with new self-adjusting clutch, is available for
the V6 engine only.
Both engines and the automatic transmission are controlled by a completely new powertrain control
system.

4
Introduction
D.303.1201
AJ-V6 ENGINEThe AJ-V6 is a water cooled six cylinder engine
configured as two banks of cylinders in a 60û V
formation. Valve operation is via chain driven
double overhead camshafts on each cylinder
bank. The engine is naturally aspirated but with a
unique air intake system which significantly
improves power output. Lightweight materials are
used extensively but the structural design is such
as to maintain a strong rigid assembly.The main features of the power unit are:
¥ three stage variable geometry intake manifold
¥ electronic throttle with cable-less operation
¥ two position variable valve timing
¥ returnless fuel system
¥ fail safe cooling system
V6 Engine
D.303.1202D.303.1201 &1202
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 Engine
8
Cylinder Head
The aluminium alloy cylinder heads have square
squish combustion chambers with four valve
ports and a central spark plug. Each head is
aligned to the cylinder block via two split hollow
dowels and sealed with a composite stainless steel
gasket. Steel balls (10.11mm diameter) are used
to plug the external bores of the oilway drillings
and cup plugs are fitted to the water jacket
openings. Two half round aluminium cap inserts
are fitted via a sealant at the rear of the head.
Cam Cover
The cylinder heads are fitted with lightweight
polyester cam covers, (bank 2 is silver colored)
with silicone seals, to save weight and reduce
airborne noise. A central aperture allows access to
the coil on plug units and a second hole has a
grommet through which the VVT oil control valve
protrudes. The oil filler hole is in the LH cover.
D.303.1368
CYLINDER HEAD
D.303.1207
CAM COVER
D.303.1207
Cylinder Head Assembly
D.303.1368
AJ-V6/AJ28

V6 EngineAJ-V6/AJ28
9
Camshafts and Valve Gear
The basic camshaft consists of individual
machined cam lobes, thrust washer and end plug
assembled on a steel tube. The exhaust camshafts
also have a pressed on drive sprocket, forming a
single camshaft assembly. On the inlet camshaft
the drive sprocket is fixed to the VVT unit which
is removable but the rear end of the camshaft is
fitted with a pressed on multi-tooth sensor ring.
Each camshaft is supported in four bearings with
the front (thrust) bearing cap having a special
oilway for the VVT unit (see VVT section): on the
exhaust camshaft this oilway is redundant. The
bearing caps are made of aluminium.
The cams actuate the valves via direct acting
mechanical bucket tappets made of lightweight
aluminium with phosphate coated cast iron shims
D.303.1209
CAMSHAFTS AND VALVE GEAR
D.303.1209
mounted on top. The valve components are of
lightweight design with 5.5mm valve stems.
VVT Unit
Inlet Camshaft
Exhaust Camshaft

V6 EngineAJ-V6/AJ28
29
D.303.1215
FUEL RAIL AND LOWER INTAKE MANIFOLD
Fuel Supply
D.303.1215
EFT Sensor
De-pressurisation
Valve
IP Sensor
Fuel System
Returnless Fuel System
The returnless fuel system is a one way system
which delivers fuel to the engine without the
requirement for fuel to be returned to the tank.
When a return line is used, the effects of fuel
pressurisation, de-pressurisation and engine heat
on the returning fuel causes extra vapour to be
generated in the tank. With increasing regulatory
controls on evaporative emissions, this is an
undesirable condition and elimination of a fuel
return line provides significant benefits.
The in-tank fuel pump supplies fuel and regulates
pressure to the injectors under control of the PCM
and the rear electronic module (REM) and a
pressure regulator is not therefore required on the
engine fuel rail. To provide feedback for closed
loop control, an injector pressure (IP) sensor on
the fuel rail detects the pressure differentialbetween the fuel and the intake manifold and the
engine fuel temperature (EFT) sensor monitors
fuel temperature. Analogue signals from both
sensors are sent to the PCM to indicate the
pressure of the fuel and to detect whether it has
reached the vapourisation point. In response to
the sensor inputs and driver or load demands, the
PCM requests the pump system to vary the fuel
flow; in particular, fuel pressure will always be
increased to avoid vapour formation and to
maintain flow through the injectors.
Fuel pump control is further described in the
ÔS-TYPE IntroductionÕ Technical Guide.
Fuel Rail and Lower Intake Manifold
The fuel injectors are seated in two lower intake
manifolds, made of a lightweight plastic
composite material, which are fitted between the
Fuel Rail
Lower Intake
Manifold

V6 EngineAJ-V6/AJ28
39
D.303.1351D.303.1352
PAS PUMPA/C COMPRESSOR
D.303.1352
D.303.1369
Idler Pulleys
Two idler pulleys are used, one fixed by a single
bolt to the front cover and a second (see
illustration) fixed via a mounting bracket to the
upper RH side of the cylinder head and front
cover.
PAS Pump
The PAS pump is fixed by a single bolt to the LH
cylinder head and by two bolts to the front cover.
The pulley is constructed of lightweight phenolic
material.
Air Conditioning Compressor
The A/C compressor is mounted on the lower LH
side of the engine and is secured by two bolts to a
bracket fixed to the bedplate and by two lower
bolts directly to the oil sump.IDLER PULLEY
D.303.1351
D.303.1369

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