Jaguar XJ (X350). Manual — part 305

Valve Spring Free Length

1. Using a vernier gauge, measure the free length of each valve spring. Verify the length is
within specification.

Valve Stem Diameter

1. Using a micrometer measure the diameter of the valve stems.

•

If the measurements are not to specification, install a new valve.

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Description and operation

Engine

Vehicles with 3.0L engine

The 3.0L engine consists of:

•

a six cylinder 60 degree 'V' configuration liquid cooled aluminium cylinder block with dry cast
liners

•

aluminium pistons with cut-outs in the piston crown to clear the valve heads for any
available combination of camshaft profile and valve phasing

•

two aluminium cylinder heads with square squish chambers

•

two steel overhead camshafts per bank

•

four valves per cylinder

•

mechanical tappets and top mounted phosphate coated cast iron shims

•

continuous variable camshaft timing (VCT) of the inlet camshafts

•

two silent timing chains with one hydraulic tensioner per chain

•

magnesium alloy valve covers with rubber seals

•

a variable intake system containing two electrically controlled intake manifold tuning valves

•

plastic lower intake manifold with integral fuel rail and injectors

•

engine front cover manufactured from aluminium which accommodates the crankshaft front
oil seal

•

an oil pump located at the front of the crankshaft

•

an aluminium bed plate

•

an aluminium oil pan

•

a steel crankshaft

•

fracture-split connecting rods in sintered-forged steel

•

cast iron exhaust manifolds

•

a single, multi-vee belt which drives the front end accessories

•

an advanced engine management system incorporating electronic throttle control

•

the requirements of the CARB OBDII USA legislation

The engine code and serial number are located on the engine front cover as well as the left-hand side

of the bed plate adjacent to the oil cooler assembly.

Vehicles with 3.5L or 4.2L engine

The 3.5L or 4.2L engine without supercharger consists of:

•

an eight cylinder 90 degree 'Enclosed V' configuration liquid cooled aluminium cylinder block
with dry cast liners

•

pistons of open-ended skirt design, with two compression rings and a three piece oil control
ring

•

two aluminium cylinder heads, each incorporating two hollow camshafts manufactured in
chilled cast iron

•

four valves per cylinder

•

aluminium tappets and top mounted shims

•

continuous variable camshaft timing (VCT) of the inlet camshafts

•

valve covers manufactured from Thermoplastic

•

fuel injectors each with twelve holes

•

engine front cover manufactured from aluminium which accommodates the crankshaft front
oil seal

•

multi row primary and single row secondary chains drive the camshafts of each cylinder bank

•

an aluminium bed plate

•

a cast iron crankshaft

•

fracture-split connecting rods in sintered-forged steel

•

brackets bolted to the front of the cylinder block which are used to mount all accessories

•

a single, multi-vee belt which drives the front end accessories

•

stainless steel exhaust manifolds

•

an advanced engine management system incorporating electronic throttle control

•

the requirements of the CARB OBDII USA legislation

The engine number is stamped onto the engine block adjacent to the thermostat housing.

Vehicles with 4.2L engine

Engines with supercharger

The 4.2L engine with supercharger consists of:

•

an eight cylinder 90 degree 'Enclosed V' configuration liquid cooled aluminium cylinder block
with dry cast liners

•

pistons of open-ended skirt design, with two compression rings and a compact two piece oil
control ring

•

two aluminium cylinder heads, each incorporating two hollow camshafts manufactured in
chilled cast iron

•

four valves per cylinder

•

aluminium tappets and top mounted shims

•

valve covers manufactured from Thermoplastic

•

fuel injectors each with twelve holes

•

engine front cover manufactured from aluminium which accommodates the crankshaft front
oil seal

•

multi row primary and single row secondary chains drive the camshafts of each cylinder bank

•

an aluminium bed plate

•

oil spray jets in each cylinder bore

•

a cast iron crankshaft

•

fracture-split connecting rods in sintered-forged steel

•

brackets bolted to the front of the cylinder block which are used to mount all accessories

•

a single, multi-vee belt which drives the front end accessories

•

stainless steel exhaust manifolds

•

an advanced engine management system incorporating electronic throttle control.

•

the requirements of the CARB OBDII USA legislation.

The engine number is stamped onto the engine block adjacent to the thermostat housing.

www.