Land Rover Lesson 2 Auto Trans Coolingine Rover Manual

							Sensor ring2
Timing rings for each camshaft position sensor are
located at the rear of both intake camshafts. A flat,
machined near the front of each camshaft, enables the
camshafts to be locked during the valve timing
procedure.
Camshaft Position Sensor
The camshaft position sensors are installed in each
cylinder head at the rear of the intake camshaft. It is a
variable reluctance sensor that provides an input to the
ECM regarding the position of the camshaft.
Inlet and Exhaust Valves
Each cylinder head incorporates dual overhead
camshafts operating four valves per cylinder via solid
shimless aluminium alloy valve lifters.
The lightweight valve gear provides good economy and
noise levels. Valve head diameters are 31mm (1.220 in)
for the exhaust and 35mm (1.378 in) for the intake. All
valves have 5mm (0.197 in) diameter stems supported
in sintered metal seats and guide inserts. Collets, valve
collars and spring seats locate single valve springs on
both intake and exhaust valves. Valve stem seals are
integrated into the spring seats.
CAUTION: Due to slight variations in length,
the valves are not interchangeable between
marques (Land Rover, Jaguar and Aston
Martin).
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							Fuel Injectors
Eight, top fed, eight hole, fuel injectors are installed in
the fuel rails. The injectors are electromagnetic solenoid
valves controlled by the ECM. Two O-rings seal each
injector to manifold interface. The fuel jets from the
injectors are directed onto the back of the intake valves.
VARIABLE VALVE TIMING (VVT)
The continuously VVT unit turns the intake camshaft
in relation to the primary chain to advance and retard
the timing.
The system improves low and high-speed engine
performance, engine idle quality and exhaust emission.
The VVT system changes the phasing of the intake
valves, relative to the fixed timing of the exhaust valves,
to alter:
•the mass of air flow into the engines cylinders,
•and the engines torque response and emissions.
The VVT unit uses a vane device to control the camshaft
angle (refer to VVT operation). The system operates
over a range of 48° and is advanced or retarded to the
optimum angle within this range.
The ECM controls the VVT, using engine speed and
load, and engine oil temperature signals to calculate the
appropriate camshaft position.
The continuous VVT system provides the following
advantages:
•Reduces engine emissions and fuel consumption by
further optimising the camshaft timing, this improves
the engines internal exhaust gas re-circulation (EGR)
effect over a wider operating range
•Improves full-load torque characteristics as the
camshaft timing is optimised at all engine speeds for
superior volumetric efficiency
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							•Improves fuel economy by optimising torque over
the engines speed range.
This system also has the added benefits of operating at
a lower oil-pressure and faster response time when
compared to a non-VVT system.
Variable Valve Timing Operation
RetardedA
AdvancedB
Engine oil pressure1
The VVT unit is a hydraulic actuator mounted on the
end of the intake camshaft, which advances or retards
the intake camshaft timing and thereby alters the
camshaft to crankshaft phasing. The oil control solenoid,
controlled by the ECM, routes oil pressure to either the
advance or retard chambers located either side of the
three vanes interspersed within the machined housing
of the unit.
The VVT unit is driven by the primary chain and rotates
relative to the exhaust camshaft sprocket. When the
ECM requests the camshaft timing to advance, the oil
control solenoid is energized moving the shuttle valve
to the relevant position to allow engine oil pressure, via
a filter, into the VVT units advance chambers. When
the camshaft timing is requested to retard, the shuttle
valve moves position to allow oil pressure to exit the
advance chambers, while simultaneously routing the oil
pressure into the retard chambers.
When directed by the ECM, the VVT unit will be set
to the optimum position between full advance and retard
for a particular engine speed and load. This is achieved
when the ECM sends the energising signal to the oil
control solenoid until the target position is met. At this
point, the energizing signal is reduced to hold the
solenoid position, and as a result the position of the
shuttle valve. This function is under closed-loop control,
where the ECM will assess any decrease in shuttle-valve
oil-pressure, via signals from the camshaft position
sensor. The ECM will increase the energizing signal,
when required, to maintain the shuttle-valve hold
position.
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							Engine oil properties and temperature can affect the
ability of the VVT mechanism to follow demand
changes to the cam phase angle. At very low
oil-temperatures, movement of the VVT mechanism is
sluggish due to increased viscosity, and at high
oil-temperatures the reduced viscosity may impair
operation if the oil pressure is too low. To maintain
satisfactory VVT performance, an increased capacity
oil pump is installed, plus an engine oil temperature
sensor to enable monitoring by the ECM. The VVT
system is normally under closed-loop control except in
extreme temperature conditions, such as cold starts
below 0°C. At extremely high oil-temperatures, the
ECM may limit the amount of VVT advance to prevent
the engine from stalling when returning to idle speed.
The VVT does not operate when engine oil-pressure is
below 1.25 bar, as there is insufficient pressure to release
the VVT units internal stopper pin. This usually occurs
when the engine is shutting-down and the VVT has
returned to the retarded position. The stopper pin locks
the camshaft to the VVT unit to ensure camshaft
stability during the next engine start-up.
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							LUBRICATION SYSTEM
General
Oil is drawn from the reservoir in the oil pan and
pressurised by the oil pump. The output from the oil
pump is then filtered, cooled and distributed through
internal oil passages.
All moving parts are lubricated by pressure or splash
oil. Pressurised oil is also provided for operation of the
variable valve timing units and the timing gear chain
tensioners.
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							The oil returns to the oil pan under gravity. Large drain
holes through the cylinder heads and cylinder block
ensure the quick return of the oil, reducing the volume
of oil required and enabling an accurate check of the
contents soon after the engine stops.
System replenishment is through the oil filler cap on
the B bank camshaft cover.
With the exception of the pump, all oil system
components are installed on the structural sump.
Oil Pick-up
The fabricated steel oil pick-up is immersed in the oil
reservoir to provide a supply to the oil pump during all
normal vehicle attitudes. A mesh screen in the inlet
prevents debris from entering the oil system.
Oil Pump
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							The oil pump is installed on the crankshaft at the front
of the engine. The pump inlet and outlet ports align with
oil passages in the bedplate.
The pumping element is an eccentric rotor, which is
directly driven by flats on the crankshaft. An integral
pressure relief valve regulates pump outlet pressure at
4.5 bar (65.25 psi).
Oil Filter and Oil Pressure Switch
The oil filter is a replaceable cartridge installed on an
adapter. An internal bypass facility permits full flow
bypass if the filter is blocked.
The oil pressure switch connects a ground input to the
instrument cluster when oil pressure is present. The
switch operates at a pressure of 0.15 to 0.41 bar (2.2 to
5.9 psi).
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							Oil Level Gauge
The oil level gauge locates along the left side of the oil
pan, supported in a tube installed in the sump. Two holes
in the end of the gauge indicate the minimum and
maximum oil levels. There is a difference of
approximately 1.5 litres (1.58 US quart) between the
two levels.
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							EXHAUST MANIFOLD
The fabricated stainless steel twin skin exhaust
manifolds are unique for each cylinder bank. The B
bank manifold has a connection for the EGR transfer
pipe.
Spacers on the securing bolts allow the manifolds to
expand and retract with changes of temperature while
maintaining the clamping loads.
Heat shields are integrated into the exhaust manifold
gaskets.
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							External View
GENERAL
The TdV6 engine is a 2.7 litre, direct injection,
six-cylinder diesel engine having two banks of three
cylinders, arranged at 60 degrees to each other. There
are 4 valves per cylinder, which are operated by two
overhead camshafts per cylinder bank. The engine
emission comply with ECD3 (European Commission
Directive) legislative requirements and employs two
catalytic converters, electronic engine management
control, positive crankcase ventilation and exhaust gas
recirculation to limit the emission of pollutants. The
unit is water cooled and turbo-charged. The fuel
injection system features common rail technology.
The cylinder block is manufactured in Compacted
Graphite Iron (CGI) and is coupled with a separate
aluminium ladder frame to provide a lightweight,
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