2002 LAND ROVER DISCOVERY oil change

ENGINE - TD5
12-1-28 DESCRIPTION AND OPERATION
Tensioner adjuster
1Oil supply hole
2Tensioner adjuster body
3Tensioner adjuster plunger
4Sealing ring
The tensioner adjuster is hydraulically operated, oil enters the adjuster from the pressurised oil supply flowing through
the cylinder head to operate a plunger which pushes against a pivoting plastic tensioner arm. The lateral movement
in the tensioner arm causes the timing chain to tension and consequently compensation for chain flutter and timing
chain wear is automatically controlled. The adjuster is located at the front right hand side of the cylinder head, just
above the timing chain cover and below the vacuum pump oil feed port. The adjuster body is threaded and screws
into a tapping in the cylinder head. Holes are contained in the adjuster body to receive oil from the cylinder head
galleries, the oil pressure is used to force the plunger out of the adjuster body to press the tensioner arm against the
timing chain and so using the oil trapped in the adjuster body to perform as a damper.
The internal damping of the hydraulic tensioner is tuned for each application. This means that pre EU3 and EU3
components are not interchangeable.
Drive train sprockets
The camshaft sprocket has a double row of teeth which locate with the duplex timing chain. The sprocket is fitted to
the camshaft by three bolts.
The oil pump sprocket is located on the front of the oil pump housing by a single retaining bolt. The sprocket has a
single row of teeth which locates on the oil pump chain.
The crankshaft sprocket contains three rows of teeth, the rear row locates on the single oil pump chain and the front
two rows locate with the duplex timing chain. The crankshaft sprocket has a slot in its internal diameter which locates
with the Woodruff key on the crankshaft. The front of the crankshaft sprocket has a timing mark.
As a consequence of thicker chain links being used on EU3 models, the thickness of the camshaft and crankshaft
sprocket teeth has been reduced. Individual pre EU3 and EU3 components are therefore not interchangeable.

ENGINE - TD5
OVERHAUL 12-1-81
54.Remove and discard spring ring retaining
rocker arm on shaft.
55.Remove rocker arm. Remove and discard 2nd
spring ring.
56.Repeat above procedures for remaining rocker
arms keeping them in their fitted order.
57.Clean rocker arms and shaft, ensure oilways
are clear.
CAUTION: Identify type of rocker shaft
fitted. Engine Serial No. Prefixes 10P to 14P
– Type A rocker shaft; Engine Serial No.
Prefixes 15P to 19P – Type B rocker shaft.
Type B rocker shafts and arms may be fitted
to Engine Serial No. Prefixes 10P to 14P as
an assembly.58.Check diameter of each rocker arm journal on
shaft, take 2 measurements at 180°:
lJournal diameter = 26.971 to 26.998 mm
(1.061 to 1.063 in)
59.Using a vernier, check internal diameter of
each rocker arm, take 2 measurements at
180
°:
l Rocker arm internal diameter = 27.0 to
27.013 mm (1.062 to 1.064 in)
60.Fit new spring ring to groove in rocker shaft.
61.Lubricate rocker shaft journals and rocker arms
with engine oil.
62.Fit rocker arm to shaft ensuring it is in its
original fitted order.
63.Fit new spring ring to retain rocker arm.
64.Repeat above procedures for remaining rocker
arms ensuring they are in their original fitted
order.
65.Fit new rocker adjusting screws and locknuts to
rocker arms; do not tighten screws fully into
arms at this stage.
CAUTION: Ensure screws are correct for
type of rocker arms fitted. Replacement
screws for Engine Serial No. Prefixes 15P to
19P have a centre punch mark adjacent to
the adjusting slot. These screws are not
interchangeable with those fitted to Engine
Serial No. Prefixes 10P to 14P.

ENGINE - TD5
12-1-94 OVERHAUL
15.Remove bolt and remove timing chain
adjustable guide.
16.Remove bolt and remove timing chain
lubrication jet.
17.Using tool LRT-12-092, remove and discard oil
seal from timing cover.
Inspection
1.Clean all components.
2.Check condition of timing chain running
surfaces on adjustable and fixed guides.
CAUTION: Adjustable guide fitted to Engine
Serial No. Prefixes 15P to 19P may be fitted
to early engines provided that timing chain
tensioner having a YELLOW coloured body
is also fitted.
3.Check timing chains and sprockets for signs of
wear.
CAUTION: Timing chains and sprockets
fitted to Engine Serial No. Prefixes 15P to
19P may be fitted to early engines as an
assembly only, oil pump drive sprockets are
interchangeable. Later timing chains have
BRONZE coloured timing links.
4.Check that drilling in timing chain lubrication jet
is clear.
5.Clean oil seal recess in timing cover and oil seal
running surface on crankshaft.
6.Remove all traces of sealant from mating faces
of timing cover and cylinder block using
suitable solvent.
CAUTION: Do not use metal scrapers.
7.Ensure bolt and dowel holes are clean and dry.
8.Clean oil pump sprocket bolt threads.Reassembly
1.Fit timing chain lubrication jet.
2.Fit timing chain lubrication jet Torx screw and
tighten to 10 Nm (7 lbf.ft).
3.If crankshaft has been rotated, check that No.1
piston is at TDC using the following
procedures:
4.Temporarily fit and lightly tighten a new
crankshaft pulley bolt.
5.Assemble a magnetic base DTI to cylinder
block top face, position stylus to cylinder block
face and zero gauge.
6.Using crankshaft pulley bolt, rotate crankshaft
clockwise until No.1 piston is at top of its stroke
and woodruff key slot in crankshaft is at 12
o'clock position.
7.Position stylus of DTI to No.1 piston crown and
rotate crankshaft until highest reading is
indicated on DTI.
8.Check that Woodruff key slot is still at 12
o'clock position indicating No.1 piston is at
TDC firing.
9.Remove DTI.
10.Remove and retain crankshaft pulley bolt.
11.Fit Woodruff key to crankshaft.
12.Fit oil pump drive chain to rear row of teeth on
crankshaft sprocket - i.e. teeth furthest away
from timing mark on sprocket.
13.Fit sprocket to crankshaft ensuring that timing
mark on sprocket is facing towards front end of
crankshaft.
14.Fit oil pump drive sprocket to oil pump and drive
chain ensuring that 'D' shape on sprocket is
located on flat on oil pump drive shaft.

ENGINE - TD5
12-1-100 OVERHAUL
12.Insert new compression and oil control rings in
turn into No.1 cylinder bore 30 mm (1.25 in)
from top of bore and check ring fitted gaps;
ensure rings are kept square to bore when
checking gaps:
l1st compression ring fitted gap = 0.30 to
0.40 mm (0.012 to 0.016 in).
l2nd compression ring fitted gap = 0.40 to
0.60 mm (0.016 to 0.024 in).
lOil control ring fitted gap = 0.25 to 0.50 mm
0.01 to 0.02 in).
CAUTION: 1st compression rings fitted to
Engine Serial No. Prefixes 10P to 14P are
not interchangeable with those fitted to
Engine Serial No. Prefixes 15P to 19P. The
later rings may, however, be fitted to early
engines together with the later type pistons
in engine sets only.
13.Repeat for each cylinder bore in turn.
CAUTION: Ensure rings are suitably
identified with the cylinder bore in which
they were checked and are fitted to the
piston for that bore.
14.Fit oil control expander and ring to piston.
15.Fit 2nd compression ring with 'TOP' marking
upwards. 16.Fit 1st compression ring with 'TOP' marking
upwards.
17.Check piston ring to groove clearance:
l1st compression ring = Not measured
l2nd compression ring = 0.050 to 0.082 mm
(0.02 to 0.003 in)
lOil control ring = 0.050 to 0.082 mm (0.02 to
0.003 in)
Reassembly
1.Lubricate gudgeon pin, gudgeon pin holes in
piston and small end bush with engine oil.
2.Position piston to connecting rod with arrow on
piston crown on the same side as the cast boss
on the connecting rod.
3.Fit gudgeon pin to its respective piston and
connecting rod; secure with new circlips
ensuring circlips are fully seated in their
grooves.
4.Repeat above procedures for remaining
pistons.
5.Lubricate piston rings and cylinder bores with
engine oil.
6.Check that rings are free to rotate, position ring
gaps at 120
° to each other and away from the
thrust, LEFT HAND side of piston - viewed
from front of piston.
7.Using a suitable ring clamp, compress piston
rings.
8.Insert connecting rod and piston into its
respective cylinder bore ensuring that the
arrow on piston crown and the cast boss on
connecting rod are facing towards the front of
the cylinder block.
9.Ensure that connecting rod does not contact
cylinder bore or oil squirt jet. Do not pull
connecting rod fully down cylinder bore at this
stage.
10.Check that cut-out in piston skirt is positioned
above oil squirt jet.

EMISSION CONTROL - V8
17-2-42 DESCRIPTION AND OPERATION
Secondary air injection system
When the engine is started, the engine control module checks the engine coolant temperature and if it is below 55°
C, the ECM grounds the electrical connection to the coil of the secondary air injection (SAI) pump relay.
A 12V battery supply is fed to the inertia switch via fuse 13 in the engine compartment fusebox. When the inertia
switch contacts are closed, the feed passes through the switch and is connected to the coil of the Main relay. An earth
connection from the Main relay coil is connected to the ECM. When the ECM completes the earth path, the coil
energises and closes the contacts of the Main relay.
The Main and Secondary Air Injection (SAI) pump relays are located in the engine compartment fusebox. When the
contacts of the Main relay are closed, a 12V battery supply is fed to the coil of the SAI pump relay. An earth connection
from the coil of the SAI pump relay is connected to the ECM. When the ECM completes the earth path, the coil
energises and closes the contacts of the SAI pump relay to supply 12V to the SAI pump via fusible link 2 in the engine
compartment fusebox. The SAI pump starts to operate, and will continue to do so until the ECM switches off the earth
connection to the coil of the SAI pump relay.
The SAI pump remains operational for a period determined by the ECM and depends on the starting temperature of
the engine, or for a maximum operation period determined by the ECM if the target engine coolant temperature has
not been reached in the usual time.
When the contacts of the main relay are closed, a 12V battery supply is fed to the SAI solenoid valve via Fuse 2 in
the engine compartment fusebox.
The ECM grounds the electrical connection to the SAI vacuum solenoid valve at the same time as it switches on the
SAI pump motor. When the SAI vacuum solenoid valve is energised, a vacuum is provided to the operation control
ports on both of the vacuum operated SAI control valves at the exhaust manifolds. The control vacuum is sourced
from the intake manifold depression and routed to the SAI control valves via a vacuum reservoir and the SAI vacuum
solenoid valve.
The vacuum reservoir is included in the vacuum supply circuit to prevent vacuum fluctuations caused by changes in
the intake manifold depression affecting the operation of the SAI control valves.
When a vacuum is applied to the control ports of the SAI control valves, the valves open to allow pressurised air from
the SAI pump to pass through to the exhaust ports in the cylinder heads for combustion.
When the ECM has determined that the SAI pump has operated for the desired duration, it switches off the earth paths
to the SAI pump relay and the SAI vacuum solenoid valve. With the SAI vacuum solenoid valve de-energised, the
valve closes, cutting off the vacuum supply to the SAI control valves. The SAI control valves close immediately and
completely to prevent any further pressurised air from the SAI pump entering the exhaust manifolds.
The engine coolant temperature sensor incurs a time lag in respect of detecting a change in temperature and the SAI
pump automatically enters a 'soak period' between operations to prevent the SAI pump overheating. The ECM also
compares the switch off and start up temperatures, to determine whether it is necessary to operate the SAI pump.
This prevents the pump running repeatedly and overheating on repeat starts.
Other factors which may prevent or stop SAI pump operation include the prevailing engine speed / load conditions.

ENGINE MANAGEMENT SYSTEM - TD5
DESCRIPTION AND OPERATION 18-1-33
The turbocharger is exposed to extremely high operating temperatures (up to 1,000 °C (1832 °F)) because of the hot
exhaust gases and the high speed revolution of the turbine (up to 150,000 rev/min). In order to resist wear of the
turbine bearings a flow of lubrication oil is supplied from the engine lubrication system to keep the bearings cool. Oil
is supplied from a tapping at the front of the full-flow filter adaptor housing via a metal pipe with banjo connections.
Oil is returned to the sump via a metal pipe which connects to the cylinder block at a port below the turbocharger
assembly.
A heatshield is attached to the left hand side of the engine to protect adjacent components from the heat generated
at the turbocharger. The heatshield is attached to the engine by two bolts an additional bolt attaches the heatshield
to the turbocharger casting.
The engine control module controls the amount of boost pressure the engine receives by way of the turbocharger.
When full boost is reached a control signal is sent to the wastegate modulator, and a vacuum is applied to the
wastegate valve. The wastegate valve opens, bypassing some of the exhaust gas away from the turbine to be output
to the exhaust system.
The engine should be allowed to idle for 15 seconds following engine start up and before the engine is switched off
to protect the turbocharger by maintaining oil supply to the turbine bearings.
Intercooler
The intercooler is an air-to-air heat exchanger which lowers the intake air temperature to obtain a higher air density
for better combustion efficiency. The intercooler receives compressed air from the turbocharger via a metal pipe; it
cools the intake air via the intercooler matrix and delivers it to the intake manifold by means of a rubber hose which
connects between the intercooler outlet and the intake manifold outlet. The rubber hose is connected to ports at each
end by metal band clips.

+ COOLING SYSTEM - Td5, DESCRIPTION AND OPERATION, Description.
The intercooler is located at the front of the engine bay, forward of the radiator.

ENGINE MANAGEMENT SYSTEM - V8
DESCRIPTION AND OPERATION 18-2-45
Ignition timing
The ignition timing is an important part of the ECM adaptive strategy. Ignition is controlled by a direct ignition system
using two four-ended coils operating on the wasted spark principle.
When the ECM triggers an ignition coil to spark, current from the coil travels to one spark plug, then jumps the gap at
the spark plug electrodes, igniting the mixture in the cylinder in the process. Current continues to travel along the earth
path (via the cylinder head) to the spark plug negative electrode at the cylinder that is on the exhaust stroke. The
current jumps across the spark plug electrodes and back to the coil completing the circuit. Since it has simultaneously
sparked in a cylinder that is on the exhaust stroke, it has not provided an ignition source there and is consequently
termed 'wasted'.
Conditions
The ECM calculates ignition timing using input from the following:
lCKP sensor.
lKnock sensors (KS).
lMAF sensor.
lTP sensor (idle only).
lECT sensor.
Function
At engine start up, the ECM sets ignition timing dependent on ECT information and starting rev/min from the CKP. As
the running characteristics of the engine change, the ignition timing changes. The ECM compares the CKP signal to
stored values in its memory, and if necessary advances or retards the spark via the ignition coils.
Ignition timing is used by the ECM for knock control.
Knock control
The ECM uses active knock control to prevent possible engine damage due to pre-ignition. This is achieved by
converting engine block noise into a suitable electrical signal that can be processed by the ECM. A major contributing
factor to engine 'knock' is fuel quality, the ECM can function satisfactorily on 91 RON fuel as well as the 95 RON fuel
that it is calibrated for.
Conditions
The ECM knock control system operates as follows:
lHot running engine.
l91 or 95 RON fuel.
Function
The ECM knock control uses two sensors located one between the centre two cylinders of each bank. The knock
sensors consist of piezo ceramic crystals that oscillate to create a voltage signal. During pre-ignition, the frequency
of crystal oscillation increases which alters the signal output to the ECM.
If the knock sensors detect pre-ignition in any of the cylinders, the ECM retards the ignition timing by 3
° for that
particular cylinder. If this action stops the engine knock, the ignition timing is restored to its previous figure in
increments of 0.75
°. If this action does not stop engine knock then the ECM retards the ignition timing a further 3° up
to a maximum of -15
° and then restores it by 0.75° and so on until the engine knock is eliminated.
The ECM also counteracts engine knock at high intake air temperatures by retarding the ignition as above. The ECM
uses the IAT signal to determine air temperature.

COOLING SYSTEM - TD5
DESCRIPTION AND OPERATION 26-1-7
Pipes and hoses
The coolant circuit comprises flexible hoses and metal formed pipes which direct the coolant into and out of the
engine, radiator and heater matrix. Plastic pipes are used for the bleed and overflow pipes to the expansion tank.
A bleed screw is installed in the radiator top hose and is used to bleed air during system filling. A drain plug to drain
the heater and cylinder block circuit of coolant is located on the underside of the coolant pump feed pipe.
Oil cooler
The oil cooler is located on the left hand side of the engine block behind the oil centrifuge and oil filter. Oil from the oil
pump is passed through a heat exchanger which is surrounded by coolant in a housing on the side of the engine.
Full water pump flow is directed along the cooler housing which also distributes the flow evenly along the block into
three core holes for cylinder cooling. This cools the engine oil before it is passed into the engine. A small percentage
of the coolant from the oil cooler passes into a metal pipe behind the engine. It then flows into the lower radiator via
a hose.
Fuel cooler
The fuel cooler is located on the right hand side of the engine and is attached to the inlet manifold. The cooler is
cylindrical in design and has a coolant feed connection at its forward end. A 'T' connection at the rear of the cooler
provides a connection for the coolant return from the heater matrix and coolant return from the fuel cooler.
The 'T' connection houses a thermostat which opens at approximately 82
°C. This prevents the cooler operating in
cold climates.
Two quick release couplings on the cooler allow for the connection of the fuel feed from the pressure regulator and
return to the fuel tank. A counter flow system is used within the cooler.
Fuel flows around a coolant jacket within the cooler and flows from the back to the front of the cooler. As the hot fuel
cools travelling slowly forwards it meets progressively colder coolant travelling in the opposite direction maintaining a
differential cooling effect.
EGR Cooler
The EGR Cooler is mounted on the front of the cylinder head. Coolant from the oil cooler flows around the EGR cooler,
cooling the exhaust gas, to improve exhaust emissions, before being returned to the expansion tank.
Coolant pump
1Drive lugs (hidden)
2Housing
3'O' rings4Cover
5Feed hose connection
6Impeller