light LAND ROVER DISCOVERY 1995 User Guide

12ENGINE
6
REPAIR CRANKSHAFT PULLEY
Service repair no - 12.21.01
Remove
1.Disconnect battery negative lead.
2.Drain coolant.
3.Remove top hose from radiator.
4.Remove intercooler to induction manifold hose.
5.Remove viscous fan and coupling.
See
COOLING SYSTEM, Repair, Viscous
Coupling, Fan Blades, Pulley and Fan Cowl
6.Remove fan cowl.
7.Remove drive belt.
See Drive Belt Renew
8.Fit crankshaft pulley retainer LRT-12-080 and
secure with four bolts.
9.Remove crankshaft pulley retaining bolt using
socket and suitable long bar.
10.Remove pulley retainer.
11.Remove pulley, if necessary using extractor
LRT-12-049 with thrust pad from LRT-12-031.Refit
12.Refit in reverse order, lightly greasing pulley
spigot. Tighten to
80 Nm + 90°.

12ENGINE
22
REPAIR
NOTE: Cylinder head retaining bolts can
be used up to a maximum of five times.
34.Lubricate threads of bolts with light oil and fit to
positions illustrated.
Bolt sizes:
M10 x 117mm locations 3, 5, 12, and 13.
M12 x 140mm locations 1, 2, 7, 8, 9, 10, 15, 16, 17,
and 18.
M12 x 100mm locations 4, 6, 11, 14.
35.Tighten bolts so that underside of heads just
make contact with cylinder head.
36.Following the sequence illustrated tighten all
bolts to
40 Nm.
37.Attach degree disc special tool LRT-12-007 to a
power bar.
38.Make a suitable pointer from welding rod and
attach to a bolt screwed into a rocker shaft
securing bolt hole.
39.Tighten all bolts through 60°strictly in sequence
illustrated.
40.Repeat 60°tightening procedure, again strictly in
sequence illustrated.
41.Tighten the ten longer bolts (M12 x 140mm) a
further 20°, again following the sequence
illustrated.
NOTE: Repositioning of the pointer will be
necessary to reach all bolts, the pointer
can be fitted to the rocker shaft securing
studs using two nuts.
CAUTION: The double tightening
procedure must be carried out, on no
account should tightening be performed in
one operation, otherwise damage to the cylinder
head may occur.
42.Fit valve stem caps.
43.Fit push rods to locations from which they were
removed.
44.Fit rocker shaft assembly evenly tightening
securing nuts and bolts to correct torque.
45.Fit rocker cover ensuring oil seal is satisfactory
for continued use.
NOTE: Rocker cover seals can be re-used
up to a maximum of five times.
46.Secure rocker cover with special seal washers
and nuts tightened to correct torque.
47.Refit remainder of items by reversing operations
1 to 22 tightening securing bolts to correct torque
where applicable.

12ENGINE
4
DESCRIPTION AND OPERATION Lubrication system
The V8i full flow lubrication system uses a gear type oil pump which is driven from the front of the crankshaft. The
oil pump gears are housed in the front cover and the pressure relief valve, warning light switch and filter are also
fitted to the front cover.
Oil drawn through the centrally located steel gauze strainer in the sump, is pumped under pressure through oil
cooler located in the lower half of the main coolant radiator. The cooled oil then passes through the filter, before
being distributed from the main gallery via drillings, to the various components in the engine.
Lubrication to the thrust side of the cylinders is by oil grooves machined in each connecting rod big end joint face,
which are timed to align with holes in the big end journals on the power and exhaust strokes.
Lubrication system
1. Oil to cooler
2. Oil from cooler

V8i
5
DESCRIPTION AND OPERATION Distributor and timing chain lubrication
The distributor and timing chain are lubricated from
the camshaft front bearing. The feed to the timing
chain is channelled along the camshaft sprocket, key
and spacer where it sprays onto the chain.
1. Bearing
2. Camshaft
3. Key
4. Camshaft timing chain sprocket
5. Spacer
6. Distributor drive gearHydraulic tappets
1. Clip
2. Pushrod seat
3. Inner sleeve
4. Upper chamber
5. Non-return ball valve
6. Spring
7. Outer sleeve
8. Lower chamber - high pressure
The purpose of the hydraulic tappet is to provide
maintenance free and quiet operation of the inlet and
exhaust valves. It achieves its designed purpose by
utilizing engine oil pressure to eliminate the
mechanical clearance between the rockers and the
valve stems.
During normal operation, engine oil pressure present
in the upper chamber 4, passes through the
non-return ball valve 5 and into the lower (high
pressure) chamber 8.
When the cam begins to lift the outer sleeve 7, the
resistance of the cylinder valve spring felt through the
pushrod seat 2, causes the inner sleeve 3, to move
downwards inside the outer. This slight downward
movement of the inner sleeve closes the ball valve 5
and increases the hydraulic pressure in the high
pressure chamber, sufficient to ensure that the push
rod opens the valve fully.
As the tappet assembly moves off the peak of the cam
the ball valve 5 opens to equalize the pressure in both
chambers which ensures that the valve fully closes
when the tappet is on the back of the cam.

12ENGINE
2
FAULT DIAGNOSIS ENGINE NOISES
Excessive or obtrusive noise from the engine
compartment originates from three main sources:
A. The exhaust system, which makes an
unmistakable and easy to diagnose noise.
B. External components emit the greatest variety of
noises, but are also easy to diagnose by simply
removing the drive belt.
C. Engine internal mechanical noises which can
vary in volume and pitch and may be a
combination of, tapping - knocking or rumbling,
are the most difficult to diagnose. The following
is therefore a guide to diagnosis of engine
internal mechanical noises only.
Engine internal mechanical noises.
Single or multiple, light tapping noise, particularly
when engine is cold.
See Description and
operation, Description
1.Is engine oil level correct?
NO - Top up to correct level.
See
LUBRICANTS, FLUIDS AND
CAPACITIES, Information,
Recommended Lubricants and Fluids
YES - Continue.
2.Is the lubricating pressure correct?
NO -
See Engine Oil Pressure Test
YES - Suspect valve operating mechanism.
3.To confirm diagnosis, remove the rocker covers
and with the engine idling, insert a feeler gauge
of 0,015mm between each rocker and valve
stem. A faulty valve operating mechanism will
emit a different noise when the feeler gauge is
inserted.
See Repair, Rocker Shaft Renew
Heavy knocking noise (particularly on load and
when engine is hot).
See Description and
operation, Description
1.Is engine oil level correct?
NO - Top up to correct level.
See
LUBRICANTS, FLUIDS AND
CAPACITIES, Information,
Recommended Lubricants and Fluids
YES - Continue.
2.Is the lubricating pressure correct?
NO -
See Engine Oil Pressure Test
YES - Drain engine oil and filter, and examine
for metallic contamination.
3.Is the oil contaminated with metal particles?
YES - Suspect faulty big end bearings. To
confirm diagnosis, short out the ignition to
each spark plug in turn. The noise will
disappear or be reduced when the
cylinder with the faulty big end is shorted
out.
4.If noise is not conclusively diagnosed, check the
security of the flywheel and crankshaft front
pulley. Temporarily release the drive belt to
reduce general noise level and use a
stethoscope to locate source of noise.
Heavy rumbling noise (particularly during hard
acceleration).
See Description and operation,
Description
1.Is engine oil level correct?
NO - Top up to correct level.
See
LUBRICANTS, FLUIDS AND
CAPACITIES, Information,
Recommended Lubricants and Fluids
YES - Continue.
2.Is the lubricating pressure correct?
NO -
See Engine Oil Pressure Test
YES - Drain engine oil and filter, and examine
for metallic contamination.
3.Is the oil contaminated with metal particles?
YES - Suspect faulty main bearings. If noise is
not conclusively diagnosed, check the
security of the flywheel and crankshaft
front pulley. Temporarily release the drive
belt to reduce general noise level and use
a stethoscope to locate source of noise.

12ENGINE
4
REPAIR CYLINDER HEAD GASKETS - RENEW
Service repair no - 12.29.01
1.Drain cooling system.
See COOLING SYSTEM,
Adjustment, Coolant
2.Remove inlet manifold.See FUEL SYSTEM,
Repair, Intake Manifold
3.Remove generator.
4.If fitted, remove compressor.
See AIR
CONDITIONING, Repair, Compressor
5.Remove rocker shafts.See Rocker Shaft
Renew
6.Remove push rods.
7.Remove both exhaust manifolds.
See
MANIFOLD AND EXHAUST SYSTEM, Repair,
Exhaust Manifold - V8i
8.Remove air cleaner assembly.See FUEL
SYSTEM, Repair, Air Cleaner Assembly
9.Remove air flow sensor.See FUEL SYSTEM,
Repair, Air Flow Sensor
10.Remove ground leads from rear of left hand
cylinder head
11.Right hand cylinder head - remove breather pipe
from lifting bracket.
12.Loosen cylinder head bolts, reversing tightening
sequence.
13.Remove cylinder heads.
14.Remove cylinder head gaskets.
15.Clean exhaust mating faces.
16.Clean head and block faces.
17.Fit new cylinder head gaskets, word TOP
uppermost. DO NOT use sealant.
18.Oil cylinder bores.
19.Clean threads of head bolts and lightly oil.
20.Locate cylinder heads on block.
21.Locate cylinder head bolts in position illustrated.
96 mm long bolts - 2, 4, 6, 7, 8, 9, 10
66 mm long bolts - 1, 3, 5
NOTE: There are no bolts fitted in the four
lower holes in each cylinder head.
NOTE: Left hand cylinder head illustrated,
arrow points to front of vehicle.
22.Tighten bolts progressively in sequence, shown
to
20 Nmthen a further 180°±5°
23.Reverse removal procedure. 1 to 11.

V8i
9
REPAIR FRONT COVER GASKET
Service repair no - 12.65.04
1.Remove crankshaft pulley.
See Crankshaft
Pulley Assembly. Do not remove pulleys
2.Remove water pump pulley.
3.Release distributor cap clips.
4.Release plug leads from plugs and clips.
5.Place cap and leads to one side.
6.Turn engine until No. 1 piston is at T.D.C.
7.Check position of rotor arm.
8.Remove fixings securing power steering pump
bracket to water pump bracket.
9.Remove power steering pump bracket from
water pump.
10.Remove clips securing wiring to generator
tensioner.
11.Disconnect distributor feed wire.
12.Pivot power steering pump away from front
cover, tighten pivot to retain in position.
13.Disconnect vacuum pipe from distributor.
14.Remove water pump bottom hose.
15.Disconnect oil pressure switch.
16.Disconnect heater hose at water pump.
17.Remove generator tensioner from water pump,
move tensioner aside.
18.Mark distributor position to front cover.
19.Remove distributor clamp, remove distributor.
See ELECTRICAL, Repair, Distributor - V8i
20.Remove fixings sump to front cover.
21.Loosen four adjacent sump fixings.
22.Remove generator support strut from front cover,
move strut aside.
23.Loosen remaining front cover fixings and remove
front cover.
24.Remove front cover gasket.Refit
25.Clean timing cover, clean block face.
26.Lightly grease gasket faces.
27.Fit new gasket to block face.
28.Apply hylosil to sump gasket.
29.Clean threads of cover fixing bolts, apply Loctite
372 to threads.
30.Fit timing cover, fit fixing bolts. Tighten to
28
Nm.
31.Fit generator support strut to front cover.
32.Tighten sump to timing cover fixings to
10 Nm.
33.Tighten sump fixings to10 Nm.
34.Lubricate distributor O ring.
35.Fit distributor in position marked.
36.Align oil pump drive, if distributor does not seat
correctly.
37.Fit distributor clamp. Tighten to
20 Nm.
38.Locate generator tensioner on water pump
bracket.
39.Connect heater hose, tighten clip.
40.Connect oil pressure switch.
41.Connect bottom hose, tighten clip.
42.Connect vacuum pipe to distributor.
43.Loosen power steering pump pivot, lower pump.
44.Connect distributor feed wire.
45.Connect wire ties to generator tensioner.
46.Fit power steering pump bracket to water pump.
Tighten to
28 Nm.
47.Fit power steering pump to bracket.
48.Position distributor cap. Fit plug leads to plugs
and clips.
49.Clip distributor cap in position.
50.Fit water pump pulley. Tighten to
10 Nm.
51.Fit crankshaft pulley.See Crankshaft Pulley
Assembly
52.Tension drive belts correctly.
53.Check ignition timing.
54.Refill cooling system.

EMISSION CONTROL
1
FAULT DIAGNOSIS REV: 09/95 TESTING EVAPORATIVE EMISSION CONTROL -
PRE ADVANCED EVAPS
The following pressure test procedure is intended to
provide a method for ensuring that the system does
not leak excessively and will effectively control
evaporative emissions.
Equipment required.
Nitrogen cylinder (compressed air may be used to
pressure the system when there has NEVER been
fuel present in the fuel or evaporative control
systems).
Water manometer (0 - 30" H2O or more).
Pipework and a "T" piece.
Method.
1.Ensure that there is at least two gallons of fuel in
the petrol tank unless there has never been any
fuel in the system.
2.Disconnect, at the adsorption canister, the pipe
to the vapour separator.
3.Connect this pipe to the nitrogen cylinder and
the water manometer using the "T" piece.
4.Pressurize the system to between 26.5 and 27.5
inches of water, allow the reading to stabilize,
then turn off the nitrogen supply.
5.Measure the pressure drop within a period of 2
minutes 30 seconds. If the drop is greater than
2.5 inches of water the system has failed the
test. Note that a fully sealed system will show a
slight increase in pressure.
6.Should the system fail the test, maintain the
pressure in the system and apply a soap
solution round all the joints and connections until
bubbles appear to reveal the source of the leak.
7.Repeat the test and if successful, dismantle the
test equipment and reconnect the pipe to the
adsorption canister.LEAK DETECTION PROCEDURE - ADVANCED
EVAPS
1.Connect TestBook to the vehicle and confirm
that the fault code(s) displayed relate to an
EVAP system fault.
2.Examine components in fuel and EVAP system
for damage or poorly connected joints.
3.Repair or replace components to rectify any
faults found, then reset the Check Engine light
using TestBook.
4.Carry out Drive Cycle,
See Drive Cycle -
Advanced EVAPS
5.Using TestBook confirm that the Evaporative
Loss Control (ELC) Inspection and Maintenance
(IM) flag has cleared. This procedure should
confirm that the ELC test was carried out during
the drive cycle and that the fault was cured.
6.If the IM flag is still shown, use TestBook to
interrogate the engine management system to
ascertain which of the following situations exists:
·If a fault code is shown then further investigation
is required, proceed to the next step.
·If the IM flag is still shown, but no faults are
indicated the conditions for the ELC check have
not been met and the drive cycle must be
repeated.
7.Connect the Leak Detection/EVAP Diagnostic
Station to the vehicle and carry out the
procedures given in the operating instructions
supplied with the equipment.
8.Rectify faults indicated by the Leak
Detection/EVAP Diagnostic Station and return to
step 4.

17EMISSION CONTROL
2
FAULT DIAGNOSISADD: 09/95 DRIVE CYCLE - ADVANCED EVAPS
1.Switch on ignition for 30 seconds.
2.Ensure that coolant temperature is less than 140
°F (30°C).
3.Start engine and allow to idle for 2 minutes.
4.Perform 2 light accelerations (0 to 35 mph with
light pedal pressure).
5.Perform 2 medium accelerations (0 to 45 mph
with moderate pedal pressure).
6.Perform 2 hard accelerations (0 to 55 mph with
heavy pedal pressure).
7.Cruise at 60 mph for 5 minutes.
8.Cruise at 50 mph for 5 minutes.
9.Cruise at 35 mph for 5 minutes.
10.Allow engine to idle for 2 minutes.
11.Connect TestBook and check for fault codes.

19FUEL SYSTEM
4
DESCRIPTION AND OPERATION OPERATION
Diesel engines operate by compression ignition. The
rapid compression of air in the cylinder during the
compression cycle heats the injected fuel, causing it
to self ignite. During cold starting, automatically
controlled glow plugs assist in raising the temperature
of the compressed air to ignition point.
A cold start advance unit advances the injection timing
to further assist starting. Idle quality is improved by
the high idle setting.
The engine is supplied with pre-compressed air by a
single stage turbocharger.
Exhaust gases passing over a turbine cause it to
rotate, driving a compressor mounted on the turbine
shaft. Air drawn from the cold air intake passes, via
the air cleaner, to the turbocharger where it is
compressed. The compressed air passes to the
cylinders via an intercooler, which reduces the
temperature of the compressed air, increasing its
density.
Fuel is drawn from the tank by a mechanical lift pump
and passes to the injection pump via a filter. In
addition to removing particle contamination from the
fuel, the filter incorporates a water separator, which
removes and stores both bound and unbound water.
The injection pump meters a precisely timed, exact
quantity of fuel to the injectors in response to throttle
variations, injection timing varying with engine speed.
Any excess fuel delivered to the injection pump is not
injected, passing back to the tank via the fuel return
line.
Fuel is injected in a finely atomised form into a
pre-combustion chamber in the cylinder head where it
ignites. The burning fuel expands rapidly into the main
combustion chamber, creating extreme turbulence
which mixes the burning fuel thoroughly with the
compressed air, providing complete combustion.
Cold Starting is assisted by glow plugs, a cold start
advance unit and a high idle setting.Glow plugs
Glow plug operation is controlled by a timer unit, start
relay and resistor. When the ignition is turned on the
timer unit is energised, the glow plugs start to operate
and a warning light on the dashboard illuminates,
remaining illuminated until the glow plugs are
automatically switched off.
The length of time the glow plugs will operate is
dependent on under bonnet temperature, which is
monitored by a sensor located in the timer unit.
Starting the engine results in the power supply to the
glow plugs passing through the resistor, which
reduces their operating temperature. The glow plugs
are cut out either by the temperature sensor in the
timer, or by a microswitch on the injection pump which
operates when the throttle is depressed.
Cold start advance
The cold start advance unit is connected to the engine
cooling system via hoses. It contains a temperature
sensitive element which is retracted when cold and
pulls the advance lever, via cable, towards the rear of
the pump against spring pressure. As coolant
temperature rises, the cold start element expands
releasing tension on the cable and allowing spring
pressure to move the advance lever forwards.