check engine LAND ROVER DISCOVERY 1995 Owner's Manual

Tdi
1
SPECIFICATIONS, TORQUE TORQUE VALUES
NOTE: Torque wrenches should be regularly checked for accuracy to ensure that all fixings are
tightened to the correct torque.
Nm
Engine block
Bearing cap 133...............................................................................................
Blanking plug, oil gallery, rear 37....................................................................
Oil squirt jet assembly 17................................................................................
Drain plug, cylinder block 25...........................................................................
Oil squirt jet, vacuum pump cam 7.................................................................
Connecting rod to cap 59................................................................................
Oil pick up assembly to bearing cap 9...........................................................
Oil pick up assembly to front cover 25............................................................
Camshaft thrust plate 9..................................................................................
Oil drain pipe to block (internal) 25.................................................................
Oil drain pipe to block (external) 25................................................................
Sump to cylinder block and front cover 25......................................................
Drain plug, oil sump 35...................................................................................
Tappet guide 14..............................................................................................
Breather side cover assembly 25....................................................................
Baffle plate to breather side cover 4..............................................................
Vacuum pump 25............................................................................................
Fuel lift pump 25.............................................................................................
Flywheel housing 45.......................................................................................
Flywheel housing clutch cover stud 10...........................................................
Plug, flywheel housing 12...............................................................................
Rear oil seal assembly 25...............................................................................
Oil filter adaptor 45..........................................................................................
Waxstat adaptor to oil filter adaptor 9............................................................
Oil pressure switch 17.....................................................................................
Oil filter, spin on 13.........................................................................................
Oil cooler unions to filter adaptor 45...............................................................
Oil level tube 25..............................................................................................
Engine mounting foot to cylinder block 85......................................................
Engine mounting foot to flywheel housing 45.................................................
Engine mounting foot rubber to mounting foot (bolt and nut) 85.....................
Flywheel to crankshaft 146..............................................................................
Clutch cover plate to flywheel 34....................................................................
Flex drive plate to crankshaft (auto) 146..........................................................
Flex drive plate to ring gear (auto) 25.............................................................
Flex drive plate to torque converter (auto) 45.................................................

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1
FAULT DIAGNOSIS ENGINE OIL PRESSURE TEST
Service tools:
LRT-12-052: Pressure test equipment
WARNING: Use suitable exhaust
extraction equipment, if test is being
carried out in workshop.
WARNING: If vehicle has been running,
engine oil will be hot, care must be taken
when fitting equipment to prevent
personal injury due to scalding.
Test
1.Check lubricant is to correct level.
2.Place vehicle on a ramp [hoist].
3.Disconnect battery negative lead. Remove oil
pressure switch.
4.Fit the test gauge.
5.Reconnect battery negative lead.
6.Start and run engine to normal operating
temperature.
7.At a steady engine speed of 2500 rev/min -
engine oil pressure reading should be - 2.75 bar
(40 lbf/in
2).
8.If the pressure is low - Remove and overhaul oil
pump
CYLINDER COMPRESSION - TEST
Equipment:
Compression pressure gauge
Test
1.Start and run engine until normal engine
operating temperature is achieved (thermostat
open).
2.Remove all spark plugs.
3.Disconnect both coil negative (WB) leads
4.Insert compression gauge, crank engine until
reading stabilises.
5.Expected readings, throttle fully open, battery
fully charged:
8.31:1 = 10.2-10.9 bar, 150-160lbf/in
2
9.35:1 = 11.5-12.2 bar, 170-180lbf/in2

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.

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FAULT DIAGNOSIS ENGINE STARTING PROBLEMS
Engine fails to crank in park or neutral (Automatic
Transmission)
1.Is battery in good state of charge?
NO -
See INTRODUCTION, Information,
Jump Starting
YES - Continue.
2.Is automatic transmission inhibitor switch faulty
or gear selection linkage incorrectly adjusted?
YES -
See AUTOMATIC GEARBOX, Repair,
Inhibitor Switch
,
NO -
See Electrical Trouble Shooting
Manual.
If problem is not diagnosed repeat tests, starting
at 1.
Engine fails to crank (Manual Transmission)
1.Is battery in good state of charge?
NO -
See INTRODUCTION, Information,
Jump Starting
YES -See Electrical Trouble Shooting
Manual.
If problem is not diagnosed repeat tests, starting
at 1.
Engine cranks but fails to start
1.Is the cranking speed fast enough (120 rpm)?
NO -
See INTRODUCTION, Information,
Jump Starting
If necessary also.See Electrical Trouble
Shooting Manual.
YES - Continue.
2.Is there combustion in any cylinder?
NO -
See ELECTRICAL, Fault diagnosis,
Lucas Constant Energy Ignition
System - V8i See Electrical Trouble
Shooting Manual.
YES - Continue.
3.Are the fuel supply, tank, pump, ventilation and
emission control systems in correct working
order or the fuel contaminated?
NO -
See FUEL SYSTEM, Repair, Fuel
Filter See FUEL SYSTEM, Repair,
Fuel Tank See FUEL SYSTEM, Repair,
Fuel pump and Sender Unit See
EMISSION CONTROL, Description and
operation, Emission control
If problem is not diagnosed repeat tests, starting
at 2.ENGINE RUNNING PROBLEMS
Engine runs at high speed but will not idle (stops)
Engine idle speed erratic Engine starts but stops
immediately
Engine stalls Engine misfires/hesitation
1.Multiport fuel injection.
See Electrical Trouble
Shooting Manual. See ELECTRICAL, Fault
diagnosis, Lucas Constant Energy Ignition
System - V8i
Check brake vacuum connections.See
BRAKES, Description and operation, Brake
Servo Unit
Check heater/ventilation unit vacuum
connections.
See HEATING AND
VENTILATION, Description and operation,
Heating and Ventilation Unit
If problem is not diagnosed continue.
2.Are HT leads correctly routed and clipped?
NO -
See ELECTRICAL, Repair, Distributor
- V8i
YES - Continue.
3.Is fuel supply, tank, pump, ventilation and
emission control systems in correct working
order or the fuel contaminated?
NO -
See FUEL SYSTEM, Repair, Fuel
Filter See FUEL SYSTEM, Repair,
Fuel Tank See FUEL SYSTEM, Repair,
Fuel Pump and Sender Unit See
EMISSION CONTROL, Description and
operation, Emission Control
If problem is not diagnosed repeat tests, starting
at 1.
Engine lacks power/poor performance
1.Is throttle travel restricted or cable incorrectly
adjusted?
YES - Check thickness of carpets.
See FUEL
SYSTEM, Repair, Throttle Cable See
FUEL SYSTEM, Repair, Accelerator
Pedal
NO - Continue.
2.Are the Ignition and Multiport Fuel Injection
systems in order?
NO -
See Electrical Trouble Shooting
Manual.A1 See ELECTRICAL, Fault
diagnosis, Lucas Constant Energy
Ignition System - V8i See
ELECTRICAL, Repair, Distributor - V8i
YES - Continue.

12ENGINE
4
FAULT DIAGNOSIS 3.Are fuel supply, tank, pump, ventilation and
emission control systems in correct working
order or the fuel contaminated?
NO -
See FUEL SYSTEM, Repair, Fuel
Filter See FUEL SYSTEM, Repair,
Fuel Tank See FUEL SYSTEM, Repair,
Fuel Pump and Sender Unit
YES - Suspect valves held open by hydraulic
tappets due to high oil pressure.
See
Engine Oil Pressure Test
4.Is oil pressure high?
YES - Remove oil filter and cooler adaptor and
check pressure relief valve strainer gauze
for blockage and that the relief valve is
not stuck closed.
See Description and
operation, Description
NO - Carry out cylinder compression tests to
determine condition of head gaskets and
valves.
See Cylinder Compression -
Test
5.Are cylinder compressions satisfactory?
NO -
See Repair, Cylinder Heads - Renew
YES - Check brake vacuum connections.See
BRAKES, Description and operation,
Brake Servo Unit
Check heater/ventilation unit vacuum connections.
See HEATING AND VENTILATION, Description and
operation, Heating and Ventilation Unit
If problem is not diagnosed: Continue.
6.Are the brakes binding?
YES - Investigate cause of binding.
NO - Continue.
7.Automatic Transmission only. Is the Torque
Converter and Transmission operating correctly?
Carry out Road test, Static tests and Stall tests
to determine condition of Automatic
transmission.
If problem is not diagnosed: repeat tests starting at 1.Engine backfires into exhaust system
1.Are there any leaking joints/connections or holes
in the exhaust system?
YES -
See MANIFOLD AND EXHAUST
SYSTEM, Repair, Exhaust System
Complete
NO - Continue.
2.Is distributor fitted correctly, HT leads in correct
firing order and routed correctly?
NO -
See ELECTRICAL, Repair, Distributor
- V8i
YES - Continue.
3.Is air fuel ratio correct?
NO - Check multiport fuel injection.
See
Electrical Trouble Shooting Manual.
Check brake vacuum connections.See
BRAKES, Description and operation, Brake
Servo Unit
Check heater/ventilation unit vacuum
connections.
See HEATING AND
VENTILATION, Description and operation,
Heating and Ventilation Unit
Check the crank case and fuel tank ventilation
system.
See EMISSION CONTROL,
Description and operation, Emission Control
YES - Continue.
4.Are cylinder compressions satisfactory?
NO - Carry out compression test to check for
leaking gaskets valves etc.
See
Cylinder Compression - Test
See Repair, Cylinder Heads - Renew
If problem is not diagnosed: repeat tests starting
at 1.

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FAULT DIAGNOSIS Engine backfires into inlet system
1.Is the Distributor, HT connections and routing
correct?
NO -
See ELECTRICAL, Repair, Distributor
- V8i
YES - Continue.
2.Is air fuel ratio correct?
NO - Check multiport fuel injection.
See
Electrical Trouble Shooting Manual.
Check brake vacuum connections.See
BRAKES, Description and operation, Brake
Servo Unit
Check heater/ventilation unit vacuum
connections.
See HEATING AND
VENTILATION, Description and operation,
Heating and Ventilation Unit
Check the crank case and fuel tank ventilation
system.
See EMISSION CONTROL,
Description and operation, Emission Control
YES - Continue.
3.Are cylinder compressions satisfactory?
NO - Carry out compression test to check for
leaking gaskets valves etc.
See
Cylinder Compression - Test
For repairSee Repair, Cylinder Heads -
Renew
If problem is not diagnosed: repeat tests starting
at 1.

12ENGINE
2
REPAIR Remove
1.Remove fan cowl upper.
2.Release drive belt tension by turning tensioner
clockwise.
3.With tension released, remove belt from
generator pulley.
4.Release tensioner pulley.
5.Remove drive belt. Mark direction of rotation on
belt if refitting
Refit
6.Clean drive belt pulley grooves and ensure
grooves are not damaged.
7.Position belt correctly around all pulleys except
generator. Illustrations RR3956 and RR3957
show correct drive belt run.
8.Turn drive belt tensioner clockwise.
9.Locate drive belt on generator pulley.
10.Ensure drive belt is squarely located on pulleys
with all grooves engaged.
11.Release tensioner to tension drive belt.
12.Fit upper fan cowl section.DRIVE BELT - CHECK TENSION
As the drive belt is automatically tensioned, no tension
check or adjustment should be necessary. If the drive
belt is believed to be slack carry out the following
checks:
1.Visually check drive belt tension.
2.Watch movement of tensioner with engine
running, 5 mm 'bounce' is normal. If tensioner
movement is 12 mm or more, fit a new tensioner.
See Drive Belt Tensioner
3.Inspect tensioner. Is the tensioner arm and
spring case in contact? If so fit a new tensioner.
4.Using a recognised drive belt tensioning gauge,
check belt tension several times, running engine
between checks. The checks should be made at
the same point on the belt, away from the
tensioner.
Drive belt tension, with used tensioner and used drive
belt should be more than:-
270N. Non air conditioning or
295N with air conditioning.

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5
REPAIR CYLINDER HEADS - RENEW
Service repair no - 12.29.15
1.Remove cylinder heads and gaskets.
See
Cylinder Head Gaskets - Renew
2.Remove spark plugs.
3.Using spring compressor LRT-12-034, remove
seals, valves, collets, springs and caps.
CAUTION: Keep components in fitted
order
4.From left hand cylinder head, remove earth lead
studs.
5.Remove three bolts securing power steering
pump mounting bracket to cylinder head.
6.Remove four bolts securing generator mounting
bracket to cylinder head.
7.Right hand cylinder head, remove rear lifting
bracket.
8.Fit lifting bracket to new right hand cylinder
head.
9.Fit mounting brackets and earth lead studs to
new cylinder head. Tighten bolts to
30 Nm.
10.Regrind valves- refer to engine overhaul
publication
11.Lubricate valve stems, fit valves, springs, and
caps. Fit new inlet and exhaust valve stem seals.
12.Using spring compressor LRT-12-034, compress
springs, fit collets. Tap valve to check correct
collet seating.
13.Fit spark plugs.
14.Fit cylinder heads with new gaskets.
See
Cylinder Head Gaskets - Renew
ROCKER COVER - RIGHT HAND - RENEW
Service repair no - 12.29.41
1.Disconnect battery negative lead.
2.Disconnect purge pipe from charcoal canister at
plenum.
3.Remove breather pipe from rocker cover.
4.Remove coolant pipes from inlet manifold.
5.Remove spark plug leads from plugs and
retaining clips.
6.Remove four rocker cover bolts. Moving fuel
pipes aside, remove rocker cover.
7.Discard rocker cover gasket.
8.Remove plug lead retaining clips from rocker
cover, fit to new rocker cover.
9.Clean and dry rocker cover and cylinder head
mating faces, using Bostik cleaner 6001.
NOTE: Gasket fits one way round only. It
must be fitted accurately, first time.
Subsequent movement will destroy
bonding.
10.Apply Bostik 1775 impact adhesive to rocker
cover seal face and gasket, using a brush to
ensure an even film. Allow adhesive to become
touch dry.

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.

12ENGINE
10
REPAIR TIMING CHAIN AND CHAINWHEELS
Service repair no - 12.65.12
Remove
1.Remove front cover.
See Front Cover Gasket
2.Remove retaining bolt and washer, remove
distributor drive gear and spacer.
3.Ensure number one piston is at TDC.
4.Remove chainwheels and chain as an assembly.
See V8i Overhaul Manual.
Refit
5.Clean chainwheels and chain.
6.Fit chainwheels to chain, aligning timing marks.
7.Ensure camshaft key is fitted parallel to shaft
axis to ensure adequate lubrication to distributor
drive gear.
8.Engage chainwheel assembly on camshaft and
crankshaft keys, ensure chain wheels are fully
located.
9.Check alignment of timing marks with straight
edge.
10.Fit spacer with flange to front,
11.Fit distributor drive gear with groove towards
spacer.
12.Fit retaining bolt and washer. Tighten to
58 Nm.
13.Fit front cover.See Front Cover Gasket
FLYWHEEL
Service repair no - 12.53.07
Remove
1.Remove gearbox and clutch.
See CLUTCH,
Repair, Clutch Assembly
2.Loosen starter motor bolts.
3.Lock flywheel, remove flywheel bolts and
flywheel.
Refit
4.Clean components for reassembly.
5.Fit flywheel.
6.Clean threads, apply Loctite 270 to threads.
7.Lock flywheel, fit flywheel bolts. Tighten to
80
Nm.