1995 LAND ROVER DISCOVERY check engine

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.

V8i
5
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.

V8i
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.

12ENGINE
12
REPAIR
12.Ensure service tools LRT-12-010 and
LRT-12-091 are scrupulously clean. Coat seal
guide and oil seal journal with clean engine oil.
CAUTION: Do not handle oilseal lip, check
it is not damaged. Ensure outside diameter
remains clean and dry.
13.Position oil seal guide LRT-12-010 on crankshaft
flange.
NOTE: Lubricant coating must cover seal
guide outer surface completely to ensure
that oil seal lip is not turned back during
assembly. Position oil seal, lipped side towards
engine, on seal guide. Seal outside diameter
MUST be clean and dry.
14.Fit oil seal using tool LRT-12-091. Remove seal
guide.
15.Tighten rear main bearing cap to
90 Nm.
16.Fit sump.
17.Fit flywheel or flexible drive plate and ring gear.ENGINE
Service repair no - 12.41.01
Remove
1.Park vehicle on level ground and apply park
brake.
2.De-pressurise fuel system.
See FUEL
SYSTEM, Repair, Depressurising Fuel
System
3.Remove bonnet [hood].See CHASSIS AND
BODY, Repair, Bonnet [Hood]
4.Remove battery.See ELECTRICAL, Repair,
Battery
5.Remove radiator/oil coolers.See COOLING
SYSTEM, Repair, Radiator/Oil Coolers
6.Place an absorbent cloth around fuel feed hose
at fuel rail and release compression nut.
Remove feed hose from rail, seal end of pipes
with masking tape to prevent ingress of dirt.
7.Release fuel return hose clamp and remove
hose from pressure regulator, seal both
openings with masking tape to prevent ingress of
dirt.
8.Remove vacuum hose from rear of regulator.
9.Manual vehicles: Disconnect throttle cable from
bracket. Automatic vehicles: Detach throttle
bracket from plenum chamber and lay assembly
to one side.
See FUEL SYSTEM, Repair,
Plenum Chamber DO NOT DISTURB KICK
DOWN CABLE SETTING.
10.Remove ram housing.See FUEL SYSTEM,
Repair, Ram Housing
11.Remove air flow sensor.See FUEL SYSTEM,
Repair, Air Flow Sensor
12.Remove air cleaner assembly.See FUEL
SYSTEM, Repair, Air Cleaner Assembly
13.Remove Generator.See ELECTRICAL,
Description and operation, Generator
14.Release air conditioning compressor from its
mounting and lay to one side. DO NOT
discharge air conditioning system.
See AIR
CONDITIONING, Repair, Compressor

V8i
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
Adaptor plate to crankshaft 84........................................................................
Generator and power steering mounting bracket to cylinder head 30............
Cylinder head:
Stage 1: 20.............................................................................................
Stage 2: - Further 180°±5°
Drive plate to converter 39..............................................................................
Engine mountings to engine and chassis 55..................................................
Engine mounting rubbers to brackets 30........................................................
Flexible drive plate to crankshaft adaptor plate 41.......................................... **
Flywheel to crankshaft bolts 78....................................................................... **
Lifting eye to cylinder heads 39......................................................................
Main bearing cap rear bolts 92....................................................................... *
Oil sump drain plug 40....................................................................................
Oil sump to cylinder block 18..........................................................................
Rocker cover to cylinder head 9....................................................................
Rocker shaft bracket to cylinder head 38........................................................
Spark plug 21..................................................................................................
Starter motor attachment 44...........................................................................
* These bolts must have threads coated in lubricant EXP16A before assembly.
** These bolts must have threads coated in sealant Loctite 270
METRIC Nm
M5 6......................................................................................................
M6 9......................................................................................................
M8 25.....................................................................................................
M10 45...................................................................................................
M12 90...................................................................................................
M14 105..................................................................................................
M16 180..................................................................................................
UNC / UNF
1/4 9......................................................................................................
5/16 24...................................................................................................
3/8 39.....................................................................................................
7/16 78...................................................................................................
1/2 90.....................................................................................................
5/8 136....................................................................................................
NOTE: Torque values above are for all screws and bolts used except for those specified.