spark plugs LAND ROVER DISCOVERY 1999 Workshop Manual

CONTENTS
CONTENTS 3
MAINTENANCE ........................................................................................ 10-1
PROCEDURES
V8 engine underbonnet view .......................................................................................................... 10-1
Diesel underbonnet view ................................................................................................................. 10-2
Seats and seat belts ...................................................................................................................... 10-3
Lamps, horns and warning indicators ............................................................................................. 10-5
Wipers and washers ...................................................................................................................... 10-5
Handbrake .................................................................................................................................. 10-6
Alarm handset battery ..................................................................................................................... 10-6
Road wheels ................................................................................................................................... 10-6
Tyres .............................................................................................................................................. 10-6
Brake pads, discs and calipers ....................................................................................................... 10-6
Road wheel speed sensors ............................................................................................................. 10-7
Brake fluid ....................................................................................................................................... 10-7
Fuel filter - diesel engine ................................................................................................................. 10-7
Fuel filter sedimenter ...................................................................................................................... 10-7
Road wheels ................................................................................................................................... 10-8
Radiator/Intercooler ........................................................................................................................ 10-8
Ambient air Temperature and pressure sensor .............................................................................. 10-8
Doors, bonnet and fuel filler flap ..................................................................................................... 10-8
Air suspension intake filter .............................................................................................................. 10-9
Anti-freeze....................................................................................................................................... 10-9
Cooling system ............................................................................................................................... 10-9
Spark plugs - V8 engine.................................................................................................................. 10-10
Air cleaner - V8 engine ................................................................................................................... 10-10
Air cleaner and dump valve - diesel engine .................................................................................... 10-10
Auxiliary drive belt ........................................................................................................................... 10-11
Auxiliary drive belt - V8 engine ....................................................................................................... 10-11
Auxiliary drive belt - diesel engine .................................................................................................. 10-11
Fluid reservoirs ............................................................................................................................... 10-12
Steering box .................................................................................................................................... 10-13
Battery ............................................................................................................................................. 10-13
Intercooler - diesel engine............................................................................................................... 10-14
Engine oil - V8 engine ..................................................................................................................... 10-14
Engine oil - diesel engine ................................................................................................................ 10-15
Centrifuge rotor – diesel engine ...................................................................................................... 10-15
Engine oil filter - diesel engine ........................................................................................................ 10-16
Engine oil filter – V8 engine ............................................................................................................ 10-16
Manual gearbox .............................................................................................................................. 10-17
Automatic gearbox ......................................................................................................................... 10-18
Transfer box .................................................................................................................................... 10-19
Front and rear axle .......................................................................................................................... 10-20
Propeller shafts ............................................................................................................................... 10-20
Anti-roll bar links ............................................................................................................................. 10-22
ACE actuators ................................................................................................................................. 10-23
ACE filter ......................................................................................................................................... 10-23

CONTENTS
CONTENTS 7
ENGINE MANAGEMENT SYSTEM - V8 .................................................. 18-2-1
DESCRIPTION AND OPERATION
Engine management component location - Passenger compartment ............................................ 18-2-1
Engine management component location - Engine compartment .................................................. 18-2-2
Engine management block diagram ............................................................................................... 18-2-4
Description - engine management .................................................................................................. 18-2-6
Operation - engine management .................................................................................................... 18-2-49
DESCRIPTION AND OPERATION
Cruise control component layout .................................................................................................... 18-2-61
Cruise control block diagram .......................................................................................................... 18-2-62
Description - cruise control ............................................................................................................. 18-2-63
Operation - cruise control................................................................................................................ 18-2-74
ADJUSTMENTS
Cable - throttle ............................................................................................................................. 18-2-77
Cable - cruise control .................................................................................................................... 18-2-77
REPAIRS
Spark plugs .................................................................................................................................. 18-2-79
Coil - ignition ................................................................................................................................. 18-2-80
Engine control module (ECM) ......................................................................................................... 18-2-81
Sensor - engine coolant temperature (ECT) ................................................................................ 18-2-82
Sensor - crankshaft position (CKP) ............................................................................................... 18-2-83
Sensor - radiator temperature ....................................................................................................... 18-2-84
Sensor - camshaft position (CMP) ................................................................................................. 18-2-84
Knock sensor (KS) .......................................................................................................................... 18-2-85
Air cleaner assembly ..................................................................................................................... 18-2-86
Element - air filter .......................................................................................................................... 18-2-87
Cable - throttle ................................................................................................................................ 18-2-88
Sensor - Mass Air Flow (MAF) ...................................................................................................... 18-2-89
Throttle Body................................................................................................................................... 18-2-90
Plenum chamber ............................................................................................................................. 18-2-91
Sensor - throttle position (TP) ....................................................................................................... 18-2-91
Valve - idle air control (IACV) ........................................................................................................ 18-2-92
Injectors ......................................................................................................................................... 18-2-92
Actuator - cruise control ................................................................................................................ 18-2-94
Vacuum control unit - up to 03MY................................................................................................... 18-2-94
Vacuum control unit - from 03MY ................................................................................................... 18-2-95
Cable - cruise control ..................................................................................................................... 18-2-96
Switch - cruise control (on/off) ........................................................................................................ 18-2-96
Switch - cruise control (set/resume) ............................................................................................... 18-2-97
Switch - clutch pedal - cruise control ............................................................................................ 18-2-97
ECU - Cruise control ..................................................................................................................... 18-2-98

GENERAL INFORMATION
03-17
Electrical Precautions
General
The following guidelines are intended to ensure the
safety of the operator while preventing damage to the
electrical and electronic components fitted to the
vehicle. Where necessary, specific precautions are
detailed in the individual procedures of this manual.
Equipment
Prior to commencing any test procedure on the
vehicle ensure that the relevant test equipment is
working correctly and any harness or connectors are
in good condition. It is particularly important to check
the condition of the lead and plugs of mains operated
equipment.
Polarity
Never reverse connect the vehicle battery and
always ensure the correct polarity when connecting
test equipment.
High voltage circuits
Whenever disconnecting live ht circuits always use
insulated pliers and never allow the open end of the
ht lead to contact other components, particularly
ECU's. Exercise caution when measuring the voltage
on the coil terminals while the engine is running, high
voltage spikes can occur on these terminals.Connectors and harnesses
The engine compartment of a vehicle is a particularly
hostile environment for electrical components and
connectors:
lAlways ensure electrically related items are dry
and oil free before disconnecting and
connecting test equipment.
lEnsure disconnected multiplugs and sensors
are protected from being contaminated with oil,
coolant or other solutions. Contamination could
impair performance or result in catastrophic
failure.
lNever force connectors apart using tools to
prise apart or by pulling on the wiring harness.
lAlways ensure locking tabs are disengaged
before disconnection, and match orientation to
enable correct reconnection.
lEnsure that any protection (covers, insulation
etc.) is replaced if disturbed.
Having confirmed a component to be faulty:
lSwitch off the ignition and disconnect the
battery.
lRemove the component and support the
disconnected harness.
lWhen replacing the component keep oily hands
away from electrical connection areas and push
connectors home until any locking tabs fully
engage.
Battery disconnection
Before disconnecting the battery, disable the alarm
system and switch off all electrical equipment. If the
radio is to be serviced, ensure the security code has
been deactivated.
CAUTION: To prevent damage to electrical
components, always disconnect the battery
when working on the vehicle's electrical system.
The ground lead must be disconnected first and
reconnected last.
CAUTION: Always ensure that battery leads are
routed correctly and are not close to any
potential chafing points.
Battery charging
Only recharge the battery with it removed from the
vehicle. Always ensure any battery charging area is
well ventilated and that every precaution is taken to
avoid naked flames and sparks.

GENERAL DATA
04-4
Engine - V8
General
Cylinder arrangement 90° V8, numbered from the front of the engine:
⇒ Left bank cylinders 1, 3, 5 and 7
⇒ Right bank cylinders 2, 4, 6 and 8
Bore 94.00 mm (3.70 in)
Stroke:
⇒ 4.0 litre
⇒ 4.6 litre71.04 mm (2.80 in)
81.92 mm (3.22 in)
Capacity:
⇒ 4.0 litre
⇒ 4.6 litre3950 cm
3 (241 in3)
4554 cm3 (278 in3)
Firing order 1 - 8 - 4 - 3 - 6 - 5 - 7 - 2
Compression ratio:
⇒ Low - 4.0 litre 8.23:1
⇒ High - 4.0 and 4.6 litre 9.35:1
Direction of rotation Clockwise viewed from the front of the engine
Maximum power - 4.0 litre:
⇒ Low compression ratio 132 kW (177 bhp) at 4750 rev/min
⇒ High compression ratio - UK/Japan/ROW 136 kW (182 bhp) at 4750 rev/min
⇒ High compression ratio - NAS 140 kW (187 bhp) at 4750 rev/min
Maximum power - 4.6 litre 162 kW (217 bhp) at 4750 rev/min
Maximum engine speed:
⇒ Continuous5000 rev/min
⇒ Intermittent 5250 rev/min
Weight (fully dressed, wet)
⇒ Manual 194 Kg (435 lb)
⇒ Automatic 179 Kg (402 lb)
Dimensions:
⇒ Length - Manual 767 mm (30.2 in) (Including fan)
⇒ Length - Automatic 777 mm (30.5 in) (Including fan and drive plate)
⇒ Width 652 mm (25.7 in)
⇒ Height 746 mm (29.4 in)
Spark plugs:
⇒ Make/Type - 4.0 litre Champion RC11 PYP B4
⇒ Make/type - 4.6 litre Champion RN11 YCC
⇒ Gap - 4.0 and 4.6 litre 1.00 ± 0.05 mm (0.040 ± 0.002 in) Non-adjustable
Coils:
⇒Make Bosch 0221 503 407
⇒Type Twin coils
Fuel injection system:
⇒Make Bosch Motronic 5.2.1 Type 4146
⇒Type Multiport fuel injection, electronically controlled with electro-
mechanical injectors

TORQUE WRENCH SETTINGS
06-6
Engine management system - Td5
Engine management system - V8
+ Apply sealant, Part No. STC 50552 to threads
TORQUE DESCRIPTION METRIC IMPERIAL
ECT sensor15 Nm (11 lbf.ft)
Fuel tank cradle45 Nm (33 lbf.ft)
CKP sensor10 Nm (7 lbf.ft)
MAP and IAT sensor 10 Nm (7 lbf.ft)
Fuel cooler to inlet manifold - upper bolts 25 Nm (18 lbf.ft)
Turbocharger to exhaust manifold 30 Nm (22 lbf.ft)
Turbocharger drain pipe 10 Nm (7 lbf.ft)
Banjo bolt to oil feed pipe 25 Nm (18 lbf.ft)
Fuel temperature sensor 14 Nm (10 lbf.ft)
Pressure regulator 25 Nm (18 lbf.ft)
Glow plugs16 Nm (12 lbf.ft)
EUI clamp bolts32 Nm (24 lbf.ft)
EGR valve to exhaust manifold 10 Nm (7 lbf.ft)
EGR valve to inlet manifold 10 Nm (7 lbf.ft)
EGR clip25 Nm (18 lbf.ft)
TORQUE DESCRIPTION METRIC IMPERIAL
Spark plugs20 Nm (15 lbf.ft)
Fuel tank cradle45 Nm (33 lbf.ft)
ECT sensor +10 Nm (7 lbf.ft)
CKP sensor6 Nm (4.4 lbf.ft)
CMP sensor8 Nm (6 lbf.ft)
KS sensor22 Nm (16 lbf.ft)
Throttle body10 Nm (7 lbf.ft)
Plenum chamber22 Nm (16 lbf.ft)
Breather adaptor6 Nm (4.4 lbf.ft)
Throttle cable abutment bracket 10 Nm (7 lbf.ft)
TP sensor 2.2 Nm (1.6 lbf.ft)
IACV sensor8 Nm (6 lbf.ft)
HO
2S sensor45 Nm (33 lbf.ft)
Ignition coils8 Nm (6 lbf.ft)
Fuel rail9 Nm (7 lbf.ft)

MAINTENANCE
10-10 PROCEDURES
Spark plugs - V8 engine
Replace
Take great care when fitting spark plugs not
to cross-thread plug, otherwise costly
damage to cylinder head will result. It is
essential that correct grade of spark plugs
are fitted. Incorrect grade of spark plugs
may lead to piston overheating and engine
failure. Use only approved spark plugs, use
of unapproved spark plugs may cause the
misfire detection system to malfunction.
1.Disconnect battery earth lead.
2.Noting their fitted position, disconnect ht leads
from spark plugs.
3.Remove 8 spark plugs.
4.Ensure that gap of new spark plugs is 1.0 ±
0.05 mm (0.040 ± 0.002 in).
Do not attempt to clean or adjust gaps. If a
spark plug problem exists, try substituting
defective spark plug(s) with new one(s).
CAUTION: Do not attempt to clean or adjust
spark plug gaps. If a spark plug problem
exists, try substituting the defective spark
plug with a new one.
5.Fit spark plugs and tighten to 20 Nm (15 lbf.ft).
6.Connect ht leads to spark plugs.
7.Connect battery earth lead.
Air cleaner - V8 engine
Replace
1.Replace air cleaner element.

+ ENGINE MANAGEMENT SYSTEM -
V8, REPAIRS, Element - air filter.
Clean
1.Clean the drain hole in filter casing.
Air cleaner and dump valve - diesel
engine
Replace/clean
1.Replace air cleaner element.

+ ENGINE MANAGEMENT SYSTEM -
Td5, REPAIRS, Element - air filter.
2.Remove all dirt from dump valve.

ENGINE - V8
12-2-14 REPAIRS
Gasket - cylinder head - LH
$% 12.29.02
Remove
1.Remove inlet manifold gasket.

+ MANIFOLDS AND EXHAUST
SYSTEMS - V8, REPAIRS, Gasket - inlet
manifold - lower.
2.Noting their fitted order, disconnect ht leads
from spark plugs.
3.Remove bolt securing engine harness to rear
of cylinder head.
4. LH drive models: Remove brake servo heat
shield.

+ MANIFOLDS AND EXHAUST
SYSTEMS - V8, REPAIRS, Heat shield -
brake servo - Without Secondary Air
Injection.
5.Remove 8 bolts securing exhaust manifold to
cylinder head, release manifold and collect 2
gaskets.6.Progressively remove 4 bolts securing the
rocker shaft and remove rocker shaft.
7.Remove push rods. Store push rods in their
fitted order.
8. Models with SAI: Using a 9 mm hexagonal
drive bit, remove 2 air injection adapters from
cylinder head; discard adapters.
Note: To release the adapter thread locking
agent and prevent damage to the cylinder
head, remove the adapters by alternately
loosening then tightening slightly. Repeat this
procedure until adapters are removed.
CAUTION: Do not use air tools to remove
adapters.

ENGINE - V8
12-2-16 REPAIRS
17.Using new gaskets, position exhaust manifold
to cylinder head, fit bolts and using sequence
shown, tighten initially to 15 Nm (11 lbf.ft), then
finally to 36 Nm (28 lbf.ft).
18. LH drive models: Fit brake servo heat shield.

+ MANIFOLDS AND EXHAUST
SYSTEMS - V8, REPAIRS, Heat shield -
brake servo - Without Secondary Air
Injection.
19.Fit engine harness bolt and tighten to 22 Nm
(16 lbf.ft).
20.Connect ht leads to spark plugs in their correct
fitted order.
21.Fit inlet manifold gasket.

+ MANIFOLDS AND EXHAUST
SYSTEMS - V8, REPAIRS, Gasket - inlet
manifold - lower.
Gasket - cylinder head - RH
$% 12.29.03
Remove
1.Remove inlet manifold gasket.

+ MANIFOLDS AND EXHAUST
SYSTEMS - V8, REPAIRS, Gasket - inlet
manifold - lower.
2.Remove bolt securing auxiliary drive belt
tensioner and remove tensioner.
3.Remove 4 bolts securing alternator mounting
bracket and remove bracket.
4.Noting their fitted order, disconnect ht leads
from spark plugs.
5.Remove bolt securing engine earth lead.

ENGINE - V8
12-2-18 REPAIRS
13.Remove cylinder head gasket.
Refit
1.Clean mating faces of cylinder block and head
using suitable gasket removal spray and a
plastic scraper, ensure that bolt holes in block
are clean and dry. Clean mating faces of
cylinder head and exhaust manifold.
CAUTION: Do not use a metal scraper or
machined surfaces may be damaged.
2.Check head and block faces for warping and
pitting. If out of specification, renew head.
3. Models with SAI: Using a 5/8 in x 20 TPI
(threads per inch) UNF tap having a class 2A
thread, remove deposits from secondary air
injection adapter tappings in cylinder head.
CAUTION: Ensure that tap used has 20 TPI.
4.Fit cylinder head gasket with the word 'TOP'
uppermost.
CAUTION: Gasket must be fitted dry.
5.Carefully fit cylinder head and locate on
dowels.
6.Lightly lubricate new cylinder head bolt threads
with clean engine oil. 7.Noting that bolts 1, 3 and 5 are longer than the
remainder, fit bolts and tighten in the sequence
shown to 20 Nm (15 lbf.ft) then 90°, and finally
a further 90°.
CAUTION: Do not tighten bolts 180° in one
operation.
8. Models with SAI: Fit new air injection adapters
and using a 9 mm hexagonal drive bit, tighten
to 33 Nm (24 lbf.ft).
CAUTION: Do not use an air tool to tighten
adapters.
9.Clean push rods.
10.Lubricate ends of push rods with clean engine
oil.
11.Fit push rods in their removed order.
12.Clean bases of rocker pillars and mating faces
on cylinder head.
13.Clean contact surfaces on rockers, valves and
push rods.
14.Lubricate contact surfaces and rocker shaft
with clean engine oil.
15.Fit rocker shaft assembly and engage push
rods.
16.Fit rocker shaft bolts and progressively tighten
to 40 Nm (30 lbf.ft).
17.Position alternator mounting bracket, fit bolts
and tighten to 40 Nm (30 lbf.ft).
18.Position auxiliary drive belt tensioner, fit bolt
and tighten to 45 Nm (33 lbf.ft).
19.Connect ht leads to spark plugs in their fitted
order.
20. Using new gaskets, fit exhaust manifold to
cylinder head. Fit bolts and using sequence
shown, tighten initially to 15 Nm (11 lbf.ft), then
finally tighten to 36 Nm (28 lbf.ft).
21. RH drive models: Fit brake servo heat shield.

+ MANIFOLDS AND EXHAUST
SYSTEMS - V8, REPAIRS, Heat shield -
brake servo - Without Secondary Air
Injection.
22.Position engine earth lead, fit bolt and tighten to
22 Nm (16 lbf.ft).
23.Fit inlet manifold gasket.

+ MANIFOLDS AND EXHAUST
SYSTEMS - V8, REPAIRS, Gasket - inlet
manifold - lower.

ENGINE - V8
12-2-48 OVERHAUL
21.Position alternator cables and tighten terminal
B+ to 18 Nm (13 lbf.ft) and terminal D+ to 5 Nm
(3.5 lbf.ft).
22.Position auxiliary housing, fit bolts and tighten
to 40 Nm (30 lbf.ft). Fit nut and tighten to 22 Nm
(17 lbf.ft).
23.Clean jockey pulley mating faces.
24.Position jockey pulley and tighten bolt to 50 Nm
(37 lbf.ft).
25.Clean PAS pump pulley mating faces.
26.Position PAS pump pulley, fit bolts and tighten
to 22 Nm (17 lbf.ft).
27.Secure injector harness and connect injector
multiplugs.
28.Connect multiplug to coolant thermistor.
Gasket - exhaust manifold
$% 30.15.12.01
Disassembly
1.Remove 8 bolts securing exhaust manifold and
collect spacers. Discard the bolts.
2.Remove exhaust manifold.
3.Remove 2 manifold gaskets and discard.
Reassembly
1.Clean exhaust manifold and cylinder head
mating face.
CAUTION: Do not use a metal scraper or
machined surfaces may be damaged.
2.Fit new gaskets, dry, fit exhaust manifold.
CAUTION: Ensure that link bar on gasket is
positioned below spark plugs.
LH bank illustrated
3.Fit spacers to new manifold bolts and, working
in the sequence illustrated, initially tighten bolts
to 15 Nm (11 lbf.ft), then finally tighten to 38 Nm
(28 lbf.ft).