1999 LAND ROVER DISCOVERY sensor

FUEL DELIVERY SYSTEM - V8
19-2-16 REPAIRS
Filler tube - fuel
$% 19.55.07
Remove
1.Raise rear of vehicle.
WARNING: Do not work on or under a
vehicle supported only by a jack. Always
support the vehicle on safety stands.
2.Ensure fuel tank is less than half full. If not,
drain fuel tank to less than half full.

+ FUEL DELIVERY SYSTEM - V8,
ADJUSTMENTS, Fuel tank - drain.
3.Remove filler cap.
Non NAS installation
4.Drill out rivet securing lower part of mud flap
support bracket and release bracket .
5. All except NAS models: Position suitable
container beneath filler tube and disconnect
filler hose, breather hose and vent pipe from
filler tube.
WARNING: TAKE ALL NECESSARY
PRECAUTIONS AGAINST FIRE AND
EXPLOSION.
NAS installation6. NAS models: Position suitable container
beneath filler tube to tank connection , loosen
securing clip and release filler tube from fuel
tank.
WARNING: TAKE ALL NECESSARY
PRECAUTIONS AGAINST FIRE AND
EXPLOSION.
7. NAS models: Disconnect vent pipes from filler
tube.
8. Release filler tube from grommet in body and
remove from under rear wing. Collect grommet.
9. NAS models: Remove cable tie securing
pressure sensor pipe to filler tube and remove
filler tube.
Refit
1. NAS models: Position filler tube to pressure
sensor pipe and secure with new cable tie.
2. Fit grommet to body, position filler tube under
rear wing and secure in grommet.
3. NAS models: Connect filler tube to fuel tank
and secure with clip. Connect vent pipes to filler
tube.
4. All except NAS models: Connect filler hose
and breather hose to filler tube and secure with
clips. Connect vent pipe to filler tube.
5. Position support bracket to mud flap and
secure with new rivet.
6.If applicable, refill fuel tank with extracted fuel.
7.Fit filler cap.
8.Remove stand(s) and lower vehicle.

COOLING SYSTEM - V8
DESCRIPTION AND OPERATION 26-2-7
Inlet manifold - Cooling connections
Coolant leaves the cylinder block via an outlet pipe attached to the front of the air intake manifold. The pipe is
connected to the thermostat housing and the radiator by a branch hose off the radiator top hose.
Hot coolant from the engine is also directed from the inlet manifold via pipes and hoses into the heater matrix. Coolant
is circulated through the heater matrix at all times when the engine is running.
A further tapping from the inlet manifold supplies coolant to the throttle housing via a hose. The coolant circulates
through a plate attached to the bottom of the housing and is returned through a plastic bleed pipe to an expansion
tank. The hot coolant heats the air intake of the throttle housing preventing ice from forming.
An Engine Coolant Temperature (ECT) sensor is fitted in the inlet manifold adjacent to the manifold outlet pipe. The
sensor monitors coolant temperature emerging from the engine and sends signals to the ECM for engine
management and temperature gauge operation.

+ ENGINE MANAGEMENT SYSTEM - V8, DESCRIPTION AND OPERATION, Description - engine
management.
Expansion tank
The expansion tank is located in the engine compartment. The tank is made from moulded plastic and attached to
brackets on the right hand inner wing. A maximum coolant when cold level is moulded onto the tank.
Excess coolant created by heat expansion is returned to the expansion tank from the radiator bleed pipe at the top of
the radiator. An outlet pipe is connected into the pump feed hose and replaces the coolant displaced by heat
expansion into the system when the engine is cool.
The expansion tank is fitted with a sealed pressure cap. The cap contains a pressure relief valve which opens to allow
excessive pressure and coolant to vent through the overflow pipe. The relief valve opens at a pressure of 1.4 bar (20
lbf.in
2) and above.
Heater matrix
The heater matrix is fitted in the heater assembly inside the passenger compartment. Two pipes pass through the
bulkhead into the engine compartment and provide coolant flow to and from the matrix. The pipes from the bulkhead
are connected to the matrix, sealed with 'O' rings and clamped with circular rings.
The matrix is constructed from aluminium with two end tanks interconnected with tubes. Aluminium fins are located
between the tubes and conduct heat away from the hot coolant flowing through the tubes. Air from the heater
assembly is warmed as it passes through the matrix fins. The warm air is then distributed into the passenger
compartment as required.

+ HEATING AND VENTILATION, DESCRIPTION AND OPERATION, Description.When the engine is
running, coolant from the engine is constantly circulated through the heater matrix.
Radiator
The 45 row radiator is located at the front of the vehicle. The cross-flow type radiator is manufactured from aluminium
with moulded plastic end tanks interconnected with tubes. Aluminium fins are located between the tubes and conduct
heat from the hot coolant flowing through the tubes, reducing the cooling temperature as it flows through the radiator.
Air intake from the front of the vehicle when moving carries heat away from the fins. When the vehicle is stationary,
the viscous fan draws air through the radiator fins to prevent the engine from overheating.
Two connections at the top of the radiator provide for the attachment of the top hose and bleed pipe. A connection at
the bottom of the radiator allows for the attachment of the bottom hose to the thermostat housing.
Two smaller radiators are located in front of the cooling radiator. The lower radiator provides cooling of the gearbox
oil and the upper radiator provides cooling for the engine oil.

+ MANUAL GEARBOX - R380, DESCRIPTION AND OPERATION, Description.

+ AUTOMATIC GEARBOX - ZF4HP22 - 24, DESCRIPTION AND OPERATION, Description.

+ ENGINE - V8, DESCRIPTION AND OPERATION, Description.
Pipes and hoses
The coolant circuit comprises flexible hoses and metal formed pipes which direct 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 is fitted
to each cylinder bank in the cylinder block. These are used to drain the block of coolant.

COOLING SYSTEM - V8
26-2-16 REPAIRS
8.Remove 6 scrivets and remove LH and RH air
deflectors from front panel. Disconnect
multiplug of gearbox oil temperature sensor
(arrowed).
9.Remove nut and move horn aside. 10.Remove 2 bolts securing radiator LH and RH
upper mounting brackets to body panel and
remove brackets.
11.Remove 4 screws securing air conditioning
condenser LH and RH upper mounting
brackets to condenser.
12.Remove brackets with rubber mounts from
radiator extension brackets.
13.Position absorbent cloth under each cooler
hose to collect oil spillage.
14.Push against coupling release rings and
disconnect hoses from gearbox oil cooler.
CAUTION: Always fit plugs to open
connections to prevent contamination.
15. If fitted: Push against coupling release rings
and disconnect hoses from engine oil cooler.

COOLING SYSTEM - V8
REPAIRS 26-2-17
16.Remove radiator assembly.
17.Release clip and remove bottom hose from
radiator.
18.Remove 2 bolts and remove extension
brackets from radiator.
19.Remove 2 captive nuts from radiator.
20.Remove 2 screws and remove gearbox oil
cooler from radiator.
21. If fitted: Remove 2 screws and remove engine
oil cooler from radiator.
22.Remove 2 rubber mountings from radiator.
23.Remove sealing strip from bottom of radiator.
24.Remove 2 cowl retaining clips from radiator. Refit
1.Fit cowl retaining clips to radiator.
2.Fit sealing strip to radiator.
3.Fit rubber mountings to radiator.
4.Fit gearbox oil cooler to radiator and secure
with screws.
5. If fitted: Fit engine oil cooler to radiator and
secure with screws.
6.Fit captive nuts to radiator.
7.Fit extension brackets to radiator and secure
with bolts.
8.Fit bottom hose to radiator and secure with clip.
9.Fit radiator and engage lower mountings in
chassis.
10.Ensure connections are clean, then secure
hoses to oil coolers.
11.Fit air conditioning condenser brackets and
secure with screws.
12.Fit radiator upper mounting brackets and
secure with bolts.
13.Fit LH horn and secure with nut.
14.Fit air deflectors and secure with scrivets.
15.Connect multiplug of gearbox oil temperature
sensor.
16.Fit front grille.

+ EXTERIOR FITTINGS, REPAIRS,
Grille - front - up to 03MY.
17.Connect bottom hose to thermostat housing
and secure with clip.
18.Connect top hose to radiator and secure with
clip.
19.Connect bleed hose to radiator and fit clip.
20.Fit lower fan cowl and secure with screws.
21.Fit viscous fan.

+ COOLING SYSTEM - V8, REPAIRS,
Fan - viscous.
22.Top up gearbox oil.
23.Top up engine oil.
24.Refill cooling system.

+ COOLING SYSTEM - V8,
ADJUSTMENTS, Drain and refill.

MANIFOLDS AND EXHAUST SYSTEMS - V8
DESCRIPTION AND OPERATION 30-2-5
Description
General
The inlet manifold on the V8 engine is located on the top of the engine, between the cylinders. The manifold directs
intake air into the cylinders. The intake air is mixed with fuel delivered by the injectors prior to ignition in the cylinders.
The inlet manifold comprises three separate aluminium castings.
Two exhaust manifolds are used, one for each bank of four cylinders. Each exhaust manifold allows combustion
gases from the cylinders to leave the engine and directs them into the exhaust system.
The exhaust system is connected to each exhaust manifold and merges into one pipe midway along the underside of
the vehicle. A catalytic converter (where fitted) is located in the front pipe from each manifold. A silencer is installed
midway along the system and a second tail silencer is located at the rear of the vehicle.
Inlet manifold
The inlet manifold comprises three aluminium castings; a lower manifold, an upper manifold and a plenum. The inlet
manifold is located on the top of the engine and feeds air into the cylinders.
Lower manifold
The lower manifold is a one piece machined aluminium casting which locates in the vee on the top of the engine and
is secured to each cylinder head with six bolts per head. A one piece coated metal gasket seals the lower manifold to
each cylinder head and also serves as a cover for the cylinder block.
Eight injectors are fitted into the lower manifold, four on each side. Each injector is sealed in the manifold with O-ring
seals and retained in position by the fuel rails. A fuel rail is attached to each side of the manifold and secured with two
bolts.
Eight air intake ports are cast and machined on the top of the manifold, each port directing intake air into one cylinder.
These ports mate with matching ports in the upper manifold and are sealed with a coated metal gasket between the
two manifolds.
A cavity at the front of the manifold collects coolant flow from the engine. A coolant outlet pipe is sealed and attached
to the front of the manifold and provides for coolant to flow through the cavity in the casting to the radiator top hose.
A smaller port in the manifold also allows coolant to flow from the cavity to the heater matrix. The lower manifold also
locates the Engine Coolant Temperature (ECT) sensor in a port in the front of the manifold.
Upper manifold
The upper manifold is a one piece machined aluminium casting. The manifold has eight ports on its lower face which
mate with the eight ports on the lower manifold. The joint between the upper and lower manifolds is sealed with a
coated metal gasket and secured with six bolts.
The manifold divides from the eight ports into eight branches, four on each side. Each set of four branches merge into
one gallery on each side of the manifold. Each gallery has an opening at its forward end which mates with the intake
plenum.
The upper manifold provides attachment for the Idle Air Control (IAC) valve and for brackets which retain pipes, plug
leads and throttle cables.
Inlet plenum
The plenum is mounted transversely on the front of the upper manifold. The plenum divides into two galleries which
connect with the galleries on the upper manifold. The plenum is secured to the upper manifold with four bolts and
sealed with a coated metal gasket.
The plenum provides attachment for the throttle housing, which is secured with four bolts and sealed with a coated
metal gasket. The plenum also has vacuum connections for brake servo, rocker cover breather and fuel vapour from
the charcoal canister. A port on the top of the plenum connects via a hose to the IAC valve.

MANIFOLDS AND EXHAUST SYSTEMS - V8
30-2-8 REPAIRS
5.Remove 2 nuts securing front pipe to
intermediate pipe/silencer.
6.Remove 6 nuts securing front pipe to exhaust
manifolds.
7.Release front pipe and collect front pipe to
manifold gaskets.
8.With assistance remove front pipe.
9.Remove HO2S from front pipe.
Refit
1.If refitting existing HO2S, apply anti-seize
compound to HO2S threads.
NOTE: A new HO2 sensor is supplied pre-
treated with anti-seize compound.
2.Fit HO2S to front pipe and tighten to 45 Nm (33
lbf.ft).
3.Clean front pipe and mating faces.
4.Position front pipe, with new front pipe to
manifold gaskets, and align front pipe with
intermediate pipe/silencer and exhaust
manifolds.
5.Fit and tighten exhaust manifold nuts to 30 Nm
(22 lbf.ft).
6.Fit and tighten intermediate pipe/silencer nuts
to 25 Nm (18 lbf.ft).
7.Fit chassis cross member and tighten bolts to
25 Nm (18 lbf. ft).
8.Connect HO2S multiplugs and secure to
support brackets.
Intermediate pipe/silencer
$% 30.10.11
Remove
1.Raise vehicle on ramp.
2.Remove 2 nuts securing intermediate pipe/
silencer to front pipe.
3.Remove 3 nuts securing intermediate pipe/
silencer to tail pipe.
4.Release intermediate pipe/silencer from
mountings and remove intermediate pipe/
silencer.
5.Collect intermediate pipe/silencer to tail pipe
gasket.
Refit
1.Clean intermediate pipe/silencer, front pipe and
tail pipe mating faces.
2.Position intermediate pipe/silencer and locate
on mountings.
3.Using a new intermediate pipe/silencer to tail
pipe gasket, align intermediate pipe/silencer
with tail pipe and front pipe.
4.Fit nuts to intermediate pipe/silencer and
tighten to 25 Nm (18 lbf.ft).

MANIFOLDS AND EXHAUST SYSTEMS - V8
REPAIRS 30-2-15
Gasket - inlet manifold - upper - Without
Secondary Air Injection
$% 30.15.24
Remove
1.Release fixings and remove battery cover.
2.Disconnect battery earth lead.
3.Remove bonnet.

+ EXTERIOR FITTINGS, REPAIRS,
Bonnet.
4.Release MAF sensor harness from clip.
5.Loosen clips securing air intake hose. Release
and remove air intake hose.
Note: Pre 03 MY air intake hose illustrated.
6.Disconnect throttle and cruise control cables.
Release cables from abutment bracket and
position aside. 7.Disconnect EVAP pipe from inlet plenum.
8.Disconnect multiplug from throttle body.
9.Remove clip securing breather hose to throttle
body and release breather hose.
10.Position a drain tray beneath the engine to
collect coolant.
11.Release clips securing coolant hoses to
throttle body and disconnect hoses.

MANIFOLDS AND EXHAUST SYSTEMS - V8
REPAIRS 30-2-17
20.Remove 6 bolts securing upper inlet manifold
and remove upper inlet manifold.
21.Collect upper inlet manifold gasket. Refit
1.Clean upper and lower inlet manifold mating
faces, dowels and dowel holes.
2.Using a new gasket, position upper inlet
manifold. Fit bolts and, working in a diagonal
sequence, tighten to 22 Nm (16 lbf.ft).
3.Connect hose and multiplug to TP sensor.
4.Connect hose and multiplug to IACV. Secure
hose with clip.
5.Secure ht leads to upper inlet manifold.
6.Position ignition coils, fit bolts and tighten to 8
Nm (6 lbf.ft).
7.Ensure clip under ignition coils is located on
fuel pipe.
8.Secure engine harness in bulkhead clips.
9.Fit coolant rail bolt and tighten to 22 Nm (16
lbf.ft).
10.Connect breather hose to inlet plenum.
11.Connect brake servo vacuum pipe to inlet
plenum.
12.Connect EVAP pipe to inlet plenum.
13.Position coolant hoses to throttle body and
secure hose clips.
14.Fit breather hose to throttle body and secure
clip.
15.Connect multiplug to throttle body.
16.Connect throttle and cruise control cables and
secure in throttle body cams.
17.Adjust throttle and cruise control cables.
l

+ ENGINE MANAGEMENT SYSTEM
- V8, ADJUSTMENTS, Cable - cruise
control.
l

+ ENGINE MANAGEMENT SYSTEM
- V8, ADJUSTMENTS, Cable - throttle.
18.Connect air intake hose and tighten clips.
Secure harness to air intake hose.
19.Top-up cooling system

+ MAINTENANCE, PROCEDURES,
Cooling system..
20.Fit bonnet.

+ EXTERIOR FITTINGS, REPAIRS,
Bonnet.
21.Connect battery earth lead.
22.Fit battery cover and secure with fixings.