1999 LAND ROVER DISCOVERY fuel

MANIFOLDS AND EXHAUST SYSTEMS - V8
DESCRIPTION AND OPERATION 30-2-3
1Upper manifold
2Bolt 5 off
3Bolt 1 off
4Gasket
5IAC Valve
6IAC valve hose 2 off
7Bolt 4 off
8Bolt 4 off
9Schraeder valve
10Injector 8 off
11Retaining clip 8 off
12Bolt 12 off
13Bolt 2 off
14Clamp 2 off
15Seal 2 off
16Lower manifold/engine gasket
17Coolant pipe18Bolt 3 off
19Bolt
20Heater return pipe
21Pipe connection
22Lower manifold
23Gasket
24Hose clip 2 off
25Throttle housing coolant hose
26Fuel rail
27Throttle housing
28Gasket
29Bolt 4 off
30Plenum
31Rocker cover breather hose connection
32Brake servo vacuum pipe connection
33Hose clip 4 off

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
30-2-6 DESCRIPTION AND OPERATION
Exhaust manifolds
Two handed, cast iron exhaust manifolds are used on the V8 engine. Each manifold has four ports which merge into
one flanged outlet positioned centrally on the manifold.
Each manifold is attached to its cylinder head with eight Torx bolts. Each bolt is fitted with a 'cotton reel' shaped spacer
which allows for a longer bolt resulting in increased torque loading on each bolt. Two laminated metal gaskets seal
each manifold to its cylinder head. The flanged outlet on each manifold provides the attachment for the front pipe of
the exhaust system.
Exhaust system
The exhaust system comprises a front pipe assembly with two front pipes each incorporating a catalytic converter, an
intermediate pipe incorporating a silencer and a tail pipe assembly which also has a silencer. The exhaust system is
constructed mainly of 63 mm (2.48 in) diameter extruded pipe with a 1.5 mm (0.06 in) wall thickness. All pipes are
aluminized to resist corrosion and the silencers are fabricated from stainless steel sheet.
Front pipe assembly
The front pipe assembly is of welded and fabricated construction. A front pipe from each exhaust manifold merges
into one flanged connection. Two captive studs on the flange provide attachment to the intermediate pipe with
locknuts. Each front pipe has a welded flange which is attached to each manifold and secured with three studs and
flanged nuts and sealed with a metal laminated gasket. The gasket comprises a heat resistant fibre between two thin
metallic layers to enhance the sealing properties of the gasket.
A catalytic converter is located in each front pipe. The catalytic converters are different shapes to allow clearance
between the body and transmission. Both catalytic converters are of similar internal construction.

+ EMISSION CONTROL - V8, DESCRIPTION AND OPERATION, Emission Control Systems.
CAUTION: Ensure the exhaust system is free from leaks. Exhaust gas leaks upstream of the catalytic
converter could cause internal damage to the catalytic converter.
From the catalytic converters, the front pipes merge into one pipe which terminates at a flanged joint. The flange
connects with the intermediate pipe, sealed with an olive and secured with studs and locknuts.
Intermediate pipe and silencer
The intermediate pipe is of welded and fabricated tubular construction. It connects at its forward end with a flange on
the front pipe assembly and is secured with locknuts to captive studs in the front pipe assembly flange. The rear
section of the intermediate pipe connects to the tail pipe assembly via a flanged joint, sealed with a metal gasket and
secured with locknuts and studs.
The forward and rear sections are joined by a silencer. The silencer is fabricated from stainless steel sheet to form
the body of the silencer. An end plate closes each end of the silencer and is attached to the body with seam joints.
Perforated baffle tubes inside the silencer are connected to the inlet and outlet pipes on each end plate. Internal baffle
plates support the baffle tubes and together with a stainless steel fibre absorb combustion noise as the exhaust gases
pass through the silencer.
The intermediate pipe is attached by two brackets, positioned at each end of the silencer, and mounting rubbers to
the chassis. The mounting rubbers allow ease of alignment and vibration absorption. The two mounting rubbers are
fitted with removable heat deflectors to prevent heat from the silencer damaging the material.
Tail pipe assembly
The tail pipe is of welded and fabricated construction. It connects to the intermediate pipe with a flanged joint secured
with studs and locknuts and sealed with a metal gasket. The pipe is shaped to locate above the rear axle allowing
clearance for axle articulation. The pipe is also curved to clear the left hand side of the fuel tank which has a reflective
shield to protect the tank from heat generated from the pipe.
A fabricated silencer is located at the rear of the tail pipe. The silencer is circular in section and is constructed from
stainless steel sheet. A baffle tube is located inside the silencer and the space around the baffle tube is packed with
a stainless steel fibre. The holes in the baffle tube allow the packing to further reduce combustion noise from the
engine. The tail pipe from the silencer is curved downwards at the rear of the vehicle and directs exhaust gases
towards the ground. The curved pipe allows the exhaust gases to be dissipated by the airflow under the vehicle and
prevents gases being drawn behind the vehicle.
The tail pipe is attached by a bracket, positioned forward of the silencer, and a mounting rubber to the chassis. The
mounting rubber allows ease of alignment and vibration absorption.

MANIFOLDS AND EXHAUST SYSTEMS - V8
30-2-12 REPAIRS
13.Remove 4 bolts securing top hose outlet and
remove outlet pipe.
14.Remove and discard 'O' ring.
15.Position absorbent cloth to catch spillage.
16.Disconnect fuel pipe.
CAUTION: Always fit plugs to open
connections to prevent contamination.17.Using the sequence shown, remove 12 bolts
securing the inlet manifold.
18.Remove inlet manifold.
19.Remove 2 bolts securing inlet manifold gasket
and collect gasket clamps.

MANIFOLDS AND EXHAUST SYSTEMS - V8
REPAIRS 30-2-13
20.Remove inlet manifold gasket.
21.Remove gasket seals.
Refit
1.Clean all traces of sealant from cylinder head
and cylinder block notches.
2.Clean mating faces of cylinder block, cylinder
head and inlet manifold.
3.Apply sealant, Part No. STC 50550 to cylinder
head and cylinder block notches.
4.Fit new gasket seals, ensuring ends engage
correctly in notches.
5.Fit new inlet manifold gasket.
6.Position gasket clamps and fit bolts, but do not
tighten at this stage.
7.Position inlet manifold to engine. Fit manifold
bolts and, working in the sequence shown,
tighten bolts initially to 10 Nm (7 lbf.ft) then to
51 Nm (38 lbf.ft).
8.Tighten gasket clamp bolts to 18 Nm (13 lbf.ft).
9.Connect fuel pipe.
10.Clean top hose outlet pipe mating faces.
11.Fit new 'O' ring to outlet pipe.
12.Position outlet pipe, fit bolts and tighten to 22
Nm (16 lbf.ft).
13.Position alternator, fit bolts and tighten to 45
Nm (33 lbf.ft).
14.Position PAS pump to auxiliary housing and
locate housing on engine. Fit bolts and tighten
to 40 Nm (30 lbf.ft).15.Fit and tighten auxiliary housing nut to 10 Nm (7
lbf.ft).
16.Fit bolts securing PAS pump and tighten to 22
Nm (16 lbf.ft).
17.Position oil cooling pipe bracket fit bolt and
tighten to 22 Nm (16 lbf.ft).
18.Fit and tighten PAS pump high pressure pipe.
19.Position jockey pulley and tighten bolt to 50 Nm
(37 lbf.ft).
20.Clean PAS pump pulley mating faces.
21.Position PAS pump pulley, fit bolts and tighten
to 22 Nm (16 lbf.ft).
22.Clean ACE pump dowels and dowel holes.
23.Position ACE pump, fit bolts and tighten to 22
Nm (16 lbf.ft).
24.Fit auxiliary drive belt.

+ CHARGING AND STARTING,
REPAIRS, Belt - auxiliary drive.
25.Secure injector harness and connect injector
multiplugs.
26.Position top hose and secure clips.
27.Fit rocker covers.
l

+ ENGINE - V8, REPAIRS, Gasket
- rocker cover - LH.
l

+ ENGINE - V8, REPAIRS, Gasket
- rocker cover - RH.
28.Check and top up PAS fluid

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.

MANUAL GEARBOX - R380
37-14 REPAIRS
22.Lower gearbox sufficiently to access top of
gearbox.
23.Ensure gear lever is released from grommet
and no wires or pipes are trapped when
gearbox is lowered.
24.Remove clevis pin and 'C' washer securing low
ratio selector cable to lever and release cable
from lever housing.
25.Remove 2 cable ties securing cable to fuel
pipes. 26.Disconnect 2 Lucars from oil temperature
sensor and disconnect reverse lamp switch
multiplug.
27.Remove banjo bolts securing breather pipes
and discard sealing washers.
28.Remove bolt securing breather pipe 'P' clip and
release breather pipes.
29. If fitted: Disconnect 2 Lucars from differential
lock switch, release and disconnect transfer
box neutral sensor multiplug.
30. If fitted: Release harness from 2 retaining
clips.
31.Position container to catch oil spillage

MANUAL GEARBOX - R380
REPAIRS 37-15
32.Remove 3 bolts securing oil cooling pipe
housing to gearbox, release housing and
discard 'O' rings.
33.Using a second jack support the weight of the
engine.
34.Remove 14 bolts securing gearbox to engine.
35.With assistance, remove gearbox from engine.
Refit
1.Clean gearbox to engine mating faces, dowels
and dowel holes.
2.Raise gear gearbox on jack and align to clutch
and engine.
3.Fit bolts securing gearbox to engine and
tighten to 45 Nm (33 lbf.ft).
4.Lubricate and fit new 'O' rings to oil cooling
pipe housing. 5.Position coolant pipe housing, fit bolts and
tighten to 25 Nm (18 lbf.ft).
6. If fitted: Secure harness in retaining clips,
connect Lucars to differential lock warning
switch and multiplug to neutral sensor.
7.Position breather pipes and secure 'P' clip with
bolt.
8.Using new sealing washers fit breather pipe
banjo bolts and tighten to 15 Nm (11 lbf.ft).
9.Connect oil temperature sensor Lucars and
reverse lamp switch multiplug.
10.Position low ratio selector cable to housing and
secure with 'C' washer and clevis pin.
11.Secure cable to fuel pipes with new cable ties.
12.Raise gearbox, ensuring gear change lever is
located in grommet.
13.Fit gearbox mountings and tighten bolts to 85
Nm (63 lbf.ft).
14.Fit nuts to mountings and tighten to 48 Nm (37
lbf.ft).
15.Remove 3 bolts securing support plate to
gearbox.
16.Position clutch slave cylinder and heat shield,
fit bolts and tighten to 25 Nm (18 lbf.ft).
17.Clean handbrake back plate and mating face.
18.Position handbrake back plate, fit bolts and
tighten to 75 Nm (46 lbf.ft).
19.Clean handbrake drum.
20.Fit handbrake drum and tighten retaining
screw.
21.Clean propeller shafts and mating faces.
22.Position propeller shafts, align to marks and
tighten bolts to 47 Nm (35 lbf.ft).
23.Clean exhaust silencer and tail pipe mating
faces.
24.Position silencer and secure on mountings,
using a new gasket align to tail pipe, fit nuts
and tighten to 25 Nm (18 lbf.ft).
25.Position rear cross member, fit bolts and
tighten to 25 Nm (18 lbf.ft).
26.Refill gearbox with oil.

+ MAINTENANCE, PROCEDURES,
Manual gearbox.
27.Refill transfer gearbox oil.

+ MAINTENANCE, PROCEDURES,
Transfer box.
28.Fit front exhaust pipe.

+ MANIFOLDS AND EXHAUST
SYSTEMS - V8, REPAIRS, Front pipe.
29.Fit gear lever extension, fit clamp bolt and
tighten to 25 Nm (18 lbf.ft).
30.Fit gear lever trim and gear change knob.
31.Connect battery earth lead.
32. Fit battery cover and cooling fan cover and
secure fixings.