2002 LAND ROVER DISCOVERY Fuel system

MANIFOLDS AND EXHAUST SYSTEMS - TD5
DESCRIPTION AND OPERATION 30-1-3
Description
General
The diesel engine has the inlet manifold attached to the right hand side of the engine and the exhaust manifold
attached to the left hand side of the engine. The inlet manifold directs cooled compressed air from the turbocharger
and intercooler into the cylinders, where it is mixed with fuel from the injectors. Exhaust gases from the exhaust
manifold can also be directed into the inlet manifold via a pipe from the exhaust manifold and an Exhaust Gas
Recirculation (EGR) valve on the inlet manifold. The exhaust manifold allows combustion gases from the cylinders to
leave the engine where they are directed into the exhaust system and turbocharger.
The exhaust system is attached to the turbocharger and is directed along the underside of the vehicle to emit exhaust
gases from a tail pipe at the rear of the vehicle. 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 is a one piece aluminium casting. The manifold is secured to the cylinder head with two studs and
flanged nuts and eight flanged bolts. A one piece laminated gasket seals the manifold to the cylinder head.
Four threaded bosses on the manifold provide for the attachment of the fuel cooler. The fuel cooler is secured to the
manifold with four bolts. A boss with two threaded holes allows for the attachment of the combined intake air
temperature/pressure sensor. The sensor is secured to the manifold with two screws and sealed with a gasket.
At the forward end of the manifold, a machined face and four threaded holes provide for the attachment of the EGR
valve. The valve is sealed to the manifold with a gasket.

+ EMISSION CONTROL - Td5, DESCRIPTION AND OPERATION, Emission Control Systems.
Exhaust manifold
The exhaust manifold is made from cast iron. The manifold has five ports, one from each cylinder, which merge into
one flanged outlet connection positioned centrally on the manifold.
The manifold is attached to the cylinder head with ten studs and flanged nuts. A laminated metal gasket seals the
manifold to the cylinder head. The flanged outlet on the manifold provides the attachment for the turbocharger, which
is attached with three studs and flanged nuts and sealed with a metal laminated gasket.
A second flanged outlet, located at the forward end of the manifold, provides attachment for the EGR pipe. The EGR
pipe is secured to the manifold with two cap screws and connected to the EGR valve mounted on the inlet manifold.
There is no gasket used between the pipe and the exhaust manifold.

+ EMISSION CONTROL - Td5, DESCRIPTION AND OPERATION, Emission Control Systems.
Exhaust system
The exhaust system comprises a front pipe, an intermediate pipe which incorporates 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.

MANIFOLDS AND EXHAUST SYSTEMS - TD5
30-1-4 DESCRIPTION AND OPERATION
Front pipe assembly
The front pipe is of welded and fabricated tubular construction. The front pipe is connected to a flange on the
turbocharger and secured with three flanged nuts and sealed with a metal laminated gasket. The front pipe
incorporates a flexible pipe near the connection with the turbocharger and terminates in a flanged connection with the
intermediate pipe.
The flexible pipe is formed into a concertina shape with woven metal strands around its outer diameter. The flexible
pipe allows for ease of exhaust system alignment and also absorbs engine vibration. The woven metal strands also
increase the longevity of the flexible pipe.
The front pipe is attached via a bracket and a mounting rubber to the chassis. The mounting rubber allows ease of
alignment and vibration absorption.
Intermediate pipe and silencer
The intermediate pipe is of welded and fabricated tubular construction. It connects at its forward end to the front pipe
flange. Two captive studs on the intermediate pipe flange allow for attachment to the front pipe with locknuts. The rear
section of 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 packing, 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 two mounting rubbers
to the chassis. The mounting rubber allows for ease of alignment and vibration absorption.
Tail pipe assembly
The tail pipe is of welded and fabricated construction. The tail pipe connects to the intermediate pipe with a flanged
joint secured with 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 the gases from 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 - TD5
30-1-6 REPAIRS
Gasket - inlet manifold
$% 30.15.08
Remove
Note: The following procedure covers engines
fitted with or without an EGR cooler. The EGR
cooler is bolted to the front of the cylinder head.
1.Remove battery cover.
2.Disconnect battery earth lead.
3.Remove 3 bolts and remove engine acoustic
cover.
4.Release retainers and remove upper fan cowl.
5.Disconnect leads from 4 glow plugs and
multiplug from MAP sensor.
6.Remove 4 bolts, release EGR valve from inlet
manifold and discard gasket. 7.Remove 4 bolts securing fuel cooler to inlet
manifold.
8.Remove 2 bolts and remove alternator support
bracket.
9.Remove bolt securing engine dip stick tube to
camshaft carrier.
10.Remove dip stick tube and discard 'O' ring.

MANIFOLDS AND EXHAUST SYSTEMS - TD5
REPAIRS 30-1-7
11.Remove 2 nuts and 8 bolts securing inlet
manifold to cylinder head.
12.Disconnect multiplugs from turbocharger
pressure sensor, ECT sensor, AAP sensor,
MAF sensor, A/C compressor and fuel injector
harness.
13.Remove 2 bolts securing harness to camshaft
carrier.
Note: Engine with EGR cooler illustrated.
14.Release harness from engine and inlet
manifold.
15.Remove inlet manifold and gasket. Refit
1.Clean inlet manifold and mating faces.
2.Fit new gasket.
3.Fitinlet manifold and, working from the centre
outwards, tighten nuts and bolts to 25 Nm (18
lbf.ft).
4.Position harness to sensors and connect
multiplugs.
5.Tighten bolts securing harness clip to camshaft
carrier to 9 Nm (7 lbf.ft).
6.Clean dip stick tube and fit new 'O' ring.
7.Fit dip stick tube and tighten bolt to 9 Nm (7
lbf.ft).
8.Connect leads to glow plugs.
9.Fit alternator support bracket and tighten bolts
to 45 Nm (33 lbf.ft).
10.Position fuel cooler and tighten bolts to 25 Nm
(18 lbf.ft).
11.Fit new gasket, position EGR valve and tighten
bolts to 9 Nm (7 lbf.ft).
12.Connect multiplug to MAP sensor.
13.Fit upper fan cowl.
14.Fit engine acoustic cover.
15.Connect battery earth lead.
16.Fit battery cover.

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.

MANIFOLDS AND EXHAUST SYSTEMS - V8
30-2-6 DESCRIPTION AND OPERATION
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.
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.

MANIFOLDS AND EXHAUST SYSTEMS - V8
DESCRIPTION AND OPERATION 30-2-7
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.