2002 LAND ROVER DISCOVERY fuel

ENGINE - TD5
12-1-12 DESCRIPTION AND OPERATION
Description
General
The Td5 diesel engine is a 2.5 litre, 5 cylinder, in-line direct injection unit having 2 valves per cylinder, operated by a
single overhead camshaft. The engine emissions, on pre EU3 models, comply with ECD2 (European Commission
Directive) and on EU3 models, comply with ECD3 legislative requirements. Both models employ electronic engine
management control, positive crankcase ventilation and exhaust gas recirculation to limit the emission of pollutants.
The unit is water cooled and turbo-charged and is controlled by an electronic engine management system.
The engine is a monobloc cast iron construction with an aluminium stiffening plate fitted to the bottom of the cylinder
block to improve lower structure rigidity. The cylinder head and sump are cast aluminium. An acoustic cover is fitted
over the upper engine to reduce engine generated noise.
The engine utilises the following features:
lElectronic Unit Injectors (EUI's) controlled by an Engine Management System for precise fuel delivery under
all prevailing operating conditions.
lTurbocharging which delivers compressed air to the combustion chambers via an intercooler for improved
power output.
lFuel Cooler
lOil Cooler
lCentrifuge Oil Filter
lHydraulic Lash Adjusters with independent finger followers
Cylinder block components
The cylinder block components are described below:
Cylinder Block
The cylinders and crankcase are contained in a single cast iron construction. The cylinders are direct bored and
plateau honed with lubrication oil supplied via lubrication jets for piston and gudgeon pin lubrication and cooling. It is
not possible to rebore the cylinder block if the cylinders become worn or damaged. Three metal core plugs are fitted
to the three centre cylinders on the right hand side of the cylinder block.
Lubrication oil is distributed throughout the block via the main oil gallery to critical moving parts through channels
bored in the block which divert oil to the main and big-end bearings via oil holes machined into the crankshaft. Oil is
also supplied from the cylinder block main gallery to the five lubrication jets which cool and lubricate the piston and
gudgeon pins. Plugs are used to seal both ends of the main oil gallery at front and rear of the engine block. An oil
cooler is fitted to the LH side of the engine block; ports in the oil cooler assembly mate with ports in the cylinder block
to facilitate coolant flow. Oil is diverted through the oil cooler, centrifuge filter and full-flow filter before supplying the
main oil gallery. A tapping in the oil filter housing provides a lubrication source for the turbocharger bearings and an
oil pressure switch is included in a tapping in the oil cooler housing which determines whether sufficient oil pressure
is available to provide engine lubrication and cooling.
Cylinder cooling is achieved by water circulating through chambers in the engine block casting. A threaded coolant
jacket plug is located at the front RH side of the cylinder block.
Cast mounting brackets are bolted to both sides of the engine block for mounting the engine to the chassis on the LH
and RH hydramount studs.
The gearbox bolts directly to the engine block; a gearbox shim plate is located between the adjoining faces of the
gearbox and the flywheel side of the engine block and is fixed to the rear of the engine block by two bolts. Two hollow
metal dowels locate the rear of the cylinder block to the gearbox shim plate. The gearbox casing provides the
mounting for the starter motor.
A port is included at the rear left hand side of the cylinder block which connects to the turbocharger oil drain pipe to
return lubrication oil to the sump.
A plug sealing the lubrication cross-drilling gallery is located at the front right hand side of the cylinder block and plugs
for the main lubrication gallery is included at the front and rear of the cylinder block.

ENGINE - TD5
12-1-14 DESCRIPTION AND OPERATION
Pistons
1Bowl in piston head
2Piston ring grooves
3Graphite coated aluminium alloy skirt
4Gudgeon pin bore
The five pistons have graphite-compound coated aluminium alloy skirts which are gravity die cast and machined.
Each of the pistons has phosphated, shaped gudgeon pin bores and a swirl chamber (bowl-in-piston) machined in the
head which partly contains the inlet air that is compressed during the combustion process and helps provide
turbulence for efficient air/fuel mixture to promote complete combustion. The recesses in the piston's crown also
provide clearance for the valve heads.
Pre EU3 and EU3 pistons are not interchangeable due to the EU3 piston combustion bowl being offset.
The pistons are attached to the small-end of the connecting rods by fully floating gudgeon pins which are retained in
the piston gudgeon pin bushings by circlips.
The pistons and gudgeon pins are gallery cooled, oil being supplied under pressure from the piston lubrication jets
when the pistons are close to bottom dead centre.
Piston rings
Each piston is fitted with two compression rings and an oil control ring. The top compression ring is located in a steel
insert ring carrier which helps to provide a minimal reaction to compression forces.
The top ring is barrel-edged and chrome-plated, the 2nd compression ring is taper-faced and the oil control ring is
chrome-plated and features a bevelled ring with spring.

ENGINE - TD5
DESCRIPTION AND OPERATION 12-1-21
Crankshaft
1Front end to crankshaft sprocket
2Oil supply cross-drillings
3Main journals
4Big-end journals
5Rear end to flywheel
The crankshaft is constructed from cast iron and is surface-hardened. The areas between the crankshaft journals and
the adjoining webs and balance weights are compressed using the cold roll process to form journal fillets.
Cross-drillings in the crankshaft between adjoining main and big-end bearings are used to divert lubrication oil to the
big-end bearings.
A torsional vibration damper is attached to the crankshaft pulley by three bolts.
The crankshaft is carried in six main bearings, with end-float being controlled by thrust washers positioned on both
sides of No. 3 main bearing.
Main bearings
There are six main bearings used to carry the crankshaft. Each of the bearing caps are of cast iron construction and
are attached to the cylinder block by two bolts.
The bearing shells are of the split cylindrical type. The upper half bearing shells are grooved to facilitate the supply of
lubrication oil to the bearings and fit into a recess in the underside of the cylinder block. The lower half bearing shells
are smooth and fit into the bearing caps.
Steel-backed thrust washers are included at each side of No. 3 main bearing to control crankshaft end-float. One side
of each of the thrust washers is grooved, the grooved side of each of the thrust washers is fitted facing outward from
No. 3 main bearing.
Cylinder head components
The cylinder head components are described below:
Cylinder head
The cylinder head is of aluminium construction. It is not possible to reface the cylinder head if it becomes worn or
damaged. An alloy camshaft carrier is bolted directly to the upper surface of the cylinder head. Two dowels are
included in the cylinder head upper face for correct location of the camshaft carrier.
The EU3 cylinder head has a single internal fuel rail for delivering fuel to the injectors and an external fuel pipe for
returning spill fuel back to the fuel connector block. Therefore, pre EU3 and EU3 model cylinder heads are not
interchangeable.
CAUTION: The cylinder head incorporates drillings for the fuel injection system, any contamination which
enters these drillings could cause engine running problems or injector failure. It is therefore, essential that
absolute cleanliness is maintained when carrying out work on the cylinder head.

ENGINE - TD5
12-1-22 DESCRIPTION AND OPERATION
The camshaft carrier and cylinder head assembly is attached to the cylinder block by twelve cylinder head retaining
bolts which pass through the camshaft carrier and the cylinder head to secure the assembly to the cylinder block.
CAUTION: The valve heads, tips of the injectors and glow plugs protrude below the face of the cylinder head
and will be damaged if the cylinder head is stored face down.
The camshaft is located between the cylinder head and the camshaft carrier, and the bearing journals are line bored
between the two components to form a matched pair.
CAUTION: Always fit plugs to open connections to prevent contamination.
The valve guides and valve seat inserts are sintered components which are interference fit to the cylinder head. The
cylinder head machining also provide the locations for the electronic unit injectors, glow plugs, hydraulic lash
adjusters, finger followers and low pressure fuel rail.
Cooling to the cylinder head is provided by coolant flow through a water jacket machined into the cylinder head.
Drillings through the block provide lubrication channels for pressurised oil supply to cylinder head components such
as the lash adjusters, finger followers, rocker arms and camshaft bearings.
A coolant outlet elbow is fitted to the front LH side of the cylinder head to allow flow of coolant from the cylinder head
back to the radiator. A metal gasket is used to seal the joint between the water outlet elbow and the cylinder head. A
coolant temperature sensor is located in a port in the side of the water outlet elbow for monitoring coolant temperature.
A stub pipe is connected at the front RH side of the cylinder block above the timing cover which connects a pipe to
supply oil to the vacuum pump. The timing chain tensioner adjuster is screwed in a thread in the cylinder head at a
location on the front RH side of the engine below the oil feed port for the vacuum pump.
An access hole for the camshaft gear is included at the front of the cylinder head which is sealed with a plastic plug
and rubber 'O'-ring. A press-fit core plug for the chain chest is located on the front face of the cylinder head.
A press-fit core plug for the cylinder head water jacket is located at the rear of the cylinder head and a threaded brass
plug for the water jacket is located on the LH side of the cylinder head beneath the exhaust manifold assembly.

ENGINE - TD5
DESCRIPTION AND OPERATION 12-1-23
Fuel connector block
A = Pre EU3 models, B = EU3 models
1Fuel connector block assembly
2Outlet stub pipe
3Stub pipe – to fuel cooler
4Fuel temperature sensor
5Fuel pressure regulator
6Spill fuel return connection (EU3 models only)
A cast and machined alloy fuel connector block assembly is located at the rear RH side of the cylinder head, attached
by three flanged bolts. A metal gasket is used to seal the faces between the fuel connector block and the cylinder
head, which must be replaced every time the fuel connector block is removed.
CAUTION: The cylinder head incorporates drillings for the fuel injection system, any contamination which
enters these drillings could cause engine running problems or injector failure. It is therefore, essential that
absolute cleanliness is maintained when carrying out work on the cylinder head.
CAUTION: The valve heads, tips of the injectors and glow plugs protrude below the face of the cylinder head
and will be damaged if the cylinder head is stored face down.
Camshaft carrier
The cast aluminium alloy camshaft carrier is bolted to the cylinder head by thirteen screws. The camshaft carrier and
cylinder head assembly is attached to the cylinder block by twelve cylinder head retaining bolts which pass through
the camshaft carrier and the cylinder head to secure the assembly to the cylinder block.
The carrier is machined together with the cylinder head to form a matched pair for carrying the camshaft.
Non-return valve
A non-return valve is located at the front, bottom LH side of the cylinder head. The non-return valve prevents oil from
draining from the lash adjusters and is an integral component within the cylinder head and is non-serviceable.

ENGINE - TD5
12-1-24 DESCRIPTION AND OPERATION
Camshaft
The camshaft is machined from cast steel and is located between the cylinder head and the camshaft carrier, and the
six bearing journals are line bored between the two components to form a matched pair. The machined camshaft has
15 lobes. Ten lobes operate the inlet and exhaust valves through hydraulic lash adjusters and finger followers which
are located below the camshaft. Five larger lobes activate the injector rockers which are located above the camshaft
on the rocker shaft and are used to generate fuel pressure in the EUI injectors.
The camshaft is sprocket driven via a duplex chain connected to the crankshaft sprocket at a speed ratio of 2:1. The
camshaft sprocket is fixed to the front end of the camshaft by three bolts.
Camshaft lubrication is splash and channel fed via pressurised oil flowing through galleries in the cylinder head.
Rocker shaft and Rocker Arms
A = Pre EU3 rocker arm, B = EU3 rocker arm
1Rocker shaft
2Rocker arm adjusting screw
3Rocker arm
4EUI pin and roller assembly
5Roller pin retention slug6Camshaft lobe
7Injector spring
8Injector push-rod
9Adjusting nut
The hollow rocker shaft is located in the camshaft carrier in six fixed mountings which sit above the camshaft. Six bolts
are used to lock the rocker shaft to the camshaft carrier. The front rocker shaft bearing has a ring dowel located at the
front rocker shaft mounting of the camshaft carrier for rocker shaft alignment. Two circlips hold each rocker arm in
position at the relevant positions on the rocker shaft.
The rocker shaft from a pre EU3 model must not be fitted to an EU3 engine. This is because the stroke of the
EU3 injector has increased which requires the rocker to articulate over a larger angle.
The camshaft end of each rocker arm features a roller which is free to rotate about a pin which passes through two
webs in the rocker arm, the roller pins are held in place by an interference fit retention slug passing through a hole in
the front web of each rocker arm.
To correctly function against the higher injection loads of the EU3 engine the geometry of the contact between the
injector pushrod and rocker arm adjusting screw has been modified. Both designs of adjusting screw are separately
available with the EU3 version being identified by an engraved dimple in the slotted end.
Rocker shaft and rocker arm lubrication is splash and channel fed via pressurised oil flowing through galleries in the
cylinder head and through the rocker shaft.

ENGINE - TD5
12-1-40 REPAIRS
13.Disconnect 4 glow plug connectors.
14.Disconnect MAP sensor multiplug from inlet
manifold.
15.Position engine harness clear of inlet manifold.
16.Disconnect vacuum hose from EGR valve.
17.Release 3 clips and disconnect coolant hoses
from fuel cooler.
18.Disconnect fuel hoses, tank to fuel cooler and
connector block on cylinder head.
CAUTION: Always fit plugs to open
connections to prevent contamination.19.Disconnect fuel hose from connector block on
cylinder head.
20.Disconnect fuel hose from fuel cooler and
secure to connector block on cylinder head.
This is to prevent contamination of the fuel
injection system.
Pre EU3 model shown
21.Loosen clip screw and disconnect air intake
hose from EGR valve.
22.Loosen vacuum pump oil feed pipe union from
cylinder head and discard 'O' ring.
23.Loosen 2 bolts and release alternator support
bracket from cylinder head.
24. Pre EU3 model: Remove bolt securing EGR
valve pipe clamp to cylinder head.
25. EU3 model: Release the clips and disconnect
the coolant hoses from the EGR cooler.
26.Remove nut and bolt securing cylinder head to
timing chain cover.
27.Release clips and disconnect top hose, heater
hose and heater feed hose.
28.Raise front of vehicle.
WARNING: Do not work on or under a
vehicle supported only by a jack. Always
support the vehicle on safety stands.

ENGINE - TD5
REPAIRS 12-1-43
11.Clean camshaft sprocket and mating face on
camshaft.
12.Ensure engine is set to TDC No. 1 cylinder and
mark on camshaft sprocket is positioned
between the 2 coloured links.
13.Position camshaft sprocket to camshaft; fit and
lightly tighten new bolts, then loosen bolts half
a turn.
14.Clean timing chain fixed guide retaining pin and
apply Loctite 242 to threads.
15.Fit timing chain fixed guide retaining pin and
tighten to 25 Nm (18 lbf.ft) .
16.Clean timing chain tensioner and fit new
sealing washer.
17.Fit timing chain tensioner and tighten to 45 Nm
(22 lbf.ft).
18.Tighten bolts securing camshaft sprocket to
camshaft to 37 Nm (27 lbf.ft).
19.Remove tool LRT-12-058 from camshaft.
20.Remove tool LRT-12-158 from gearbox bell
housing.
21.Fit new camshaft bore blanking plug and 'O'-
ring seal in recess in cylinder head.
22.Clean vacuum pump union.
23.Tighten union securing vacuum pump oil feed
pipe to cylinder head to 10 Nm (7 lbf.ft) .
24.Fit bolts securing alternator support bracket to
cylinder head and tighten to 25 Nm (18 lbf.ft) .
25.Connect top hose and heater hoses and secure
with clips.
26. Pre EU3 model:Fit bolt securing EGR pipe
clamp to cylinder head bolt and tighten to 10
Nm (7 lbf.ft) .
27. EU3 model: Connect coolant hoses to EGR
cooler and secure with the clips.
28.Position air intake hose to EGR valve and
tighten clip screw.
29.Disconnect fuel hose from connector block and
connect to fuel cooler.
30.Connect fuel hoses to fuel cooler and
connector block on cylinder head.
31.Connect coolant hoses to fuel cooler and
secure clips.
32.Connect vacuum hose to EGR valve.
33.Position engine harness and connect multi
plugs and glow plug connectors.
34.Fit and tighten bolts, engine harness to
camshaft carrier.
35.Clean exhaust manifold and turbocharger
interface.
36.Fit new gasket to exhaust manifold, position
turbocharger and tighten – nuts securing
turbocharger to manifold to 30 Nm (22 lbf.ft).
37.Clean turbocharger oil feed hose bolt.
38.Position turbocharger oil feed hose using new
sealing washers. Fit banjo bolt securing
turbocharger oil feed hose and tighten to 25 Nm
(18 lbf.ft) . 39.Position exhaust manifold heatshield and
tighten M6 bolts to 9 Nm (7 lbf.ft) and M8 bolt to
25 Nm (18 lbf.ft).
40.Fit cooling fan coupling.

+ COOLING SYSTEM - Td5, REPAIRS,
Fan - viscous.
41.Fit camshaft cover with new seal.

+ ENGINE - Td5, REPAIRS, Gasket -
cover - camshaft.
42.Refill cooling system.

+ COOLING SYSTEM - Td5,
ADJUSTMENTS, Drain and refill.
43.Connect battery earth lead.
44.Fit battery cover and secure fixings.
45.Fit bonnet.

+ EXTERIOR FITTINGS, REPAIRS,
Bonnet.