engine LAND ROVER DEFENDER 1999 Service Manual

ENGINE
9
DESCRIPTION AND OPERATION 1.Acoustic cover
2.Oil filler flap
3.Rear acoustic cover
4.Rear acoustic cover inserts (2 off)
5.Rear acoustic cover grommets (2 off)
6.Rear acoustic cover screws (2 off)
7.Acoustic cover grommets (3 off)
8.Acoustic cover bolts (3 off)
9.Camshaft cover isolators (13 off)
10.Camshaft cover flange screws (13 off)
11.Breather hose clip
12.Breather hose
13.Breather hose to breather valve clip
14.Breather valve
15.Camshaft cover gasket
16.Oil separator plate
17.Oil separator plate gasket
18.Camshaft cover
19.Acoustic cover to camshaft cover seal
20.Oil filler cap and seal
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12ENGINE
10
DESCRIPTION AND OPERATION Camshaft timing chain components
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ENGINE
11
DESCRIPTION AND OPERATION 1.Vacuum pump stub pipe
2.Cylinder head to timing chain cover bolt
3.Cylinder head to timing chain cover nut
4.Cylinder head to timing chain cover stud
5.Tensioner assembly pivot screw
6.Tensioner adjuster
7.Tensioner arm assembly
8.Duplex timing chain - crankshaft to camshaft sprocket
9.Camshaft sprocket bolts (3 off)
10.Camshaft sprocket
11.Fixed chain guide
12.Fixed guide pin
13.Fixed chain guide to cylinder block screws
14.Oil pump drive chain
15.Oil pump sprocket
16.Oil pump sprocket screw
17.Crankshaft sprockets
18.Bearing to viscous fan shaft
19.Viscous fan to cover bearing
20.Circlip
21.Hub - viscous fan to bearing flange
22.Timing chain cover
23.Timing chain cover to crankshaft seal
24.Timing chain to cylinder head screws (8 off)
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12ENGINE
12
DESCRIPTION AND OPERATION 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) legislative requirements. EU3 models comply with ECD3 legislative requirements. Both units 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 cylinder block 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:
Electronic Unit Injectors (EUI’s)controlled by an Engine Management System for precise fuel delivery under
all prevailing operating conditions.
Turbochargingwhich delivers compressed air to the combustion chambers via an intercooler for improved
power output.
Fuel Cooler
Oil Cooler
Centrifuge Oil Filter
Hydraulic Lash Adjusterswith independent finger followers
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ENGINE
13
DESCRIPTION AND OPERATION 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 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 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 are located at the front and rear of the
cylinder block. Two plastic dowels are used to locate the cylinder head to the cylinder block and must be replaced
every time the cylinder head is removed from the cylinder block.
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12ENGINE
14
DESCRIPTION AND OPERATION Connecting rods
1.Small-end oil holes
2.Small-end bushing3.Connecting rod
4.Serrated fracture
The connecting rods are machined, H-section steel forgings which feature a fracture-split at the big-end between
the connecting rod and the bearing cap. The connecting rod features a serrated fracture across the big-end at
right angles to the length of the connecting rod, this forms a unique mating surface between the connecting rod
and the fractured end which is used as the big-end cap. The use of a fracture split in the big-end of the connecting
rod ensures a perfect match for assembly on the crankshaft bearing journals and provides the connecting rod with
strong resistance to lateral movement.
The end-cap fixing bolts are offset to ensure that the cap is fitted to the connecting rod in the correct orientation. If
the end-cap is fitted incorrectly and the end-cap bolts tightened, the connecting rod must be replaced, since the
matching serrations will have been damaged.
The big-end bearing shells are plain split halves without location tags. On EU2 vehicles the two halves of the
bearing shells are of different construction. The upper half bearing shell fitted to the connecting rod is treated
using the sputtering process to improve its resistance to wear. The connecting rod bearing shell can be identified
by having a slighter darker colouration than the big-end bearing cap shell, and the back face of the connecting rod
bearing shell has a shinier finish than the front face.
On EU3 vehicles both bearing shells are of the same construction as the connecting rod bearing shell.
The small-end of the connecting rod has a bushed solid eye which is free to move on the gudgeon pin, the
bushing is a hand push, interference fit. The steel bushing has two slots machined in its upper surface for
providing oil lubrication to the moving surface of the gudgeon pin. The oil slots must be correctly aligned to the oil
slots provided in the small end of the connecting rod. The small-end lubrication is supplied by squirt feed from the
piston lubrication jets.
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ENGINE
15
DESCRIPTION AND OPERATION Pistons
1.Bowl in piston head
2.Piston ring grooves3.Graphite coated aluminium alloy skirt
4.Gudgeon 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 crowns also
provide clearance for the valve heads.
CAUTION: 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.
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12ENGINE
16
DESCRIPTION AND OPERATION Oil cooler
1.Front oil gallery - full-flow filter to oil cooler matrix
2.Full-flow filter adaptor outlet port to oil cooler
(opens at 74°C)
3.Full-flow filter inlet port
4.Oil cooler housing
5.Full-flow filter outlet port to cylinder block
6.Coolant inlet port
7.Oil cooler banjo bolt seals (2 off)
8.Banjo bolts (2 off)
9.Banjo bolt oil holes - to oil cooler matrix
10.Rear oil gallery - full-flow filter / oil cooler outlet
to cylinder block11.Centre oil gallery - from pump to full-flow filter
12.Inlet port to centrifuge filter
13.Sealing ring - centrifuge filter housing to oil
cooler housing
14.Port - oil cooler matrix
15.Oil cooler matrix
16.Inlet port from pump via cylinder block to oil
cooler housing
17.Outlet port from oil cooler housing to cylinder
block
18.Rear view of oil cooler housing
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ENGINE
17
DESCRIPTION AND OPERATION The engine oil cooler assembly is located on the left hand side of the engine block behind the oil centrifuge and oil
filter. The housing is bolted to the engine block by seven bolts. A matrix is included in the oil cooler housing which
acts as a heat exchanger. Coolant flow circulates through the oil cooler housing under pressure from the coolant
pump and distributes the flow evenly around the matrix fins and then along the block into three core holes for
cylinder cooling. Coolant enters the oil cooler through a pipe with a rubber hose extension at the rear side of the
engine. The coolant hose is attached to the stub pipe of the oil cooler by a spring clip.
Oil, drawn from the sump by the oil pump, passes through the oil cooler via the cylinder block. The flow of coolant
around the exterior surface of the oil cooler matrix cools a proportion of the engine oil flow as it passes through the
oil cooler.
The oil cooler is sealed to the cylinder block by a gasket which must be replaced every time the oil cooler housing
is removed.
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12ENGINE
18
DESCRIPTION AND OPERATION Oil filters
The Td5 engine features two types of oil filter; the main filter is a standard disposable cartridge-type full flow oil
filter which is augmented with a by-pass centrifuge filter used to filter out particulate matter having a smaller
diameter smaller than 15 micron but greater than 3 micron.
1.Centre spindle
2.Spindle oil holes (2 off)
3.Centrifuge filter housing
4.Centrifuge filter drain pipe
5.Port - centrifuge filter drain pipe to sump6.Filter rotor
7.Internal seal
8.Cover
9.Cover screws (2 off)
The centrifuge filter is located on the left hand side of the engine block by the exhaust manifold and is housed in a
pot which is bolted to the oil cooler housing by means of three bolts. The pot contains a rotor located on a central
spindle which spins at up to 15,000 rev/min when oil is flowing through the unit under pressure. The rotor contains
two fine holes drilled at obtuse angles which cause the rotor to spin about the centre spindle when high pressure
oil is passing through it. The inner surface of the rotor captures carbon deposits and small particulate matter as it
is thrown outwards under centrifugal force to form a sludge on the inner walls of the rotor. The unit is able to trap
very fine impurities that build up in the oil that would be too small to filter using the normal paper-element type
full-flow filters alone.
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