1999 LAND ROVER DEFENDER cooling

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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ENGINE
23
DESCRIPTION AND OPERATION Oil pump
1.Stiffener plate
2.Ring dowel
3.Outlet port
4.Outer rotor
5.Inner rotor6.Spring dowel
7.Oil pressure relief valve cap
8.Oil pressure relief valve spring
9.Oil pressure relief valve plunger
10.Inlet port
The eccentric rotor oil pump is integrated with the stiffener plate and contains no serviceable parts except for the
pressure relief valve spring. The oil pump drive sprocket is attached to the front of the stiffener plate and is driven
through a chain and sprocket system.
A pressure relief valve is included at the outlet side of the oil pump to restrict oil pressure at high engine speeds by
recirculating oil through the relief valve back around the pump to the inlet. The relief valve and spring is a plunger
type. When oil pressure is great enough to lift the plunger, oil is allowed to escape past the plunger to relieve
pressure and prevent further rise.
Oil is delivered to the pump from the pick-up through a channel in the stiffener plate. The outlet side of the oil
pump delivers pressurised oil flow to the engine block main oil delivery gallery through a port in the stiffener plate.
Piston lubrication jets
Piston lubrication jets are fitted to the cylinder block to provide lubrication to the cylinder walls and to the piston
underskirt for cooling the pistons and lubricating the gudgeon pins. The input port to each lubrication jet mates
with a port provided in each mounting position tapped at the underside of the cylinder block from the main oil
delivery gallery. When oil pressure is sufficient to supply flow through the jets, oil is squirted to the inside of the
cylinder walls to provide piston to wall lubrication and cooling and to the underside of the piston skirt at the bottom
of the piston stroke (gallery cooled piston). The squirt jets also provide splash feed lubrication supply to the small
end bearings of the connecting rods.
Each lubrication jet is fixed to a mounting position on the underside of the engine block by a single Torx screw.
Chain lubrication jet
A chain lubrication jet is located on the front face of the cylinder block, behind the front engine timing chain cover.
The inlet port to the lubrication jet mates with an oil supply port from the cylinder block main oil delivery gallery.
The lubrication jet is fixed to the front of the engine block by a single screw. Additional chain lubrication is provided
by oil supply through a small aperture tapped from the cylinder head oil delivery gallery.
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ENGINE
25
DESCRIPTION AND OPERATION 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 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.
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 an 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.
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ENGINE
35
DESCRIPTION AND OPERATION 1.To cylinder block main gallery (from rear of oil cooler housing)
2.Oil cooler housing
3.Oil pressure switch
4.Full-flow filter
5.Centrifuge filter
6.Return to sump
7.Flow from oil pump (via cylinder block)
8.Oil cooler matrix
When the engine temperature is below 74°C, the thermostat in the full-flow filter adaptor housing is closed and a
proportion of the oil flow to the main oil gallery is diverted to the oil cooler to supply an oil feed to the turbocharger
bearings. Oil passes through the oil cooler to the front gallery in the oil cooler housing where there is a tapping to
connect the feed pipe to the turbocharger. Oil used by the turbocharger bearings is returned to the sump through
an oil drain pipe which connects to a port in the LH side of the cylinder block.
The remainder of the oil flow leaving the full-flow filter outlet is passed into the cylinder block via a port at the rear
of oil cooler rear gallery.
When the oil temperature rises above 74°C the thermostat in the full-flow filter housing begins to open to allow a
proportion of the oil from the full-flow filter to pass through the oil cooler before it reaches the main oil gallery in the
cylinder block. In this instance, oil supply to the turbocharger bearings is fed directly from the full-flow filter without
first passing through the oil cooler. Between 74°C and 88°C the thermostat valve plunger opens by about 9 mm
(0.3 in) to allow proportionally more oil to flow through the oil cooler before being passed to the cylinder block main
oil delivery gallery. Above 88°C the thermostat valve continues to open by about 1mm (0.03 in) for every 10°C
increase in temperature until the valve is fully open, when all the oil flow to the cylinder block is forced to pass to
the cylinder block via the oil cooler.
An oil pressure switch is located in a port in the rear gallery of the oil cooler housing to sense the oil pressure level
before flow enters the main oil gallery in the engine block. A warning lamp in the instrument cluster is switched on
if the oil pressure is detected as being too low.
Drillings from the cylinder block main oil gallery direct oil to the crankshaft main bearings and cross drillings in the
crankshaft direct oil to the big-end bearings. An additional five drillings in the cylinder block supply oil at reduced
pressure to the oil squirt jets for piston cooling and gudgeon pin lubrication.
Oil supply from the cylinder block is then passed to the cylinder head galleries through a non-return valve which is
included as an integral item in the lower face of the cylinder head.
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ENGINE
3
REPAIR
25.Using sequence shown, progressively tighten
bolts to25 Nm (18 lbf.ft).
26.Lubricate a new camshaft rear oil seal with
engine oil, fit seal using a suitable mandrel.
27.Fit rocker shaft ensuring it is located on dowel, fit
new bolts and working from the centre outwards,
tighten bolts progressively to32 Nm (24 lbf.ft).
28.Fit new’O’ring to injector harness multiplug, fit
harness and connect injector multiplugs.
29.Fit cylinder head gasket.See this Section.
30.Before refitting the camshaft cover the fuel
injector rockers must be adjusted.
31.Rotate engine clockwise until No. 1 injector lobe
is at full lift.
32.Rotate rocker adjusting screw clockwise until the
injector plunger is felt to bottom out.
33.Rotate rocker adjusting screw anti-clockwise 1
complete turn to give plunger the required bump
clearance and tighten rocker adjusting screw
locknut to16 Nm (12 lbf.ft).
34.Carry out above procedure for the remaining 4
rockers.
35.After completion of rocker adjustment, slowly
rotate engine clockwise 2 complete turns by
hand to ensure that no injectors are bottoming
out on their plungers.PULLEY - CRANKSHAFT
Service repair no - 12.21.01
Remove
1.Remove underbelly panel.See CHASSIS AND
BODY, Repair.
2.Remove radiator.See COOLING SYSTEM,
Repair.
3.Using a 15 mm ring spanner release the
auxiliary drive belt tensioner.
4.Remove auxiliary drive belt.
5.Remove 3 bolts and remove crankshaft damper.
6.PositionLRT-51-003to crankshaft pulley and
secure with 2 bolts.
7.Remove and discard crankshaft pulley bolt.
Remove crankshaft pulley.
8.Remove 2 bolts and removeLRT-51-003.
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12ENGINE
4
REPAIR Refit
9.Position new crankshaft pulley to vice.
10.Remove 3 bolts and remove damper from
crankshaft pulley.
11.Using a lint free cloth, thoroughly clean oil seal
recess and the running surface on crankshaft
pulley.
12.Fit crankshaft pulley.
13.FitLRT-51-003to crankshaft pulley and secure
with 2 bolts.
14.Fit new crankshaft pulley bolt and tighten to460
Nm (340 lbf.ft).
NOTE: It is recommended that a torque
multiplier is used to tighten crankshaft
pulley bolt.
15.Remove 2 bolts and removeLRT-51-003from
crankshaft pulley.
16.Fit damper to crankshaft pulley, fit bolts and
tighten to80 Nm (60 lbf.ft).
17.Fit auxiliary drive belt.
18.Fit radiator.See COOLING SYSTEM, Repair.
19.Fit underbelly panel.See CHASSIS AND
BODY, Repair.OIL SEAL - CRANKSHAFT - REAR
Service repair no - 12.21.20
Remove
1.Remove flywheel.See this Section.
2.Remove sump gasket.See this Section.
3.Remove 5 bolts securing oil seal housing to
cylinder block.
4.Remove seal housing.
Refit
5.Clean seal housing mating face on cylinder
block.
6.Position seal protector,LRT-12-061over
crankshaft boss. Fit new seal and housing
assembly and remove toolLRT-12-061.
CAUTION: Oil seal must be fitted dry.
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12ENGINE
6
REPAIR GASKET - CYLINDER HEAD
Service repair no - 12.29.02
Remove
NOTE: The following procedures cover
engines fitted with or without an EGR
cooler. The EGR cooler is bolted to the
front of the cylinder head.
1.Remove underbelly panel.See CHASSIS AND
BODY, Repair.
2.Drain cooling system.See COOLING
SYSTEM, Adjustment.
3.Remove camshaft cover gasket.See this
Section.
4.Remove cooling fan.See COOLING SYSTEM,
Repair.
5.Release clips and disconnect air flow meter from
air filter.
6.Disconnect multiplug from air flow meter.
7.Loosen clip and remove air inlet hose from
turbocharger.
8.Remove 3 bolts and remove exhaust manifold
heat shield.
9.Remove turbocharger oil feed banjo bolt and
discard sealing washers.
10.Remove 3 nuts, release turbocharger from
exhaust manifold, discard gasket and tie
turbocharger aside.
11.Remove 2 bolts securing engine harness to
camshaft carrier.
12.Disconnect fuel injector, coolant and compressor
sensors.
13.Disconnect 4 heater plug connectors.
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ENGINE
11
REPAIR 63. Pre EU3 model:-Fit bolt, EGR valve pipe to
cylinder head and tighten to25 Nm (18 lbf.ft).
64. EU3 model:-Connect coolant hoses to EGR
cooler and secure with clips.
65.Position air intake hose to EGR valve and
tighten clip screw.
66.Disconnect fuel hose from connector block and
connect to fuel cooler.
67.Connect fuel hoses to fuel cooler and connector
block on cylinder head.
68.Connect coolant hoses to fuel cooler and secure
clips.
69.Connect vacuum hose to EGR valve.
70.Position engine harness and connect multiplugs
and heater plug connectors.
71.Fit and tighten bolts, engine harness to camshaft
carrier.
72.Clean exhaust manifold and mating face.
73.Fit new gasket to exhaust manifold, position
turbocharger and tighten nuts to30 Nm (22 lbf.
ft).
74.Clean turbocharger feed hose bolt.
75.Position feed hose using new sealing washers,
tighten bolt to25 Nm (18 lbf.ft).
76.Position exhaust manifold heat shield, and
tighten M6 bolts to10 Nm (7 lbf.ft)and M8 bolt
to25 Nm (18 lbf.ft).
77.Position air inlet hose to turbocharger and
tighten clip screw.
78.Connect air flow meter to air filter and secure
clips.
79.Connect air flow meter multiplug.
80.Fit cooling fan.See COOLING SYSTEM,
Repair.
81.Fit camshaft cover gasket.See this Section.
82.Refill cooling system.See COOLING SYSTEM,
Adjustment.
83.Fit underbelly panel.See CHASSIS AND
BODY, Repair.ROCKER SHAFT ASSEMBLY
Service repair no - 12.29.29
Remove
1.Remove cooling fan.See COOLING SYSTEM,
Repair.
2.Remove camshaft cover gasket.See this
Section.
3.Loosen lock nuts and fully retract rocker
adjusting screws to prevent damage on
reassembly.
4.Rotate engine clockwise, until camshaft gear
and timing chain marks are aligned and fit
LRT-12-058through camshaft carrier to lock
camshaft.
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