1999 LAND ROVER DEFENDER fuel

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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12ENGINE
26
DESCRIPTION AND OPERATION Fuel connector block
Type A - Non EU3 Models - Engine Serial No. Prefixes 10P to 14P
Type B - EU3 Models - Engine Serial No. Prefixes 15P to 19P
1.Fuel connector block assembly
2.Outlet stub pipe
3.Stub pipe - to fuel cooler4.Fuel temperature sensor
5.Fuel pressure regulator
6.Spill return fuel connection (EU3 models only)
A cast and machined aluminium 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.
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ENGINE
27
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 sprocket is 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 by splash and channel fed via pressurised oil flowing through galleries in the cylinder head.
Rocker shaft and rocker arms
Type A - Non EU3 Models - Engine Serial No. Prefixes 10P to 14P
Type B - EU3 Models - Engine Serial No. Prefixes 15P to 19p
1.Rocker arm adjusting screw
2.Rocker shaft
3.Rocker arm
4.EUI pin and roller assembly
5.Roller pin retention slug6.Camshaft lobe
7.Injector spring
8.Injector push-rod
9.Adjusting 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.
CAUTION: The rocker shaft from a pre EU3 engine 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 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 identified by an engraved dimple on the slotted end.
Rocker shaft and rocker arm lubrication is by splash and channel fed via pressurised oil flowing through galleries
in the cylinder head and through the rocker shaft.
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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
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
7
REPAIR
14.Disconnect MAP sensor multiplug from inlet
manifold.
15.Position engine harness clear of inlet manifold.
16.Disconnect vacuum hose from EGR valve.
17.Loosen clip screw and disconnect air intake
hose from EGR valve.
18.Release 3 clips and disconnect coolant hoses
from fuel cooler.
19.Disconnect fuel hoses, tank to fuel cooler and
connector block on cylinder head.
CAUTION: Plug the connections.
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.
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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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ENGINE
13
REPAIR 11.Before refitting the camshaft cover, the fuel
injector rockers must be adjusted.
12.RemoveLRT-12-058.
13.Rotate engine clockwise until No. 1 injector lobe
is at full lift.
14.Rotate rocker adjusting screw clockwise until the
injector plunger is felt to bottom out.
15.Rotate rocker adjusting screw anti-clockwise 1
complete turn to give the plunger the required
bump clearance and tighten rocker adjusting
screw locknut to16 Nm (12 lbf.ft).
CAUTION: Ensure screw does not turn as
locknut is tightened.
16.Carry out above procedure for the remaining 4
rockers.
17.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.
18.Fit camshaft cover gasket.See this Section.
19.Fit cooling fan.See COOLING SYSTEM,
Repair.GASKET - COVER - CAMSHAFT
Service repair no - 12.29.40
Remove
1.Remove battery cover.
2.Disconnect battery negative lead.
3.Remove 3 bolts and remove engine acoustic
cover.
4.Release clip and disconnect breather hose from
camshaft cover.
5.Remove 13 bolts, spacers and sealing washers
from camshaft cover.
6.Remove camshaft cover and gasket.
Refit
7.Clean camshaft cover and mating face.
8.Renew sealing washers and spacers as
necessary.
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