1999 LAND ROVER DEFENDER engine

ENGINE
33
DESCRIPTION AND OPERATION 1.Oil squirt jets (5 off)
2.Main oil delivery gallery
3.Inflow from oil cooler housing
4.Flow to oil cooler / filters (from oil pump via cylinder block)
5.Sump
6.Oil pick-up pipe
7.Flow from oil pump (relief-valve in housing)
8.Oil pump
9.Cross-drilling supply to main and crankshaft bearings
10.To cylinder head
Oil from the sump is drawn up through a two-piece plastic pick-up which contains a mesh to siphon any relatively
large pieces of material which could cause damage to the pump. The head of the pick-up is centrally immersed in
the sump oil and oil is delivered to the inlet side of the eccentric rotor pump through a gallery in the stiffener plate.
Pressurised oil from the pump is passed through to the cylinder block where it is delivered to the centrifuge filter
and full-flow filter via a port in the RH cylinder block which interfaces with a port in the centre gallery of the oil
cooler housing. The oil pump contains an oil pressure relief valve which opens to allow oil to be recirculated back
around the pump if the oil pressure increases to a high enough level.
10% of the oil flow from the pump is diverted through the centrifuge filter and returned to the sump via the
centrifuge filter drain tube. The remaining 90% of the oil passes through the standard full-flow filter to the main oil
gallery in the cylinder block.
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12ENGINE
34
DESCRIPTION AND OPERATION OIL COOLER / FILTER FLOW
(THERMOSTAT OPEN)
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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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12ENGINE
36
DESCRIPTION AND OPERATION CYLINDER HEAD FLOW
1.Cast-in groove between cylinder head and
camshaft carrier
2.Rocker shaft flow
3.Lash adjuster supply channels (10 off)
4.Non-return valve
5.Chain lubrication jet supply6.Oil return from vacuum pump
7.Oil supply to timing chain tensioner adjuster
8.Oil supply to vacuum pump
9.Oil supply hole to camshaft sprocket and timing
chain
Oil passes to the cylinder head from the cylinder block via a non-return valve which is included to prevent oil
draining away from the lash adjusters when the engine is switched off.
Oil is passed to a cast-in groove between the top of the cylinder head and the camshaft carrier. The part of the
channel on the top left hand side of the cylinder head has ten cross-drillings which supply oil to the hydraulic lash
adjusters and finger followers. Lubrication oil fed to the lash adjusters passes up through the lash adjuster body
and into the socket of the finger followers. The oil exits the finger followers through a small hole to lubricate the
surfaces between the camshaft lobes and rollers.
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ENGINE
37
DESCRIPTION AND OPERATION An additional tapping is included at the front left hand side of the cylinder head to supply oil to the chain lubrication
jet and a through hole near the front centre of the cylinder head allows a passage of oil through from the cast-in
groove to lubricate the timing chain and camshaft sprocket.
At the centre front of the cylinder head, the cast-in groove channels oil into the rocker shaft via the front rocker
shaft fixing. Oil flow through the rocker shaft and clearance around the rocker shaft fixings provides oil feed to the
camshaft bearings.
A tapping towards the right hand side of the cylinder head diverts oil supply from the cast-in groove down to a stub
pipe which attaches to a feed line to the vacuum pump. An hydraulic tensioner is located below the vacuum stub
pipe which receives oil through a small hole in the side of the tensioner body to force a plunger against a plastic
faced adjuster shoe for timing chain tensioning. Oil from the vacuum pump is returned to the a port in the timing
chain cover via a short hose which connects to stub pipes at both ends using spring clips.
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12ENGINE
38
DESCRIPTION AND OPERATION
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ENGINE
1
ADJUSTMENT ENGINE OIL PRESSURE CHECK
Service repair no - 12.90.09.01
Check
1.Remove oil pressure switch.See Repair.
2.Connect pressure check kitLRT-12-052C
adaptor and gauge to oil pressure switch
position on oil cooler.
3.Check and if necessary, top-up engine oil.
4.Run engine at idle speed and check that oil
pressure is within limits given.
5.Switch off ignition.
6.Remove oil pressure check kitLRT-12-052C.
7.Clean oil spillage.
8.Fit oil pressure switch.See Repair.
Adjust
1.If engine oil pressure is not within specified
limits, check condition of oil pump and/or main
and connecting rod bearings.
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ENGINE
1
REPAIR CAMSHAFT
Service repair no - 12.13.02
Remove
1.Remove cylinder head gasket.See this
Section.
2.Note the gasket thickness indicator and ensure
the same thickness gasket is used on refitment
of cylinder head.
3.Disconnect multiplug from injector units and
remove harness from camshaft carrier.
4.Remove and discard multiplug’O’ring.
5.Loosen lock nuts and fully retract rocker
adjusting screws.
6.Progressively loosen then remove and discard 6
bolts securing rocker shaft, remove shaft.
7.Using sequence shown, progressively loosen
then remove 13 bolts securing camshaft carrier
to cylinder head.
8.Gently tap the camshaft carrier upwards to break
the sealant bond and remove carrier noting it is
located by 2 dowels.
9.Remove camshaft.
10.Remove and discard camshaft rear oil seal.
11.Remove and discard lock nuts and rocker
adjusting screws.
12.Check bearing surfaces in cylinder head and
camshaft carrier for signs of scoring and wear.
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