1999 LAND ROVER DEFENDER oil pressure

12ENGINE
28
DESCRIPTION AND OPERATION Inlet and exhaust valves
The inlet and exhaust valves are mounted directly above the engine block cylinders.
Each valve is a forged and ground solid one-piece head and stem which is hardened by heat treatment. The
stems are chrome-plated then ground for improved heat transfer, wear resistance and smooth operation. It is not
possible to recut the valve’s face angle, but the valves can be lapped to their seats using grinding paste.
The valve springs are made from spring steel and are of the parallel single-coil type. The bottom end of the spring
rests on the flange of a spring seal which has a centre bore that locates on a recess ground into the lower valve
stem. The top end of the spring is held in place by a spring cap which is held in position at the top end of the valve
stem by split taper collets. The taper collets have grooves on the internal bore that locate in grooves ground into
the upper stems of the valves.
The valve seats and valve guides are sintered and are an interference fit into the cylinder head. The valve seats
and guides are non-serviceable.
Finger followers and lash adjusters
1.Valve stem
2.Finger follower
3.Lash adjuster plunger4.Oil supply hole
5.Lash adjuster body
The valves are operated through finger followers and lash adjusters, actuated by the camshaft lobes. When the
camshaft lobe presses down on the top of a finger follower roller mechanism, the respective valve is forced down
opening the inlet or exhaust port.
The lash adjuster body contains a plunger and two chambers for oil feed and pressurised oil. Pressurised oil is
supplied to the lash adjusters via the oil galleries in the cylinder head and through a hole in the side of the lash
adjuster body. The oil passes into a feed chamber in the lash adjuster then through to a separate pressure
chamber via a one way ball valve. Oil flow from the pressure chamber is determined by the amount of clearance
between the lash adjuster outer body and the centre plunger, oil escapes up the side of the plunger every time the
lash adjuster is operated, the downward pressure on the plunger forcing a corresponding amount of oil in the lash
adjuster body to be displaced. When the downward pressure from the camshaft and finger follower is removed
(i.e. after the trailing flank of the camshaft lobe has passed), oil pressure forces the lash adjuster’s plunger up
again. This pressure is not sufficient to effect the valve operation, but eliminates the clearance between the finger
follower and top of the valve stem.
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ENGINE
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DESCRIPTION AND OPERATION Tensioner adjuster
1.Oil supply hole
2.Tensioner adjuster body3.Tensioner adjuster plunger
4.Sealing ring
The tensioner adjuster is hydraulically operated, oil enters the adjuster from the pressurised oil supply flowing
through the cylinder head to operate a plunger which pushes against a pivoting plastic tensioner arm. The lateral
movement in the tensioner arm causes the timing chain to tension and consequently compensation for chain
flutter and timing chain wear is automatically controlled. The adjuster is located at the front right hand side of the
cylinder head, just above the timing chain cover and below the vacuum pump oil feed port. The adjuster body is
threaded and screws into a tapping in the cylinder head. Holes are contained in the adjuster body to receive oil
from the cylinder head galleries, the oil pressure is used to force the plunger out of the adjuster body to press the
tensioner arm against the timing chain and so using the oil trapped in the adjuster body to act as a damper.
The internal damping of the hydraulic tensioner is tuned for each application. This means that pre-EU3 and EU3
components are not interchangeable.
Drive train sprockets
The camshaft sprocket has a double row of teeth which locate with the duplex timing chain. The sprocket is fitted
to the camshaft by three bolts.
The oil pump sprocket is located on the front of the oil pump housing by a single retaining bolt. The sprocket has a
single row of teeth which locates with the oil pump drive chain.
The crankshaft sprocket contains three rows of teeth, the rear row locates on the single oil pump chain and the
front two rows locate with the duplex timing chain. The crankshaft sprocket has a slot in its internal diameter which
locates with the Woodruff key on the crankshaft. The front of the crankshaft sprocket has a timing mark.
As a consequence of thicker chain links being used on EU3 vehicles, the thickness of the camshaft and crankshaft
sprocket teeth has been reduced. Individual pre-EU3 and EU3 components are therefore not interchangeable.
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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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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
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
17
REPAIR
23.Disconnect oil pressure switch multiplug.
24.Release engine harness from underside of inlet
manifold and tie aside.
25.Release clips and remove coolant top hose from
cylinder head and coolant rail.
26.Remove 4 bolts and move A/C compressor
aside.
27.Remove 3 bolts and remove PAS pump pulley.
28.Remove 4 bolts and move PAS pump aside.
29.Raise vehicle on ramp.
30.Remove 6 bolts securing gearbox housing to
engine.
31.Lower vehicle ramp.
32.Remove 2 upper bolts securing gearbox housing
to engine.
33.Remove bolt securing engine closing panel to
gearbox.
34.Release clip and coolant hose from engine oil
cooler.
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12ENGINE
18
REPAIR
35.Remove 2 bolts and remove acoustic cover from
rear of cylinder head.
36.FitLRT-12-138to suitable lifting chains and
connect to lifting eyes on engine.
37.Remove 2 nuts from RH and LH front engine
mountings.
38.Fit trolley jack to support gearbox.
39.With assistance raise chains and remove engine
from vehicle.Refit
40.With assistance, raise engine from bench and
position in vehicle.
41.With assistance, align engine to gearbox input
shaft.
42.Position 2 upper bolts securing gearbox housing
to engine and tighten to50 Nm (37 lbf.ft).
43.Lower engine onto mountings and tighten nuts to
85 Nm (63 lbf.ft).
44.RemoveLRT-12-138from engine.
45.Fit and tighten bolt securing engine closing panel
to gearbox.
46.Raise vehicle on ramp.
47.Fit bolts securing gearbox housing to engine and
tighten to50 Nm (37 lbf.ft).
48.Lower ramp.
49.Fit acoustic cover to rear of cylinder head and
tighten bolts.
50.Position coolant hose to engine oil cooler and
secure clip.
51.Position PAS pump and tighten bolts to25 Nm
(18 lbf.ft).
52.Position PAS pulley and tighten bolts to25 Nm
(18 lbf.ft).
53.Position A/C compressor and tighten bolts to25
Nm (18 lbf.ft).
54.Route engine harness beneath inlet manifold
and connect multiplugs to oil pressure switch,
A/C compressor, and ECT sensor.
55.Fit and tighten bolts securing engine harness to
camshaft carrier.
56.Connect multiplug to alternator.
57.Connect battery lead to alternator and tighten
nut.
58.Clean CKP sensor and mating face.
CAUTION: If originally fitted:- Fit spacer to
CKP sensor.
59.Using a new’O’ring, fit CKP sensor, tighten bolt
to10 Nm (7 lbf.ft).
60.Connect CKP sensor multiplug.
61.Connect multiplugs to EGR solenoid, inlet
manifold sensor, injector harness, fuel
temperature sensor and CKP sensor.
62.Connect glow plug leads.
63.Connect multiplug to condensor cooling fan.
64.Connect vacuum hose to EGR valve.
65.Connect EGR vacuum hose to vacuum pipe.
66.Position pipe to vacuum pump and secure pipe
to acoustic cover clips.
67.Position fuel cooler. Apply Loctite 242 to bolts
and tighten to18 Nm (13 lbf.ft).
68.Disconnect fuel hose from connector block and
connect to fuel cooler.
69.Connect fuel hoses to fuel cooler and connector
block on cylinder head.
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12ENGINE
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REPAIR SWITCH - OIL PRESSURE
Service repair no - 12.60.50
Remove
1.Remove fixings and remove engine acoustic
cover.
2.Release clip and disconnect breather hose from
camshaft cover.
3.Release clips and disconnect air flow meter from
air filter.
4.Disconnect multiplug from air flow meter.
5.Release clip screw and remove air inlet hose
from turbocharger.
6.Remove 3 bolts and remove exhaust manifold
heat shield.
7.Disconnect multiplug from oil pressure switch.
8.Position container below switch to catch oil
spillage.
9.Remove oil pressure switch.
Refit
10.Clean oil pressure switch threads.
11.Fit oil pressure switch and tighten to9Nm(7
lbf.ft).
12.Connect switch multiplug.
13.Position exhaust manifold heat shield and
tighten M6 bolts to10 Nm (7 lbf.ft)and M8 bolt
to25 Nm (18 lbf.ft).
14.Position air inlet hose to turbocharger and
tighten clip screw.
15.Connect air flow meter to air filter and secure
clips.
16.Connect air flow meter multiplug.
17.Connect breather hose and secure clip.
18.Fit and secure engine acoustic cover.
19.Top up engine oil.
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