1999 LAND ROVER DEFENDER oil pressure

ENGINE
29
REPAIR VALVE - RELIEF - OIL PRESSURE
Service repair no - 12.60.56
Remove
1.Remove sump gasket.See this Section.
2.Remove and discard oil pressure relief valve
plug from oil pump housing.
3.Remove spring and valve.
Refit
4.Clean valve and spring.
5.Clean valve seating inside oil pump housing.
6.Lubricate valve and seating.
7.Fit valve and spring to pump.
8.Apply Loctite 243 sealant to threads of a new
plug.
9.Fit plug and tighten to23 Nm ( 17 lbf.ft).
10.Fit sump gasket.See this Section.
11.Check engine oil level, top-up if necessary.COOLER - ENGINE OIL
Service repair no - 12.60.68
Remove
1.Drain cooling system.See COOLING
SYSTEM, Adjustment.
2.Remove centrifuge assembly.See this
Section.
3.Remove clutch housing bolt and release coolant
pipe from rear of engine.
4.Release clip and coolant hose from oil cooler.
5.Disconnect oil pressure switch multiplug.
6.Remove oil filter element using a suitable strap
wrench.
7.Remove 3 bolts, remove oil filter adaptor and
discard gasket.
8.Remove 7 bolts, remove oil cooler and discard
gasket.
9.Remove oil pressure switch.
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12ENGINE
30
REPAIR Refit
10.Clean oil cooler and mating faces.
11.Fit oil pressure switch and tighten to9Nm(7
lbf.ft).
12.Position oil cooler using a new gasket and
tighten bolts to25 Nm (18 lbf.ft).
13.Position oil filter adaptor, fit new gasket and
tighten bolts to25 Nm (18 lbf.ft).
14.Position oil filter element hand tight then a
further half turn.
15.Position coolant hose to oil cooler and secure
clip.
16.Position coolant pipe and tighten clutch housing
bolt to50 Nm (37 lbf.ft).
17.Connect oil pressure switch multiplug.
18.Fit centrifuge assembly.See this Section.
19.Refill cooling system.See COOLING SYSTEM,
Adjustment.
20.Top up engine oil.CENTRIFUGE ASSEMBLY
Service repair no - 12.60.90
Remove
1.Remove fixings and remove underbelly panel.
See CHASSIS AND BODY, Repair.
2.Remove 2 bolts securing centrifuge drain pipe to
engine sump and discard gasket.
3.Remove turbocharger.See FUEL SYSTEM,
Repair.
Models with air conditioning only
4.Remove auxiliary drive belt.See
ELECTRICAL, Repair.
5.Remove 4 bolts securing compressor and move
to one side.
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ENGINE
25
OVERHAUL
8.Place a straight edge across pump body and
using feeler gauges, measure end-float of outer
rotor:
Outer rotor end-float =0.038 to 0.075 mm
(0.001 to 0.003 in)
9.Check drive shaft bush in pump cover for signs
of scoring and wear.
10.Renew oil pump and stiffener plate assembly if
excessive scoring exists or clearances exceed
limits given.
11.Lubricate pump rotors and drive shaft bush with
engine oil.
12.Fit rotors ensuring reference marks are aligned
and identification mark on inner rotor is facing
forwards.
13.Fit cover to pump, fit 5 new screws and tighten
by diagonal selection to6 Nm (4.5 lbf.ft).
14.Check that pump rotors rotate freely.Oil pressure relief valve
1.Remove and discard oil pressure relief valve
plug.
2.Remove spring and relief valve plunger.
3.Clean valve plunger and spring.
4.Check valve plunger and relief valve bore for
scoring and corrosion.
NOTE: Light scoring and corrosion may be
removed using grade 600 emery cloth
soaked in oil.
5.Check spring for distortion, check free length of
spring:
Spring free length =42.00 mm (1.65 in)
CAUTION: Renew relief valve as an
assembly.
6.Lubricate valve plunger and seating.
7.Fit valve plunger and spring to oil pump.
8.Apply Loctite 243 sealant to threads of a new
plug.
CAUTION: Do not attempt to fit original
plug.
9.Fit plug and tighten to23 Nm (17 lbf.ft).
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EMISSION CONTROL
7
DESCRIPTION AND OPERATION CRANKCASE EMISSION CONTROL
All internal combustion engines generate oil vapour and smoke in the crankcase as a result of high crankcase
temperatures and piston ring and valve stem blow-by. A closed crankcase ventilation system is used to vent
crankcase gases back to the air induction system and so reduce the emission of hydrocarbons.
Gases from the crankcase are drawn into the inlet manifold to be burnt in the combustion chambers with the fresh
air/fuel mixture. The system provides effective emission control under all engine operating conditions.
Crankcase gases are drawn through the breather port in the top of the camshaft cover and routed through the
breather hose and breather valve on the flexible air intake duct to be drawn into the turbocharger intake for
delivery to the air inlet manifold via the intercooler.
An oil separator plate is included in the camshaft cover which removes the heavy particles of oil before the
crankcase gas leaves via the camshaft cover port. The rocker cover features circular chambers which promote
swirl in the oil mist emanating from the cylinder head and camshaft carrier. As the mist passes through the series
of chambers between the rocker cover and oil separator plate, oil particles are thrown against the separator walls
where they condense and fall back into the cylinder head via two air inlet holes located at each end of the rocker
cover.
The breather valve is a pressure depression limiting valve which progressively closes as engine speed increases,
thereby limiting the depression in the crankcase. The valve is of moulded plastic construction and has a port on
the underside which plugs into a port in the flexible air duct. A port on the side of the breather valve connects to
the camshaft cover port by means of a breather hose which is constructed from a heavy duty braided rubber hose
which is held in place by hose clips. A corrugated plastic sleeve is used to give further protection to the breather
hose. The breather valve is orientation sensitive, and’TOP’is marked on the upper surface to ensure it is
mounted correctly.
It is important that the system is air tight. Hose connections to ports should be checked and the condition of the
breather hose should be periodically inspected to ensure it is in good condition.
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ENGINE MANAGEMENT SYSTEM
27
DESCRIPTION AND OPERATION The turbocharger is exposed to extremely high operating temperatures (up to 1000°C, 1832°F) because of the
hot exhaust gases and the high speed revolution of the turbine (up to 15,000 rev/min). In order to resist wear of
the turbine bearings a flow of lubrication oil is supplied from the engine lubrication system to keep the bearings
cool. Oil is supplied from a tapping at the front of the full-flow filter adaptor housing via a metal pipe with banjo
connections. Oil is returned to the sump via a metal pipe which connects to the cylinder block at a port below the
turbocharger assembly.
A heatshield is attached to the LH side of the engine to protect adjacent components from the heat generated at
the turbocharger. The heatshield is attached to the engine by 2 bolts. An additional bolt attaches the heatshield to
the turbocharger casting.
The ECM controls the amount of boost pressure the engine receives by way of the turbocharger. When full boost
is reached a control signal is sent to the wastegate modulator, and a vacuum is applied to the wastegate valve.
The wastegate valve opens, bypassing some of the exhaust gases away from the turbine to be output to the
exhaust system.
The engine should be allowed to idle for 15 seconds following engine start up and before the engine is switched
off to protect the turbocharger by maintaining oil supply to the turbine bearings.
INTERCOOLER
The intercooler is an air-to-air heat exchanger which lowers the intake air temperature to obtain a higher air
density for better combustion efficiency. The intercooler receives compressed air from the turbocharger via a
metal pipe. It cools the intake air via the intercooler matrix and delivers it to the intake manifold by means of a
rubber hose which connects between the intercooler outlet and the intake manifold. The rubber hose is connected
to ports at each end by metal clips.
The intercooler is located at the front of the engine bay, forward of the radiator.
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19FUEL SYSTEM
4
DESCRIPTION AND OPERATION Fuel Pump
The fuel pump assembly comprises a top cover which locates the electrical connector, and four fuel pipe
couplings. The top cover is attached to a plastic cup shaped housing and retained on three sliding clips. Two coil
springs are located between the cover and the housing and ensure that the fuel pump remains seated positively at
the bottom of the tank when installed.
The housing locates the two stage fuel pump and also the fuel gauge sender unit. The lower part of the housing is
the swirl pot which maintains a constant level of fuel at the fuel pick-up. A coarse filter is located in the base of the
housing and prevents the ingress of contaminants into the pump and the fuel system from the fuel being drawn
into the pump. A fine filter is located in the intake to the low pressure stage to protect the pump from
contaminants. Flexible pipes connect the couplings on the top cover to the pump.
A non-return valve is located in the base of the housing. When the fuel tank is full, fuel pressure keeps the valve
lifted from its seat, allowing fuel to flow into the swirl pot. As the tank level reduces, the fuel pressure in the tank
reduces causing the valve to close. When the valve is closed, fuel is retained in the swirl pot, ensuring that the
swirl pot remains full and maintains a constant supply to the fuel pump.
The two stage pump comprises a high and low pressure stage. The low pressure stage draws fuel from the swirl
pot through a filter. The low pressure stage pumps fluid at a pressure of 0.75 bar (10.9 lbf.in) and a flow of 30
litres/hour (8 US Gallons/hour) to the fuel filter. A proportion of the fuel from the low pressure stage also passes,
via a restrictor, through a jet pump which keeps fuel circulating in the swirl pot. The high pressure stage draws the
low pressure fuel from the fuel filter and pressurises it to a pressure of 4.0 bar (58 lbf.in). The pressurised fuel is
then passed from the pump to the injectors at a flow of 180 litres/hour (47.6 US Gallons/hour). A fuel pressure
regulator is located at the rear of the engine and ensures that the delivery pressure remains at 4.0 bar (58 lbf.in)
by controlling the amount of fuel returning to the fuel tank.
The fuel pump has a maximum current draw of 15 Amps at 12 Volts and is supplied a feed (C0114-1) from the fuel
pump relay (C0730-2) on a white/purple wire.
Fuel Gauge Sender
The fuel gauge sender unit comprises a rotary potentiometer operated by a float. The float rises and falls with the
fuel level in the tank and moves the potentiometer accordingly.
A feed is supplied to the fuel gauge sender (C0114-1) by the fuel pump relay (C0730-2) on a purple/white then
white/purple wire. The sender is earthed (C0114-3) on a slate/black wire via header 287. The output voltage
(C0114-2) from the sender to the instrument pack (C1061-3) varies in relation to the fuel level. This output voltage
is connected to the fuel gauge C1054-2). The fuel gauge receives a battery voltage input (C1054-3) on a
white/green wire. This is compared with the output voltage from the potentiometer. The difference between the two
voltages determines the deflection of the fuel gauge pointer.
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COOLING SYSTEM
3
DESCRIPTION AND OPERATION
NOTE: Inset A shows differences for Pre
EU3 models
1.Pressure cap
2.Overflow pipe
3.Heater return hose
4.Heater matrix
5.Heater inlet hose
6.Oil cooler return pipe - EU3 models
7.Connecting hose
8.Oil cooler housing assembly
9.Heater inlet pipe
10.Connecting hose
11.Outlet housing
12.Engine Coolant Temperature (ECT) sensor
13.Bleed screw
14.Radiator top hose
15.Radiator - upper
16.Intercooler
17.Gearbox oil cooler
18.Radiator - lower
19.Viscous fan
20.Drain plug
21.Connecting hose
22.Fuel cooler feed hose
23.Radiator bottom hose
24.Thermostat housing
25.Connecting hose
26.Coolant pump feed pipe
27.Coolant by-pass pipe
28.Radiator bleed pipe
29.Connecting hose
30.Coolant pump
31.Fuel cooler
32.Heater/expansion tank return hose
33.Expansion tank
34.EGR Cooler - EU3 models
35.Connecting hose - EU3 models
36.Connecting hose - EU3 models
37.Hose - EGR Cooler to oil cooler return pipe -
EU3 models
38.Radiator lower feed hose - Pre EU3 models
39.Oil cooler return pipe - Pre EU3 models
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COOLING SYSTEM
5
DESCRIPTION AND OPERATION A - EU 3 Models
B- Pre EU3 Models
GENERAL
The cooling system used on the Diesel engine is a pressure relief by-pass type system which allows coolant to
circulate around the engine block and heater circuit when the thermostat is closed. With coolant not passing
through the by-pass or the radiator promotes faster heater warm-up which in turn improves passenger comfort.
A coolant pump is mounted on a casting behind the PAS pump and is driven from the PAS pump at crankshaft
speed by the auxiliary drive belt. The pump mounting casting connects with passages in the cylinder block and
pumps coolant from the radiator through the cylinder block.
A viscous fan is attached to an idler pulley at the front of the engine. The fan is attached to a threaded spigot on
the pulley with a right hand threaded nut. The fan draws air through the radiator to assist in cooling when the
vehicle is stationary. The fan rotational speed is controlled relative to the running temperature of the engine by a
thermostatic valve regulated by a bi-metallic coil.
The cooling system uses a 50/50 mix of anti-freeze and water.
Thermostat Housing
A plastic thermostat housing is located behind the radiator. The housing has three connections which locate the
radiator bottom hose, top hose and coolant pump feed pipe. The housing contains a wax element thermostat and
a spring loaded by-pass flow valve.
Thermostat - Main valve
The thermostat is used to maintain the coolant at the optimum temperature for efficient combustion and to aid
engine warm-up. The thermostat is closed at temperatures below approximately 82°C (179°F). When the coolant
temperature reaches approximately 82°C the thermostat starts to open and is fully open at approximately 96°C
(204°F). In this condition the full flow of coolant is directed through the radiator.
The thermostat is exposed to 90% hot coolant from the engine on one side and 10% cold coolant returning from
the radiator bottom hose on the other side.
Hot coolant from the engine passes from the by-pass pipe through four sensing holes in the flow valve into a tube
surrounding 90% of the thermostat sensitive area. Cold coolant returning from the radiator, cooled by the ambient
air, conducts through 10% of the thermostat sensitive area.
In cold ambient temperatures, the engine temperature is raised approximately 10°C (50°F) to compensate for the
heat loss of 10% exposure to the cold coolant returning from the radiator bottom hose.
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