1996 LAND ROVER DEFENDER engine

12ENGINE
24
REPAIR Refit
8.Fit oil pump rotors in front cover.
9.Apply a bead of RTV sealant around retaining
plate.
10.Fit oil pump retaining plate to front cover,
securely tighten screws.
11.Fit front cover to cylinder block.
See Front
cover gasket
OIL PRESSURE RELIEF VALVE
Service repair no - 12.60.56
Remove
1.Remove engine oil sump.
See Engine oil
sump
2.Unscrew relief valve retaining plug from base of
front cover.
3.Withdraw valve spring and plunger and check for
wear.
Valve spring free length, 68.00 mm (2.68 in).
NOTE: If the valve plunger sleeve is badly
worn, pitted or scored, a new front cover
must be fitted.
See Front cover gasket
Always renew valve spring and plunger as a pair.
Refit
4.Insert valve plunger and spring into sleeve in
front cover and secure with retaining plug.
5.Fit engine oil sump.
See Engine oil sump

ENGINE
1
SPECIFICATIONS, TORQUE REV: 05/99 TORQUE VALUES
NOTE: Torque wrenches should be regularly checked for accuracy to ensure that all fixings are
tightened to the correct torque.
Nm
Engine block
Bearing cap 133...............................................................................................
Blanking plug, oil gallery, rear 37....................................................................
Oil squirt jet assembly 17................................................................................
Drain plug, cylinder block 25...........................................................................
Oil squirt jet, vacuum pump cam 7.................................................................
Connecting rod to cap 59................................................................................
Oil pick up assembly to bearing cap 9...........................................................
Oil pick up assembly to front cover 25............................................................
Camshaft thrust plate 9..................................................................................
Oil drain pipe to block (internal) 25.................................................................
Oil drain pipe to block (external) 25................................................................
Sump to cylinder block and front cover 25......................................................
Drain plug, oil sump 35...................................................................................
Tappet guide 14..............................................................................................
Breather side cover assembly 25....................................................................
Baffle plate to breather side cover 4..............................................................
Vacuum pump 25............................................................................................
Fuel lift pump 25.............................................................................................
Flywheel housing 45.......................................................................................
Flywheel housing clutch cover stud 10...........................................................
Plug, flywheel housing 12...............................................................................
Rear oil seal assembly 25...............................................................................
Oil filter adaptor 45..........................................................................................
Waxstat adaptor to oil filter adaptor 9............................................................
Oil pressure switch 17.....................................................................................
Oil filter, spin on 13.........................................................................................
Oil cooler unions to filter adaptor 45...............................................................
Oil level tube 25..............................................................................................
Engine mounting foot to cylinder block 85......................................................
Engine mounting foot to flywheel housing 45.................................................
Engine mounting foot rubber to mounting foot (bolt and nut) 85.....................
Flywheel to crankshaft 146..............................................................................
Clutch cover plate to flywheel 34....................................................................
Flex drive plate to crankshaft (auto) 146..........................................................
Flex drive plate to ring gear (auto) 25.............................................................
Flex drive plate to torque converter (auto) 45.................................................

12ENGINE
2
SPECIFICATIONS, TORQUE REV: 05/99Nm
Cylinder head
Cylinder head to cylinder block
M10 x 117 40 Nm + 60° ..........................................................................................
M12 x 100 40 Nm + 60° ..........................................................................................
M12 x 140 40 Nm + 60°+20° ......................................................................................
Stub pipe heater feed 22.................................................................................
Water temperature sensor 14.........................................................................
Blanking plug cylinder head 14.......................................................................
Engine lifting brackets 25................................................................................
Electrical harness clip bracket 25...................................................................
Exhaust manifold stud 10................................................................................
Exhaust manifold nut 45.................................................................................
Inlet manifold stud 8.......................................................................................
Inlet manifold nut and bolt 25..........................................................................
Air temperature sensor, inlet manifold 14.......................................................
Blanking plug, inlet manifold 14......................................................................
Heatshield to inlet manifold 6.........................................................................
Glow plug 20...................................................................................................
Glow plug terminal nut 2................................................................................
Injector clamp (stud) 8...................................................................................
Injector clamp (nut) 25....................................................................................
Thermostat housing 25...................................................................................
Water outlet elbow to thermostat housing 25..................................................
Water temperature switch, thermostat housing 11..........................................
Plug thermostat housing 6.............................................................................
Rocker shaft pedestal bolt 5 Nm + 50° ..................................................................
Rocker cover (stud) 8.....................................................................................
Rocker cover (fixing nut) 10............................................................................
Breather cyclone to rocker cover 9................................................................
Tappet adjusting nut 16..................................................................................
Front cover to cylinder block 25......................................................................
Front cover plate to front cover 25..................................................................
Static idler - timing belt (stud) 10.....................................................................
Static idler - timing belt (nut) 45......................................................................
Tensioner (timing belt) 45...............................................................................
Camshaft hub bolt 80......................................................................................
Timing pulley to camshaft hub 25...................................................................
Fuel injection pump (stud) 8...........................................................................
Fuel injection pump (nut) 25...........................................................................
Abutment bracket to injection pump 25...........................................................
Support bracket injection pump to cylinder block 25.......................................
Fuel injection pump access plate to front cover plate 25................................
Timing pulley to injection pump hub 25...........................................................
TV Damper pulley bolt to crankshaft 80 Nm + 90° ..................................................
Fan pulley to hub 25.......................................................................................
Fan and viscous coupling to hub 45...............................................................
Auto tensioner, auxiliary drive (stud) 14..........................................................
Auto tensioner, auxiliary drive (nut) 45...........................................................
Auxiliary mounting bracket to cylinder block (stud) 8.....................................
Auxiliary mounting bracket to cylinder block (bolt and nut) 25........................
Water pump to block and mounting plate 25..................................................
Water pump pulley to hub 25..........................................................................

ENGINE
3
SPECIFICATIONS, TORQUENm
Turbo charger oil drain adaptor to block 42....................................................
Oil drain pipe to turbocharger 25....................................................................
Turbocharger oil drain pipe to adaptor 38.......................................................
Turbocharger oil feed pipe adaptor to block 25...............................................
Turbocharger oil feed pipe to adaptor 25........................................................
Oil feed pipe to turbocharger 19.....................................................................
Turbocharger to cylinder head (stud) 10.........................................................
Turbocharger to cylinder head (nut) 45...........................................................
Turbocharger to blanking plate 25..................................................................
Turbocharger to EGR valve 25.......................................................................
EGR delivery tube to valve 25........................................................................
EGR delivery tube to mixing tube 25..............................................................
Fuel lift pump to filter (union) 15.....................................................................
Fuel filter from lift pump (banjo bolt) 33...........................................................
Fuel filter to fuel injection pump (banjo bolt) 33..............................................
Fuel injection pump from fuel filter (banjo bolt) 25..........................................
Injector pipes to injectors and fuel injection pump 29.....................................
Spill rail to injectors (banjo bolt) 10.................................................................
Spill rail to injection pump (banjo bolt) 25.......................................................
Boost pipe injection pump (banjo bolt) 10.......................................................
Plug, rear of injection pump 29.......................................................................
PAS pump to mounting plate 25.....................................................................
PAS pump mounting plate to auxiliaries mounting bracket 25........................
PAS pump pulley to hub 25............................................................................
Starter motor (bolt and nut) 45........................................................................
Air conditioning compressor
Compressor mounting bracket to front cover 45.............................................
Compressor to mounting bracket (stud) 8......................................................
Compressor to mounting bracket (nut) 25......................................................
Belt tensioner pulley to tensioner arm 45........................................................
Belt tensioner assembly to front cover plate 25..............................................
Idler pulley to front cover plate 45...................................................................
Compressor belt guard (nut) 25......................................................................
Sensors to water outlet elbow (air/con) 25......................................................
Blanking plug, water outlet elbow (air/con) 25................................................
Generator
Generator mounting bracket to front cover 45................................................
Generator to mounting bracket 85..................................................................
Generator pulley to hub 95.............................................................................
Generator belt guard 25..................................................................................
Generator to auxiliaries mounting bracket 25.................................................
Tachometer electrical connection 4...............................................................

12ENGINE
4
SPECIFICATIONS, TORQUEMETRIC Nm
M5 6......................................................................................................
M6 9......................................................................................................
M8 25.....................................................................................................
M10 45...................................................................................................
M12 90...................................................................................................
M14 105..................................................................................................
M16 180..................................................................................................
UNC / UNF
1/4 9......................................................................................................
5/16 24...................................................................................................
3/8 39.....................................................................................................
7/16 78...................................................................................................
1/2 90.....................................................................................................
5/8 136....................................................................................................
NOTE: Torque values above are to be used as a guide where no torque is specified.

19FUEL SYSTEM
2
DESCRIPTION AND OPERATION A mechanical lift pump, with a hand priming facility, is
driven by the camshaft, and is mounted on the RH
side of the engine.
A fuel filter, with a replaceable element and
incorporating a water separator, is mounted on the
front RH side of the engine compartment.
A fuel sedimentor may be fitted when the vehicle is
operating in more arduous conditions, and is used to
minimise water deposits in the fuel system before
reaching the fuel pump and filter.
Fuel injection is carried out by a Bosch direct injection
pump, incorporating a cold start advance unit and a
high idle setting. The pump is mounted on the RH side
of the engine and is driven directly by gears in the
front cover from the crankshaft. The pump meters and
distributes fuel to 4 pintle type injectors located in
pre-combustion chambers in the cylinder head. Four
heater plugs, located in the cylinder head directly
below each injector, are fitted to improve cold starting.
An optional hand throttle, for use with a centre power
take off, is located on the fascia to the LH side of the
fuse box, and is linked independently to the fuel
injection pump throttle lever.
Air intake
The air cleaner is mounted on the RH side of the
engine and is connected by hoses to the cold air
intake duct and turbocharger inlet. Fitted between the
air cleaner and turbocharger is the crankcase breather
hose which connects to a breather filter on the rocker
cover.
A single stage turbocharger, fitted between the
exhaust manifold and exhaust down pipe, is
connected by hoses to the air cleaner and an
intercooler which is mounted on the LH side of the
radiator. The intercooler is connected by a hose to the
inlet manifold. When an EGR valve is fitted to the
turbocharger, additional pipes/hoses are used to
connect the components.Exhaust gas recirculation (EGR), when fitted.
Exhaust gas recirculation is controlled by an ECU
mounted under the front centre seat or cubby box and
receives the following inputs:
·Engine temperature from coolant temperature
sender unit on LH side of cylinder head.
·Throttle position from potentiometer on injection
pump.
·Engine speed from speedometer.
When all correct signals are received, the EGR
solenoid allows vacuum to open EGR valve and
recirculate a portion of the exhaust gas. See J6196 for
the EGR system component location and 'Operation'
for full system function.

FUEL SYSTEM
9
DESCRIPTION AND OPERATION OPERATION
Diesel engines operate by compression ignition. The
rapid compression of air in the cylinder during the
compression cycle heats the air and when fuel is
injected into the heated air, it ignites instantaneously.
During cold tarting, automatically controlled heater
plugs assist in raising the temperature of the
compressed air to ignition point.
A cold start advance unit advances the injection timing
to further assist starting. Idle quality is improved by
the high idle setting.
The engine is supplied with pre-compressed air by a
single stage turbocharger.
Exhaust gases passing over a turbine cause it to
rotate, driving a compressor mounted on the turbine
shaft. Air drawn from the cold air intake passes, via
the air cleaner, to the turbocharger where it is
compressed. Compression in the turbocharger warms
up the air considerably, so that it expands. As a result
the air mass per cylinder is reduced, having a
negative effect on power output. By fitting a charge-air
intercooler, located on the LH side of the radiator, the
air is cooled before reaching the cylinders. This
increases power output through increased mass of
oxygen in the combustion process, as well as
maximising engine durability, through maintaining
lower piston and head temperatures.
Fuel is drawn from the tank by a mechanical lift pump
and passes to the injection pump via a filter. In
addition to removing particle contamination from the
fuel, the filter incorporates a water separator, which
removes and stores water.
The sedimentor/s, when fitted, is located adjacent to
the fuel tank/s and separates contamination and water
particles in the fuel before reaching the fuel lift pump.
The injection pump meters a precisely timed, exact
quantity of fuel to the injectors in response to throttle
variations, injection timing varying with engine speed.
Any excess fuel delivered to the injection pump is
passed back to the tank via the spill return line.
Fuel is injected in a finely atomised form into the main
combustion chamber, the burning fuel expands
rapidly, creating extreme turbulence which mixes the
burning fuel thoroughly with the compressed air,
providing complete combustion.Cold Starting is assisted by heater plugs, a cold start
advance unit and a high idle setting.
Heater plugs
Heater plug operation is controlled by a timer unit,
start relay and resistor. When the ignition is turned on
the timer unit is energised, the heater plugs start to
operate and a warning light on the dashboard
illuminates, remaining on until the heater plugs are
automatically switched off.
The length of time the heater plugs will operate is
dependent on under bonnet temperature, which is
monitored by a sensor located in the timer unit.
Starting the engine results in the power supply to the
heater plugs passing through the resistor, which
reduces their operating temperature. The heater plugs
are cut out either by the temperature sensor in the
timer, or by a microswitch on the injection pump which
operates when the throttle is depressed.
Cold start advance
The cold start advance unit is connected to the engine
cooling system via hoses. It contains a temperature
sensitive element which is retracted when cold and
pulls the advance lever, via cable, towards the rear of
the pump against spring pressure. As coolant
temperature rises, the cold start element expands
releasing tension on the cable and allowing spring
pressure to move the advance lever forwards.
Exhaust gas recirculation (EGR), when fitted
Operation of the EGR system is dependent on the
following:
·Engine temperature - must be between 20°C and
100°C approx.
·Engine speed - must be between 630 and 2850
rev/min.
·Engine load - calculated by throttle position
sensor.
·EGR valve lift position.
·Duration of engine idling.

19FUEL SYSTEM
10
DESCRIPTION AND OPERATION Under varying engine speed and load condition the
control unit sends a signal to open the vacuum
modulator which allows a vacuum to be applied above
the EGR diaphragm. The vacuum supply is taken from
a 'T' connector in the brake servo hose. This process
is controlled by an engine speed/load map stored in
the EGR control unit memory.
Engine speed is measured by monitoring the
waveform present on one phase of the generator.
Throttle position is measured via a sensor mounted on
the fuel injection pump throttle lever. Closed loop
control is achieved by allowing the control unit (ECU)
to continually monitor EGR valve lift via the sensor
mounted on the valve; this valve lift is compared with
the actual valve lift required on the control unit map
and adjusted, if necessary.
With coolant temperature between 20°C and 100°C,
the engine having just returned to idle, EGR will shut
off after 25-30 seconds idling.