exhaust LAND ROVER DEFENDER 1996 User Guide

ENGINE
23
REPAIR
43.Check and adjust valve clearances.
See Adjustment, Valve clearances - check
and adjust
44.Fit rocker cover, ensuring oil seal is satisfactory
for continued use, and renew if necessary.
45.Secure rocker cover with special seal washers
and nuts. Tighten to
10 Nm (7 lbf/ft).
46.Fit rear engine lifting bracket, securing breather
pipe and multi-plug retaining clips. Tighten fixing
bolts to
25 Nm (18 lbf/ft).
47.Fit engine harness bracket to cylinder head.
48.Secure air cleaner mounting bracket to support
strut.
49.Connect heater hose to rear of cylinder head.
50.Position heater rail and connect hose from water
pump.
51.Fit exhaust manifold and turbocharger assembly.
See MANIFOLD AND EXHAUST SYSTEM,
Repair, Exhaust manifold
52.Fit induction manifold.See MANIFOLD AND
EXHAUST SYSTEM, Repair, Induction
manifold
53.Connect water temperature sensor lead.
54.Connect water pump hose at thermostat.
55.Fit bleed hose at thermostat.
56.Connect radiator top hose at thermostat.
57.Fit heater plugs.
See FUEL SYSTEM, Repair,
Heater plugs
58.Fit fuel injectors.See FUEL SYSTEM, Repair,
Fuel injectors
59.Fit crankcase ventilation valve and side breather
hose.
60.Fit air cleaner.
See FUEL SYSTEM, Repair,
Air cleaner
61.Refill cooling system.See COOLING SYSTEM,
Repair, Drain and refill cooling system
62.Fit bonnet.
63.Reconnect battery.OIL PUMP
Service repair no - 12.60.26
Remove
1.Remove engine front cover.
See Front cover
gasket
2.Remove 7 screws and release oil pump retaining
plate from engine front cover.
3.Mark oil pump inner gear rotor, outer gear rotor
and front cover housing for reassembly.
4.Check for rotor clearances:
Outer rotor to housing, 0,025 - 0,075 mm (0.010
- 0.030 in).
Inner rotor to outer rotor, 0,025 - 0,075 mm
(0.010 - 0.030 in).
Rotor end float, 0,026 - 0,135 mm (0.010 - 0.054
in).
5.Remove inner and outer rotors.
6.Check condition of oil pump components.
NOTE: If the oil pump seating in the front
cover or retaining plate is badly worn,
pitted or scored, a new front cover must
be fitted.
See Front cover gasket
Always renew oil pump rotors as a pair.
7.Clean sealant from pump retaining plate and
front cover.

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..........................................................................

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
14
REPAIR TURBOCHARGER INLET HOSE
Service repair no - 19.42.11
Remove
1.Disconnect battery.
2.Slacken retaining clip and disconnect intake
hose from turbocharger.
3.Slacken retaining clip and disconnect hose from
air cleaner.
4.If fitted, disconnect EGR modulator valve
vacuum spill pipe from inlet hose.
5.Slacken retaining clip and disconnect breather
valve hose from inlet hose.
6.Remove inlet hose.
Refit
7.Fit inlet hose to air cleaner.
8.Fit cyclone breather hose to inlet hose.
9.If applicable, fit vacuum spill pipe to inlet hose.
10.Fit inlet hose to turbocharger.
11.Reconnect battery.TURBOCHARGER OIL FEED PIPE
Service repair no - 19.42.14
Remove
1.Disconnect battery.
2.Remove exhaust front pipe.
See MANIFOLD
AND EXHAUST SYSTEM, Repair, Exhaust
front pipe
3.Remove banjo bolt securing oil feed pipe to
turbocharger and discard 2 joint sealing
washers.
4.Unscrew union and remove feed pipe from
cylinder block.
5.Plug connections to prevent ingress of dirt.
Refit
6.Using new joint washer, fit oil feed pipe to
cylinder block. Tighten union connector to
25
Nm (18 lbf/ft).
7.Fit a new joint washer to both sides of banjo and
secure feed pipe to turbocharger. Tighten banjo
bolt to
20 Nm (15 lbf/ft).
8.Fit exhaust front pipe.See MANIFOLD AND
EXHAUST SYSTEM, Repair, Exhaust front
pipe
9.Check/top-up engine oil level.See SECTION
10, Maintenance, Under bonnet maintenance
10.Reconnect battery.

FUEL SYSTEM
15
REPAIR TURBOCHARGER OIL DRAIN PIPE
Service repair no - 19.42.12
Remove
1.Disconnect battery.
2.Remove exhaust front pipe.
See MANIFOLD
AND EXHAUST SYSTEM, Repair, Exhaust
front pipe
3.Unscrew union and disconnect oil drain pipe
from cylinder block.
4.Remove 2 bolts securing oil drain pipe to
turbocharger.
5.Remove drain pipe and discard gasket.
6.Plug connections to prevent ingress of dirt.
Refit
7.Ensure mating surfaces of oil pipe, turbocharger
and engine block are clean.
8.Using new gasket, fit oil drain pipe to
turbocharger. Tighten bolts to
25 Nm (18 lbf/ft).
9.Fit drain pipe to cylinder block and tighten union
connector to
38 Nm (28 lbf/ft).
10.Fit exhaust front pipe.See MANIFOLD AND
EXHAUST SYSTEM, Repair, Exhaust front
pipe
11.Check/top-up engine oil level.See SECTION
10, Maintenance, Under bonnet maintenance
12.Reconnect battery.

FUEL SYSTEM
17
REPAIR EGR VALVE
Service repair no - 17.45.01
Remove
1.Disconnect multi-plug from EGR valve.
2.Disconnect vacuum pipe from EGR valve.
3.Remove 2 Allen screws securing EGR valve to
exhaust manifold.
4.Remove 2 bolts securing air inlet delivery tube to
EGR valve.
5.Remove EGR valve and discard gaskets.
Refit
6.Clean mating faces of EGR valve and exhaust
manifold.
7.Position new gaskets and fit EGR valve to
delivery tube and exhaust manifold. Tighten
bolts to
25 Nm (18 lbf/ft).
8.Fit vacuum pipe and multi-plug to EGR valve.EGR VALVE MODULATOR
Service repair no - 17.45.04
Remove
1.Disconnect multi-plug from modulator.
2.Disconnect spill pipe (green), modulator to air
cleaner hose.
3.Disconnect vacuum pipe (blue), modulator to
EGR valve.
4.Disconnect vacuum pipe (white), modulator to
brake servo pipe.
5.Unscrew 2 nuts securing modulator to flexible
mountings.
6.Remove modulator.
Refit
7.Fit modulator to flexible mountings and tighten
nuts to
8 Nm (6 lbf/ft).
8.Fit modulator pipes, ensuring they are connected
to correct ports.
9.Connect modulator multi-plug.

COOLING SYSTEM
1
DESCRIPTION AND OPERATION ENGINE COOLING SYSTEM
Description
The complete cooling system of the 300Tdi engine
incorporates three independent functions:- Engine
(coolant) cooling; Turbo (charge air) intercooling;
Engine oil cooling.The intercooler is a separate aluminium unit, located
on the LH side of the engine compartment adjacent to
the radiator, sharing the same upper and lower
mountings. For details of turbo intercooling
See
FUEL SYSTEM, Description and operation,
Operation
. The oil cooler matrix is an integral part of
the radiator. Pre-formed pipes/hoses are used to link
the components within the separate systems as
shown below.
Engine cooling system
1.Radiator
2.Thermostat housing
3.Radiator bottom hose
4.Viscous fan
5.Water pump
6.Radiator top hose
7.Heater return hose
8.Coolant supply hose
9.By-pass hose
10.Radiator bleed (purge) hose
11.Bleed (purge) hose, thermostat housing
12.'Y' piece ejector
13.Expansion tank14.Heater rail
15.Heater unit
16.Heater feed hose
17.Intercooler
18.Air cleaner
19.Air feed hose
20.Turbocharger
21.Charge air supply pipe/hose
22.Cooled charge air supply hose
23.Exhaust manifold
24.Engine oil cooler
25.Feed pipe, engine oil cooler
26.Return pipe, engine oil cooler
27.Oil filter

MANIFOLD AND EXHAUST SYSTEM
1
DESCRIPTION AND OPERATION MANIFOLDS AND EXHAUST SYSTEM
Description
The exhaust systems fitted on all models with the
300Tdi engine comprise three sections; front pipe
assembly, intermediate silencer assembly, and tail
pipe and silencer assembly. All sections, including
silencers, are manufactured from luminised steel to
give the system a durable working life under all
conditions. Special clamps are provided to ensureleak proof jointing between the various sections,
which are supported by flexible rubber mountings.
Catalytic convertor
When fitted, the catalytic converter is integral with the
front pipe assembly, which also incorporates a flexible
joint. The catalyst forms part of the engine emission
control that can also include an EGR valve system
See FUEL SYSTEM, Repair, EGR valve
Exhaust system - 90
1.Gasket
2.Front pipe
3.Front pipe with catalytic converter
4.Front mounting bracket
5.Intermediate silencer6.Intermediate mounting brackets
7.Tail pipe silencer*
8.Tail pipe silencer mounting
9.Tail pipe mounting
* Deleted on later models

30MANIFOLD AND EXHAUST SYSTEM
2
DESCRIPTION AND OPERATION The catalyst comprises platinum coated ceramic
elements. The Hydrocarbons (HC), Oxides of nitrogen
(NOx) and Carbon monoxide (CO) emitted by the
engine react with the catalytic element and exhaust
temperature to convert the toxic gas into Nitrogen
(N
2), Carbon dioxide (CO2) and water vapour.
Exhaust system - 110/130
1.Gasket
2.Front pipe
3.Front pipe with catalytic converter
4.Front mounting bracket
5.Intermediate silencer6.Intermediate mounting brackets
7.Tail pipe silencer
8.Tail pipe silencer mounting
9.Tail pipe mounting