1996 LAND ROVER DEFENDER engine

FUEL SYSTEM
11
REPAIR HEATER PLUGS
Service repair no - 19.60.31
Remove
1.Disconnect battery.
No.1 heater plug - air conditioning models:
2.Release drive belt from compressor pulley.See
AIR CONDITIONING, Repair, Compressor
drive belt
3.Remove 4 bolts securing compressor to front
cover, move compressor aside.
No.3 heater plug:
4.Remove retaining bolt and withdraw breather
valve from rocker cover. Remove and discard 'O'
ring.
All heater plugs:
5.Remove terminal nut and disconnect wire from
heater plug terminal.
6.Unscrew heater plug.
Refit
7.Clean heater plug and seating.
8.Coat threads of heater plug with suitable
anti-seize compound operational to a
temperature of 1000°C.
9.Fit heater plug, tighten to
23 Nm (17 lbf/ft).
10.Connect wire to heater plug terminal and secure
with nut.
NOTE: Feed wire must be connected to
No. 4 heater plug terminal.
No. 3 heater plug:
11.Lubricate new 'O' ring with engine oil and fit to
breather valve.
12.Fit valve to rocker cover, tighten to bolt to
15 Nm
(11 lbf/ft).
No. 1 heater plug - air conditioning models
13.Position compressor to front cover, fit bolts and
tighten to
25 Nm (18 lbf/ft).
14.Fit drive belt to compressor pulley and adjust
tension.
See AIR CONDITIONING, Repair,
Compressor drive belt
All models:
15.Reconnect battery.

FUEL SYSTEM
13
REPAIR THROTTLE CABLE
Service repair no - 19.20.06
Remove
1.Disconnect battery.
2.Remove split pin and clevis pin securing throttle
cable to injector pump throttle lever .
3.Depress ferrule retaining tags, release ferrule
from abutment bracket and withdraw throttle
cable.
4.Release throttle cable from clip on bulkhead.
5.Remove pin and clevis pin securing throttle
cable to pedal lever.
6.Release grommet from bulkhead.
7.Withdraw throttle cable from engine
compartment.Refit
8.Feed throttle cable through bulkhead from
engine compartment and fit grommet.
9.Secure throttle cable to pedal lever. Use new
split pin to secure clevis.
10.Secure throttle cable in bulkhead clip.
11.Guide throttle cable through abutment bracket
and fit ferrule.
12.Secure cable to injection pump throttle lever.
Use new split pin to secure clevis.
13.Adjust throttle cable.
See Adjustment,
Throttle cable
THROTTLE PEDAL
Service repair no - 19.20.01
Remove
1.Remove throttle cable from pedal.
See Throttle
cable
2.Remove 6 bolts securing throttle pedal assembly
to engine bulkhead.
3.Remove pedal assembly from footwell, complete
with trim retainer.
4.Release return spring from pedal lever.
5.Remove roll pin securing pivot shaft to pedal
assembly.
6.Withdraw pivot shaft and remove pedal from
mounting bracket.
7.Remove return spring from pedal boss.
Refit
8.Fit return spring to pedal boss.
9.Fit pedal to mounting bracket and locate return
spring.
10.Fit pivot shaft to pedal assembly and secure with
roll pin.
11.Locate return spring on pedal lever.
12.Secure throttle pedal assembly and trim retainer
to bulkhead. Tighten bolts to
9 Nm (7 lbf/ft).
13.Fit throttle cable to pedal.See Throttle cable
14.Adjust pedal, if necessary.See Adjustment,
Throttle pedal adjustment

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.

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

26COOLING SYSTEM
2
DESCRIPTION AND OPERATION ENGINE (COOLANT) COOLING
Description
The 300Tdi engine uses a pressurised cooling system
and cross flow radiator which is supplied with coolant
from an expansion tank mounted on the RH side of
the engine compartment. A belt driven centrifugal
water pump, fitted to an auxiliary mounting assembly,pumps coolant to the engine crankcase, cylinder head
and vehicle heater unit.
An eleven bladed fan, incorporating a viscous
coupling, is driven by an independent pulley secured
to the front cover plate. The thermostat housing,
bolted to the front of the cylinder head, is fitted with a
vent valve that purges excessive air pressure and
coolant back to the expansion tank.
Engine coolant circulation (engine warm - thermostat open).
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 hose9.By-pass hose
10.Radiator bleed (purge) hose
11.Thermostat housing bleed (purge) hose
12.'Y' piece ejector
13.Expansion tank
14.Heater rail
15.Heater unit
16.Heater feed hose

COOLING SYSTEM
3
DESCRIPTION AND OPERATION COOLANT CIRCULATION
Operation
When the engine is started from cold the thermostat
(2) prevents coolant circulation through the radiator by
closing off the top hose (6). During the engine warm
up period the water pump (5) circulates coolant to the
cylinders in the crankcase and through separate ports
to the cylinder head. At the rear of the cylinder head a
proportion of the flow is diverted through a heater feed
pipe (16) to the matrix of the heater unit (15). The
coolant is then carried, via a heater return rail (14) and
hoses (7), back to the water pump. The remaining
coolant flows through a by-pass hose (9) at the
thermostat housing and back to the water pump to
complete the first cycle.
When the normal engine running temperature is
reached, the thermostat opens, closing off the by-pass
hose (9). Coolant is then circulated via the top hose
(6) and through the radiator, where it is cooled and
drawn from the radiator bottom hose (3) by the water
pump (5). The coolant circulation through the
crankcase and cylinder head remains the same.
Two bleed pipes (10) and (11) help control the system
pressure by purging excess air and coolant to the
expansion tank via the 'Y'piece ejector (12).VISCOUS FAN
Description
The viscous drive unit for the engine cooling fan,
provides a means of controlling the speed of the fan
relative to the running temperature of the engine. The
viscous unit is a type of fluid coupling, which drives
the fan blades by means of 'silicone fluid'.
1.Input (drive) member
2.Output (driven) member
3.Sensing mechanism (bi-metal coil)
The fan drive has to be engaged only periodically,
between 5% and 10%, during normal operating
conditions, because the engine is cooled by ram air
for most of the time.

26COOLING SYSTEM
4
DESCRIPTION AND OPERATION Operation
To engage and disengage the fan drive the bi-metal
coil senses air temperature behind the radiator. When
a pre-determined temperature is reached, the coil
opens a valve (5) which allows fluid to enter the drive
area and, due to centrifugal force, circulates to the
annular drive area.
There are two sets of annular grooves (3), one in the
drive clutch and the other in the drive body, a specific
clearance being provided between the two sets of
grooves.
Viscous unit disengaged (engine at normal
running temperature)
1.Input (drive) member
2.Output (driven) member
3.Running clearance
4.Pump plate
5.Valve (closed)
6.Sensing mechanism (bi-metal coil)
7.Fluid seal
8.Bearing, input member
9.Fluid chamber
10.Fluid reservoirWhen this clearance is filled with viscous fluid, a
shearing action, caused by the speed differential
between the two drive components, transmits torque
to the fan. The fluid is thrown to the outside of the unit
by centrifugal force from where it is recirculated to the
reservoir (10) via the pump plate (4) adjacent to the
drive member.
If the engine speed is increased the amount of slip will
also increase to limit the maximum fan speed.
When the air temperature from the radiator drops
sufficiently, the bi-metal coil closes the valve and
prevents fluid entering the drive area. The fluid that is
in the drive area will gradually pump out into the
reservoir (10) and the fan will return to an idle
condition.
Viscous unit engaged (hot running temperature)
Bi-metal coil (6) expanded, valve (5) open.