1996 LAND ROVER DEFENDER engine oil

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

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.

MANIFOLD AND EXHAUST SYSTEM
1
REPAIR INDUCTION MANIFOLD
Service repair no - 30.15.02
Remove
1.Disconnect battery.
2.Remove oil filler cap and remove rocker cover
insulation.
3.Remove hose intercooler to induction manifold. If
fitted, remove EGR valve.
See FUEL SYSTEM,
Repair, EGR valve
4.Remove 2 screws and release heat shield from
induction manifold.
5.Slacken induction manifold lower securing nuts,
located below exhaust manifold.
6.Remove induction manifold upper securing bolts.
7.Remove induction manifold. Plug apertures in
cylinder head with clean rag to prevent any items
falling into engine.
8.Check gasket is satisfactory for further use.
Refit
9.Clean induction manifold mating face.
10.Position induction manifold and secure with
upper and lower fixings.
11.Tighten securing nuts and bolts to
25 Nm (18
lbf/ft).
12.Fit manifold heat shield.
13.Fit hose intercooler to induction manifold.
14.Fit rocker cover insulation.
15.Reconnect battery.INDUCTION/EXHAUST MANIFOLD GASKET
Service repair no - 30.15.15
Remove
1.Remove induction manifold
See Induction
manifold
.
2.Remove turbocharger outlet hose.
3.Raise vehicle and slacken exhaust front pipe to
intermediate silencer flange nuts. Ensure pipe is
free to turn.
NOTE: If removing exhaust manifold and
turbocharger assembly from vehicle,
remove manifold to exhaust front pipe
nuts while working under vehicle.
4.Remove exhaust manifold securing nuts,
removing centre lower nut first.
5.Move heater rail clear of exhaust manifold.
6.With exhaust manifold and turbocharger still
attached to exhaust front pipe, withdraw from
head by turning front pipe until sufficient access
is gained to remove gasket.
7.Suitably support exhaust manifold and
turbocharger assembly to prevent damage.
8.Remove induction manifold lower nuts.
9.Remove gasket.
10.Clean mating faces.

30MANIFOLD AND EXHAUST SYSTEM
2
REPAIR Refit
11.Fit new gasket over manifold studs.
12.Loosely fit induction manifold lower nuts to
studs.
13.Fit exhaust manifold and secure with central
upper and lower nuts.
14.Locate heater rail to its correct position and
secure with outer exhaust manifold nuts.
15.Tighten all exhaust manifold nuts to
45 Nm (33
lbf/ft).
16.Tighten exhaust front pipe to intermediate
silencer nuts to
50 Nm (37 lbf/ft).
17.Fit turbocharger outlet pipe.
18.Fit induction manifold
See Induction manifold
.EXHAUST MANIFOLD/TURBOCHARGER
ASSEMBLY
Service repair no - 30.15.10
Remove
1.Remove induction manifold
See Induction
manifold
.
2.Disconnect turbocharger inlet hose.
3.Disconnect boost pressure pipe at turbocharger.
4.Remove intercooler bottom hose.
5.Place suitable container under engine and
disconnect turbocharger oil feed and return
pipes at cylinder block.
6.Remove 3 nuts securing exhaust front pipe to
manifold flange.
7.Remove 7 nuts and lift exhaust manifold and
turbocharger assembly from cylinder head.
8.Discard manifold gasket.
Refit
9.Fit new manifold gasket.
10.Position exhaust manifold assembly onto
location studs and secure to cylinder head.
Tighten nuts to
45 Nm (33 lbf/ft).
11.Secure exhaust front pipe to manifold flange.
Tighten fixings to
50 Nm (37 lbf/ft).
12.Reconnect turbocharger oil feed and return
pipes at cylinder block.
13.Fit intercooler bottom hose.
14.Fit boost pressure pipe at turbocharger.
15.Fit turbocharger inlet hose.
16.Fit induction manifold
See Induction manifold
.

CLUTCH
1
FAULT DIAGNOSIS CLUTCH ASSEMBLY CONDITIONS
For the clutch to operate correctly it is important the
following conditions are satisfied:-
·The primary shaft (15) must be free in the
crankshaft spigot bush (17).
·The friction plate (2) must be able to slide easily on
the splines on the primary shaft (15), to a position
where it does not contact either the flywheel or the
pressure plate.
·The friction plate must not be distorted or the
linings contaminated with oil, which may cause it to
stick or continue to run in contact with the flywheel
or pressure plate.
A number of faults can develop in the operation of the
clutch for a variety of reasons and most faults are due
to normal wear at high mileage. Problems can also
occur if the unit has been renewed by an unskilled
operator.
Recognising and diagnosing a particular clutch fault is
therefore of paramount importance in ensuring that
the problem is rectified at the first attempt.
Problems which develop in the clutch are as follows:-
·Clutch spin/drag
·Clutch slip
·Clutch judder/fierceCLUTCH SPIN - DRAG
Symptoms
Clutch spin is that, with engine running and clutch
pedal depressed, the gears cannot be immediately
engaged without making a grinding noise. This
indicates the clutch is not making a clean break.
However, if the clutch pedal is held depressed for
several seconds the friction plate will eventually break
free from the engine and the gear will engage silently.
Clutch spin as it becomes more severe develops into
clutch drag, making the silent engagement of a gear
impossible, regardless of how long the pedal is held
depressed.
CLUTCH SLIP
Symptoms
Clutch slip is most evident climbing a hill or when the
vehicle is moving off from stationary with a heavy
load. As the clutch is released, slip occurs between
the engine and the transmission, allowing the engine
speed to increase without a corresponding increase in
vehicle speed.
Clutch slip can develop to the stage where no power
is transmitted through the clutch as the pedal is
released.
CLUTCH JUDDER - FIERCE
Symptoms
Clutch judder or fierce engagement, like slip, is most
likely to occur when the vehicle is moving off from
stationary. As the clutch pedal is released the vehicle
will move rapidly or in a series of jerks, which cannot
be controlled even by careful operation of the clutch
by the driver.
It should be noted that a vehicle may display all the
symptoms or any combination of the symptoms
described, depending on the driving conditions vehicle
load and operating temperatures.

33CLUTCH
2
FAULT DIAGNOSIS FAULT/SYMPTOM CHART
Symptoms
Slip Spin/Drag Judder/Fierce Fault Item
* * * Worn or oil on clutch linings 2
* * * Mechanical damage45678
* * Distorted clutch plate 2
* Failed or air in hydraulic system 12 13
* * Primary shaft tight fit in crankshaft bush 15 17
* Clutch splines sticking 2 15
* Weak clutch plate springs or insecure/worn
engine/gearbox mountings6
* Insecure/worn propeller shafts
* Insecure/worn suspension components/rubber
bushes
The items refered to in this chart relate to the clutch components shown in J6270 and J6271.See Description
and operation, Description
CLUTCH NOISE - MECHANICAL FAULTS
Noise from clutch or gearbox in neutral, which
disappears when clutch is depressed.
Suspect gearbox input/primary shaft bearings
See MANUAL GEARBOX, Fault diagnosis,
R380 gearbox
.
Noise from clutch or gearbox in neutral, which
changes tone or becomes worse when the clutch
is depressed.
Suspect worn release bearing.
Knocking/rattling from clutch or gearbox in
neutral, which is reduced or disappears when the
clutch is depressed.
Suspect worn/weak release lever retainer or
clutch unit.
Noise from clutch or gearbox in neutral, which
disappears when clutch is depressed.
Suspect gearbox fault
See MANUAL
GEARBOX, Fault diagnosis, R380 gearbox
.HYDRAULIC FAULTS
Unable to dis-engage clutch, little or no pedal
resistance.
1.Check condition, specification and level of fluid.
2.Check pipes and cylinders for leaks.
3.Check that air vent in reservoir lid is clear.
Suspect faulty master cylinder if no fluid leaks
present
See Repair, Master cylinder.
Spongy pedal operation
1.Check condition, specification and level of fluid.
2.Check that air vent in reservoir lid is clear.
Suspect air in fluid
See Repair, Bleed
hydraulic system
.
Clutch is difficult to dis-engage and/or does not
immediately re-engage when pedal is released.
1.Check condition, specification and level of fluid.
2.Check that air vent in reservoir lid is clear.
Suspect pedal pivot, master cylinder or slave
cylinder seizure
See Repair, Master cylinder.

MANUAL GEARBOX
1
DESCRIPTION AND OPERATION R380 GEARBOX
Description
The all synchromesh five speed manual gearbox unit,
is married to a two speed transfer gearbox.
All the gears, including reverse, run on needle roller
bearings and the main, layshaft and primary shafts
are supported by tapered roller bearings.The whole of the geartrain is lubricated through
drillings in the shafts, supplied by a low pressure
pump driven from the rear of the layshaft. The gear
change has a single rail selector and spool type
interlock. The main and transfer gearboxes ventilate
through nylon pipes, which terminate high up in the
engine compartment to prevent water entry when the
vehicle is operating in adverse conditions.
R380 Gearbox Components
1.Mainshaft 1st gear
2.Mainshaft 2nd gear
3.Mainshaft 3rd gear
4.Primary input shaft/4th gear
5.Mainshaft 5th gear
6.Layshaft
7.Mainshaft
8.Lubrication pump
9.Oil filter10.Ventilation pipe
11.Single rail gear shift
12.1st/2nd synchromesh
13.Oil seals
14.3rd/4th synchromesh
15.5th/reverse gear synchromesh
16.Selective spacers (mainshaft/layshaft end float)
17.Selective spacer (5th gear/reverse hub)