1999 LAND ROVER DEFENDER overheating

12ENGINE
12
OVERHAUL Lash adjusters and finger followers - Inspection
1.Check lash adjuster bores for scoring and signs
of wear or damage.
2.Check lash adjusters for signs of wear, scoring
and overheating, replace as necessary. Ensure
oil hole in each lash adjuster is clear.
CAUTION: Store lash adjusters upright
and in their fitted order.
3.Check finger followers for wear and that rollers
are free to rotate.
CAUTION: Store finger followers in their
fitted order.
Camshaft - Inspection
1.Check camshaft lobes and bearing journals for
signs of scoring and wear.
2.Check bearing surfaces in cylinder head and
camshaft carrier for signs of scoring and wear.
CAUTION: Cylinder head and camshaft
carrier are machined together as an
assembly, if bearing surfaces in either
component are damaged, both components must
be replaced as an assembly.Camshaft - Check end-float
1.Position camshaft in camshaft carrier.
2.Check end-float of camshaft using a DTI.
Camshaft end-float =0.06 to 0.16 mm (0.002 to
0.006 in).
3.Renew components as necessary to achieve
correct end-float.
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COOLING SYSTEM
7
DESCRIPTION AND OPERATION Radiator
The 44 row radiator is located at the front of the vehicle in the engine compartment. The cross flow type radiator is
manufactured from aluminium with moulded plastic end tanks interconnected with tubes. The bottom four rows are
separate from the upper radiator and form the lower radiator for the fuel cooler. Aluminium fins are located
between the tubes and conduct heat from the hot coolant flowing through the tubes, reducing the coolant
temperature as it flows through the radiator. Air intake from the front of the vehicle when moving carries the heat
away from the fins. When the vehicle is stationary, the viscous fan draws air through the radiator fins to prevent
the engine from overheating.
Two connections at the top of the radiator provide for the attachment of the top hose from the outlet housing and
bleed pipe to the expansion tank. Three connections at the bottom of the radiator allow for the attachment of the
bottom hose to the thermostat housing and the return hose from the oil cooler and the feed hose to the fuel cooler.
The bottom four rows of the lower radiator are dedicated to the fuel cooler. The upper of the two connections at
the bottom of the radiator receives coolant from the oil cooler. This is fed through the four rows of the lower
radiator in a dual pass and emerges at the lower connection. The dual pass lowers the coolant temperature by up
to 24°C before being passed to the fuel cooler. Two smaller radiators are located in front of the cooling radiator.
The upper radiator is the intercooler for the air intake system and the lower radiator provides cooling of the
gearbox oil.
Pipes and Hoses
The coolant circuit comprises flexible hoses and metal formed pipes which direct the coolant into and out of the
engine, radiator and heater matrix. Plastic pipes are used for the bleed and overflow pipes to the expansion tank.
A bleed screw is installed in the radiator top hose and is used to bleed air during system filling. A drain plug to
drain the heater and cylinder block circuit of coolant is located on the underside of the coolant pump feed pipe.
Oil Cooler
The oil cooler is located on the left hand side of the engine block behind the oil centrifuge and oil filter. Oil from the
oil pump is passed through a heat exchanger which is surrounded by coolant in a housing on the side of the
engine.
Full water pump flow is directed along the cooler housing which also distributes the flow evenly along the block
into three core holes for cylinder cooling. This cools the engine oil before it is passed into the engine. A small
percentage of the coolant from the oil cooler passes into a metal pipe behind the engine. It then flows into the
lower radiator via a hose.
Fuel Cooler
The fuel cooler is located on the right hand side of the engine and is attached to the inlet manifold. The cooler is
cylindrical in design and has a coolant feed connection at its forward end. A’T’connection at the rear of the cooler
provides a connection for the coolant return from the heater matrix and coolant return from the fuel cooler.
The’T’connection houses a thermostat which opens at approximately 82°C. This prevents the cooler operating in
cold climates. Two quick release couplings on the cooler allow for the connection of the fuel feed from the
pressure regulator and return to the fuel tank. A counter flow system is used within the cooler.
Fuel flows around a coolant jacket within the cooler and flows from the back to the front of the cooler. As the hot
fuel cools travelling slowly forwards it meets progressively colder coolant travelling in the opposite direction
maintaining a differential cooling effect.
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PANEL REPAIRS
5
PROCEDURES Welding
13.When plug welding, begin weld approximately 15
mm (0.6’) from hole. This will allow the weld
area to be preheated which will enhance weld
penetration. It also allows the operator to see
more easily where penetration takes place. Fill
hole with weld by moving in a circular direction
around the hole.
14.When MIG seam welding do not carry out
lengthy operations. Divide the welds into short
operations, this will reduce the chances of
overheating the workpiece which inturn will avoid
distortion and strain.
15.Dress all welds using a sander with 36 grit disc,
or a belt-type sander and/or wire brush.
CAUTION: Only use a Stainless Steel wire
brush for Aluminium.
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ELECTRICAL
15
DESCRIPTION AND OPERATION CENTRAL DOOR LOCKING (CDL) - FROM 02MY
The Central Door Locking (CDL) system is a new feature for 2002MY Defender.
NOTE: CDL operates all doors on Station Wagon and County Station Wagons. On all other
Defender 2002MY variants, CDL operates on the driver and front and rear passenger doors only.
General
CDL operates on all doors, including the tail door and is operated by pressing the appropriate button on the
remote handset, using the vehicle key in the drivers door lock or using the drivers door sill button.
The CDL system introduces electrically operated door latches which are controlled by the anti-theft alarm ECU,
located behind the instrument pack. The anti-theft ECU receives a permanent power supply from fuse 6 in the
passenger compartment fuse box. Each CDL latch motor is connected by two wires to the anti-theft ECU which
alternately supplies power and earth connections to drive each motor to the lock or unlock positions.
If the latch motors are continually operated in a short period of time, the anti-theft ECU will suspend all CDL latch
motor operation for 15 seconds to prevent the motors from overheating. Before suspension occurs the anti-theft
ECU ensures that all the doors are left in the unlocked condition.
If the vehicle is locked, and the key is in the ignition switch or the ignition is on and the anti-theft alarm ECU inertia
switch is tripped, all doors will be unlocked immediately and the hazard warning lamps will operate. To prevent
accidental relocking, all latch motors will be inhibited until the anti-theft ECU senses that the drivers door is
opened with the key removed from the ignition switch.
Locking of the vehicle using the remote handset is inhibited with the key in the ignition switch.
Slam Locking
With the introduction of CDL, slam locking of the drivers door is disabled. If an attempt is made to slam lock the
vehicle, the anti-theft alarm ECU will unlock all doors.
CDL Using the Drivers Door Sill Button
Each door has a sill button to allow that door to be individually locked from inside the vehicle. The drivers door sill
button has additional functionality which allows all doors to be locked from inside the vehicle from this one button.
When the driver door sill lock button is depressed, the CDL system enters a sill locked state, where all doors are
locked but immobilisation and perimetric and volumetric sensing is suspended. CDL using the drivers sill lock
button can be achieved with or without the key in the ignition switch and without the ignition being on.
If the CDL is in the sill locked state and the lock button on the remote handset is pressed, the volumetric and
perimetric functions of the alarm system will become active and active engine immobilisation will be invoked.
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