LR3/Disco 3
for the expansion of the coolant as the engine gets hot and also supplies the engine with coolant as the coolant in the
engine contracts. The tank also allows any air trapped in the coolant to be removed.
The liquid cooled transmission fluid cooler (automatic models only) is mounted in the cold side radiator end tank. It is
positioned in the middle of the LH end tank.
The 2nd fuel cooler is fed from the cold side end tank of the radiator from a sub cooled section and returns into the PRT
housing on the radiator side.
On vehicles fitted with a FBH, the unit is located forward of the LH suspension turret. Coolant flows through the FBH
whether it is active or not. The exhaust from the burner is vented into the front LH wheel arch. For additional information,
refer to
Auxiliary Heater
(412-02B Auxiliary Heating)
For additional airflow through the radiator matrix, particularly when the vehicle is stationary, there is an engine driven
electro-viscous fan unit fitted to the rear of the radiator. The fan is used for engine cooling and for Air Conditioning (A/C)
system cooling. This unit functions as a normal viscous fan, but with electronic control over the level engagement of the
clutch. The Engine Control Module (ECM), which determines the required fan speed, controls the level of clutch
engagement. The ECM determines engagement based on the coolant, charge air, ambient and transmission oil
temperatures and the A/C pressure. The fan is mounted using a left hand thread.
The viscous fan unit is electronically controlled by the ECM to optimise fan speed for all operating conditions.
NOTE :
ENGINE COOLING SYSTEM OPERATION
Cooling System Coolant Flow – Manual Gearbox Without FBH
If the electrical connections to the viscous fan are disconnected the fan will 'idle' and overheating may result. The
ECM stores the appropriate fault codes in this case.
