COOLING SYSTEM - V8 (Description): DESCRIPTION AND OPERATION (page 2 of 4)

COOLING SYSTEM - V8

DESCRIPTION AND OPERATION

26-2-7

Inlet manifold - Cooling connections
Coolant leaves the cylinder block via an outlet pipe attached to the front of the air intake manifold. The pipe is 
connected to the thermostat housing and the radiator by a branch hose off the radiator top hose.

Hot coolant from the engine is also directed from the inlet manifold via pipes and hoses into the heater matrix. Coolant 
is circulated through the heater matrix at all times when the engine is running.

A further tapping from the inlet manifold supplies coolant to the throttle housing via a hose. The coolant circulates 
through a plate attached to the bottom of the housing and  is returned through a plastic bleed pipe to an expansion 
tank. The hot coolant heats the air intake of the throttle housing preventing ice from forming.

An Engine Coolant Temperature (ECT) sensor is fitted in the inlet manifold adjacent to the manifold outlet pipe. The 
sensor monitors coolant temperature emerging from the engine and sends signals to the ECM for engine 
management and temperature gauge operation.
 

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 ENGINE MANAGEMENT SYSTEM - V8, DESCRIPTION AND OPERATION, Description - engine 

management.

Expansion tank
The expansion tank is located in the engine compartment. The tank is made from moulded plastic and attached to 
brackets on the right hand inner wing. A maximum coolant when cold level is moulded onto the tank.

Excess coolant created by heat expansion is returned to the expansion tank from the radiator bleed pipe at the top of 
the radiator. An outlet pipe is connected into the pump feed hose and replaces the coolant displaced by heat 
expansion into the system when the engine is cool.

The expansion tank is fitted with a sealed pressure cap. The cap contains a pressure relief valve which opens to allow 
excessive pressure and coolant to vent through the overflow pipe. The relief valve opens at a pressure of 1.4 bar (20 
lbf.in

2

) and above.

Heater matrix
The heater matrix is fitted in the heater assembly inside the passenger compartment. Two pipes pass through the 
bulkhead into the engine compartment and provide coolant flow to and from the matrix. The pipes from the bulkhead 
are connected to the matrix, sealed with 'O' rings and clamped with circular rings.

The matrix is constructed from aluminium with two end tanks interconnected with tubes. Aluminium fins are located 
between the tubes and conduct heat away from the hot coolant flowing through the tubes. Air from the heater 
assembly is warmed as it passes through the matrix fins. The warm air is then distributed into the passenger 
compartment as required.
 

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 HEATING AND VENTILATION, DESCRIPTION AND OPERATION, Description.When the engine is 

running, coolant from the engine is constantly circulated through the heater matrix.

Radiator
The 45 row radiator is located at the front of the vehicle. The cross-flow type radiator is manufactured from aluminium 
with moulded plastic end tanks interconnected with tubes. Aluminium fins are located between the tubes and conduct 
heat from the hot coolant flowing through the tubes, reducing the cooling temperature as it flows through the radiator. 
Air intake from the front of the vehicle when moving carries 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 and bleed pipe. A connection at 
the bottom of the radiator allows for the attachment of the bottom hose to the thermostat housing.

Two smaller radiators are located in front of the cooling radiator. The lower radiator provides cooling of the gearbox 
oil and the upper radiator provides cooling for the engine oil.
 

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 MANUAL GEARBOX - R380, DESCRIPTION AND OPERATION, Description.

 + 

 AUTOMATIC GEARBOX - ZF4HP22 - 24, DESCRIPTION AND OPERATION, Description.

 + 

 ENGINE - V8, DESCRIPTION AND OPERATION, Description.

Pipes and hoses
The coolant circuit comprises flexible hoses and metal formed pipes which direct 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 is fitted 
to each cylinder bank in the cylinder block. These are used to drain the block of coolant.