OVERVIEW
Because of its powerful engine, sophisticated transmission and traction system; the vehicle in the most demanding conditions will need to continually dissipate as much as 120 kW of heat to atmosphere. To compound the situation this typically occurs at low speeds when there is insufficient air being forced through the radiator to aid the cooling system. With this in mind and considering that the majority of vehicles rarely need to dissipate more than 10 kW of heat, the cooling system has been specially developed to cope with the severity of off-road driving and variable extremes of climate.
The cooling system functions using the cross-flow principle. The coolant is routed from the coolant pump into the engine block on the exhaust side of the engine and leaves the engine block at the rear edge, via the thermostat housing, on the intake side.
The thermostat is a wax thermostat. The coolant temperature sensor is located in the thermostat housing.
The coolant is pumped from the coolant pump to the engine through 2 connections. After passing through the engine, some of the coolant exits the engine block at the rear edge of the exhaust side to be routed through the passenger compartment element and onwards to the coolant pump.
| Item Number | Description |
|---|---|
| 1 | Engine |
| 2 | Thermostat |
| 3 | Cabin heater core |
| 4 | By-pass |
| 5 | Radiator |
| 6 | Venturi exit |
| 7 | Transmission oil cooler |
| 8 | Coolant pump |
| 9 | Coolant expansion tank |
| 10 | Engine oil cooler |
PRINCIPLES OF OPERATION
At idle, and low outdoor temperatures (lower than -10°C (14°F)) the engine's idle speed increases from approximately 650 rpm to approximately 750 rpm. This is to increase the coolant flow through the passenger compartment element, which, in turn, makes it possible to increase the heat in the passenger compartment. The coolant pump is driven by the power steering pump through a flange.
For a detailed description of the cooling system, refer to the relevant Description and Operation. See ENGINE COOLING - 3.2L .