General information
The engine cooling system works on the thermosyphon principle with a water pump and a fan. The system is pressurized and pressurized, which raises the boiling point of the coolant, thereby increasing the cooling efficiency. The radiator cap is equipped with a control valve that prevents excessive deviation of the internal pressure in the system from atmospheric (round trip).
During thermal expansion, the coolant is forced out of the radiator through the valve into the expansion tank, and when the engine cools down after it stops, it returns to the radiator. The coolant temperature is controlled by a wax-filled thermostat. The thermostat is located in a casing fixed to the engine block (on 3.0 l models) or on the inlet pipe (on 4.2 l models). In order to prevent the development of corrosion, the cooling system must be filled with a mixture of water and antifreeze containing anti-corrosion additives.
The water pump is driven by a V-belt (common with generator) from the crankshaft pulley.
The thermostatic fan clutch is filled with a silicone fluid whose viscosity changes markedly with temperature, allowing the fan speed to be automatically adjusted to match engine RPM and airflow through the radiator. This reduces the loss of engine power and the intensity of background noise when driving at high speeds
A bimetal spring at the front of the clutch operates a valve that controls the degree of fan slip.
On vehicles with AT, transmission oil cooling tanks are built into the radiator.