Cooling System: Description and Operation

DESCRIPTION
The cooling system removes heat from the engine created during the combustion process. The water pump, driven by the timing belt, circulates coolant through the cooling system. The radiator transfers heat from the coolant to the air flowing across it. The thermostat maintains a minimum coolant temperature of 190°F and allows for rapid coolant warm-up on cold starts. The coolant fan and coolant temperature switch maintain a maximum operating temperature of 221°F

OPERATION
With a cold engine the thermostat remains closed forcing the coolant to recirculate through the block allowing it to warm up rapidly. At 190°F the thermostat opens and allows coolant to circulate through the radiator. With no air flow across the radiator the coolant temperature continues to rise. When the coolant temperature rises to 221°F the coolant temperature switch closes, energizing the electric cooling fan. The cooling fan will continue to run until the coolant temperature reaches 193°F, at which point the coolant temperature switch will open and the fan will de-energized.

With A/C
A cooling fan controller is also used to coordinate the operation of the cooling fan with A/C use and Wide Open Throttle (WOT) operation.