How Does a Vehicle's Radiator & Thermostat Work?

An engine would overheat without a cooling system. Various parts contribute to the cooling mechanism, but two items in particular, the thermostat and the radiator, work in conjunction with one another to control the temperature of the coolant liquid that flows through the radiator.

Identification

The radiator is the portion of the cooling system that actively cools the coolant liquid that circulates between the cooling system and the engine. Affiliated with the radiator is the thermostat, which is in control of regulating the temperature of the coolant.

Function

Coolant that has left the engine block arrives at the thermostat. The thermostat determines if the temperature is at the minimum allowed within the radiator. If the temperature is within an acceptable range for the radiator to function, a valve will release the coolant into the radiator to cool. If the coolant is not an acceptable temperature, normally set by the manufacturer, it is routed back into the engine block for another pass through the system.

Expert Insight

When permitted by the thermostat, coolant flows through the compressed tubes of the radiator. Air flowing across the tubes cools the liquid.