Thermostat

The thermostat is the brain of the cooling system. It senses the temperature of the coolant and allows the fluid to exit from the engine to the radiator, controlling the temperature. Thermostats are rated at a specified temperature – usually between 180-195ºF (82-91ºC). When an engine is cold, the thermostat is closed. Once the engine temperature reaches the thermostat rating, the thermostat opens.