How Does a Radiator Thermostat Work?

The radiator thermostat is a small device, about 2 inches in diameter, located between the engine and the radiator. Its job is to regulate the temperature inside the engine in order to keep your car from overheating. It is a very important part of the cooling system in your vehicle, as it controls how much coolant flows through the car or truck.

How Does the Radiator Thermostat Work?

When the engine is off, the thermostat does not allow any coolant to pass. Even when the engine is on, the thermostat keeps the coolant in place. Only when the temperature of the engine reaches more than 185-195 degrees F does the thermostat open and allow the coolant to flow.

The thermostat has a cylinder filled with wax that is situated close to the engine. As the temperature increases, the wax begins to liquefy. When this occurs, the wax expands and pushes a rod out of the cylinder. The rod opens the valve and allows the coolant to flow. When the coolant decreases the temperature in the engine, the rod returns to its normal position and the wax begins to cool. This is a simple yet effective way to regulate the engine's temperature.