How Do You Test A Cooling System Thermostat?
One of the most common reasons a car or truck engine overheats is a faulty thermostat. The thermostat closes when the engine is cold and opens as the engine warms up to allow the coolant to circulate through the engine. Follow these steps to test a cooling system thermostat. Locate the engine’s thermostat, normally at the front of the engine, by tracing the water hoses from the radiator to the engine. One hose goes from the radiator into the thermostat housing on one side, and the other hose goes out of the housing back to the radiator on the other side. Open the radiator cap and verify that the radiator is full. Replace the radiator cap and start the engine. Turn the vehicle’s heater on high. Allow the engine to warm up for a few minutes. Be careful not to let the engine overheat. Feel each of the hoses leading to and from the thermostat housing. If both hoses are hot and the heater is pushing out hot air, the thermostat is functioning properly. If not, the thermostat may be stuck, an
