This water thermostat controls the flow of engine coolant to maintain the operating temperature within the specified range. It is positioned in the engine cooling circuit, where it opens at the calibrated temperature to allow coolant to circulate through the radiator. A failed thermostat that sticks open delays engine warm-up, while one that sticks closed causes overheating and potential gasket or head damage. This replacement part is built to the same opening-temperature specification as the original, so the engine reaches and holds its designed operating temperature under load. On installation, ensure the housing sealing surfaces are clean and replace the gasket to prevent coolant loss.