A failed and stuck shut thermostat or damaged housing can cause problems ranging from a coolant leak to overheating. On the other hand, a thermostat stuck open causes your engine to take much longer to reach operating temperature. Driving an improperly heated engine hard can significantly shorten its lifespan. Signs of a bad thermostat include overheating, lack of heat while the vehicle is in motion, or coolant leaks.

During your thermostat change, fluid loss is inevitable. Be sure to pick up some replacement coolant to keep your vehicle in good shape.