The thermostat in a vehicle’s cooling system regulates engine temperature by controlling coolant flow between the engine and radiator. It remains closed when the engine is cold to facilitate quick warm-up and gradually opens as the engine reaches its optimal operating temperature. This process ensures efficient combustion, improves fuel economy, and reduces emissions by maintaining consistent engine temperature.

Typically lasting between 80,000 to 160,000 kilometers (50,000 to 100,000 miles), thermostats may need replacement if they fail to open or close properly, causing overheating or temperature fluctuations. Regular inspection and maintenance are crucial to detect thermostat issues early. Timely replacement of a faulty thermostat is essential to maintain proper engine cooling and prevent potential damage.