Posted on 9/25/2026
Your engine should warm up gradually and reach its normal operating temperature within a reasonable amount of driving. On a cold morning, that naturally takes longer, but if the temperature gauge stays low after twenty or thirty minutes on the road, something may be preventing the engine from holding heat. You may notice weak cabin heat at the same time, especially at highway speeds. Fuel economy can also drop because the engine computer keeps treating the engine as though it is still warming up. When this becomes a regular pattern rather than an occasional cold-weather complaint, the cooling system deserves a closer look. A Thermostat Stuck Open Is the Most Common Cause The thermostat stays closed while the engine is cold so coolant can warm quickly. Once the engine reaches the proper temperature, the thermostat opens and sends coolant through the radiator. If it sticks partly or fully open, coolant begins circulating through the radiator too early. The engine sti ... read more