What Causes the Engine Water Temperature Not to Rise?
2 Answers
Engine water temperature not rising can be caused by thermostat failure, water temperature sensor failure, or abnormal electric fan operation. Here are the detailed explanations: Thermostat failure: The thermostat is always in the large circulation position. After a cold start, the engine operates in large circulation, resulting in excessively low water temperature and preventing the engine from warming up. Water temperature sensor failure: A faulty water temperature sensor may detect incorrect water temperature readings, which may not reflect the actual engine water temperature. If the water temperature sensor fails or malfunctions, the engine ECU will detect that the output signal from the water temperature sensor is unreliable. Abnormal electric fan operation: If the electric fan operates continuously without being controlled by the engine, it can prevent the engine water temperature from rising.
I've been driving my own car for several years, and a common reason for the engine coolant temperature not rising is a faulty thermostat stuck open, causing the coolant to flow too quickly and dissipate heat. Another issue could be a worn or stuck water pump impeller, leading to poor circulation and preventing the temperature from rising. Insufficient or leaking coolant is also a factor, like when I discovered a leak in the reservoir last time. A faulty sensor might falsely report low temperature data. This is especially noticeable in cold weather—if the temperature remains low after driving for ten minutes, the engine runs inefficiently at low temperatures, fuel consumption spikes, and component wear increases. It's advisable to promptly check these points and inspect the cooling system and fluid levels every six months to prevent engine damage and extend its lifespan.
