Why does the Cruze's fan keep running when the water temperature is not high?
2 Answers
The reason is a faulty thermostat. Below is an introduction to the thermostat: 1. Definition: The car thermostat is a valve that controls the flow path of the engine coolant. 2. Function: The thermostat automatically adjusts the amount of water entering the radiator based on the coolant temperature to ensure the engine operates within an appropriate temperature range, which can help save energy. 3. Impact: The thermostat must maintain good working condition; otherwise, it will severely affect the normal operation of the engine. For example, if the main valve of the thermostat opens too late or fails to open, it will cause the engine to overheat. If it opens too early, the engine's warm-up time will be prolonged, resulting in the engine temperature being too low.
When I drove my Cruze, I also encountered the strange issue where the fan kept running but the temperature gauge showed normal. It felt quite odd at the time. After checking, I found it could be a faulty coolant temperature sensor—this part tends to misreport high-temperature signals when it ages, causing the computer to command the fan to run nonstop. It could also be a stuck relay locked in the 'on' position, or the A/C being on triggering the fan—turning off the A/C can help rule this out. Sensor failures are quite common in the Cruze. During my own inspection, I noticed the relay box was a bit hot to the touch, but I didn’t dare tamper with it. Prolonged issues like this can drain the battery quickly, making it hard to start after parking and increasing driving risks. After discovering the problem, I immediately took it to the repair shop, where the technician diagnosed it as a sensor issue—replacing it fixed the problem. Remember, don’t delay—safety comes first. Regular maintenance and checking these small details can save a lot of headaches.
