At approximately what temperature does the car's cooling fan start operating?
2 Answers
Car's cooling fan typically starts operating when the coolant temperature reaches around 90 degrees Celsius, though this threshold varies across different vehicle models. The fan operates at low speed when the temperature is between 92°C to 95°C, and switches to high speed between 102°C to 105°C. When the air conditioning system is in use, the radiator fan will also activate since the AC condenser requires fan-assisted cooling - in this scenario, the fan runs at low speed. When engine coolant temperature rises and requires additional cooling, the radiator fan will engage high-speed operation mode, resulting in noticeably higher fan rotation speed and noise compared to low-speed mode.
I've observed many cars during repairs, where the cooling fan typically starts operating when the coolant temperature reaches around 95 to 105 degrees Celsius. This is standard design to assist heat dissipation and prevent engine overheating. Engine overheating is dangerous and may lead to head gasket failure or more severe issues. Most modern vehicles activate the fan within this temperature range, such as during traffic jams or uphill driving when coolant temperature tends to rise rapidly - the timely fan operation protects the system. I recommend car owners regularly check coolant levels and fan operation status, with particular attention to the temperature gauge in summer. If the fan fails to activate, don't force the vehicle to run; immediately seek professional inspection. Proper maintenance of the cooling system can prevent major troubles.