What Causes the Loud Noise from a Car Radiator Fan?
2 Answers
It may be due to a dirty radiator causing poor heat dissipation, which affects the air intake volume, leading to the electronic fan increasing its speed and resulting in increased wind noise. Below is some relevant information about car radiator fans: 1. Not controlled by the key: The radiator fan is directly connected to the battery, so as long as the battery has power and the engine temperature is high, it will continue to run until the temperature drops. This is because the set values for the engine-off state and the driving state are different. 2. Operating conditions: While driving, the fan starts working when the temperature exceeds 100 degrees and stops at 85 degrees. When the engine is off, the fan starts working at 105 degrees and stops at 85 degrees. Upon restarting the engine, it switches to driving mode, where the fan stops working below 100 degrees. After turning off the engine again, the temperature will certainly not reach 105 degrees, so the fan naturally won't operate.
I've been driving for half my life, and it's quite common for the radiator fan to get louder. Common reasons include fan blades being stuck by stones or debris, or the blades becoming bent, causing a constant squeaking sound when the wind blows. Another reason is worn-out or aged bearings; without maintenance over time, they can dry grind, making a sound like humming. A loose or aged and cracked fan belt can also cause unstable rotation and amplify the noise. Additionally, in the summer when the car gets hot, the cooling system is under high pressure, and the fan spins at high speed to dissipate heat, naturally making more noise. When I was younger, I thought it was a minor issue and ignored it, only for the fan to seize up and cause the engine to overheat and smoke, resulting in expensive repair costs. Now, every six months, I pop the hood and gently spin the fan by hand to check if it moves smoothly. Only when there's no oddity do I feel at ease driving.
