What Causes Loud Noise from Car AC Fan When Turned On?

[OAshley]

Reasons for loud noise from car AC fan when turned on: The blades of the exhaust fan inside the AC may be deformed, suggesting replacement of the exhaust fan; the motor of the exhaust fan inside the AC may be damaged, suggesting replacement of the exhaust fan; there may be excessive dirt inside the AC, suggesting cleaning of the AC. Below is a brief introduction to car AC fans: 1. Car fan: The car fan generally cools the radiator. The fan's operation drives air flow, which helps lower the water temperature, but the water temperature is not the lower the better. An engine temperature that is too low is also not good. Of course, there are also components like the thermostat and water pump working together, so cooling only starts when a certain temperature is reached. 2. Car AC: Generally includes refrigeration devices, heating devices, and ventilation devices. This combined system makes full use of the limited space inside the car, with a simple structure and easy operation, making it a popular modern car AC system internationally.

[VonMia]

I noticed that the air conditioning fan makes loud noises when I'm driving. The reason could be foreign objects blocking the fan blades, such as leaves, small insects, or dust, which causes a buzzing sound when the fan rotates. Another common factor is bearing wear or lack of lubrication—over time, the grease dries up and produces squeaky noises. Motor aging is also an issue; when the fan spins at high speeds, the noise becomes more pronounced. I regularly check the air conditioning filter and replace it when it's dirty to reduce air resistance, so the fan doesn't have to work as hard. It's recommended to turn off the air conditioning before parking and let the fan dry the system to prevent debris buildup. Ignoring these issues can easily lead to fan damage, which can be expensive to repair.

[DelKaleb]

When encountering loud noises from the air conditioning fan, I suspect it may be due to the fan's design or operational issues. When the airflow is set too high, the fan speed increases, naturally causing more noise. Check if the filter is dirty—a clogged filter forces the fan to work harder, and cleaning it often reduces the noise significantly. Insufficient lubrication in the bearings can also increase friction noise, which can be alleviated by adding some lubricant. Alternatively, if the air conditioning system is under heavy load, the compressor may not shut off, keeping the fan noisy. I recommend trying a lower fan speed first; if the noise persists, clean the fan blades. To minimize noise, avoid parking in dusty areas during daily driving and maintain the system properly.

[DiBrianna]

I find that when the fan noise is loud, it's usually not a serious issue and can be handled by myself. For example, if the fan blades are stuck or foreign objects get inside causing noise, a simple cleaning will suffice. Or if the motor bearings need lubrication, the noise will decrease after lubrication reduces friction. Replacing the air filter also helps a lot, as a dirty filter obstructs airflow, making the fan work harder. If not addressed promptly, the fan may wear out prematurely, and replacement costs can be high. I regularly maintain these components to keep the system clean, which naturally reduces noise.

[DiAutumn]

The air conditioning fan is too loud, which I believe is not just an annoying noise but also a potential risk. If the bearings are excessively worn, the fan's lifespan will be shortened; a clogged filter increases the fan's load and fuel consumption. During long drives in hot weather, this noise affects driving comfort. The solution is to first clean the fan and filter, and if that doesn't work, check the motor or bearings. For prevention, it's recommended to perform maintenance every six months to ensure the fan operates normally without strange noises.