What Causes the Abnormal Noise in a Car's Air Conditioning Blower?
2 Answers
Car air conditioning blower abnormal noise is caused by: 1. Damaged compressor belt tensioner; 2. Excessive wear or damage to the blower motor; 3. Malfunction of the internal/external circulation motor; 4. High pressure in the air conditioning system; 5. Incomplete engagement of the compressor clutch; 6. Long overdue replacement of the air conditioning filter. Solutions for abnormal noise in car air conditioning blowers: 1. Timely cleaning of air conditioning vents; 2. Removing fan blades for lubrication and debris removal; 3. Replacing the blower with a new one; 4. Replacing the air conditioning filter. The working principle of car air conditioning is: The compressor sucks in low-temperature and low-pressure refrigerant gas from the evaporator outlet and compresses it into high-temperature and high-pressure gas before discharging it from the compressor.
The last time I encountered this situation was during an inspection of an old car at the shop. There are usually several common reasons for abnormal noises from the blower. Debris like leaves or small stones stuck in the blades can cause a flapping or clicking sound when rotating; prolonged use leading to dry friction due to lack of lubrication in the bearings can result in a squeaky, harsh noise; deformed fan blades causing imbalance can lead to shaking and abnormal sounds; a severely clogged filter causing abnormal blower speed can produce a whooshing sound; or it could be an issue with the motor coil, resulting in a buzzing noise. These abnormal sounds are not only annoying but also indicate that the blower's lifespan is nearing its end, especially when the air conditioning is used for long periods during summer. I usually advise car owners not to delay when they hear such noises—first, turn off the blower and check if the filter needs replacement. If the fan blades are visible, clean out any debris. If the issue persists, the blower assembly may need to be disassembled for repair or parts replacement. Regularly cleaning the air conditioning intake vents can indeed help reduce such occurrences.
