What Causes Abnormal Noise in Car Air Conditioning Cooling?
2 Answers
Here are the specific reasons for abnormal noise in car air conditioning cooling: 1. Throttle valve clogging or sticking: After the air conditioning is turned on, the compressor will also start working. Since the compressor is driven by the engine, turning on the air conditioning increases the engine load, requiring the throttle valve to open wider to allow more air intake. When the throttle valve has carbon buildup or is stuck, it can cause engine vibration and abnormal noise. 2. Air conditioning pump noise: There are two main reasons for air conditioning pump noise—the electromagnetic clutch and the bearings inside the air conditioning pump. Noise from the electromagnetic clutch is mainly due to wear, which increases the gap, while noise from the air conditioning pump bearings is primarily caused by insufficient lubrication. If not addressed promptly, it can lead to the air conditioning pump burning out, rendering the cooling function inoperable. 3. Improper tension of the compressor drive belt: If the drive belt is too loose, the electromagnetic clutch is prone to slipping; if it's too tight, the load on the electromagnetic clutch increases. Improper drive belt tension can cause abnormal noise in mild cases and damage the air conditioning compressor in severe cases.
When the car air conditioner makes strange noises while cooling, I've encountered this issue many times over my years of driving. The most common cause is compressor problems, such as worn bearings or foreign objects stuck inside, producing an annoying buzzing sound. Loose or misaligned belts can also create squeaking noises, especially noticeable during hot summer days. Insufficient refrigerant or air mixed into the system may lead to unstable internal pressure, resulting in gurgling or hissing sounds. Last year, my car's AC made noises, and the diagnosis revealed aging fan blades causing vibrations—replacing them at a small cost fixed the issue. Additionally, clogged expansion valves or evaporators can produce abnormal noises when cooling efficiency drops. I advise everyone not to ignore these signs and visit a repair shop early to save hassle and ensure a safer, more comfortable drive.
