After turning on the air conditioning, the noise in the car will increase. As mentioned before, this is the sound of the electronic fan rotating at high speed in front, which is normal. However, many cars have also encountered the problem of abnormal noise, usually a squeaking sound. When the air conditioning is turned on, there is an abnormal noise, but when it is turned off, it disappears. This indicates that the source of the abnormal noise must be related to the air conditioning. How do we determine the source of the abnormal noise? How can I solve it myself?

There are two sources of abnormal noise, one is the blower inside the car, and the other is the engine pulley or compressor. Firstly, listen to whether the abnormal noise is inside or outside the car. If it is inside the car, it must be a problem with the blower. If it is outside the car, it is usually a compressor or other pulley, and it requires some experience to accurately determine. First of all, let's talk about the abnormal noise inside the car. It may not necessarily be a malfunction, but it may be due to large leaves or other debris entering the blower blades, which make a noise when the blades rotate and hit the debris. This kind of noise is not sharp, usually a clattering sound. I have encountered this situation multiple times, which is caused by large leaves entering the blower. As long as the leaves are removed, the abnormal noise will disappear. Only cars with the blower in front of the air conditioning filter have this situation. Most car blowers are located behind the air conditioning filter, with the air conditioning core blocking them. Large debris generally cannot enter the blower, so there will be no such abnormal noise.

The second situation is that the blower itself is broken, the shaft is flooded or lacks lubrication, and even the shaft itself is worn, making a squeaking sound. Although the sound is not very loud, it is a bit sharp and can be clearly heard. This situation requires the replacement of the blower, which is generally not repairable and there is no repair shop willing to repair it. After cleaning the air conditioning in some cars, there is often a squeaking noise from the blower, which is caused by incorrect air conditioning cleaning methods. Most air conditioning cleaning nowadays involves spraying cleaning agent onto the blower, allowing the blower's air to blow the cleaning agent in. This is possible, but you cannot spray towards the center shaft of the blower, you need to spray towards its blades. If sprayed towards the central shaft, it is easy to cause water ingress or wash away the lubricating grease on the shaft, which will result in abnormal noise. Don't worry if there is any abnormal noise, and there is no need to deal with it. Wait for a few days until the water dries and it may return to normal. If the noise persists, the only solution is to replace the blower or find a place for repair.

The above mentioned is the abnormal noise inside the car, and another situation is the abnormal noise outside the car. The abnormal noise outside the car when the air conditioning is turned on may not necessarily be caused by the compressor, but it is only most likely to be caused by other wheels. Before turning on the air conditioning, the overall load was very low and the pulley could operate normally. After turning on the air conditioning, the load increases, and the wheels that were about to break will make abnormal noises. Just like how we rub our fingers against glass, if we gently put it on and rub it, it won't make a sound, but if we press it hard and rub it, it will make a sound. The same principle applies. The sound emitted from the pulley needs to be accurately judged, usually with the help of a stethoscope or other auxiliary tools, and requires some experience. As a car owner, as long as you can determine whether the problem of abnormal noise is serious and whether it can still be driven, it is sufficient. Of course, it can only be roughly judged. If the noise is not loud, it can be driven normally. If the noise is loud, it is best not to drive, or drive at low speed to the repair shop.

From: WONDEE Autoparts

2024-3-5