1. Noise caused by compressor bearing and internal plunger of compressor.
2. Abnormal sound appears after the compressor is switched on and off, which may be caused by the air conditioning belt slipping and the tension of the belt tensioner being too small.
3. There is something wrong with the high-voltage switch of the air conditioner, and the compressor will be turned on and off intermittently, which will also produce abnormal sound.
4. The installation bracket of air conditioner compressor is loose or the compressor itself is damaged, resulting in abnormal sound.
5. Improper clearance of compressor pump head, excessive wear, oil stain on mating surface, improper installation of coil and low battery voltage lead to electromagnetic clutch slipping and abnormal sound.
6. Abnormal sound is caused by excessive wear or damage of the blower motor and foreign objects in the blower.
7. There is too little cooling oil in the air conditioning system, which leads to insufficient internal lubrication of the air conditioning compressor, dry grinding of the fire plug, or close to dry friction, which leads to abnormal sound of the air conditioning.