Why is the fan noise very loud when the Jetta's air conditioning is turned on?
2 Answers
The specific reasons for abnormal noise when the Jetta's air conditioning is turned on are as follows: 1. Compressor electromagnetic clutch failure: Since the compressor often operates at high loads with speed variations from low to high, it places high demands on the electromagnetic clutch. The clutch is usually installed close to the ground and frequently exposed to rain and mud. When the bearing inside the electromagnetic clutch is damaged, it will cause noise. 2. Improper tightness of the compressor drive belt: Whether the compressor drive belt is too tight or too loose can affect the lifespan of the electromagnetic clutch. If the drive belt is too loose, the electromagnetic clutch is prone to slipping. If the drive belt is too tight, the load on the electromagnetic clutch will increase. 3. Lack of lubricating oil in the compressor: Improper use of lubricating oil may lead to compressor wear and scrapping.
One common reason for loud fan noise when the Jetta's air conditioning is on is fan blade issues. Having driven an old Jetta for over a decade, the buzzing sound from the fan when the AC is on in summer is a regular occurrence, mostly due to dust or leaves stuck on the blades. Excessive dust buildup causes imbalance in the fan's operation, leading to noise. Over time, wear and tear on the internal bearings of the fan motor can also cause unusual sounds. It's normal for the fan to be louder when spinning at high speeds in hot weather. However, a sudden increase in noise or unusual knocking sounds should be taken seriously, as it might indicate deformed blades or foreign object intrusion. Opening the hood to check the fan's rotation smoothness can help identify the issue. Cleaning the blades with a soft brush or using an air gun is recommended, but avoid direct contact with the fan for safety. For older vehicles with aging motors, replacing parts is an affordable solution. Regular maintenance reduces dust accumulation. During car washes, pay attention to cleaning the fan area to prevent foreign objects from getting stuck and prolong its lifespan.
