What is the reason for the belt noise when the air conditioner is turned on but stops after a while?
2 Answers
If the belt makes noise when the air conditioner is turned on but stops after a while, it may be caused by belt slippage. Here are detailed explanations on how to resolve belt noise issues: 1. Check the belt: Inspect whether the driven accessories have bearing damage, jamming, looseness, or increased power demand. 2. Replace the belt: This type of noise is often caused by the contact surfaces between the belt and pulley becoming too smooth. Replace the belt or use 100-grit sandpaper to roughen the contact surfaces of the pulley and belt. 3. Temporary solution: You can apply 1-2 drops of engine oil to the contact surfaces between the belt and pulley.
In my many years of car repair experience, I've encountered numerous car owners complaining about squeaky belts after turning on the AC, which usually stops after a while. This is typically caused by belt slippage. When the AC starts, the compressor adds extra load to the engine, causing loose belts to temporarily slip and produce annoying noises. After running for a while, the belt tightens due to heat expansion and contraction from the engine, restoring friction and naturally eliminating the noise. Another common cause is aging or worn belts, where surface cracks lead to initial slippage that quiets down after heating up during operation. Don't underestimate this small signal—I've seen many cases where ignoring it eventually led to belt breakage, AC failure, and compromised driving safety. I recommend promptly visiting a repair shop to check belt tension, with normal values typically ranging between 800-1000 Newtons. Loose belts should be adjusted or replaced entirely to prevent more significant failures. Regular maintenance of the belt system during routine servicing can extend component lifespan and ensure driving comfort.
