What Causes the Noise from the Car Belt?
2 Answers
It may be due to the belt slipping on the generator, causing intense friction and vibration between the belt and the pulley, which produces a noise at a certain frequency. Relevant explanations are as follows: 1. Cause: The main reason for belt slipping is belt looseness or aging. Factors that can lead to belt looseness include improper adjustment of the belt tensioner or insufficient tensioner elasticity. In this case, the tension of the belt tensioner should be adjusted first. If there is no improvement, the tensioner should be replaced. 2. Replacement: Belt aging mainly refers to the belt gradually hardening and losing elasticity over prolonged use, resulting in reduced friction with the pulley. In this situation, the only solution is to replace the belt.
I've been running an auto repair shop for over a decade, and squeaky car belts are extremely common. Usually, it's caused by aging belts that have hardened and cracked - the chirping noise is especially noticeable during cold starts. It could also be due to a loose tensioner pulley causing belt slippage, which produces a bird-like squealing sound. Last time, a customer's belt got contaminated with engine oil that wasn't cleaned promptly, resulting in sudden belt breakage during highway driving - the steering wheel locked up instantly and nearly caused an accident. When inspecting belts, I usually press the middle with my thumb - about half a centimeter of deflection is normal. Too loose causes slippage, too tight accelerates wear. I recommend checking water pump and alternator bearings during belt replacement, as faulty linked components can misalign the belt.