What causes the abnormal noise from the Volkswagen Polo belt pulley?

[MacJasmine]

Volkswagen Polo belt pulley abnormal noise reasons are as follows: Insufficient tension: Insufficient belt tension can cause abnormal noise when starting the vehicle. In fact, when the belt tension is insufficient, the belt is also very prone to slipping just like aging. Many car enthusiasts should know that most cars on the market today use automatically adjusted belts, which rely on a large spring design to press the belt and adjust its tightness. When the belt becomes too loose, the friction decreases, leading to abnormal noise due to slipping. Severe wear: Severe belt wear can cause abnormal noise when starting the vehicle. When a car's belt is severely worn, the contact area between the belt and the pulley is significantly reduced. At this point, even slight pressure on the belt will cause it to sink deeply into the pulley groove. When the belt rotates, it becomes very strenuous, and the friction increases significantly. This is similar to a bicycle chain making a harsh noise when it can't turn smoothly. In such cases, it is necessary to replace the belt with a new one as soon as possible.