Why Does the Car Pulley Squeak?
3 Answers
Reasons for car pulley squeaking: Insufficient tension: Insufficient belt tension can cause abnormal noises when starting the vehicle. In fact, when the belt tension is insufficient, the belt is very prone to slipping, just like when it is aged. 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 against the belt and regulate its tension. When the belt is too loose, the friction decreases, leading to abnormal noises due to slipping. Severe wear: Severe belt wear can cause abnormal noises when starting the vehicle. When the car belt is severely worn, the contact area between the belt and the pulley is significantly reduced. At this point, pressing the belt lightly will cause it to sink deeply into the pulley groove. When the belt rotates, it becomes very difficult, and the friction increases significantly, similar to how a bicycle chain makes a harsh noise when it struggles to turn. In this case, it is necessary to replace the belt with a new one as soon as possible.
I remember once my car's pulley started squeaking, the sound was particularly piercing, like a little squirrel jumping on the wheel. Having driven for over a decade, I knew this usually happens because the belt is old and loose, or there's some oil residue on the surface causing it to slip and make noise. The pulley itself could also be worn out or have a damaged bearing. I checked it myself, sprayed some water on the belt, and the noise stopped, confirming it was a slipping issue. If left unfixed, the belt might snap, leaving the car undrivable, and could potentially affect the alternator or air conditioning pump. I suggest quickly tightening the belt tensioner with a tool or heading to a repair shop to replace the belt. Trying to save a little money might lead to bigger problems.
My car used to squeak too, and then I asked a mechanic to take a look. He analyzed that it was caused by the belt being too loose or having insufficient tension. When the belt slips, it can produce that screeching sound, or it could be due to dust on the pulley or slight wear. I learned a little trick myself: you can open the hood, start the car, and listen for the location of the noise, then gently press the belt with your hand. If the sound changes, it indicates the issue is with the tension. Ignoring it could lead to bigger problems, like belt breakage or damage to transmission components. It's best to address it immediately; otherwise, the car breaking down midway could be dangerous. During regular maintenance, make sure to periodically check the belt's lifespan—generally, it should be replaced every 50,000 to 60,000 kilometers to avoid issues.
