Why Does the Car Belt Squeak?
3 Answers
Belt squeaking may be caused by the belt slipping on the generator or excessive wear of the belt. Belt slipping on the generator: Intense friction and vibration between the belt and the pulley produce a sound at a certain frequency. Applying a polyol solution to the belt surface and thoroughly moistening it can alleviate the belt hardening and icing in winter, maintaining some elasticity and reducing slipping. For a new car, one application is sufficient, whereas for an older belt, it needs to be applied for three consecutive days. Excessive belt wear: Due to a reduced friction coefficient on the belt surface, the belt has worn excessively and needs timely inspection and replacement by the owner. If the noise occurs under vehicle load, the owner can observe one set of the drive belts to detect any abnormalities in the belt's automatic tensioning device. Generally, there is a wear length indicator at the bottom of the belt automatic tensioner. If the pointer exceeds the range, it indicates excessive belt wear, requiring immediate replacement to avoid further malfunctions while driving, which could compromise safety. Methods to address belt noise: While driving, if noticeable abnormal noise is heard from the engine, it may be due to a loose belt or excessive wear. The owner should first inspect the engine belt. If unable to identify the issue, it's best to seek professional help to avoid causing other faults. Moreover, inspecting the car belt while the engine is running poses certain dangers, so it's not recommended for owners to attempt this themselves. Another method is to identify the problematic belt by listening to the noise. If the belt noise occurs when using the air conditioning, the issue may lie with the air compressor belt. If the noise appears during a cold start, it might be the engine belt. This approach can help roughly determine the belt abnormality.
I've had the annoying issue of squeaky belts while driving, the sound is always particularly harsh, like a mouse squeaking. The most common causes are either the belt has aged or it's loose and not tight enough. There are several types of belts, such as the alternator belt and power steering belt, which over time can wear out or develop cracks, leading to squeaking when they slip. If the belt is too loose or gets wet, like after driving in the rain, it's more prone to squeaking. If not addressed promptly, the belt might snap, causing the alternator to stop charging, the battery to drain quickly, and the car to suddenly stall on the road, which is extremely dangerous. Other possibilities include a worn tensioner pulley or a faulty bearing—these are small components that adjust the belt's tension, and if they fail, they can worsen the problem. You can do a preliminary check yourself: pop the hood and inspect if the belt is loose or shows signs of wear. But it's best not to delay; take it to a professional repair shop as soon as possible. Replacing the belt with a new one will quiet things down, usually costing just a couple hundred bucks to fix.
As an experienced driver, I've encountered squeaky belts several times. Most often, it's because the belt surface has worn and hardened, becoming too slippery, causing friction noise during rotation. It could also be due to the belt grooves being contaminated with oil or dust, increasing resistance. When checking, first stop the car to locate the sound source. If it's from the belt area, try gently pressing the belt to see if it feels loose or slack. Another common issue is a failing tensioner device – that component is responsible for keeping the belt tight, and when it ages, it can't function properly. If not repaired promptly, it may damage other components. For example, a broken alternator belt can prevent battery charging, and power steering belt issues can make steering difficult. I recommend paying attention to regular maintenance, replacing belts periodically, and not waiting until the noise becomes severe to take action, as repair costs could be higher. Safety first – if unusual noises occur, stop to check or seek help from a technician.
