What Causes Loud Belt Noise in Cars?
4 Answers
The causes and solutions for loud belt noise in cars are as follows: 1. Pulley Contact Surface: The noise is often caused by excessive smoothness of the contact surface between the belt and pulley. This usually occurs when the engine speed changes rapidly, and sometimes increased load on belt-driven accessories can also cause belt damage. Solution: On vehicles without an automatic belt tensioner, measure the belt elongation using a standard belt elongation gauge at the midpoint between the two pulleys. If it differs from the standard value, it’s best to replace the belt. 2. Accessory Issues: Dirt such as sand on the pulley surface or incorrect belt installation (reverse direction) can cause prolonged squealing or sharp noises, often due to improper accessory assembly. Solution: Try reversing the belt installation direction to see if the issue resolves. 3. Bearing Lubrication: Continuous hissing or rattling noises that increase with engine RPM usually indicate insufficient lubrication in the accessory drive bearings. Solution: Replace the bearings or corresponding components. Important Note: Whenever replacing accessory drive parts, always remember to replace the belt tensioner pulley and automatic tensioner as well.
Recently, I noticed a loud noise from the belt while driving, which made me quite concerned. After inspecting it myself and consulting friends, I learned about several common causes. First, the belt might be loose, causing insufficient tension and resulting in slippage noise. Second, the belt could be aged or worn, with cracks increasing friction. Third, there might be issues with the pulley or tensioner, such as rust or dirt affecting rotation. I remember the belt made a particularly loud noise on a rainy day last time, and the mechanic said damp conditions make slippage more likely—applying some lubricant helped. It’s advisable to regularly listen for changes in noise and inspect the belt’s condition. If the noise persists, visit a professional shop promptly, as a broken belt could leave the car stranded on the road, compromising travel safety. Personally, I now check the belt tension and wear every six months to prevent issues.
Having driven for over a decade, I have deep experience with belt noises. The main causes are incorrect belt tension or belt wear itself. If the pulleys or tensioner fail, they can produce squeaking sounds. Last year, my car had a loud noise, and it turned out to be a stuck tensioner pulley—replacing it made things much quieter. Weather also plays a big role; belts slip more easily and make noise in humid conditions. For those who are handy, a simple check of belt tightness and applying some soapy water to the sliding tracks can reduce noise. But in the long run, it's best to replace old belts promptly to avoid damaging other components. Keeping belts clean and properly tensioned is key to maintenance, ensuring peace of mind and safety.
Loud belt noise? I think it's mostly due to being loose or old. I've experienced it while driving, the squeaking was really annoying. Check if the belt is cracked or dirty, a dirty pulley could also cause this. Simple fix: go to a repair shop to tighten it, or replace the belt. Don't delay too long, otherwise the noise will only get worse. Just pay attention to changes in the sound yourself.
