What Causes Abnormal Noise from Car Engine Belts?

[KennedyRose]

Engine belt abnormal noise may result from the following reasons: 1. Friction sound between the timing belt and timing cover: This usually occurs even when the engine is warm. If the noise is not loud, it can be ignored and won't affect the belt's lifespan. 2. Aging of the drive belt may cause a "squeaking" sound during vehicle startup: Since drive belts are primarily made of rubber, which hardens and becomes brittle in winter, the friction coefficient decreases. 3. Excessive belt wear can also produce a "squealing" sound: Aged rubber belts have reduced friction and cannot effectively transmit power, leading to slipping phenomena.

[ChristopherLynn]

I've driven quite a few cars and encountered engine belt noise issues several times. The most common cause is belt looseness, which creates a squeaking sound while driving due to insufficient tension causing slippage. Another reason is belt aging or wear, especially after several years when the rubber cracks and deforms, producing a whistling-like noise. Also, pay attention to tensioner pulley problems, such as bearing damage, which creates louder noises. Once I heard a sudden rattling noise on the road, and later found it was caused by oil or dust contamination on the belt, worsening the slippage. If these issues aren't addressed promptly, a broken belt can cause major trouble, potentially leading to breakdowns or damage to other components. Regular inspections are crucial—I usually check my belt condition every six months, testing the elasticity by hand or using soapy water to assess tension. Don't skimp on replacing an aged belt to avoid being stranded midway.

[DeCarson]

As a car repair enthusiast, I often troubleshoot engine belt noise issues myself. First, if the belt is too loose, it squeals during acceleration - adjusting the tensioner usually fixes this. Second, belt wear is common, especially after long trips when the rubber cracks or frays, creating a metallic scraping sound. Additionally, faulty tensioner or idler pulley bearings are frequent culprits, causing rumbling noises at startup. Contamination from dust or oil leaks makes belts slip more frequently. During DIY inspections, I first stop the engine, visually check for belt cracks, then test tension elasticity. If problems are found, I replace the belt (typical lifespan is 50,000-60,000 km). Safety first though - don't just save money, go to a professional if unsure. A broken belt can stop the alternator and AC compressor.

[DiParker]

The engine belt noise is quite concerning, mainly because it affects safety. Common causes include aging and cracking of the belt, which causes squeaking while driving. Alternatively, a faulty tensioner or corroded bearings can amplify the noise. Loose or dirty belts slipping are also frequent issues. These cannot be ignored, as a broken belt could stop the coolant pump, leading to engine overheating and potential stalling. I once encountered a similar situation and immediately pulled over to check, briefly inspecting the extent of the cracks. If unsure, I promptly towed it to the repair shop. During regular maintenance, asking the technician to take a closer look can prevent unexpected incidents. Addressing it early brings peace of mind.

[DelAniyah]

I usually pay attention to vehicle maintenance, and belt noise is mostly caused by maintenance issues. Reasons include wear and tear of the belt itself, insufficient tension causing noise; slipping sounds due to damaged tensioners or guide pulleys; and oil accumulation degrading belt performance. This reminds me to check the belt condition every six months, looking for cracks or elongation, and replace it early if necessary, typically every 40,000 to 50,000 kilometers. Ignoring these small issues can lead to bigger problems, such as belt breakage affecting engine performance, which ends up costing more. Regular maintenance is not expensive and ensures smooth and fuel-efficient driving. It's recommended that car owners develop the habit of checking; those with good DIY skills can inspect the tension themselves for peace of mind.