A noisy serpentine belt is more than an annoyance. It can point to slipping, misalignment, or a failing accessory that can leave you stranded. Use these five sound patterns to narrow down the cause and determine the next steps. Our technicians hear these every week across Virginia, and a quick, accurate diagnosis saves pads, pulleys, and time. What Your Serpentine Belt Actually Does One EPDM belt drives the alternator, A/C compressor, power steering pump, and water pump on most vehicles. A spring-loaded tensioner keeps the belt tight while idler pulleys guide its path. If tension drops or a pulley goes rough or crooked, the belt slips and sings. Today’s belts rarely crack like older rubber; they wear by material loss, so looks can be deceiving. Why Belts Make Noise on Modern CarsNoise usually comes from three issues: low tension, contamination, or ... read more