A serpentine belt is a single, continuous belt that drives multiple accessories on an engine, such as the alternator, power steering pump, and air conditioning compressor. Over time, serpentine belts can stretch and become loose, which can lead to squealing noises, decreased performance, and even engine damage. Tightening a serpentine belt is a relatively simple task that can be completed in a few minutes with the right tools.
There are two main types of serpentine belts: automatic tensioner belts and manual tensioner belts. Automatic tensioner belts use a spring-loaded tensioner to keep the belt tight. Manual tensioner belts require you to adjust the tension yourself using a wrench.