The MINI Cooper S uses a serpentine belt to drive the various ancillary components on the engine. This includes the alternator, A/C compressor and the supercharger/water pump. The serpentine belt is kept in place by a small dampener and a coil spring mounted to the end of an idler pulley. This is called a belt tensioner. Over time, the serpentine belt can stretch. The tensioner setup is designed to allow a certain amount of flex to account for stretching as well as vibration.

With a socket set & serpentine belt tool, you are less than two hours away from replacing your tensioner!

R50/52/53 & R55/56/57 Shop here for tensioners!

Follow these instructions for install guidance:
MINI Belt Tensioner Replacement

Let us know what questions you have!
Mark/Pelican Parts