Belt Tensioner, BMW - F30H, F10H, F02 ActiveHybrid N55

This is a mechanical belt tensioner used on ActiveHybrid F30H 3-series, F10H 5-series, and F02H 7-series models (N55 engine). This tensioner is closest to the alternator/generator. The tensioner keeps the main accessory belt at the proper tension for driving the alternator/generator. A failing tensioner will allow the belt to loosen or slip resulting in diminished performance from the alternator. In extreme cases the belt can slip off the pulleys and potentially lead to a catastrophic engine failure (rare but documented). As a preventative maintenance plan, we recommend replacing the tensioner at every belt change, or 40-60,000 miles. The extent of damage from a failed belt is worth the extra cost every few years.

This tensioner includes the roller pulley.

This is a Genuine BMW belt tensioner with a two year warranty. Buying a Genuine part will usually be more expensive than an OEM or aftermarket brand but you are assured that it meets BMW's designs for fitment, performance, and longevity. It will also be the very latest design, incorporating any updates or revisions that an aftermarket brand typically will ignore.

BMW Fitments:

3 Series
F30 / F31 / F34 (2012+) > Hybrid 3
5 Series
F10 / F11 (11-16) > Hybrid 5