A/C Belt Tensioner with Pulley, OEM - E46 M3, E46, E39, X5, Z4

This is the mechanical A/C belt tensioner used on the 2001-2006 E46 M3, MZ3 S54, and Z4M. The tensioner keeps the A/C belt at the proper tension for driving the A/C compressor. A failing tensioner will allow the belt to loosen or slip resulting in diminished performance.

This tensioner is made by INA - the original supplier to BMW for this part and other pulleys and tensioners. It comes with a two year warranty.