The N55 engine only uses one serpentine belt but that one serpentine belt is responsible for driving the alternator, power steering pump, and A/C compressor. Only Fit For BMW E8X E9X N55 Engine. Drive Belt Pulley Tensioner Kit with Bolt For BMW 335i 135i E90 E91 E92 E93 E82 E88 X1 E84.
