A/C Belt, 4PK863 - E46, E39, X3, X5, Z4 (11287512762)
Continental A/C Belt, 4PK863 - M54
The A/C drive belt runs air conditioner compressor and is driven from the crankshaft pulley on the M54 engines. It's very important not to neglect your drive belts as a failure will leave you stranded. They're easy to inspect during normal maintenance such as an oil change or refilling your washer tank. If there are cracks running across the ribs, sections missing, the edges are frayed, or the threads are visible on the belt surface, the belt should be replaced immediately.
If you can, inspect and test the A/C compressor pulley and tensioner before ordering your belt. Or plan to order these parts at the same time. These are made of plastic and shatter with age, causing potentially expansive/expensive damage to your engine, radiator, etc. They usually last longer than the belt but now is the best time to replace them. Since they are bolted on, not pressed, they are easy to replace.
Fitment note: 4PK863 fits models from 2003-2005 (E46 up through 2006). Prior to 2003 a wider 5PK863 was used.
E46 (99-05) > 320i
E46 (99-05) > 325Ci
E46 (99-05) > 325i
E46 (99-05) > 325xi
E46 (99-05) > 330Ci
E46 (99-05) > 330i
E46 (99-05) > 330xi
E39 (97-03) > 525i
E39 (97-03) > 530i
E83 X3 (04-10) > X3 2.5i M54 (2003-2005)
E83 X3 (04-10) > X3 3.0i M54 (2003-2006)
E53 X5 (00-06) > X5 3.0i M54
E85 / E86 Z4 (03-08) > Z4 2.5i M54
E85 / E86 Z4 (03-08) > Z4 3.0i M54