Mishimoto has developed a direct-fit replacement thermostat for the BMW M52, M54, and M56 engines. This Mishimoto thermostat is the ideal replacement for your failed stock thermostat. The Mishimoto thermostat comes pre-installed in a durable OEM-quality housing and fits many BMWs including E46, E39, and E85 chassis. Like all Mishimoto cooling products, this BMW M52, M54, and M56 thermostat is backed by the Mishimoto Lifetime Warranty. Applications: 1999-2000 BMW 323i (all body types)2000 BMW 323Ci (all body types)2001-2006 BMW 325Ci (all body types)2001-2005 BMW 325i (all body types)2001-2005 BMW 325xi (all body types)1999-2000 BMW 328i (all body types)2000 BMW 328Ci (all body types)2001-2005 BMW 330i (all body types)2001-2005 BMW 330xi (all body types)2001-2005 BMW 525i (all body types)1999-2000 BMW 528i (all body types)2001-2005 BMW 530i (all body / chassis types)2001-2006 BMW X5 (6cyl engine only)2004-2006 BMW X31998-2002 BMW Z3 (from 9/1998)2003-2005 BMW Z4