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. Our 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 our Mishimoto Lifetime Warranty.