Secondary Air Pump - 11727571591 - E83 X3 and E85 Z4

This part is listed by BMW as BMW part number 11727571591 (11 72 7 571 591) and is described as Secondary Air Pump for the first generation BMW X3 (this is the E83 chassis) and first generation BMW Z4 roadster (which is the E85 chassis). 

The E83 X3 and E85 Z4 both came powered by the M54 2.5 liter and 3.0 liter engine variants also found in the 3 series of the similar years. For both of these engines, BMW used this air pump as part of its emissions equipment. The purpose of the pump is to pump fresh air into the exhaust gasses for the first moments after a cold start. When the pump fails, the emissions control systems will record a fault code and trigger a check engine light. Having this issue will prevent your X3 or Z4 from passing an emissions test, making this a serious issue. 

Fortunately the repair isn't that difficult, making it a perfect DIY repair. We carry the OEM replacement pump made by Pierburg, the original manufacturer to BMW. 

For full BMW fitment information or for assistance from one of our BMW experts, we recommend calling us at 877-639-9648.