Pierburg W0133-1664491-APG Auxiliary Water Pump 100% NEW Pierburg Engine Auxiliary Pump. Also Known as the Heater / HVAC System Water Pump. Pierburg #'s: 7.02078.37.0 and 7.02078.05.0 BMW OE #'s: 64118381989, 64116922699, and 64116955122