Engine coolant reservoirs can crack and leak when they become brittle over time. This replacement reservoir is designed to match the fit, function, and performance of an original reservoir on specified BMW vehicles. This reservoir includes a thermostat, mounting clip, reservoir cap, and coolant level sensor for a complete repair. This part is compatible with the following vehicles. Before purchasing, enter your vehicle trim in the garage tool to confirm fitment. [BMW 320i: 2001, 2002, 2003, 2004, 2005] - [BMW 323Ci: 2000] - [BMW 323i: 1999, 2000, 2001] - [BMW 323ti: 2000, 2001] - [BMW 325Ci: 2001, 2002, 2003, 2004, 2005, 2006, 2007] - [BMW 325i: 2000, 2001, 2002, 2003, 2004, 2005, 2006] - [BMW 325xi: 2001, 2002, 2003, 2004, 2005] - [BMW 328Ci: 2000] - [BMW 328i: 1999, 2000] - [BMW 328iC: 1999] - [BMW 330Ci: 2001, 2002, 2003, 2004, 2005, 2006] - [BMW 330i: 2001, 2002, 2003, 2004, 2005] - [BMW 330xi: 2001, 2002, 2003, 2004, 2005] - [BMW X1: 2010, 2011] - [BMW X3: 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011] - [BMW X5: 2001, 2002, 2003, 2004, 2005, 2006]