[OEM Part Number] Replaces 11531436823, 11531437040, 11530139877, 11537509227. 1 x Thermostat Housing Assembly [Vehicle Fitment] Compatible with BMW 320i/325i/325xi/330i/330xi/525i/530i 2001-2005, 323Ci 2.5L 2000, 323i 2.5L1999-2000, 325Ci 2.5L 2001-2006, 328i 1999-2000, 330i 330xi 2001-2005; Compatible with BMW X3 2.5L 2004-2005, X3 3.0L 2004-2006, X5 3.0L 2001-2006, Z3 2.5L 1999-2002, Z3 2.8L 1999-2000, Z3 3.0L 2001-2002, Z4 2.5L 2003-2005, Z4 3.0L 2003-2005 [Aluminium Alloy Material] The Upgraded Engine Coolant Thermostat Housing Assembly is made of high quality aluminium alloy, compared with plastic parts, it has stronger resistance to abrasion, deformation and cracking, and can withstand extreme temperature changes, preventing rupture and leakage of the diameter tube, thus prolonging the service life [Excellent Cooling Performance] The BMW E46 Thermostat is designed to regulate the flow of coolant to the radiator, maintaining a stable engine operating temperature, preventing engine overheating, and reducing engine wear, deposits and emissions [Choosing the Right Part] Before buying, research to make sure the part fits your vehicle; enter all vehicle information (year, make, model, engine, and interior) to ensure compatibility, and check the qualifying instructions and that a professional installation is recommended Replaces 11531436823, 11531437040, 11530139877, 11537509227. 1 x Thermostat Housing Assembly. Compatible with BMW 320i/325i/325xi/330i/330xi/525i/530i 2001-2005, 323Ci 2.5L 2000, 323i 2.5L1999-2000, 325Ci 2.5L 2001-2006, 328i 1999-2000, 330i 330xi 2001-2005; Compatible with BMW X3 2.5L 2004-2005, X3 3.0L 2004-2006, X5 3.0L 2001-2006, Z3 2.5L 1999-2002, Z3 2.8L 1999-2000, Z3 3.0L 2001-2002, Z4 2.5L 2003-2005, Z4 3.0L 2003-2005. The Upgraded Engine Coolant Thermostat Housing Assembly is made of high quality aluminium alloy, compared with plastic parts, it has stronger resistance to abrasion, deformation and cracking, and can withstand extreme temperature changes, preventing rupture and leakage of the diameter tube, thus prolonging the service life. The BMW E46 Thermostat is designed to regulate the flow of coolant to the radiator, maintaining a stable engine operating temperature, preventing engine overheating, and reducing engine wear, deposits and emissions