Thermostat Assembly, Behr - E39 540i, E38 740i/iL, X5 4.4/4.6is, M62TU

This is a direct replacement thermostat for the 1999-2003 E39 540i, E38 740i/iL, X5 4.4/4.6is M62TU.

Your engine's thermostat regulates coolant flow and temperature in the cooling system. When open it allows hot coolant to flow into the radiator to be cooled. When closed the coolant circulates through the engine, where it stays warm. A failed thermostat will either be open or closed with the engine running too cold (poor fuel economy and performance) or too hot (overheating). It can also impact your cabin heating/cooling since that system is drawn from your heater core. Modern cars are much more complex and have computer-controlled cooling strategies to regulate various temperature systems in the car, which makes the thermostat a more critical piece.

This is an OEM thermostat manufactured by Mahle Behr - the original supplier to BMW for this part, as well as many other cooling components. As the OEM it meets all of BMW's original design, fitment, and performance requirements and is TUV approved. OEM parts are the best alternative to more expensive Original BMW parts because they are virtually identical without the inflated price tag. This part has a two year warranty.