Thermostat, 71C - E30, E36, E28, E34, E39, E24, E32, Z3, M20, M50, S52

Your engine's thermostat regulates coolant flow and temperature in the cooling system. When open it allows 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 is drawn from your heater core.

BMW used the same design of thermostat for many models from the 1980s-1990s but with different temperature ratings. This is the 71C degree thermostat (at the coolest end of the temp scale). Thermostats are interchangeable among the models listed below but note that using a non-standard thermostat will alter your engine's performance. On other models this may be a Performance thermostat used with engine fan delete kits.

This is an OEM 71C thermostat manufactured by an 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.