Thermostat, 88C - 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 88C degree thermostat (near the hottest end of the temp scale). 88C was standard on E30 318i M42, E36 323i/325i/328i/M3, E34 525i M50, and MZ3 S52. Thermostats are interchangeable among the models listed below bute note that using a non-standard thermostat will alter your engine's performance.

 The o-ring seal is included but a housing profile gasket is sold separately.

Supersedes BMW Part # 11531721002 (11-53-1-721-002)