Thermostat, OEM - 128i/135i, 325i/328i/330i/335i, X3, Z4

This is a direct replacement thermostat for the N52 engine in the E82 128i, E90/E91/E92/E93 325i/328i/330i, 2006+ E60 525i/528i/530i, 2006+ E83 X3, 2006+ E85 Z4 and the N54 engine in the E82 135i/1M, E90/E92/E93 335i, and E60 535i. 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. On the modern cars like above the car's electronics control the thermostat to regulate various temperature systems in the car.

This thermostat is a direct replacement made by an original equipment (OE) manufacturer, in this case either Wahler or Mahle/Behr. Both are original suppliers to BMW for this thermostat and other cooling components. This thermostat comes with a two year warranty.

Supersedes the following BMW Part Numbers:
11537544788 (11-53-7-544-788), 11537536655 (11-53-7-536-655)