Thermostat, Rein - 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 manufactured by Rein (CRP) Automotive - an original supplier to BMW for many various BMW parts. As an OEM Rein strives to meet all of BMW's original design, fitment, and performance requirements. OEM-type 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.

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