The MSW E46 Enhanced Thermostat Housing is an upgrade for all hard-use M52TU and M54 powered BMWs. It replaces the factory plastic housing with a machined billet aluminum piece that allows you to run a more dependable mechanical thermostat.

Running a pure mechanical thermostat allows for selecting a cooler temperature opening point, we typically run an 80C thermostat for Spec E46 and similar applications.  Any M20 or M50 style thermostat will work, and we provided extra internal clearance for taller thermostats like the Mahle.

Eliminating the electronically controlled thermostat on the M52TU and M54 removes a major failure point in the critical cooling system.  While the e-stat does have a failsafe mode, it’s opening temperature is extremely high and will often still lead to engine damage should it occur under race or track conditions. $299.99 at time of publication.

Image courtesy of Morehead Speed Works

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