Turner Motorsport LTD

Turner Mechanical Thermostat Conversion - M52TU/M54

Show more

Replace the Achilles heel of your factory cooling system with a stout and reliable mechanical thermostat setup.

The factory E46 thermostat housing is a combined unit featuring a plastic housing and a built in thermostat that you cannot replace separately. These plastic all-in-one units are commonly know to crack or fail causing a headache, a trip on the tow truck and possible damage to your engine. 

Taking cues from the reliable M50 thermostat setup we designed an assembly that not only converts your plastic housing into a beautiful billet aluminum unit, but also exchanges the integrated thermostat for a standalone replaceable thermostat. The ability to swap out thermostats independently from the housing opens up doors to change thermostats to different temperature ratings based on your application, while also providing lower maintenance costs. No longer do you have to replace the entire housing but just the thermostat itself. 

The billet housing is designed to be utilized with E46 M3 upper and lower radiator hoses and also features -16 ORB connections for custom radiator hoses. A supreme upgrade from the factory and aftermarket plastic units. Our thermostat housing kit can be used for the savvy daily driver or the track hero who wants to ensure the durability of their cooling system.

Key benefits:

  • Uses M50/S50 mechanical thermostat for increased reliability
  • Option to use aftermarket colder thermostats if desired
  • Thermostat can be replaced separately for lower maintenance cost
  • Barbed hose connections for use with E46 M3 hoses or built in -16 ORB connections for custom radiator hoses


  • Machined out of a single piece of billet 6061 aluminum, this thermostat housing will withstand higher prolonged temperatures and abuse for performance applications
  • Black anodized with engraved Turner logo on the front to match the Turner Motorsports Power Steering Reservoir
  • Viton gasket for superior sealing performance
  • Billet aluminum block off port extension to ensure circulation port is fully blocked off while thermostat is closed
  • For use with E46 M3 radiator hoses 11537830715 and 11537830716

Kit contents:

  • 6061 Billet Aluminum Thermostat Housing
  • Mechanical Thermostat
  • Thermostat Housing Gasket
  • Thermostat Harness
  • Optional Silicone or Rubber E46 M3 coolant hoses

Replacement Thermostat P#: 11537511580, 11537511083S1, 11537511083, 11531713040

Product Development:

Our Billet Thermostat Housing upgrade was designed, engineered, tested and quality inspected by our Research and Development team at Turner. Nothing but the highest level of precision and quality through leading-edge product development technology including FARO laser scanning for reverse engineering and quality inspection, SolidWorks 3D CAD modeling, rapid prototyping utilizing our in-house 3D printer and rigorous long term product testing.

BMW E46 323Ci M52 2.5L
BMW E46 323i M52 2.5L
BMW E46 325Ci M54 2.5L
BMW E46 325i M54 2.5L
BMW E46 325xi M54 2.5L
BMW E46 328Ci M52 2.8L
BMW E46 328i M52 2.8L
BMW E46 330Ci M54 3.0L
BMW E46 330i M54 3.0L
BMW E46 330xi M54 3.0L