BMW Thermostats for BMW 3 Series E46 (1999-2005)

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BMW thermostats are known to fail, but luckily they typically fail wide open - meaning that your car can still cool. We offer thermostats from various OE suppliers we trust along with upgraded motorsport specific thermostats where applicable to make sure your BMW stays cool on track.
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Mechanical Thermostat Conversion - M52TU/M54
10X Entries Into Our F80 M3 Sweepstakes
Turner Motorsport - Corporate Logo
T#:20617634
Part#: 008785LA01T
Ships on Nov 11, 2026
Sale - Save 17% $ 376.99

This product was last offered at the strikethrough price on
06-14-2026

Starting at $ 312.37 USD
Free Shipping on orders $49 and up
Sale - Save 17%
$ 376.99

This product was last offered at the strikethrough price on
06-14-2026

Starting at $ 312.37 USD
Free Shipping on orders $49 and up

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 a an assembly that not only converts your plastic housing into a billet aluminum unit but also swaps out the integrated thermostat for a separate replaceable thermostat. The ability to swap out thermostats separately from the whole housing opens up doors to changing thermostats to different temperature ratings based on your application while also providing lower maintenance costs. No longer do you have to replace the whole 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 major upgrade from the factory and aftermarket plastic units. Our thermostat housing kit can be used by 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
Design:

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
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
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.

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Bav Auto Thermostat With Aluminum Housing - M52TU M54
10X Entries Into Our F80 M3 Sweepstakes
Bavarian Autosport - Corporate Logo
T#:12544802
Part#: 11531437040
In Stock
Sale - Save 19% $ 104.99

This product was last offered at the strikethrough price on
05-03-2026

$ 84.99 USD
Free Shipping on orders $49 and up
Sale - Save 19%
$ 104.99

This product was last offered at the strikethrough price on
05-03-2026

$ 84.99 USD
Free Shipping on orders $49 and up
The plastic thermostat cover in your BMW is a known point of failure. Throughout years of repeated contact with hot coolant, the plastic can crack and cause massive coolant leaks and potential overheating. Eliminate one of the weak links in your cooling system with a replacement aluminum thermostat housing. By installing this aluminum unit, you have no worries as far as plastic housing cracks go
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Genuine BMW - Corporate Logo
T#:360689
Part#: 11537509227
In Stock
Sale - Save 8% $ 169.69

MSRP stands for Manufacturer's Suggested Retail Price. This is the suggested retail price provided by the manufacturer, supplier or seller.

$ 156.96 USD
Free Shipping
Sale - Save 8%
$ 169.69

This product was last offered at the strikethrough price on
08-26-2026

$ 156.96 USD
Free Shipping

Genuine BMW - Corporate Logo
T#:12502
Part#: 11531318274
In Stock
16% off MSRP $ 147.44

MSRP stands for Manufacturer's Suggested Retail Price. This is the suggested retail price provided by the manufacturer, supplier or seller.

$ 123.15 USD
Free Shipping
16% off MSRP
$ 147.44

MSRP stands for Manufacturer's Suggested Retail Price. This is the suggested retail price provided by the manufacturer, supplier or seller.

$ 123.15 USD
Free Shipping
GENUINE BMW THERMOSTAT - E46 M3, MZ3 (S54), MZ4. This is just the thermostat itself and does not include the housing o-ring or any others that are advised for replacement. See thermostat kit or our water pump kit for a complete package.

When doing any sort of repair or maintenance there is no replacement for genuine factory parts. Turner Motorsport carries the Genuine BMW brand with pride and has the parts you need to complete your next project with confidence.
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Genuine BMW - Corporate Logo
T#:2303
Part#: 11531318274-K
In Stock
$ 149.25 USD
Free Shipping
$ 149.25 USD
Free Shipping
Replacement stock thermostat for E46 M3, Z3M w S54 engine, Z4M.The thermostat can be replaced on the E46 M3 without removing the water pump. This can save you money if the pump still has life left on it but the thermostat needs to be done now. Symptoms of a bad thermostat include an erratic temp gauge and a fault code. When replacing the thermostat, there are three o-rings that will likely need to be replaced between the thermostat and the water pump housing, and two on the coolant tube going to the head. We also recommend new hoses, clamps, and BMW coolant. Replacement should take about one hour.

Note: even though this can be done without replacing the water pump, the job involves removing the same items to access this area. And opening the thermostat housing will spill a lot of coolant. In other words, if you don't replace the water pump at the same time, you're going to repeat this process when the pump needs replacing. We offer a complete water pump overhaul package that covers everything you need if you want to it all at once. You can the thermostat to that package and get everything without any duplicate parts. Click here for the E46 M3 water pump kit.

On S54 engines (E46 M3, MZ3, Z4 M) there is a flanged head bolt going into the cylinder head, behind the thermostat cover. This holds the left side timing chain guide rail in place and if it's loose or falls out you could have a very serious engine failure to deal with. Make sure to check this bolt while you have the thermostat cover off. You only need to make sure it's tight. But if it's come loose you may want to replace the seal ring and use a small touch of oil-resistant thread sealer.

This item fits the following BMWs:
2000-2001 E46 3 Series M3 M3 Convertible 2000-2006
2001-2002 Z3 Roadster / Coupe Z3 M Roadster Z3 M Coupe w S54 Engine
2006-2008 E86 E86 Z4 Z4 M Roadster Z4 M Coupe
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Genuine BMW - Corporate Logo
T#:348485
Part#: 17111437362
Ships in 3 Business Days
4% off MSRP $ 134.99

MSRP stands for Manufacturer's Suggested Retail Price. This is the suggested retail price provided by the manufacturer, supplier or seller.

$ 130.00 USD
Free Shipping
4% off MSRP
$ 134.99

MSRP stands for Manufacturer's Suggested Retail Price. This is the suggested retail price provided by the manufacturer, supplier or seller.

$ 130.00 USD
Free Shipping

Ensure optimal performance and temperature regulation in your BMW's automatic transmission with the Turner Motorsport Genuine Automatic Transmission Thermostat, part number 17111437362. This thermostat serves as a crucial component of the heat exchanger system, maintaining proper fluid temperatures for smooth transmission operation. Typically replaced during expansion tank maintenance, this Genuine BMW part guarantees reliability and compatibility with your vehicle.

Key Benefits:

  • Genuine BMW quality assurance
  • Maintains proper transmission fluid temperatures
  • Ensures smooth transmission operation
  • Direct replacement for OEM thermostat
  • Compatible with expansion tank replacement
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Thermostat With Housing
2X Entries Into Our F80 M3 Sweepstakes
Rein - Corporate Logo
T#:582356
Part#: 11537509227
Ships in 3 Business Days
$ 89.99 USD
Free Shipping
$ 89.99 USD
Free Shipping
Stop leaks before they start with this new Thermostat With Housing from Rein.
Automatic Transmission Thermostat
2X Entries Into Our F80 M3 Sweepstakes
Rein - Corporate Logo
T#:13661147
Part#: 17111437362
In Stock
$ 43.99

This product was last offered at the strikethrough price on
07-14-2026

$ 34.99 USD
Free Shipping on orders $49 and up
$ 34.99 USD
Free Shipping on orders $49 and up
This unit controls the temperature of your automatic transmission fluid

Genuine BMW - Corporate Logo
T#:367704
Part#: 11537509357
Ships in 3 Business Days
14% off MSRP $ 9.74

MSRP stands for Manufacturer's Suggested Retail Price. This is the suggested retail price provided by the manufacturer, supplier or seller.

$ 8.33 USD
Free Shipping on orders $49 and up
14% off MSRP
$ 9.74

MSRP stands for Manufacturer's Suggested Retail Price. This is the suggested retail price provided by the manufacturer, supplier or seller.

$ 8.33 USD
Free Shipping on orders $49 and up
Needs to be replaced once removed