BMW Thermostats

Mosselman S55 Billet Oil Thermostat - Silver - BMW F8X S55 3.0L ...

T#:4621129

Part#: OTS55.T85

In Stock

$ 459.00 USD

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$ 459.00 USD

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**** DOES NOT INCLUDE HARDWARE ****** The S55 engine is no stranger to oil cooling problems, that’s why we recommend installing the MSL Oil Thermostat. The standard oil thermostat will reach around 120 degrees Celsius with a normal driving style. The MSL Oil Thermostat will open at a lower temperature than the standard oil thermostat (at 85 degrees Celsius) and will keep the temperature stable between 95 and 105 degrees Celsius. Installing the MSL thermostat ensures a cooler oil temperature which will result in more stable performance, but above all this improves the reliability of the engine. It is recommended to install the thermostat, especially for cars that are tuned. The Thermostat is plug-and-play and made out of a solid block of high-grade aluminum at our own facility. It is equipped with a real thermostat, not an always open solution. The oil will still reach the operating temperature at the same time as a stock thermostat Features Include: 20°C/68F Lower Than Stock Rock Solid Housing - CNC machined housing. Real Thermostat - Equipped with a real thermostat, not an always open solution. For use in hot and cold climates Quick Installation - Takes only 30 minutes to install.

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N55 Mosselman Billet Oil Thermostat

T#:4621130

Part#: OTN55.T85

In Stock

$ 399.99 USD

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$ 399.99 USD

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**** DOES NOT INCLUDE HARDWARE ****** Hardware - ES4772301 The N55 engine is no stranger to oil cooling problems, that�s why we recommend installing the MSL Oil Thermostat. The standard oil thermostat will reach around 120 degrees Celsius with a normal driving style. The MSL Oil Thermostat will open at a lower temperature than the standard oil thermostat (at 85 degrees Celsius) and will keep the temperature stable between 95 and 105 degrees Celsius. Installing the MSL thermostat ensures a cooler oil temperature which will result in more stable performance, but above all this improves the reliability of the engine. It is recommended to install the thermostat, especially for cars that are tuned. The Thermostat is plug-and-play and made out of a solid block of high-grade aluminum at our own facility. It is equipped with a real thermostat, not an always open solution. The oil will still reach the operating temperature at the same time as a stock thermostat Features Include: 20�C/68F Lower Than Stock Rock Solid Housing - CNC machined housing. Real Thermostat - Equipped with a real thermostat, not an always open solution. For use in hot and cold climates Quick Installation - Takes only 30 minutes to install.

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N54 & E8x/E9x N55 Mosselman Billet Oil Thermostat

For Gasket/Install kit see T#4799665

T#:4621131

Part#: OTN54.T85

In Stock

$ 379.99 USD

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$ 379.99 USD

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The N54 engine is no stranger to oil cooling problems, that’s why we recommend installing the MSL Oil Thermostat. The standard oil thermostat will reach around 120 degrees Celsius with a normal driving style. The MSL Oil Thermostat will open at a lower temperature than the standard oil thermostat (at 85 degrees Celsius) and will keep the temperature stable between 95 and 105 degrees Celsius. Installing the MSL thermostat ensures a cooler oil temperature which will result in more stable performance, but above all this improves the reliability of the engine. It is recommended to install the thermostat, especially for cars that are tuned.

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BMW E46 M54 AAF Low Temp Thermostat Kit - Partial

T#:7624632

Part#: 116211.2

In Stock

$ 85.00 USD

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$ 85.00 USD

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BMW E46 M54 AAF Low Temp Thermostat Kit - Partial is an essential upgrade for enthusiasts looking to optimize engine performance and reliability. Developed by Advanced Auto Fabrication (AAF), this kit addresses the limitations of the factory M54 thermostat, which maintains a temperature range of 80-103°C and opens the mechanical failsafe at 110°C. For race conditions where maintaining a lower temperature is crucial, this kit replaces the stock electronic thermostat with a manual unit, allowing the engine to run at a safer and more efficient temperature. This upgrade not only enhances engine longevity but also reduces stress from high-temperature operation, minimizes heat soak, and increases power.

Optimal Temperature Control: Replaces the factory thermostat for improved engine temperature management.
Enhanced Engine Longevity: Operates at safer temperatures, reducing stress and extending engine life.
Increased Power: Lower operating temperatures can lead to better engine performance.
Reduced Heat Soak: Helps prevent overheating and ensures efficient cooling.
Improved Reliability: Manual thermostat unit offers more consistent performance in racing conditions.

Partial Kit Contents:

Thermostat housing plate
Thermostat
Installation hardware

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Mosselman Billet Oil Thermostat With Installation Kit

T#:27338734

Part#: OTN54.T85KT

In Stock

$ 434.99 USD

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$ 434.99 USD

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The N54 engine is no stranger to oil cooling problems, that’s why we recommend installing the MSL Oil Thermostat. The standard oil thermostat will reach around 120 degrees Celsius with a normal driving style. The MSL Oil Thermostat will open at a lower temperature than the standard oil thermostat (at 85 degrees Celsius) and will keep the temperature stable between 95 and 105 degrees Celsius. Installing the MSL thermostat ensures a cooler oil temperature which will result in more stable performance, but above all this improves the reliability of the engine. It is recommended to install the thermostat, especially for cars that are tuned.

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Aluminum Thermostat Housing Kit - M50

T#:397222

Part#: 14-009

Ships on Oct 26, 2026

$ 56.99 USD

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$ 56.99 USD

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Plastic thermostat housing cracked on your M50?

Here are your choices: you can wait for the plastic factory thermostat housing cover to break and cause major overheating. (Even with a new stock cover, it won’t take long.) Or you can install a thoughtfully engineered all-aluminum thermostat housing cover from Active Autowerke and never experience this type of failure again. Currently there is no factory upgraded part to this problem. This is an aluminum extruded part that has all of the openings machine properly to fit like factory; from the mounting bolt holes, the seating of the thermostat to the sealing opening for the ORANGE gasket. Forged to exact factory tolerances, everything fits and this unit is a true easy bolt-on – especially suited for racing or load conditions like heavy traffic, where engine temp can rise rapidly. The housing is guaranteed never to break from overheating or over-tightening, and its CNC machined surface ensures a precise seat.

Unit comes complete with a new ORANGE sealing gasket; a new thermostat is recommended but not included.
For hotter climates, a 71 degree thermostat is recommended over the 82 degree unit.

Anything and everything BMW is the mantra at Active Autowerke. Since 1981 they have been serving the BMW community with custom turbocharger kits to a myriad of other innovative and inspiring performance parts.

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AAF Low Temp Thermostat Kit - Full Kit - E46

T#:7624630

Part#: 116211

In Stock

$ 175.00 USD

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$ 175.00 USD

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Since 2010, Advanced Auto Fabrication has been producing and developing both parts and full fledged race cars. Their knowledge base covers a wide range of vehicles both domestic and imported. In the specific case of BMW, the team at AAF has a particular affinity for building and designing components for BMW race cars. The factory M54 thermostat is electronically controlled to keep the engine running between 80-103°C, whereas race cars like to maintain 80°C or less for maximum power. Additionally, the mechanical failsafe doesn’t open up until the coolant temperature reaches 110°C, or 230°F, which is about the point when most race cars are turned off and parked which is no good for the motor! The AAF E46 M54 Low Temp Thermostat Kit is designed to give the control of proper engine operating temperature back by replacing the stock electronic thermostat with a manual unit. This allows the engine to run at the proper, and much safer, operating temperature, improving engine longevity, reduces stress from high-temp. operation, reduces heat soak, and increases power! Full Kit Contents: Thermostat housing Thermostat housing plate Thermostat install hardware sealant

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Active Autowerke Thermostat Bypass/Delete Tube - S65

T#:2302749

Part#: 14-016

Ships on Oct 26, 2026

$ 141.99 USD

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$ 141.99 USD

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CNC machined coolant/water thermostat bypass tube to improve flow on and off the track. Easy plug and play installation and a durable anodized coating make this a simple and reliable temperature control solution.

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N55 Mosselman Billet Oil Thermostat - Black

T#:50101777

Part#: 30210057

Ships in 8 Business Days

$ 399.00 USD

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$ 399.00 USD

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The N55 engine is no stranger to oil cooling problems, that’s why we recommend installing the MSL Oil Thermostat. The standard oil thermostat will reach around 120 degrees Celsius with a normal driving style. The MSL Oil Thermostat will open at a lower temperature than the standard oil thermostat (at 85 degrees Celsius) and will keep the temperature stable between 95 and 105 degrees Celsius. Installing the MSL thermostat ensures a cooler oil temperature which will result in more stable performance, but above all this improves the reliability of the engine. It is recommended to install the thermostat, especially for cars that are tuned.

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SELECT YOUR BMW

Mosselman S55 Billet Oil Thermostat - Silver - BMW F8X S55 3.0L ...

N55 Mosselman Billet Oil Thermostat

N54 & E8x/E9x N55 Mosselman Billet Oil Thermostat

BMW E46 M54 AAF Low Temp Thermostat Kit - Partial

Mosselman Billet Oil Thermostat With Installation Kit

Aluminum Thermostat Housing Kit - M50

AAF Low Temp Thermostat Kit - Full Kit - E46

Active Autowerke Thermostat Bypass/Delete Tube - S65

N55 Mosselman Billet Oil Thermostat - Black

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