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Mishimoto BMW Thermostats

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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Mishimoto Racing Thermostat - 68 Degree - E24, E28, E30, E32, E34, E3...
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Mishimoto - Corporate Logo
T#:363172
Part#: MMTSE3692
In Stock
$ 68.99 USD
Free Shipping on orders $49 and up

The thermostat regulates the temperature of your coolant. At a predetermined temperature the thermostat will open to let coolant flow to the radiator and be cooled by airflow or the fan. Over time the thermostat will become stuck open or closed, leading to a variety of issues. A closed thermostat will never allow the coolant to reach the radiator and be cooled. Hot coolant will continue to circulate through the engine and absorb even more heat until boiling and the system overheats. An open thermostat is not as bad but is still not ideal - the coolant is always cool, with the temp needle always reading in the cool range. This tells the ECU to richen the fuel mixture to bring the car up to normal operating temp. So your fuel mileage decreases and the car runs rich.  

Replacing the thermostat is an easy but messy job. This thermostat includes the main o-ring (but a housing gasket may be required). Consider replacing the housing and any associated temp sensors while you're in there. The cooling system will need to be bled after.  

Most of the engines from the mid-1980s through the 1990s use the same thermostat design and they are interchangeable among the different temperatures. This is the 68*C thermostat, at the bottom of the temperature range. It should only be used in racing situations such as when deleting the engine fan. However, keep in mind that BMW spent a lot of time engineering the cooling system to work in all kinds of conditions and changing thermostat temperature is not recommended to fix any failures in the cooling system.  

Mishimoto makes coolant tanks, radiators and much more for your Mini/BMW. Established in 2003 their commitment to absolute quality in the aftermarket world is evident through the quality and performance enhancing products they offer.
 

This thermostat fits the following BMWs:   
1977-1983  E21 BMW  323i  
1986-1991  E30 BMW  318is 318ic 325e 325es 325i 325ic 325is 325ix  
1992-1999  E36 BMW  318i 318is 318ti 318ic 323is 323ic 325i 325is 325ic 328i 328is 328ic M3  
1982-1988  E28 BMW  528e  
1986-1988  E28 BMW  535i  
1989-1995  E34 BMW  525i 535i  
1997-1998  E39 BMW  528i  
1986-1989  E24 BMW  635csi  
1988-1994  E32 BMW  735i 735il  
1997-2000  Z3 BMW  Z3 2.8 M Roadster M Coupe 

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Racing Thermostat - 70C
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Mishimoto - Corporate Logo
T#:640347
Part#: MMTS-E46-99V2
In Stock at Vendor
$ 135.99 USD
Free Shipping
$ 135.99 USD
Free Shipping
Mishimoto 74 Degree Performance Thermostat - N52 N54 N55
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Mishimoto - Corporate Logo
T#:363461
Part#: MMTS-E90-07
In Stock
$ 83.99 USD
Free Shipping
$ 83.99 USD
Free Shipping

The thermostat regulates the temperature of your coolant. At a predetermined temperature the thermostat will open to let coolant flow to the radiator and be cooled by airflow or the fan. Over time the thermostat will become stuck open or closed, leading to a variety of issues. A closed thermostat will never allow the coolant to reach the radiator and be cooled. Hot coolant will continue to circulate through the engine and absorb even more heat until boiling and the system overheats. An open thermostat is not as bad but is still not ideal - the coolant is always cool, with the temp needle always reading in the cool range. This tells the ECU to richen the fuel mixture to bring the car up to normal operating temp. So your fuel mileage decreases and the car runs rich.   

Replacing the thermostat is an easy but messy job. This thermostat includes the main o-ring (but a housing gasket may be required). Consider replacing the housing and any associated temp sensors while you're in there. The cooling system will need to be bled after.  

For vehicles with plastic thermostat housing 

  

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Racing Thermostat - 180°F
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Mishimoto - Corporate Logo
T#:23615496
Part#: MMTSWRA03L
In Stock
$ 68.99 USD
Free Shipping on orders $49 and up

Elevate your Mini's performance with this lower temperature thermostat, perfect for racing or demanding everyday setups requiring cooler thermostat settings. Specifically crafted for the 2002–2008 Gen 1 Mini Cooper, this thermostat significantly enhances cooling efficiency by reducing high engine temperatures. Operating at 180°F, lower than standard thermostats, it ensures early coolant flow through the engine, effectively lowering overall engine temperatures. Digitally calibrated for precise and consistent operation, this thermostat comes with a Lifetime Warranty. Please note, Proposition 65 (Safe Drinking Water and Toxic Enforcement Act of 1968) may apply to this product. For more details about California Prop 65 warnings, visit www.P65Warnings.ca.gov.

  • Direct fit for 2002–2008 Gen 1 Mini Cooper
  • Enhances cooling efficiency by decreasing high engine temperatures
  • Opens at a lower temperature (180°F) for earlier coolant flow, reducing engine temperatures
  • Digitally calibrated for precise, consistent operation
  • Lifetime Warranty
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Mishimoto Thermostat W/ Housing & Sensor - BMW M52, M54, M56 Engines ...
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Mishimoto - Corporate Logo
T#:51075086
Part#: MMTS-E46-99E
In Stock
New Item
$ 91.99 USD
Free Shipping on orders $49 and up
The Mishimoto Thermostat Assembly focuses on precision fitment and long-term durability.
Mishimoto Racing Thermostat & Housing - BMW F8X M2, M3, M4
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Mishimoto - Corporate Logo
T#:51075075
Part#: MMTS-F80-15
Ships in 3 Business Days
New Item
$ 139.99 USD
Free Shipping on orders $49 and up
The Mishimoto S55 Racing Thermostat provides superior thermal control compared to standard equipment.