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
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
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.
This product was last offered at the strikethrough price on
10-22-2026
Rein Thermostat With Housing 88C is designed to maintain precise engine temperature control in your vehicle's cooling system. This premium thermostat, featuring an 88°C temperature rating, ensures optimal cooling performance by regulating coolant flow, preventing overheating, and enhancing overall engine efficiency. Built with a durable housing, this thermostat is an ideal replacement for your factory part, offering reliable fitment and long-lasting performance.
Available at Turner Motorsport, the Rein Thermostat With Housing 88C is engineered to withstand extreme conditions, ensuring consistent operation even under heavy loads. This OE-quality component is a must-have for maintaining your car’s peak performance and fuel efficiency.
Upgrade your vehicle’s cooling system with the Rein Thermostat With Housing 88C and enjoy enhanced engine performance and longevity.
In German, Rein means Pure. In the automotive industry the Rein name has quickly come to represent quality. With fitments for some of the world’s finest automobiles including BMW and Mini and guaranteed OE quality, Rein is a name you can trust.
Includes gasket and O-rings
This product was last offered at the strikethrough price on
07-14-2026
Rein Thermostat 92C is an essential component designed to regulate the temperature in BMW engines, ensuring the vehicle runs at optimal performance while preventing overheating. Engineered to open at 92°C, this high-quality thermostat allows for precise coolant flow, keeping the engine at the correct temperature for maximum efficiency. Available at Turner Motorsport, the Rein Thermostat 92C is designed specifically for BMW vehicles, offering a direct-fit replacement that ensures easy installation and reliable operation.
The Rein Thermostat 92C is the ideal solution for BMW owners who want to ensure their vehicle’s engine operates efficiently and reliably, providing optimal temperature control and enhanced performance.
This product was last offered at the strikethrough price on
06-10-2026
This product was last offered at the strikethrough price on
04-28-2026
Thermostat Assembly 82C is a high-quality, precision-engineered component designed to regulate the engine's cooling system effectively. Manufactured to meet or exceed OEM specifications, this thermostat helps ensure optimal engine performance by maintaining the ideal operating temperature. Available from Turner Motorsport, this part offers superior durability and reliability for a wide range of vehicle models.
Upgrade your vehicle's cooling system with this essential Thermostat Assembly 82C, ensuring smooth engine operation under various driving conditions.
Thermostat 80C is a crucial component for controlling the temperature in BMW engines, ensuring optimal performance and protection. Designed to open at 80°C, this thermostat helps your engine reach its ideal operating temperature quickly while preventing overheating. Engineered specifically for BMW vehicles, the Thermostat 80C ensures precise temperature regulation, enhancing both engine efficiency and longevity. Available at Turner Motorsport, this direct-fit replacement offers easy installation and reliable performance.
The Thermostat 80C from Turner Motorsport is the perfect choice for BMW owners looking to maintain optimal engine temperature, ensuring smooth operation and extending the life of their vehicle.
