BMW Cooling System Parts & Accessories for BMW 5 Series E34 (1987-1995)

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The cooling system is arguably the weakest point in numerous BMWs. If you drive an aging BMW or plan on taking your car to the track like we do, we recommend beefing up your cooling system before going to the track. Generally, the main components in your cooling system that are prone to failure include the following: expansion tank, factory hoses, water pump, thermostat, fan (especially if your vehicle comes factory with a clutch fan), and radiator. Factory BMW expansion tanks are plastic and prone to either breaking off at connection points or combusting. As factory rubber hoses age they either crack or break over time - we offer silicone cooling hose upgrades for most applications to avoid future failures. If you have an older vehicle, your water pump likely comes from the factory with a plastic impeller - we offer upgraded water pumps with metal impellers that are far more reliable. Newer model BMWs utilize electric water pumps - BMW spent millions of dollars engineering these water pumps, but they fail so often that we recommend replacing at 60,000 mile service intervals to avoid being stranded on the side of the road. In terms of thermostats, we offer various upgraded thermostats for racing applications. If your BMW utilizes a clutch fan from the factory, we have several options available in terms of universal electric fans - we recommend replacing these to avoid sending brittle plastic fan blades through your hood. For radiators, we recommend swapping out your radiator for one that does not use plastic connection points like your factory radiator.

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Mishimoto - Corporate Logo
T#:363172
Part#: MMTSE3692
In Stock
$ 68.99 USD
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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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Mishimoto - Corporate Logo
T#:29002063
Part#: MMOC10
In Stock
$ 126.99 USD
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BMW & MINI Universal Oil Cooler - 10 Row is a versatile cooling solution designed to enhance the performance and reliability of BMW and MINI vehicles. This high-quality oil cooler provides efficient cooling for the engine oil, ensuring optimal operating temperatures and extending the life of vital engine components.

Crafted with precision engineering and durable materials, the BMW & MINI Universal Oil Cooler - 10 Row is compatible with a wide range of BMW and MINI models, offering versatility and ease of installation. It effectively dissipates heat from the engine oil, reducing the risk of overheating and engine damage.

  • Enhances performance and reliability of BMW and MINI vehicles
  • Efficient cooling for engine oil, ensuring optimal operating temperatures
  • Extends the life of vital engine components
  • Compatible with a wide range of BMW and MINI models
  • Versatile and easy to install
  • Crafted with precision engineering and durable materials

Investing in the BMW & MINI Universal Oil Cooler - 10 Row is a smart choice for BMW and MINI owners looking to improve their vehicle's performance and longevity.

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Active Autowerke - Corporate Logo
T#:397222
Part#: 14-009
Ships in 10 Business Days
$ 56.99 USD
Free Shipping on orders $49 and up
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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Mishimoto - Corporate Logo
T#:51075091
Part#: MMWP-M50-92
In Stock
$ 72.99 USD
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The Mishimoto Performance Water Pump provides the thermal stability required for modified engines.

Redline - Corporate Logo
T#:640436
Part#: 81215
In Stock
$ 54.99 USD
Free Shipping on orders $49 and up
Red Line SuperCool Performance Coolant fortified with WaterWetter is a 50/50 prediluted antifreeze/coolant designed to maximize the performance of your cooling system with superior protection against cavitation corrosion/erosion. Using 100% SuperCool Performance protects the entire cooling system, keeping new components like new for 5 years/150,000 miles and prevents further damage to older components. Red Line’s proprietary coolant additive formula enhances the fluid’s ability to transfer heat, reducing operating temperatures by up to 20*F and prolonging the life of the entire cooling system. Red Line's SuperCool is an OAT coolant that is a Nitrate and Silicate Free product with its own proprietary corrosion technology to offer superior protection for aluminum engines found in all European vehicles, performance vehicles, as well as other applications. SuperCool will not void the factory warranty either. It can be used to top off the existing coolant of any BMW and will not cause any ill-effects on the cooling system because it is silicate and nitrate free. It is still better to flush it out and switch completely to SuperCool to get all the full benefits of the product in performance and protection.
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Mishimoto - Corporate Logo
T#:31291020
Part#: MMOC10BK
Ships in 3 Business Days
$ 126.99 USD
Free Shipping on orders $49 and up

Universal Oil Cooler Black - 10 Row is engineered to maintain optimal oil temperatures and ensure peak engine performance under various driving conditions. This high-performance oil cooler effectively reduces oil temperatures, preventing a drop in pressure and maintaining proper engine lubrication. Featuring a robust 10-row design, it offers superior cooling efficiency compared to standard coolers.

  • Efficient Cooling: The 10-row design enhances cooling capacity to manage high oil temperatures effectively.
  • Durable Construction: Black finish provides durability and resistance to environmental factors.
  • Optimized Performance: Helps prevent a drop in oil pressure and maintains proper engine lubrication.
  • Versatile Fitment: Universal design suitable for various vehicles and applications.
  • Compact Size: Overall dimensions of 12.95" x 3.8" x 1.97" and core dimensions of 11" x 2.76" x 1.97" ensure a good fit in most engine bays.

WARNING! Prop 65 may apply to this product. Proposition 65 (Safe Drinking Water and Toxic Enforcement Act of 1968) is a California law that applies to all companies selling products in California. Prop 65 requires any listed chemical present above very low levels that are known to cause cancer, birth defects, or other reproductive harm. For more information about California Prop 65 warning see: www.P65Warnings.ca.gov.

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Mishimoto - Corporate Logo
T#:19593926
Part#: MMOCULT
In Stock at Vendor
$ 599.99 USD
Free Shipping on orders $49 and up

Enhance your BMW's performance and protect its engine with this high-quality oil cooler kit

Even under ideal driving conditions, elevated oil temperatures can lead to decreased lubrication efficiency and pressure. With this oil cooler, you can maintain optimal oil temperatures for peak driving performance.

Kit Includes:

  • Four feet of stainless braided line for durability
  • Adapter fittings for easy installation
  • Oil filter sandwich adapter for seamless integration

Specifications:

  • Rows: 19
  • Overall Dimensions: 13" x 5.5" x 2"
  • Core Dimensions: 11.25" x 5.5" x 2"
  • Braided Hoses: 4ft .75 inch & 4ft 9 inch
  • Braided Hose Fittings: -10AN
  • Sandwich Plate Fittings: -10AN
  • Includes Thermostat for precise temperature and flow control

*WARNING: This product may be subject to Proposition 65 regulations in California. For more information, visit www.P65Warnings.ca.gov.

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Mishimoto - Corporate Logo
T#:363171
Part#: MMFANMOUNT
In Stock
$ 15.99 USD
Free Shipping on orders $49 and up
The Mishimoto universal fan mount kit is used to mount a Mishimoto electric fan to any Mishimoto aluminum radiator. Great for custom applications, the Mishimoto fan can be mounted in any convenient position on the radiator. Universal fan mount fits any Mishimoto electric fan Ideal for custom applications Mounts fan in any convenient position Mishimoto Lifetime Warranty
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Bavarian Autosport - Corporate Logo
T#:640208
Part#: 17117639022
In Stock
Sale - Save 15% $ 13.99

This product was last offered at the strikethrough price on
06-03-2026

$ 11.89 USD
Free Shipping on orders $49 and up
Sale - Save 15%
$ 13.99

This product was last offered at the strikethrough price on
06-03-2026

$ 11.89 USD
Free Shipping on orders $49 and up
This radiator expansion tank cap is used most BMW's from 1991-2006. It is a common failure item. When this item fails, it cannot hold pressure which results in your BMW overheating. If you are overhauling your coolant system, now is the time to consider preventative replacing this cap. It is also referred to as the coolant reservoir cap. From 1974 to 2019, Bavarian Autosport was one of the premier vendors for BMW and MINI auto parts. We are happy to preserve the Bav Auto legacy by continuing to carry their high-quality products into the future. All Bav Auto parts will remain unchanged in design and sourced from the same OEM suppliers to ensure long-lasting reliability. We trust these parts, accessories, and upgrades so confidently that we back every Bavarian Autosport branded component with a 2-year warranty.
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Redline - Corporate Logo
T#:394769
Part#: REDLINE5A
In Stock
Starting at $ 15.99 USD
Free Shipping on orders $49 and up
Starting at $ 15.99 USD
Free Shipping on orders $49 and up
Water Wetter is a unique wetting agent for cooling systems which reduces coolant temperatures by as much as 30*F. This liquid product can be used to provide rust and corrosion protection in plain water for racing engines, which provides much better heat transfer properties than glycol-based antifreeze.
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Redline - Corporate Logo
T#:3607
Part#: 1-WW-12Z
In Stock
$ 15.99 USD
Free Shipping on orders $49 and up
Water Wetter is a unique wetting agent for cooling systems which reduces coolant temperatures by as much as 30*F. This liquid product can be used to provide rust and corrosion protection in plain water for racing engines, which provides much better heat transfer properties than glycol-based antifreeze. Or it can be added to new or used antifreeze to improve the heat transfer of ethylene and propylene glycol systems. Designed for modern aluminum, cast iron, copper, brass, and bronze systems.

We have been using RedLine Oil in our street cars and race cars for years. Hands-down, it is the Number One brand of high performance lubricant for BMWs.
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