BMW Cooling System Parts & Accessories for BMW 3 Series G20 (2019+)

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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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Silver Auxiliary Coolant Reservoir Cap
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Precision Raceworks - Corporate Logo
T#:38128032
Part#: 201-0394-SIL
Ships in 7 Business Days
$ 99.99

This product was last offered at the strikethrough price on
01-22-2026

$ 94.99 USD
Free Shipping on orders $49 and up
$ 94.99 USD
Free Shipping on orders $49 and up

BMW Silver Auxiliary Coolant Reservoir Cap is the perfect upgrade for BMW owners looking to enhance both the aesthetics and functionality of their engine bay. Unlike generic aftermarket caps that overlook critical pressure regulation, this precision-engineered cap retains the OEM pressure release functionality, ensuring safe and reliable coolant system performance.

Crafted from high-quality billet aluminum, this reservoir cap offers superior durability and resistance to heat and fluids, preventing warping or degradation over time. Unlike adhesive-based cap covers that can loosen or fall off, this cap is a direct replacement for the factory component, providing a secure, high-performance solution.

  • OEM pressure release functionality – Maintains proper system regulation for optimal coolant performance
  • Premium billet aluminum construction – Offers enhanced durability and longevity
  • Direct replacement design – Secure fit without adhesives or modifications
  • Resistant to heat and fluids – Ensures long-lasting reliability in extreme conditions
  • Performance-inspired look – Adds a sleek, high-end appearance to your engine bay
  • Upgraded durability – Prevents cracking, leaks, and premature wear

Upgrade your BMW’s cooling system with the BMW Silver Auxiliary Coolant Reservoir Cap, blending performance, reliability, and premium styling.

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Rein Aluminum Oil Filter Housing - BMW B58
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Rein - Corporate Logo
T#:49404665
Part#: 11428583901
In Stock
New Item
$ 408.99 USD
Free Shipping on orders $49 and up
For those who push their engines to the limit, "good enough" is a liability. Upgrade to the Rein HEU0116 Aluminum Oil Filter Housing—the professional’s choice for durability and peace of mind.
OEM Rein Turbocharger Coolant Supply Line - BMW Gen2 B46/B48 2.0L ...
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
2X Entries For Our G87 M2 Sweepstakes! We Price Match - Give Us A Call or Chat!
Rein - Corporate Logo
T#:34315143
Part#: 11538629971
Ships in 3 Business Days
$ 47.99

This product was last offered at the strikethrough price on
04-28-2026

$ 42.99 USD
Free Shipping on orders $49 and up
$ 42.99 USD
Free Shipping on orders $49 and up
Turbo coolant supply lines feed coolant to the turbocharger, ensuring temperatures are kept in check. If your coolant line is leaking, it is important to replace it as soon as possible to prevent coolant loss, overheating, and turbo damage.
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Coolant Return Line
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Rein - Corporate Logo
T#:53856300
Part#: 11538650087
In Stock at Vendor
New Item
$ 60.99 USD
$ 60.99 USD
Rein Automotive turbo hoses are engineered to meet these rigorous demands, providing the reliability required for both the track and the street.

Rein Water Feed Tube with O-Ring G20 330i, G30 530i, G01 X3 30i ...
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
2X Entries For Our G87 M2 Sweepstakes! We Price Match - Give Us A Call or Chat!
Rein - Corporate Logo
T#:34181294
Part#: 11538854737
Ships in 3 Business Days
$ 46.99 USD
Free Shipping on orders $49 and up

The Rein Water Feed Tube with O-ring CHT0924 is a premium replacement part designed for BMW vehicles, ensuring optimal engine cooling performance. Manufactured with high-quality materials, this water feed tube guarantees durability and a precise fit, making it an ideal solution for restoring or upgrading your BMW’s cooling system. Available through Turner Motorsport, this part ensures the prevention of coolant leaks and maintains the efficiency of your vehicle’s cooling system.

This water feed tube is engineered to withstand the intense heat and pressure found in high-performance engines, delivering long-lasting reliability. It’s compatible with a variety of BMW models, making it a versatile choice for both professional mechanics and DIY enthusiasts.

Benefits:

  • Precise fitment: Specifically designed for BMW applications to ensure seamless replacement.
  • High-quality materials: Built to endure high-temperature and high-pressure environments.
  • O-ring seal: Ensures a leak-proof connection, preventing coolant loss and engine overheating.
  • Optimized engine performance: Helps maintain consistent engine temperatures for improved vehicle performance.
  • Available at Turner Motorsport: Trusted source for BMW parts and accessories.

Keep your BMW running smoothly with the Rein Water Feed Tube with O-ring CHT0924, designed to restore your cooling system’s functionality and keep your engine in peak condition.

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BMW Black Auxiliary Coolant Reservoir Cap
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Precision Raceworks - Corporate Logo
T#:38128031
Part#: 201-0394-BLK
Ships in 9 Business Days
$ 99.99

This product was last offered at the strikethrough price on
01-22-2026

$ 94.99 USD
Free Shipping on orders $49 and up
$ 94.99 USD
Free Shipping on orders $49 and up

BMW Black Auxiliary Coolant Reservoir Cap is the perfect upgrade for BMW owners looking to enhance both the aesthetics and functionality of their engine bay. Unlike generic aftermarket caps that overlook critical pressure regulation, this precision-engineered cap retains the OEM pressure release functionality, ensuring safe and reliable coolant system performance.

Crafted from high-quality billet aluminum, this reservoir cap offers superior durability and resistance to heat and fluids, preventing warping or degradation over time. Unlike adhesive-based cap covers that can loosen or fall off, this cap is a direct replacement for the factory component, providing a secure, high-performance solution.

  • OEM pressure release functionality – Maintains proper system regulation for optimal coolant performance
  • Premium billet aluminum construction – Offers enhanced durability and longevity
  • Direct replacement design – Secure fit without adhesives or modifications
  • Resistant to heat and fluids – Ensures long-lasting reliability in extreme conditions
  • Performance-inspired look – Adds a sleek, high-end appearance to your engine bay
  • Upgraded durability – Prevents cracking, leaks, and premature wear

Upgrade your BMW’s cooling system with the BMW Black Auxiliary Coolant Reservoir Cap, blending performance, reliability, and premium styling.

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BMW Blue Auxiliary Coolant Reservoir Cap
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Precision Raceworks - Corporate Logo
T#:38128029
Part#: 201-0394-BLU
Ships in 9 Business Days
$ 99.99

This product was last offered at the strikethrough price on
01-22-2026

$ 94.99 USD
Free Shipping on orders $49 and up
$ 94.99 USD
Free Shipping on orders $49 and up

BMW Blue Auxiliary Coolant Reservoir Cap is the perfect upgrade for BMW owners looking to enhance both the aesthetics and functionality of their engine bay. Unlike generic aftermarket caps that overlook critical pressure regulation, this precision-engineered cap retains the OEM pressure release functionality, ensuring safe and reliable coolant system performance.

Crafted from high-quality billet aluminum, this reservoir cap offers superior durability and resistance to heat and fluids, preventing warping or degradation over time. Unlike adhesive-based cap covers that can loosen or fall off, this cap is a direct replacement for the factory component, providing a secure, high-performance solution.

  • OEM pressure release functionality – Maintains proper system regulation for optimal coolant performance
  • Premium billet aluminum construction – Offers enhanced durability and longevity
  • Direct replacement design – Secure fit without adhesives or modifications
  • Resistant to heat and fluids – Ensures long-lasting reliability in extreme conditions
  • Performance-inspired look – Adds a sleek, high-end appearance to your engine bay
  • Upgraded durability – Prevents cracking, leaks, and premature wear

Upgrade your BMW’s cooling system with the BMW Blue Auxiliary Coolant Reservoir Cap, blending performance, reliability, and premium styling.

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Coolant Cap Bundle - Silver
For model years up to 2023
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Precision Raceworks - Corporate Logo
T#:47679259
Part#: 622-0291-SIL
Ships in 9 Business Days
$ 184.99 USD
Free Shipping on orders $49 and up
$ 184.99 USD
Free Shipping on orders $49 and up
The Precision Raceworks Billet Coolant Cap Set is a functional and stunningly stylish way to add a nice touch to any engine bay! These caps come in three color options, so there is always a color that will work for you! Black with Billet Silver, Black with Blue, and the Stealth series (all black). Many people don't realize it, but the OEM caps have a pressure release valve built into them. Oftentimes, aftermarket companies don't know this either or just don't care. But our team cares about proper function just as much as we care about the appearance of every product we design. For pressure relief, our caps incorporate the OEM internals, so you get all the functionality of the original caps, ensuring a safe and reliable system in place. These caps offer superior style and performance-grade components that guarantee a reliable fit every time. Durable billet aluminum construction provides long-lasting protection and dependability that will upgrade your engine bay for years to come. PLEASE NOTE: These do require assembly and swapping the pressure relief valves from your old caps to your new billet caps.
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Precision Raceworks Coolant Cap Bundle - Black - Most BMWs from 2016 ...
For model years up to 2023
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Precision Raceworks - Corporate Logo
T#:47679257
Part#: 622-0291-BLAK
Ships in 9 Business Days
$ 184.99 USD
Free Shipping on orders $49 and up
$ 184.99 USD
Free Shipping on orders $49 and up
The Precision Raceworks Billet Coolant Cap Set is a functional and stunningly stylish way to add a nice touch to any engine bay! These caps come in three color options, so there is always a color that will work for you! Black with Billet Silver, Black with Blue, and the Stealth series (all black). Many people don't realize it, but the OEM caps have a pressure release valve built into them. Oftentimes, aftermarket companies don't know this either or just don't care. But our team cares about proper function just as much as we care about the appearance of every product we design. For pressure relief, our caps incorporate the OEM internals, so you get all the functionality of the original caps, ensuring a safe and reliable system in place. These caps offer superior style and performance-grade components that guarantee a reliable fit every time. Durable billet aluminum construction provides long-lasting protection and dependability that will upgrade your engine bay for years to come. PLEASE NOTE: These do require assembly and swapping the pressure relief valves from your old caps to your new billet caps.
Show More Show Less