Find Parts That Fit Your Vehicle

BMW Cooling System Parts & Accessories

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.

Sub-Categories

Sort By:

Precision Raceworks - Corporate Logo
T#:38094360
Part#: 601-0003
In Stock
$ 24.99 USD
Free Shipping on orders $49 and up
The Black Market Parts (by Precision Raceworks) BMW Billet Coolant Flange was designed as a replacement for the factory plastic flange that is found in the hose that connects the thermostat to the cylinder head. The plastic flange commonly cracks, which leads to coolant loss and engine overheating. Replace your coolant flange before disaster occurs and leaves you stuck on the side of the road.
Show More Show Less
Precision Raceworks - Corporate Logo
T#:38229115
Part#: 622-0079
In Stock
$ 69.99 USD
Free Shipping on orders $49 and up
The E9X / E8X Coolant Tank & Power Steering Bracket w/ Harness is all of the hardware necessary to relocate your power steering pump and install a factory coolant tank on the driver's side of your vehicle. These are the same high-quality components that are included with our E9X/ E8X relocated inlet kits.
Show More Show Less
Moroso - Corporate Logo
T#:568945
Part#: 63793
In Stock at Vendor
$ 433.99 USD
Free Shipping
$ 433.99 USD
Free Shipping
If you have ever experienced a leaking plastic BMW expansion tank you will realize the value of this aluminum version straight away. Even if a failure has not happened to you, it's easy to tell this tank is much stronger and more durable than the plastic used in the stock design. The original BMW plastic tanks suffer from leaks and failures with no warning. While being lightweight and recyclable, the design and construction of the stock tank is just not up for reliable long-term use. Moroso coolant expansion tanks are all pressure tested for guaranteed leak-free operation. Features: Direct bolt-in replacement to stock, cracked, or discolored tanks Fabricated Aluminum for strength, factory tanks fail after repeated high heat situations & age No cutting of factory hoses is required and accepts the factory clip-on hose Included is a Moroso Part No. 63324 racing radiator cap that operates in the same pressure range as the factory cap The Moroso radiator cap mounts to a billet aluminum neck that will not strip out like plastic threaded necks Easy to read slight level is included
Show More Show Less

Moroso - Corporate Logo
T#:29666105
Part#: 63851
In Stock at Vendor
$ 488.99 USD
Free Shipping on orders $49 and up

The coolant expansion tank provides hot coolant with a place to travel, preventing pressure buildup within your cooling system. On many BMWs, this component is constructed from plastic. While cheap to replace and manufacture, a failed cooling tank can cause costly engine damage.

With this issue in mind, Moroso designed a high-quality replacement. Featuring TIG welded, 100% aluminum construction, this tank is sure to outperform it's factory counterpart.

Features:

Key Benefits:

Direct bolt-in replacement for stock, 2 piece plastic tank Fabricated Aluminum for strength, factory tanks fail after repeated high heat situations & age Features billet aluminum mounting tab/bleeder assembly for strength and precision No cutting of factory hoses is required and accepts the factory clip-on hose Moroso part (63324) racing radiator cap included; operates in the same pressure range as the factory cap Moroso radiator cap mounts to a billet aluminum neck that will not strip out like plastic threaded necks This aluminum tank can be polished, chromed, powder coated or left as-is

Show More Show Less

Precision Raceworks - Corporate Logo
T#:38161689
Part#: 201-0393-BLU
In Stock
$ 109.99 USD
Free Shipping on orders $49 and up

BMW Blue Engine Coolant Reservoir Cap is the perfect upgrade for BMW owners looking to enhance both the performance and appearance of their engine bay. Constructed from high-quality billet aluminum, this cap replaces the flimsy plastic factory cap, offering improved durability and a sleek, high-performance aesthetic.

Designed with precision, this coolant reservoir cap incorporates the OEM pressure relief function to maintain proper cooling system operation. Unlike inferior stick-on covers that may loosen over time, this cap is a complete replacement, ensuring a secure, leak-free fit. The blue anodized finish provides superior corrosion resistance, making it a reliable upgrade for daily drivers and track enthusiasts alike.

  • OEM pressure relief function – Ensures proper cooling system performance and safety
  • Billet aluminum construction – Provides enhanced durability and strength over factory plastic caps
  • Direct-fit replacement – Fully replaces the stock cap for a precise, secure fit
  • Blue anodized finish – Resists corrosion, heat, and wear for long-lasting performance
  • Motorsport-inspired design – Adds a sleek, professional look to the engine bay
  • Built for longevity – Engineered to withstand extreme temperatures and coolant exposure

Upgrade your BMW’s cooling system with the BMW Blue Engine Coolant Reservoir Cap, designed for superior reliability and style.

Show More Show Less
Precision Raceworks - Corporate Logo
T#:38128032
Part#: 201-0394-SIL
Ships in 7 Business Days
$ 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.

Show More Show Less

Moroso - Corporate Logo
T#:29666103
Part#: 63799
Ships in 2 Business Days
$ 459.99 USD
Free Shipping on orders $49 and up

The coolant expansion tank provides hot coolant with a place to travel, preventing pressure buildup within your cooling system. On many BMWs, this component is constructed from plastic. While cheap to replace and manufacture, a failed cooling tank can cause costly engine damage.

With this issue in mind, Moroso designed a high-quality replacement. Featuring TIG welded, 100% aluminum construction, this tank is sure to outperform it's factory counterpart.

Features:

Bolt-in replacement for stock cracked or discolored tanks Fabricated aluminum Features billet aluminum filler neck and integrated sight glass to monitor coolant level Can be polished, painted, powder coated or left as-is Moroso radiator cap (63320) included

Show More Show Less
Precision Raceworks - Corporate Logo
T#:38161688
Part#: 201-0393-BLK
Ships in 9 Business Days
$ 109.99 USD
Free Shipping on orders $49 and up

BMW Black Engine Coolant Reservoir Cap is a premium upgrade designed to enhance both the functionality and aesthetics of your BMW’s engine bay. Unlike flimsy plastic OEM caps, this high-performance cap is CNC-machined from durable billet aluminum, providing long-lasting strength and a sleek, motorsport-inspired look.

Built with precision, this cap retains the essential OEM pressure release function, ensuring proper cooling system operation without compromise. Unlike inferior adhesive covers that may detach over time, this cap fully replaces the factory component, delivering a secure and reliable fit. With a corrosion-resistant black anodized finish, it withstands extreme temperatures and harsh conditions while elevating your BMW’s under-hood appearance.

  • OEM pressure regulation – Maintains factory-designed pressure release for optimal cooling performance
  • CNC-machined billet aluminum – Provides exceptional durability and long-term reliability
  • Direct replacement – Fully replaces the stock cap, ensuring a perfect fit without modifications
  • Corrosion-resistant anodized finish – Prevents wear and adds a stealthy, high-performance look
  • Heat and fluid-resistant design – Built to withstand extreme temperatures and coolant exposure
  • Enhanced engine bay styling – Offers a sleek, motorsport-inspired upgrade

Upgrade your BMW’s cooling system with the BMW Black Engine Coolant Reservoir Cap, designed for superior performance and long-lasting durability.

Show More Show Less

Precision Raceworks - Corporate Logo
T#:47679259
Part#: 622-0291-SIL
In Stock
$ 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

Precision Raceworks - Corporate Logo
T#:38094357
Part#: 601-0055
Ships in 5 Business Days
$ 39.99 USD
Free Shipping on orders $49 and up
This driver-side coolant tank mounting bracket set is ideal for those with relocated inlets or single turbo kits. It enables you to reposition your factory coolant tank to the driver's side of the engine bay. Best of all, it’s fully compatible with all known charge pipes.
Show More Show Less
Moroso - Corporate Logo
T#:568887
Part#: 63791
In Stock
$ 445.99

This product was last offered at the strikethrough price on
08-07-2026

$ 418.99 USD
Limited Qty Sale
Free Shipping on orders $49 and up
$ 445.99

This product was last offered at the strikethrough price on
08-07-2026

$ 418.99 USD
Limited Qty Sale
Free Shipping on orders $49 and up
If you have ever experienced a leaking plastic BMW expansion tank you will realize the value of this aluminum version straight away. Even if a failure has not happened to you, it's easy to tell this tank is much stronger and more durable than the plastic used in the stock design. The original BMW plastic tanks suffer from leaks and failures with no warning. While being lightweight and recyclable the design and construction of the stock tank is just not up for reliable long term use. Moroso coolant expansion tanks are all pressure tested for guaranteed leak-free operation and utilizes the stock pressure cap to prevent excessive pressure in the cooling system from blowing off a radiator hose or seal! Features: Each cooling system expansion tank includes a 1/8 in. pipe overflow fitting at neck, a 1/4 in. NPT water intake bung, and a 1/2 in. bung at the bottom for plumbing a line to the radiator Rugged 6061-T6 billet aluminum filler necks welded to tank to withstand continuous removal and installation of cap 100% pressure tested to eliminate leaks Accepts a standard-size radiator cap
Show More Show Less
Precision Raceworks - Corporate Logo
T#:1332002
Part#: 201-0050
In Stock
$ 19.99 USD
Free Shipping on orders $49 and up
The E9X/ E8X coolant tank level sensor extension harness is the same great product that comes standard with Precision Raceworks' E9X/ E8X relocated inlet kits. The coolant tank level sensor extension harness is perfect for those running a relocated coolant reservoir tank or 335D coolant reservoir. This harness plugs right into the factory connector allowing you to extend the position of the sensor without the need to splice any wires.
Show More Show Less


Precision Raceworks - Corporate Logo
T#:38161691
Part#: 201-0393-SIL
Ships in 8 Business Days
$ 109.99 USD
Free Shipping on orders $49 and up

BMW Silver Engine Coolant Reservoir Cap is a premium upgrade for BMW owners looking to enhance both the performance and appearance of their engine bay. Crafted from high-strength billet aluminum, this cap replaces the factory plastic version, offering superior durability and a refined, professional look.

Designed with functionality in mind, it integrates the OEM pressure relief system to ensure your engine's cooling system remains safe and efficient. Unlike adhesive covers, which can peel or wear over time, this cap is a direct-fit replacement, providing a secure and leak-proof seal. The silver anodized finish not only enhances the visual appeal but also ensures resistance to corrosion, high temperatures, and wear, making it perfect for daily driving and track use.

  • OEM pressure relief integration – Maintains proper cooling system performance and reliability
  • Durable billet aluminum – Outperforms factory plastic caps in longevity and strength
  • Precision-machined for perfect fitment – Replaces the stock cap securely, not just a cover
  • Anodized silver finish – Offers corrosion, heat, and wear resistance
  • Elevates engine bay aesthetics – Adds a clean, professional appearance
  • Built for both street and track use – Designed to withstand extreme conditions

Enhance your BMW’s cooling system with the BMW Silver Engine Coolant Reservoir Cap, providing both style and functionality for years to come.

Show More Show Less
Precision Raceworks - Corporate Logo
T#:38128031
Part#: 201-0394-BLK
Ships in 9 Business Days
$ 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.

Show More Show Less
Precision Raceworks - Corporate Logo
T#:38128029
Part#: 201-0394-BLU
Ships in 9 Business Days
$ 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.

Show More Show Less

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

Moroso - Corporate Logo
T#:29666104
Part#: 63850
In Stock at Vendor
$ 586.00 USD
Free Shipping on orders $49 and up

The coolant expansion tank provides hot coolant with a place to travel, preventing pressure buildup within your cooling system. On many BMWs, this component is constructed from plastic. While cheap to replace and manufacture, a failed cooling tank can cause costly engine damage.

With this issue in mind, Moroso designed a high-quality replacement. Featuring TIG welded, 100% aluminum construction, this tank is sure to outperform it's factory counterpart.

Features:

Key Benefits:

Direct bolt-in replacement for stock, 2 piece plastic tank Fabricated Aluminum for strength, factory tanks fail after repeated high heat situations & age Features billet aluminum mounting tab/bleeder assembly for strength and precision No cutting of factory hoses is required and accepts the factory clip-on hose Included is a Moroso (63324) racing radiator cap that operates in the same pressure range as the factory cap Moroso radiator cap mounts to a billet aluminum neck that will not strip out like plastic threaded necks Can be polished, chromed, or powder coated or left as-is

Show More Show Less