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BMW Cooling System Parts & Accessories for BMW E71 X6 ActiveHybrid N63 4.4L

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

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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

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$ 94.99 USD

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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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BMW Black Auxiliary Coolant Reservoir Cap

affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms

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

Add to Wish List

Qty

$ 94.99 USD

Add to Wish List

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.

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

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

Add to Wish List

Qty

$ 94.99 USD

Add to Wish List

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.

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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Auxillary Fan Switch

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We Price Match - Give Us A Call or Chat!

T#:4934936

Part#: 3148210000

Special Order: No Guaranteed ETA

$ 18.99 USD

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$ 18.99 USD

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The auxiliary fan switch activates the auxiliary cooling fan to provide additional cooling under high heat loads, and when the car is stationary. Also known as the coolant temperature sending unit, comes with related o-ring

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Meyle Coolant Expansion Tank - BMW E70 E71

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We Price Match - Give Us A Call or Chat!

T#:35998394

Part#: 17138621092

Special Order: No Guaranteed ETA

$ 85.99 USD

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$ 85.99 USD

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The coolant expansion tank in your vehicle provides extra space for fluid expansion and contraction due to temperature changes. Because it regularly experiences these fluctuations, it can become prone to cracks or breaks over time. To ensure that all coolant remains within the system, it's important to replace the tank if it has been damaged, such as with cracks, broken nipples, or damaged mounting points.

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