BMW Coolant Expansion Tanks for BMW F90 M5 S63 4.4L

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On certain models, namely E36, E46, and E90, the factory BMW expansion tank is prone to either breaking at connection points or blowing apart altogether. If you're starting to feel like your expansion tank is on borrowed time, it's probably time to replace with either a direct OE replacement, or strengthen your cooling setup with an aluminum expansion tank - we offer numerous performance upgrades for your expansion tank. Especially if you're someone who likes to track your BMW, we recommend upgrading your expansion tank to avoid ruining your track day.
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Genuine BMW - Corporate Logo
T#:194502
Part#: 17117639021
In Stock
22% off MSRP $ 34.96

MSRP stands for Manufacturer's Suggested Retail Price. This is the suggested retail price provided by the manufacturer, supplier or seller.

$ 27.29 USD
Free Shipping on orders $49 and up
22% off MSRP
$ 34.96

MSRP stands for Manufacturer's Suggested Retail Price. This is the suggested retail price provided by the manufacturer, supplier or seller.

$ 27.29 USD
Free Shipping on orders $49 and up
This radiator expansion tank cap is used most BMW's from 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.
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Genuine BMW - Corporate Logo
T#:29699315
Part#: 17135A1BD89
In Stock
6% off MSRP $ 34.99

MSRP stands for Manufacturer's Suggested Retail Price. This is the suggested retail price provided by the manufacturer, supplier or seller.

$ 32.99 USD
Free Shipping on orders $49 and up
6% off MSRP
$ 34.99

MSRP stands for Manufacturer's Suggested Retail Price. This is the suggested retail price provided by the manufacturer, supplier or seller.

$ 32.99 USD
Free Shipping on orders $49 and up


Genuine BMW Cover Lid
This item fits the following BMW Chassis:
E70 X5M,E71 X6M,E70 X5,E71 X6,F01,F02,F06,F10,F12,F13,F15,F16,F30,F80 M3,F82 M4,F83,i3i12

Genuine BMW - Corporate Logo
T#:10225927
Part#: 17137889450
In Stock
Sale - Save 3% $ 226.99

MSRP stands for Manufacturer's Suggested Retail Price. This is the suggested retail price provided by the manufacturer, supplier or seller.

$ 220.50 USD
Free Shipping
Sale - Save 3%
$ 226.99

This product was last offered at the strikethrough price on
05-15-2026

$ 220.50 USD
Free Shipping

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.

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MMX Performance - Corporate Logo
T#:29002094
Part#: MMR03-1502
Ships in 2 Business Days
$ 127.99 USD
Free Shipping on orders $49 and up
The MMX Performance 90mm billet coolant expansion cap for BMWs has been designed from the ground up in the UK, from a solid piece of billet aluminum. Each cap was designed to directly replace the OE cap, not merely stuck in place. Fitment is for models with the matching OE (17 11 7 639 021) part number.
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IND - Corporate Logo
T#:27572122
Part#: LVL.EN.22.326
Back Ordered
$ 618.99 USD
Free Shipping
$ 618.99 USD
Free Shipping
The coolant trap shield serves to stop antifreeze from the expansion tank from reaching the engine compartment and potentially causing damage to costly electrical parts, especially during periods of high fluid expansion. In the event of fluid splashing from the expansion tank, this shield intercepts it, guiding it through a designated outlet at the base of the trap for proper drainage. **Please note that this component is compatible with all North American models and European vehicles adhering to EU6c Emissions Standards (up to January 2021), but it is not suitable for Euro models meeting EU6d with RDE Level 2 standards.**
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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.

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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.

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2 Pin Connector
10X Entries Into Our F80 M3 Sweepstakes
ECS - Corporate Logo
T#:33412932
Part#: 61132359999
In Stock
Sale - Save 25% $ 10.99

This product was last offered at the strikethrough price on
06-14-2026

$ 8.24 USD
Free Shipping on orders $49 and up
Sale - Save 25%
$ 10.99

This product was last offered at the strikethrough price on
06-14-2026

$ 8.24 USD
Free Shipping on orders $49 and up

Includes connector housing with terminals and seals. Commonly used for the coolant level sensor.

ECS Tuning replacement harness connectors include all necessary pins and wire seals for a complete harness repair. Whether you have a broken harness connector or need a complete wiring repair, we have the components you need.

Each connector includes an additional terminal in case one becomes lost or damaged during installation.

*OEM cross reference PN# 61132359999 - Commonly used for the coolant level sensor.

Please reference the original part number from the existing connector to confirm fitment, before ordering.

Suggested tools:

Suggested crimping pliers: T#387193
Wire De-pin tools:
12pc De-Pin Tool Set - T#386379
23pc De-Pin Tool Set - T#641943

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