BMW Coolant Expansion Tanks for BMW I12 i8 B38 1.5L

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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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ECS Tuning Aluminum Coolant Bleeder Screw
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
ECS - Corporate Logo
T#:363070
Part#: 003530ECS01A
In Stock
Sale - Save 40% $ 34.99

This product was last offered at the strikethrough price on
05-02-2026

$ 20.99 USD
Free Shipping on orders $49 and up
Sale - Save 40%
$ 34.99

This product was last offered at the strikethrough price on
05-02-2026

$ 20.99 USD
Free Shipping on orders $49 and up

Replace the flimsy plastic bleeder screw used in the coolant expansion tank or in one of the cooling system hoses with this high quality, durable, aluminum bleeder screw. The stock plastic screw can deform over time due to heat or even regular use. We have even seen the head of the screw snap off, leaving the threaded body stuck in the expansion tank. This aluminum screw will help to prevent sudden failure of the bleeder screw, which can result in immediate overheating of the car.

ECS Tuning's Aluminum Coolant Bleeder Screw replaces Genuine BMW Part Number 17111712788

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Genuine BMW Engine Coolant Expansion Tank Cap - 17135A1BD89
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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

Silver Auxiliary Coolant Reservoir Cap
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Precision Raceworks - Corporate Logo
T#:38128032
Part#: 201-0394-SIL
Ships in 8 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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Coolant Expansion Tank
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2X Entries For Our G87 M2 Sweepstakes! We Price Match - Give Us A Call or Chat!
URO - Corporate Logo
T#:587608
Part#: 17137823626
In Stock
$ 47.99

This product was last offered at the strikethrough price on
05-03-2026

$ 41.99 USD
Limited Qty Sale
Free Shipping on orders $49 and up
$ 47.99

This product was last offered at the strikethrough price on
05-03-2026

$ 41.99 USD
Limited Qty Sale
Free Shipping on orders $49 and up

Genuine MINI Engine Coolant Expansion Tank Cap - 17135A1BD89 ...
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Genuine MINI - Corporate Logo
T#:28337931
Part#: 17135A1BD89
Ships in 6 Business Days
9% 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.

$ 31.99 USD
Free Shipping on orders $49 and up
9% 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.

$ 31.99 USD
Free Shipping on orders $49 and up
Coolant Expansion Tank - R56 MINI Cooper S
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Mahle-Behr - Corporate Logo
T#:46488
Part#: 17137823626
Back Ordered
$ 67.99 USD
Free Shipping on orders $49 and up
This high-quality BEHR brand expansion tank is used on MINI Cooper R55 R56 and is a common failure item. BEHR was the original equipment supplier to BMW, so you know the BEHR made expansion tank will be the highest quality available. Be cautious of competitors selling this part for less -- is it a BEHR? Probably not. We only carry the BEHR brand expansion tank as it is the only one we use in our own MINIs. If you are overhauling your coolant system, now is the time to consider preventative replacing this expansion tank. These are known to go bad, causing a leak which can leave you stranded. We have found that the expansion tanks should be replaced based on age as well as condition. Expansion tanks seem to have a lifespan of fewer than six years before they show signs of fatigue and wear. Pre-emptively replacing the expansion tank as part of an overall maintenance plan can prevent you from getting stranded from a sudden failure later on.

Hailing from Stuttgart, Mahle-Behr specializes in automotive cooling systems. From air conditioning to engine cooling M-B has you covered with OE-quality replacement parts.

This item fits the following MINIs:
2007+ R56 MINI MINI Cooper, MINI Cooper S
2007+ R55 MINI MINI Cooper Clubman, MINI Cooper S Clubman
2007+ R57 MINI MINI Cooper Convertible, MINI Cooper S Convertible,
2011+ R60 MINI MINI Cooper Countryman, MINI Cooper Countryman S


This item fits the following BMWs:
2015+ I01 BMW i3
2015+ I12 BMW i8
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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 10 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 10 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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2 Pin Connector
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
ECS - Corporate Logo
T#:33412932
Part#: 61132359999
Ships on Jul 28, 2026
Sale - Save 25% $ 10.99

This product was last offered at the strikethrough price on
05-03-2026

$ 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
05-03-2026

$ 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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