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BMW Coolant Expansion Tanks

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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Expansion Tank Mounting Plate
2X Entries Into Our F80 M3 Sweepstakes
URO - Corporate Logo
T#:593026
Part#: 17101439110
Ships in 2 Business Days
$ 68.99 USD
Free Shipping on orders $49 and up
These plastic supports mount to the side of the radiator, and are used to hold the expansion tank in place.
Coolant Expansion Tank W/ Cap
2X Entries Into Our F80 M3 Sweepstakes
Rein - Corporate Logo
T#:592210
Part#: 17137529273
Back Ordered
Sale - Save 5% $ 44.99

This product was last offered at the strikethrough price on
08-31-2026

$ 42.74 USD
Free Shipping on orders $49 and up
Sale - Save 5%
$ 44.99

This product was last offered at the strikethrough price on
08-31-2026

$ 42.74 USD
Free Shipping on orders $49 and up
Mahle-Behr - Corporate Logo
T#:369633
Part#: 17111742232
Ships in 2 Business Days
$ 18.99 USD
Free Shipping on orders $49 and up
$ 18.99 USD
Free Shipping on orders $49 and up
This radiator expansion tank cap fits E30 325e 325es 325i 325is 325ix 325ic with M20 engine from 1988 . 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.

This item fits the following BMWs:
1988-1991  E30 BMW  325e 325es 325i 325ic 325is 325ix
1989-1990  E34 BMW  525i with M20 engine
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BMW Expansion Tank With Cap - 17107514964
2X Entries Into Our F80 M3 Sweepstakes
Rein - Corporate Logo
T#:46616026
Part#: EPK0025
Ships in 4 Business Days
Sale - Save 6% $ 74.99

This product was last offered at the strikethrough price on
08-31-2026

$ 70.63 USD
Free Shipping on orders $49 and up
Sale - Save 6%
$ 74.99

This product was last offered at the strikethrough price on
08-31-2026

$ 70.63 USD
Free Shipping on orders $49 and up
The coolant expansion tank provides a place for excess coolant to flow as temperatures rise and fall. Because it’s exposed to constant heat cycles and pressure changes, it can eventually crack, split, or suffer damage to its nipples or mounting points. Keeping coolant properly contained within the system is essential, so if your tank shows signs of wear or damage, replacement is necessary. This direct-fit replacement installs easily and delivers the same heating and cooling performance as the factory unit. When replacing the tank, be sure to have additional coolant on hand. ECS Tuning carries a full range of vehicle-specific coolants designed to meet OEM specifications. Most German vehicles require specialized formulas—using the correct coolant will help prevent corrosion and ensure long-term reliability.
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Coolant Expansion Tank
We Price Match - Give Us A Call or Chat!
Febi - Corporate Logo
T#:16242201
Part#: 17137590626
Ships in 2 Business Days
$ 123.99

This product was last offered at the strikethrough price on
05-08-2026

$ 120.99 USD
$ 120.99 USD
Coolant Expansion Tank
2X Entries Into Our F80 M3 Sweepstakes
URO - Corporate Logo
T#:25507167
Part#: 17138742660
Ships in 2 Business Days
$ 136.99 USD
Free Shipping on orders $49 and up
The coolant expansion tank is essential for your vehicle, acting as a reservoir for extra fluid during temperature shifts. However, frequent exposure to extreme conditions makes it susceptible to cracks or breaks. Maintaining all coolant within the system is vital for optimal engine function. If you detect any damage, such as cracks, broken nipples, or compromised mounting points, swift replacement of the tank is necessary to uphold your vehicle's cooling system integrity.
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Coolant Level Sensor - 109mm Long
2X Entries Into Our F80 M3 Sweepstakes
URO - Corporate Logo
T#:380458
Part#: 61311375715
Ships in 2 Business Days
$ 15.99 USD
Free Shipping on orders $49 and up
Replace your coolant level sensor and ensure that your levels are accurately monitored
URO Radiator Mounting Plate for Expansion Tank - Z4
2X Entries Into Our F80 M3 Sweepstakes
URO - Corporate Logo
T#:639486
Part#: 17112248408
Ships in 2 Business Days
$ 69.99 USD
Free Shipping on orders $49 and up
URO Parts is one of the leading manufacturers of high quality direct replacement aftermarket components, covering a wide range of makes and models. All of their replacement parts are manufactured to ISO 9000 certification standards, so you can expect long lasting performance from URO Parts. As a leading source of high performance BMW parts and accessories since 1993, we at Turner Motorsport are honored to be the go-to supplier for tens of thousands of enthusiasts the world over. With over two decades of parts, service, and racing experience under our belt, we provide only quality performance and replacement parts. All of our performance parts are those we would (and do!) install and run on our own cars, as well as replacement parts that are Genuine BMW or from OEM manufacturers. We only offer parts we know you can trust to perform! URO Mounting Plate - This item fits the following BMW Chassis: E85,E86 Fits BMW Engines including: M54,N52
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Coolant Level Switch - E31 E38 E39 Z8
2X Entries Into Our F80 M3 Sweepstakes
URO - Corporate Logo
T#:20203
Part#: 61318360876
In Stock
$ 12.99

This product was last offered at the strikethrough price on
04-10-2026

$ 10.99 USD
Free Shipping on orders $49 and up
$ 10.99 USD
Free Shipping on orders $49 and up
This is the radiator coolant level sensor that mounts into the bottom of the cooling system expansion tank. With more than 4,000 European vehicle replacement parts, URO is no stranger to the market. Superior metal stock and extremely strict quality control are at the forefront of URO’s agenda and it shows as they become the OE supplier for more and more car companies every single day.

With more than 4,000 European vehicle replacement parts, URO is no stranger to the market. Superior metal stock and extremely strict quality control are at the forefront of URO’s agenda and it shows as they become the OE supplier for more and more car companies every single day.​

This item fits the following BMWs:
1999-2000 E39 BMW 528i 540i
2001-2003 E39 BMW 525i 530i 540i
1995-2001 E38 BMW 740i 740il 750il
1990-1998 E31 BMW 840i 840ci
2000-2003 E52 BMW Z8 Roadster
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Expansion Tank Mounting Clamp
2X Entries Into Our F80 M3 Sweepstakes
URO - Corporate Logo
T#:591954
Part#: 17111707777
Ships in 2 Business Days
$ 6.99 USD
Free Shipping on orders $49 and up
Locks the expansion tank into the mounting plate via the large hole in the bottom of the tank
Expansion Tank - Priced Each
2X Entries Into Our F80 M3 Sweepstakes
URO - Corporate Logo
T#:639209
Part#: 17138610656
Ships in 2 Business Days
$ 117.99 USD
Free Shipping on orders $49 and up
Replace your leaky coolant tank!
URO - Corporate Logo
T#:362008
Part#: 17111712835
Ships in 2 Business Days
$ 18.99 USD
Free Shipping on orders $49 and up
The coolant expansion tank in your vehicle gives additional fluid a place to go after expansion and contraction from temperature change. Because it is subjected to such drastic changes on a regular basis, it can often crack or break
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Rein Expansion Tank Cap - E30, E34
2X Entries Into Our F80 M3 Sweepstakes
Rein - Corporate Logo
T#:592018
Part#: 17137639023
Ships in 4 Business Days
Sale - Save 5% $ 14.99

This product was last offered at the strikethrough price on
08-31-2026

$ 14.24 USD
Free Shipping on orders $49 and up
Sale - Save 5%
$ 14.99

This product was last offered at the strikethrough price on
08-31-2026

$ 14.24 USD
Free Shipping on orders $49 and up
1.4 Bar pressure
Coolant Expansion Tank
2X Entries Into Our F80 M3 Sweepstakes
URO - Corporate Logo
T#:593078
Part#: 17138616418
Ships in 2 Business Days
$ 63.99 USD
Free Shipping on orders $49 and up
The coolant expansion tank in your vehicle gives additional fluid a place to go after expansion and contraction from temperature change. Because it is subjected to such drastic changes on a regular basis, it can often crack or break.
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BMW Bracket
We Price Match - Give Us A Call or Chat!
Febi - Corporate Logo
T#:17339421
Part#: 17111438819
Ships in 2 Business Days
$ 67.99

This product was last offered at the strikethrough price on
05-07-2026

$ 65.99 USD
Free Shipping on orders $49 and up
$ 65.99 USD
Free Shipping on orders $49 and up
This plastic piece ensures proper mounting of the radiator.

Rein - Corporate Logo
T#:45757471
Part#: 17125A02485
Ships in 4 Business Days
Sale - Save 5% $ 41.99

This product was last offered at the strikethrough price on
08-31-2026

$ 39.89 USD
Free Shipping on orders $49 and up
Sale - Save 5%
$ 41.99

This product was last offered at the strikethrough price on
08-31-2026

$ 39.89 USD
Free Shipping on orders $49 and up
This hose connects the expansion tank to the radiator. If your coolant expansion tank hose is cracked or leaking, replace it early to prevent further coolant loss and eventual overheating.

Rein Coolant Expansion Tank - With Cap
2X Entries Into Our F80 M3 Sweepstakes
Rein - Corporate Logo
T#:53891623
Part#: 17135A6A030C
Ships in 4 Business Days
New Item
Sale - Save 6% $ 99.99

This product was last offered at the strikethrough price on
08-31-2026

$ 94.07 USD
Sale - Save 6%
$ 99.99

This product was last offered at the strikethrough price on
08-31-2026

$ 94.07 USD
Replace your old brittle expansion tank
Rein Coolant Expansion Tank - E70
2X Entries Into Our F80 M3 Sweepstakes
Rein - Corporate Logo
T#:592023
Part#: 17137647290
Ships in 4 Business Days
Sale - Save 5% $ 85.99

This product was last offered at the strikethrough price on
08-31-2026

$ 81.69 USD
Free Shipping
Sale - Save 5%
$ 85.99

This product was last offered at the strikethrough price on
08-31-2026

$ 81.69 USD
Free Shipping
Plastic expansion tanks have a limited lifespan - replace every 80,000 miles

Rein Reservoir Hose R50 / R52
2X Entries Into Our F80 M3 Sweepstakes
Rein - Corporate Logo
T#:34114213
Part#: 17127526414
Ships in 4 Business Days
Sale - Save 13% $ 9.99

This product was last offered at the strikethrough price on
08-31-2026

$ 8.71 USD
Free Shipping on orders $49 and up
Sale - Save 13%
$ 9.99

This product was last offered at the strikethrough price on
08-31-2026

$ 8.71 USD
Free Shipping on orders $49 and up

Reservoir Hose CHE0885 is a top-quality replacement part designed for BMW vehicles, ensuring a reliable connection between your vehicle’s reservoir and cooling system. Engineered for durability and heat resistance, this hose provides a seamless flow of coolant to maintain optimal engine temperature, preventing overheating. Reservoir Hose CHE0885 is made to meet or exceed OEM specifications, ensuring a perfect fit for your BMW. Available through Turner Motorsport, this hose is an essential component for keeping your vehicle's cooling system functioning efficiently.

  • High-quality reservoir hose for BMW vehicles
  • Ensures reliable coolant flow for optimal engine performance
  • Made from heat-resistant, durable materials
  • Prevents overheating and engine damage
  • Meets or exceeds OEM specifications
  • Perfect fit for a variety of BMW models
  • Available from trusted supplier Turner Motorsport
  • Easy to install with secure connections
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Expansion Tank Mounting Plate
2X Entries Into Our F80 M3 Sweepstakes
Rein - Corporate Logo
T#:591946
Part#: 17101439110
Ships in 4 Business Days
Sale - Save 5% $ 80.99

This product was last offered at the strikethrough price on
08-31-2026

$ 76.94 USD
Free Shipping
Sale - Save 5%
$ 80.99

This product was last offered at the strikethrough price on
08-31-2026

$ 76.94 USD
Free Shipping

BMW Expansion Tank With Cap - 17138570079
2X Entries Into Our F80 M3 Sweepstakes
Rein - Corporate Logo
T#:46616019
Part#: EPK0146
Ships in 4 Business Days
Sale - Save 6% $ 93.99

This product was last offered at the strikethrough price on
08-31-2026

$ 88.70 USD
Free Shipping on orders $49 and up
Sale - Save 6%
$ 93.99

This product was last offered at the strikethrough price on
08-31-2026

$ 88.70 USD
Free Shipping on orders $49 and up
The coolant expansion tank serves as a reservoir for excess coolant as it expands and contracts with changing temperatures. Since it’s constantly exposed to extreme heat cycles, it can eventually crack, split, or suffer broken nipples or mounting points. To keep your cooling system sealed and operating properly, any damaged tank should be replaced.
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URO Expansion Tank Mounting Plate - BMW E83 X3
2X Entries Into Our F80 M3 Sweepstakes
URO - Corporate Logo
T#:639534
Part#: 17113400018
Ships in 2 Business Days
$ 90.99 USD
Free Shipping on orders $49 and up
$ 90.99 USD
Free Shipping on orders $49 and up
Secures the expansion tank to the radiator
Vargas Turbo Technologies - Corporate Logo
T#:51848504
Part#: VTT-B58-CEBLUE
Ships on Sep 18, 2026
New Item
$ 59.99 USD
Free Shipping
$ 59.99 USD
Free Shipping
Elevate your BMW's engine bay while safeguarding your cooling system with the VTT B58 Expansion Tank Hose in Blue.
Vargas Turbo Technologies - Corporate Logo
T#:52164880
Part#: N54CLVTBLKO
Ships on Sep 18, 2026
New Item
$ 54.99 USD
Free Shipping
$ 54.99 USD
Free Shipping
The VTT N54 Upper Vent Hose is a critical upgrade for any BMW enthusiast looking to eliminate the weakest links in their cooling system.


Coolant Expansion Tank
2X Entries Into Our F80 M3 Sweepstakes
Rein - Corporate Logo
T#:57086700
Part#: 17137642158
Ships in 4 Business Days
New Item
Sale - Save 7% $ 55.99

This product was last offered at the strikethrough price on
08-31-2026

$ 52.35 USD
Sale - Save 7%
$ 55.99

This product was last offered at the strikethrough price on
08-31-2026

$ 52.35 USD
The factory expansion tank is one of the most common failure points in modern BMW cooling systems, often failing along seam welds or developing micro-cracks around fluid quick-connect fittings. Replacing a degraded reservoir with this direct-fit Rein expansion tank restores pressure containment, ensures accurate coolant expansion volume, and prevents fluid loss before it turns into severe engine damage.
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Genuine BMW - Corporate Logo
T#:613870
Part#: 17138610652
Ships in 6 Business Days
6% off MSRP $ 198.99

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

$ 187.99 USD
Free Shipping
6% off MSRP
$ 198.99

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

$ 187.99 USD
Free Shipping
If your coolant reservoir tank has cracked or if one of the mounting points has broken, this is the perfect replacement to ensure your coolant system remains leak-free. This reservoir specifically works with the high-temp circuit, which is responsible for cooling your engine block and cylinder head.
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Genuine BMW - Corporate Logo
T#:613871
Part#: 17138610653
Ships in 4 Business Days
6% off MSRP $ 170.99

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

$ 160.99 USD
Free Shipping on orders $49 and up
6% off MSRP
$ 170.99

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

$ 160.99 USD
Free Shipping on orders $49 and up
If your coolant reservoir tank has cracked or if one of the mounting points has broken, this is the perfect replacement to ensure your coolant system remains leak-free. This reservoir specifically works with the low-temp circuit, which is responsible for cooling your manifold-integrated intercooler
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Genuine BMW - Corporate Logo
T#:31655876
Part#: 17135A6A030
Ships in 4 Business Days
6% off MSRP $ 189.99

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

$ 178.99 USD
Free Shipping on orders $49 and up
6% off MSRP
$ 189.99

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

$ 178.99 USD
Free Shipping on orders $49 and up

Genuine BMW Expansion Tank - F97 F98 G01 G02 B46 B58 S58 is an essential component designed to regulate coolant levels and pressure in the engine's cooling system. Over time, exposure to high temperatures and constant expansion and contraction can cause plastic tanks to become brittle, leading to cracks and leaks. A failing expansion tank can result in coolant loss, overheating, and reduced engine performance. This genuine BMW replacement ensures a precise fit, optimal cooling efficiency, and long-lasting durability for BMW F97, F98, G01, and G02 models equipped with B46, B58, and S58 engines.

  • Regulates coolant levels and pressure for efficient engine cooling
  • Prevents coolant leaks and potential overheating issues
  • OE BMW part ensures perfect fit and compatibility
  • High-quality construction resists wear from thermal cycling
  • Direct replacement for BMW F97, F98, G01, and G02 models with B46, B58, and S58 engines
  • Designed for long-term durability and reliable performance
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Genuine MINI - Corporate Logo
T#:393093
Part#: 17137823626
Ships in 4 Business Days
7% off MSRP $ 129.99

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

$ 120.99 USD
Free Shipping
7% off MSRP
$ 129.99

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

$ 120.99 USD
Free Shipping
Genuine BMW - Corporate Logo
T#:374427
Part#: 17111723520KT2
Ships in 4 Business Days
$ 400.99

This product was last offered at the strikethrough price on
08-13-2026

$ 395.99 USD
Free Shipping
$ 395.99 USD
Free Shipping

Genuine BMW - Corporate Logo
T#:380426
Part#: 17117573781OEKT1
Ships in 4 Business Days
$ 589.99

This product was last offered at the strikethrough price on
07-10-2026

$ 499.99 USD
Free Shipping
$ 499.99 USD
Free Shipping
Genuine BMW - Corporate Logo
T#:374589
Part#: 17111741167KT4
Ships in 4 Business Days
$ 388.99

This product was last offered at the strikethrough price on
06-23-2026

$ 384.99 USD
Free Shipping
$ 384.99 USD
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Replace your expansion tank with all Genuine BMW parts for guaranteed reliability and longevity.

The kit includes:

Genuine BMW expansion tank with level sensor
Genuine BMW expansion tank cap and seal
Genuine BMW bleeder screw
Genuine BMW hose clamps
Genuine BMW coolant level sensor
When doing any sort of repair or maintenance there is no replacement for genuine factory parts. Turner Motorsport carries the Genuine BMW brand with pride and has the parts you need to complete your next project with confidence.

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Genuine BMW - Corporate Logo
T#:191374
Part#: 17137604431
Ships in 5 Business Days
6% off MSRP $ 162.99

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

$ 152.99 USD
Free Shipping
6% off MSRP
$ 162.99

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

$ 152.99 USD
Free Shipping

Genuine BMW Expansion Tank -

When doing any sort of repair or maintenance there is no replacement for genuine factory parts. Turner Motorsport carries the Genuine BMW brand with pride and has the parts you need to complete your next project with confidence.

This item fits the following BMW Chassis:
i01 i3
 

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Genuine BMW - Corporate Logo
T#:46468
Part#: 17137589526
Ships in 6 Business Days
6% off MSRP $ 202.99

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

$ 190.99 USD
Free Shipping
6% off MSRP
$ 202.99

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

$ 190.99 USD
Free Shipping


Genuine BMW Expansion Tank
This item fits the following BMW Chassis:
E70 X5M,E71 X6M,E70 X5,E71 X6

Fits BMW Engines including:
S63

Meyle - Corporate Logo
T#:50066859
Part#: 17135A6A030
In Stock
$ 75.99 USD
Free Shipping on orders $49 and up
Replaces cracked or aged coolant expansion tank.
Genuine BMW - Corporate Logo
T#:49857448
Part#: 17135A270D3
Ships in 6 Business Days
6% off MSRP $ 170.99

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

$ 160.99 USD
Free Shipping on orders $49 and up
6% off MSRP
$ 170.99

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

$ 160.99 USD
Free Shipping on orders $49 and up
If your coolant reservoir tank has cracked or if one of the mounting points has broken, this is the perfect replacement to ensure your coolant system remains leak-free. This reservoir specifically works with the low-temp circuit, which is responsible for cooling your manifold-integrated intercooler
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Genuine BMW - Corporate Logo
T#:63355
Part#: 34331160304
Ships in 9 Business Days
3% off MSRP $ 211.99

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

$ 204.99 USD
Free Shipping
3% off MSRP
$ 211.99

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

$ 204.99 USD
Free Shipping


Genuine BMW Expansion Tank - Ate

Genuine BMW - Corporate Logo
T#:45000
Part#: 16131153314
Ships in 9 Business Days
3% off MSRP $ 109.99

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

$ 106.99 USD
Free Shipping
3% off MSRP
$ 109.99

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

$ 106.99 USD
Free Shipping
Genuine BMW EXPANSION TANK
Fits BMW Engines including:
M30,S38

Genuine BMW - Corporate Logo
T#:44522
Part#: 16121118911
Ships in 9 Business Days
3% off MSRP $ 93.99

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

$ 90.99 USD
Free Shipping
3% off MSRP
$ 93.99

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

$ 90.99 USD
Free Shipping


Genuine BMW EXPANSION TANK

Fits BMW Engines including:
M10


Precision Raceworks - Corporate Logo
T#:38161691
Part#: 201-0393-SIL
Ships in 9 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.

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MTC - Corporate Logo
T#:371228
Part#: 17111742232
Ships in 10 Business Days
$ 6.99 USD
Free Shipping on orders $49 and up
$ 6.99 USD
Free Shipping on orders $49 and up
1.4 Bar pressure. Older radiator caps being to lose their ability to hold pressure over time. Resulting in a lower boiling point for the coolant system.
Precision Raceworks - Corporate Logo
T#:38128031
Part#: 201-0394-BLK
Ships in 10 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 10 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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MTC - Corporate Logo
T#:27405534
Part#: 17138617045
Ships in 10 Business Days
$ 64.46 USD
Free Shipping on orders $49 and up
Your charge air cooler's coolant expansion tank acts as a reservoir, housing extra coolant, and gives fluid a place to go after expansion and contraction from temperature change. Because the plastic tank is subjected to regular temperature changes, the plastic can become brittle over time and will often crack or break. If your tank is leaking and you lose too much coolant, your charge air cooler will not function properly and your air intake temperatures will begin to rise, reducing horsepower and efficiency. If your tank has experienced damage such as cracking, nipples breaking off, or mounting point damage, you will need to replace it.
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Precision Raceworks - Corporate Logo
T#:47679257
Part#: 622-0291-BLAK
Ships in 10 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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Bremmen Parts - Corporate Logo
T#:640497
Part#: 17107514964
In Stock
Sale - Save 50% $ 63.99

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

$ 32.00 USD
Free Shipping on orders $49 and up
Sale - Save 50%
$ 63.99

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

$ 32.00 USD
Free Shipping on orders $49 and up
This radiator expansion tank is used on E53 X5 4.4i and 4.6is with M62 engine, and Z3 2.3 2.5i 2.8 3.0i from 1999-2002. It is a common failure item as the plastic weakens over time and stress cracks will lead to coolant leaks. 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 less 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. From 1974 to 2019, Bavarian Autosport was one of the premier vendors for BMW and MINI auto parts. We are happy to preserve the Bav Auto legacy by continuing to carry their high-quality products into the future. All Bav Auto parts will remain unchanged in design and sourced from the same OEM suppliers to ensure long-lasting reliability. We trust these parts, accessories, and upgrades so confidently that we back every Bavarian Autosport branded component with a 2-year warranty.
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Mahle-Behr - Corporate Logo
T#:186486
Part#: 17137647713
Ships on Sep 21, 2026
$ 81.99 USD
Free Shipping
$ 81.99 USD
Free Shipping
This high quality BEHR brand expansion tank is used on E65/E66 7 series with the N62 and N73 engines, 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 BMWs.

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 less 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. Replaces part numbers 17137543003 and 17138600275.

This item fits the following BMWs:
2002-2008 E65 BMW 745i 745li 750i 750li 760i 760li
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Coolant Expansion Tank
5X Entries Into Our F80 M3 Sweepstakes
Meyle - Corporate Logo
T#:54959296
Part#: 314 223 0004
Ships on Sep 22, 2026
New Item
$ 75.99 USD
Free Shipping on orders $49 and up
This Meyle original-quality expansion tank provides a durable, reliable solution to get your cooling system back to performing exactly as it should.


Canton Racing - Corporate Logo
T#:31423679
Part#: 80-272BLKKT1KT
Ships on Sep 24, 2026
$ 493.00 USD
Free Shipping on orders $49 and up

MINI R50 to R53 Expansion Tank / Power Steering Tank - Wrinkle Black Aluminum is a high-quality solution designed to address both coolant expansion and power steering needs in one kit. This kit includes a billet-style expansion tank with a radiator neck that accepts the Canton Racing part #81-030 pressure cap or any 30 psi radiator cap, ensuring a secure and leak-proof seal.

Key benefits of the MINI R50 to R53 Expansion Tank / Power Steering Tank - Wrinkle Black Aluminum include:

  • Dual Functionality: Combines both expansion tank and power steering tank into a single, convenient kit.
  • Durable Construction: Made from aluminum with a wrinkle black finish, providing long-lasting performance and a sleek appearance.
  • Enhanced Sealing: Features a billet radiator-style neck that fits standard 30 psi radiator caps, preventing leaks and ensuring reliable operation.
  • Reliable Design: Eliminates the issues associated with plastic tanks, such as separation and leakage.
  • Complete Kit: Includes a black expansion tank, black power steering tank, and a Stant cap for easy installation.
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Canton Racing - Corporate Logo
T#:19428688
Part#: 80-272BLK
Ships on Sep 24, 2026
17% off MSRP $ 272.99

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

$ 227.00 USD
Free Shipping on orders $49 and up
17% off MSRP
$ 272.99

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

$ 227.00 USD
Free Shipping on orders $49 and up

Upgrade your Gen1 Mini Cooper or Cooper S with the coolant expansion/fill tank featuring a billet radiator-style neck. This tank accepts the Canton Racing part #81-030 pressure cap or any 30 psi radiator-style cap. The Canton Racing Aluminum tank with Powdercoated Wrinkle Black finish not only enhances the engine bay aesthetics but also resolves expansion tank issues with its solid build and built-in mount. Say goodbye to concerns about separating and leaking plastic expansion tanks. Pair it with the Canton Racing 77-272 MINI power steering tank for a perfect combination.

  • Features a billet radiator-style neck
  • Accepts Canton Racing pressure cap or any 30 psi radiator-style cap
  • Enhances engine bay aesthetics with Powdercoated Wrinkle Black finish
  • Resolves expansion tank issues with solid build and built-in mount
  • Eliminates worries about separating and leaking plastic tanks
  • Perfect complement to Canton Racing 77-272 MINI power steering tank
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