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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 Replacement Kit
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Packaged by Turner - Corporate Logo
T#:15744017
Part#: N524ECSTNKKT-KT
In Stock
Sale - Save 21% $ 127.99

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$ 100.95 USD
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$ 100.95 USD
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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. You want to keep all the coolant in your vehicle in the cooling system. If your tank has experienced damage such as cracking, nipples breaking off, or mounting point damage, you will need to replace it. The kit includes: Expansion tank with level sensor URO expansion tank cap Genuine BMW expansion tank grommet Genuine BMW mounting bolts
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Coolant Expansion Tank - E46 (non-M), X3, X5 3.0
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Packaged by Turner - Corporate Logo
T#:338020
Part#: 17117573781
In Stock
Sale - Save 10% $ 137.99

This product was last offered at the strikethrough price on
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Starting at $ 123.98 USD
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This coolant reservoir is for the non-M E46 3-series models from 1999-2006 (M3 takes a different expansion tank). 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. This is the most recent expansion tank design from Hella-Behr, the OEM supplier to BMW. It replaces the original BMW part number 17137787039.

Other items to consider replacing at the same time are the radiator cap, coolant level sensor, lower radiator hose, coolant temp sensor in the lower hose, and the hose clamps. If your car has an automatic transmission you should also replace the oil cooler thermostat in the radiator frame, which is a common source for leaks.

This coolant expansion tank fits:

1999-2006 E46 3 series - 323i, 323Ci, 325i, 325Ci, 325xi, 328i, 328Ci, 330i, 330Ci & 330xi (**no M)
2004-2008 X3 SAV - X3 2.5, X3 3.0, X3 3.0si
2000-2005 X5 SAV - X5 3.0
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OEM Coolant Expansion Tanks Kit - F22/23 F3X B48 B58
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Packaged by Turner - Corporate Logo
T#:27605427
Part#: 17138677649TKT
Ships in 2 Business Days
Sale - Save 3% $ 208.99

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$ 202.62 USD
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Genuine BMW expansion tanks have a bad habit of failing after a few years. This has primarily been caused by the plastic construction of the expansion tanks. After enough heat cycles, the plastic becomes brittle and can crack, causing coolant to leak out and air to enter the coolant system. If a failing expansion tank is not addressed soon enough, the coolant loss can lead to an overheating engine. This kit includes two brand new high quality expansion tanks and caps
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Coolant Expansion Tank - E36/E39/Z3 6 cylinder 1992-1998
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Packaged by Turner - Corporate Logo
T#:338018
Part#: 17111723520
Ships in 1 Business Day
$ 99.99

This product was last offered at the strikethrough price on
10-22-2026

Starting at $ 63.18 USD
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Starting at $ 63.18 USD
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This high quality BEHR brand expansion tank is used on M50, M52, S50 and S52 engines, and is a common failure item on all E36 3 series with 6 cylinder engines (325/328/323 and M3) 1992-1999, Z3 with 2.8 liter, MZ3 Roadster/Coupe (S52), and E39 528i from 1997-1998. BEHR was the original equipment supplier to BMW, so you know the BEHR made expansion tank will be the highest quality available. Be leary 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.

Need a new coolant level sensor too? If your coolant level sender is bad, your on board computer will constantly display a "low coolant" message (unless your coolant is actually low...). If you're replacing your expansion tank, now is a great time to replace this failure prone sensor. If you want a new coolant level sensor, simply choose from the option below. Because there are different sensors for different year/model BMWs, please be as specific as possible when you give us your car info during checkout (model, year, production date). Thanks!


This item fits the following BMWs:
1992-1998 E36 BMW 323ic 325i 325is 325ic 328i 328is 328ic M3
1997-1998 E39 BMW 528i
1997-1998 Z3 BMW Z3 2.8
1998-2000 Z3 BMW M Roadster M Coupe (S52)
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ECS Cooling System Refresh Kit - Level 1
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Packaged by Turner - Corporate Logo
T#:15677493
Part#: 11517527910-KT
In Stock
Sale - Save 4% $ 336.99

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$ 323.65 USD
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Stop the problems before they arise. If you vehicle has 80,000 miles or more, replace all of these components to ensure that your vehicle stays healthy. To keep everything in top order, continue to replace these components at 80,000 mile intervals. Water pump failure, cracked plastic housings, and expansion tank leaks will not be a concern once all these problem parts are replaced. This kit was put together by Turner including the basic parts that need replaced. Water pump with metal impeller Fan switch Thermostat and thermostat housing Sealing gaskets Expansion tank with level sensor, clamp and cap 1 Gallon Coolant Upper & lower radiator hoses
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Expansion Tank Replacement Kit - E60 M5,E63 M6
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Packaged by Turner - Corporate Logo
T#:584232
Part#: 17112283345KT
In Stock
$ 250.99 USD
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$ 250.99 USD
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The expansion tank in your BMW is a vital component of the cooling system, and because of the constant abuse from heat and temperature changes, it often fails. This kit contains all of the basic items needed for a tank replacement.
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ECS Cooling System Refresh Kit - Level 2
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Packaged by Turner - Corporate Logo
T#:15677514
Part#: 11281706545-KT
Ships in 2 Business Days
Sale - Save 3% $ 474.99

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$ 460.17 USD
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Stop the problems before they arise. If your BMW has 80,000 miles or more, replace all of these components to ensure that your vehicle stays healthy. Avoid water pump failure, cracked thermostat housings, and expansion tank leaks, which all lead to overheating and subsequent damage. This kit was put together by Turner for a complete cooling system service. GEBA water pump with metal impeller ECS aluminum water pump pulley Fan switch Thermostat and thermostat housing Sealing gaskets Expansion tank with level sensor, clamp and cap 1 Gallon Coolant Upper & lower radiator hoses Accessory drive belts Radiator drain plug
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N52 ECS Cooling System Refresh Kit - E8x E9x
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Packaged by Turner - Corporate Logo
T#:59440849
Part#: TWTRPMPPIEBRPRKT
In Stock
New Item
$ 665.99 USD
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Be sure your cooling system is up to the task

ECS Cooling System Refresh Kit - Level 2
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Packaged by Turner - Corporate Logo
T#:15710821
Part#: 17137607482-KT
In Stock
Sale - Save 20% $ 917.99

This product was last offered at the strikethrough price on
10-13-2026

$ 736.19 USD
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As your mileage increases, so does wear and tear on your engine's cooling components. Cooling system components live a rough life, going through extreme temperature changes and being exposed to the elements. A cooling system failure can, and probably will leave you stranded. Included in this kit Water pump with new bolts Thermostat & housing Expansion tank with level sensor Expansion tank cap 1 Gallon of OEM Coolant Waterpump & thermostat hoses Upper and lower radiator hoses Accessory belt
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Cooling System Refresh Kit - Level 2
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Packaged by Turner - Corporate Logo
T#:15744066
Part#: 11287837898-KT
Ships on Dec 18, 2026
Sale - Save 3% $ 808.99

This product was last offered at the strikethrough price on
07-15-2026

$ 786.20 USD
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BMW has been designing notoriously failure-prone cooling systems since the late 1980s. The coolant capacity in most BMW engines is not sufficient to accommodate any driving or overheating near red zone temperatures. After the gauge reaches this critical area, it is common for thousands of dollars in damage to occur. Stop the problems before they arise. If your vehicle has 80,000 miles or more, replace all of these components to ensure that your vehicle stays healthy. To keep everything in top order, continue to replace these components at 80,000 mile intervals. Water pump failure, cracked housings, and expansion tank leaks will not be a concern once all these problem parts are replaced. Saleri water pump with metal impeller ECS aluminum water pump pulley Fan switch Vaico Q+ thermostat - made in Germany! Sealing gaskets Expansion tank with level sensor, clamp and cap 1 Gallon Coolant Upper & lower radiator hoses Accessory drive belts Radiator drain plug
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Cooling System Refresh Kit - Level 2 - E9x, E82, E88, Z4
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Packaged by Turner - Corporate Logo
T#:42099868
Part#: 11537558523TKT
In Stock
Sale - Save 20% $ 829.99

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

$ 667.28 USD
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Keep your BMW running at the proper temperature and avoid costly engine repairs with the Cooling System Refresh Kit, the complete maintenance solution trusted by enthusiasts and professionals alike.
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Automatic Transmission Thermostat Kit
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Packaged by Turner - Corporate Logo
T#:57122955
Part#: 17111438819KT2
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10-19-2026

$ 91.86 USD
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Keeping your E53 X5 automatic transmission cool is essential for longevity and peak performance. The factory transmission thermostat circuit relies on plastic housings and o-ring seals that deteriorate over time. When the transmission thermostat fails or it's mounting assembly cracks, coolant loss follows putting your transmission at risk of overheating under load.
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Cooling System Refresh Kit - Level 2
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Packaged by Turner - Corporate Logo
T#:15677500
Part#: 82141467704-KT
In Stock
Sale - Save 20% $ 832.99

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$ 669.06 USD
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As your mileage increases, so does wear and tear on your engine's cooling components. Cooling system components live a rough life, going through extreme temperature changes and being exposed to the elements. A cooling system failure can, and probably will leave you stranded. For automatic transmission (or DCT) vehicles only This kit includes: Thermostat with mounting hardware 1 gallon of BMW coolant Water pump with mounting hardware Primary cooling system hoses and radiator hose gasket, and bleeder screw Expansion tank with cap Accessory belt
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Precision Raceworks - Corporate Logo
T#:38229115
Part#: 622-0079
In Stock
$ 69.99 USD
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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.
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Engine Coolant Expansion Tank
10X Entries Into Our F80 M3 Sweepstakes
Bremmen Parts - Corporate Logo
T#:30729009
Part#: 17138677649
In Stock
Sale - Save 12% $ 85.99

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$ 75.59 USD
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$ 75.59 USD
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Coolant Expansion Tank
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Bremmen Parts - Corporate Logo
T#:36032353
Part#: 17111741167
In Stock
Sale - Save 15% $ 60.99

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$ 51.84 USD
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Canton Racing - Corporate Logo
T#:19428667
Part#: 80-272
Ships on Dec 4, 2026
17% off MSRP $ 226.99

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$ 189.00 USD
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17% off MSRP
$ 226.99

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

$ 189.00 USD
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Upgrade your Gen1 Mini Cooper & Cooper S with this high-quality coolant expansion/fill tank from Canton Racing. With a billet radiator-style neck designed to accept the Canton Racing part #81-030 pressure cap or any 30 psi radiator-style cap, this aluminum tank offers superior performance and style.
  • Features a billet radiator-style neck for enhanced durability
  • Resolves expansion tank issues with a solid, built-in mount
  • Eliminates worries about separating and leaking plastic tanks
  • Perfectly complements Canton Racing 77-272 MINI power steering tank
Ensure reliability and improve the aesthetic appeal of your engine bay with this Canton Racing Aluminum coolant expansion/fill tank for your Gen1 Mini Cooper & Cooper S.
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Coolant Expansion Tank - 17111436381
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Bremmen Parts - Corporate Logo
T#:36303285
Part#: 17111436381
In Stock
Sale - Save 39% $ 65.99

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$ 40.00 USD
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BMW E39 Coolant Expansion Tank is an essential component designed to maintain the proper coolant level in your vehicle's cooling system. Manufactured with high-quality materials, this expansion tank ensures reliable performance and durability, preventing engine overheating by accommodating the expansion of coolant as it heats up. The kit includes a level sensor and cap, providing everything needed for a seamless installation. This expansion tank is specifically engineered to meet the exact specifications of your BMW E39, offering a perfect fit and optimal functionality.

Complete Kit: Includes level sensor and cap for easy installation. High-Quality Construction: Built with durable materials for long-lasting performance. Prevents Overheating: Helps manage coolant expansion, ensuring engine protection. Exact Fit: Designed to meet the precise specifications of your BMW E39. Enhanced Reliability: Ensures proper coolant level maintenance for optimal cooling system function.

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Bremmen Parts - Corporate Logo
T#:640497
Part#: 17107514964
In Stock
Sale - Save 15% $ 64.99

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$ 55.24 USD
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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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Precision Raceworks - Corporate Logo
T#:38161689
Part#: 201-0393-BLU
In Stock
$ 109.99 USD
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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.

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Coolant Expansion Tank
10X Entries Into Our F80 M3 Sweepstakes
Bremmen Parts - Corporate Logo
T#:30728965
Part#: 17137823626
In Stock
Sale - Save 20% $ 47.99

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

$ 38.34 USD
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$ 38.34 USD
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Precision Raceworks - Corporate Logo
T#:38128032
Part#: 201-0394-SIL
Ships in 8 Business Days
$ 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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Coolant Expansion Tank W/O Cap
10X Entries Into Our F80 M3 Sweepstakes
Bremmen Parts - Corporate Logo
T#:639188
Part#: 17137529273
In Stock
Sale - Save 16% $ 38.99

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$ 32.94 USD
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Canton Racing - Corporate Logo
T#:19428666
Part#: 81-030
In Stock
17% off MSRP $ 45.99

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$ 38.00 USD
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17% off MSRP
$ 45.99

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

$ 38.00 USD
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Ensure optimal performance of your Mini's cooling system with the Expansion Tank Pressure Cap - 30 Lbs W10 W11 1.6L Engine. Designed for use with Canton Racing aluminum expansion tanks or similar applications, this 30psi radiator style cap provides reliable pressure control. Keep your engine running smoothly with this essential component.
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Precision Raceworks - Corporate Logo
T#:38161688
Part#: 201-0393-BLK
Ships in 10 Business Days
$ 109.99 USD
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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.

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Precision Raceworks - Corporate Logo
T#:38094357
Part#: 601-0055
Ships in 6 Business Days
$ 39.99 USD
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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.
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Precision Raceworks - Corporate Logo
T#:47679259
Part#: 622-0291-SIL
In Stock
$ 184.99 USD
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$ 184.99 USD
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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 Water Pipe Connector - E83, Z4
10X Entries Into Our F80 M3 Sweepstakes
Bremmen Parts - Corporate Logo
T#:1195932
Part#: 17112248409
Ships on Nov 10, 2026
Sale - Save 3% $ 31.61

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$ 30.66 USD
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Located underneath the expansion tank

Coolant Expansion Tank Cap
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Bremmen Parts - Corporate Logo
T#:36032339
Part#: 17117639020
In Stock
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This product was last offered at the strikethrough price on
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$ 11.99 USD
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Bremmen Parts - Corporate Logo
T#:640140
Part#: 17111712788
Ships on Dec 16, 2026
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$ 2.44 USD
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Plastic bleeder screw for cooling system is used to bleed air that would otherwise create an air pocket and lead to overheating. Includes o-ring seal.

Precision Raceworks - Corporate Logo
T#:1332002
Part#: 201-0050
In Stock
$ 19.99 USD
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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.
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Coolant Level Sensor
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Bremmen Parts - Corporate Logo
T#:30728984
Part#: 61311378320
In Stock
Sale - Save 56% $ 34.99

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

$ 15.29 USD
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Sale - Save 56%
$ 34.99

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

$ 15.29 USD
Free Shipping on orders $49 and up

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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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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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#: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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Coolant Expansion Tank - With Cap
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Bremmen Parts - Corporate Logo
T#:55497428
Part#: 17137640514
Ships on Nov 10, 2026
New Item
Sale - Save 10% $ 69.99

This product was last offered at the strikethrough price on
10-08-2026

$ 62.99 USD
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Sale - Save 10%
$ 69.99

This product was last offered at the strikethrough price on
10-08-2026

$ 62.99 USD
Free Shipping on orders $49 and up
Canton Racing - Corporate Logo
T#:31423679
Part#: 80-272BLKKT1KT
Ships on Nov 13, 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 Nov 13, 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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Canton Racing - Corporate Logo
T#:31390597
Part#: 80-272BLKKT
Ships on Nov 13, 2026
$ 265.00 USD
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MINI R50 to R53 Expansion Tank Aluminum Wrinkle Black & Cap - Kit offers the premium quality of Canton Racing for MINI enthusiasts. This high-grade aluminum expansion tank features a sleek Wrinkle Black powder-coated finish, designed to replace the original plastic tank with ease.

  • Premium Quality: Made from durable aluminum with a Wrinkle Black powder-coated finish for enhanced aesthetics and longevity.
  • Direct Replacement: Utilizes the original mountings for a hassle-free installation, ensuring a perfect fit.
  • Enhanced Functionality: Upgrades from the standard plastic tank to improve both appearance and performance over time.
  • Kit Includes:
    • Canton Racing Coolant Tank in Wrinkle Black Powdercoating
    • Canton Racing Stant Tank Cap
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Coolant Expansion Tank
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Bremmen Parts - Corporate Logo
T#:45723154
Part#: 17137642158
In Stock
Sale - Save 25% $ 67.99

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

$ 50.99 USD
Free Shipping on orders $49 and up
Sale - Save 25%
$ 67.99

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

$ 50.99 USD
Free Shipping on orders $49 and up
E30 Coolant Expansion Tank
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Bremmen Parts - Corporate Logo
T#:57507437
Part#: 17111712641
Ships on Jan 11, 2027
New Item
Sale - Save 6% $ 49.99

This product was last offered at the strikethrough price on
10-21-2026

$ 46.99 USD
Free Shipping on orders $49 and up
Sale - Save 6%
$ 49.99

This product was last offered at the strikethrough price on
10-21-2026

$ 46.99 USD
Free Shipping on orders $49 and up

Coolant Expansion Tank
10X Entries Into Our F80 M3 Sweepstakes
Bremmen Parts - Corporate Logo
T#:53044121
Part#: 17137601948
In Stock
New Item
Sale - Save 8% $ 72.99

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

$ 67.49 USD
Free Shipping on orders $49 and up
Sale - Save 8%
$ 72.99

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

$ 67.49 USD
Free Shipping on orders $49 and up
MINI F5X F6X Expansion Tank
10X Entries Into Our F80 M3 Sweepstakes
Bremmen Parts - Corporate Logo
T#:28138156
Part#: 17137617362
Special Order: No Guaranteed ETA
Sale - Save 5% $ 81.99

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

$ 77.51 USD
Free Shipping on orders $49 and up
Sale - Save 5%
$ 81.99

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

$ 77.51 USD
Free Shipping on orders $49 and up

MINI F5X F6X Expansion Tank

For Mini owners looking to maintain optimal engine performance, the MINI F5X F6X Expansion Tank is an essential component. This expansion tank ensures proper cooling system functionality, preventing overheating and potential engine damage. Crafted with high-quality materials, it guarantees durability and reliability for long-term use, providing peace of mind to Mini enthusiasts.

  • Ensures proper cooling system functionality
  • Prevents overheating and potential engine damage
  • Crafted with high-quality materials for durability
  • Provides peace of mind to Mini enthusiasts
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