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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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Rein - Corporate Logo
T#:340541
Part#: 17111742231
Ships in 2 Business Days
$ 17.99 USD
Free Shipping on orders $49 and up
This radiator expansion tank cap is used most BMW's from 1991-2006. 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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URO - Corporate Logo
T#:373591
Part#: 17117521071
Ships Today
$ 18.99

This product was last offered at the strikethrough price on
03-09-2026

$ 14.49 USD
Free Shipping on orders $49 and up
$ 14.49 USD
Free Shipping on orders $49 and up
Keep that coolant expansion tank sealed
Meyle Coolant Expansion Tank - E53 X5, E46 M52/54, E83 X3
We Price Match - Give Us A Call or Chat!
Meyle - Corporate Logo
T#:369184
Part#: 17117573781
In Stock
$ 66.99 USD
Free Shipping on orders $49 and up

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.

Other items to consider replacing at the same time are the radiator cap, coolant level sensor, lower radiator hose, coolant temp sensor, 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.

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!

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Genuine BMW - Corporate Logo
T#:185110
Part#: 17137642160
In Stock
6% off MSRP $ 180.99

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

$ 169.99 USD
Free Shipping
6% off MSRP
$ 180.99

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

$ 169.99 USD
Free Shipping

Replace your damaged expansion tank to prevent coolant loss or potential overheating issues.

Genuine BMW Expansion Tank -
This item fits the following BMW Chassis:
F22,F30,F31,F32,F33,F34,F36

Fits BMW Engines including:
N55

 

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Febi - Corporate Logo
T#:340723
Part#: 17137607482
In Stock
$ 151.99

This product was last offered at the strikethrough price on
04-16-2026

$ 104.99 USD
Free Shipping on orders $49 and up
$ 104.99 USD
Free Shipping on orders $49 and up
Includes level sensor
Febi Coolant Level Sensor - E31, E38, E39
We Price Match - Give Us A Call or Chat!
Febi - Corporate Logo
T#:341632
Part#: 61318360876
In Stock
$ 14.99 USD
Free Shipping on orders $49 and up
$ 14.99 USD
Free Shipping on orders $49 and up
Monitors the coolant level in the expansion tank

URO - Corporate Logo
T#:48608189
Part#: 17112283344
Ships in 2 Business Days
New Item
$ 155.99 USD
Free Shipping on orders $49 and up
​This radiator coolant reservoir/expansion tank for E46 M3 is a common failure item as the plastic weakens and cracks, causing coolant leaks. If your E46 M3 has over 80k miles and still has the original expansion tank, we highly recommend replacing it during your next major service.
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URO - Corporate Logo
T#:373102
Part#: 17111723520
In Stock
$ 30.99 USD
Free Shipping on orders $49 and up
Does not include cap or coolant level sensor

Rein - Corporate Logo
T#:402141
Part#: 17117573781
In Stock
$ 76.39 USD
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$ 76.39 USD
Free Shipping
Includes cap and level sensor

URO - Corporate Logo
T#:384250
Part#: 17137640514
Ships in 2 Business Days
$ 60.74 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. 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.
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Genuine BMW - Corporate Logo
T#:217490
Part#: 17138621092
Ships in 1-2 days
6% off MSRP $ 236.99

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

$ 222.99 USD
Free Shipping
6% off MSRP
$ 236.99

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

$ 222.99 USD
Free Shipping


Genuine BMW Expansion Tank -

This item fits the following BMW Chassis:
E70,E71,F15,F16,

This item fits the following BMW Engines:
N63,N63N,S63,N62N

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Genuine BMW - Corporate Logo
T#:527196
Part#: 17138677649
Ships in 1-2 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
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
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 regularly, the plastic will become brittle and will often crack or break. You want to keep all the coolant in your vehicle in the cooling system to prevent overheating issues. 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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Genuine BMW - Corporate Logo
T#:374557
Part#: 17117573781OEKT
In Stock
$ 273.99 USD
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$ 273.99 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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Mahle-Behr - Corporate Logo
T#:399788
Part#: 17111719110
In Stock
$ 75.99

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

$ 65.99 USD
Limited Qty Sale
Free Shipping on orders $49 and up
$ 75.99

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

$ 65.99 USD
Limited Qty Sale
Free Shipping on orders $49 and up
Goldenwrench Supply Co - Corporate Logo
T#:641290
Part#: FXXCCT
In Stock
$ 52.00 USD
Free Shipping on orders $49 and up
Give the plain plastic factory coolant caps an upgrade with the brand new BLACKLINE Performance Charge Cooler Tank Cap Cover from Goldenwrench. Each cap is CNC formed from T6 Aluminum and anodized with an Anthracite Gray color to compliment the factory engine cover. All logos and decorations are finalized through a precision 3D milling process, machined into each cap for the ultimate premium finish. The BLACKLINE Performance Charge Cooler Reservoir Cap Cover will fit most BMW vehicles equipped with the S55 and S63 engines with the charge cooler reservoir tank found in the following vehicles: F87 M2 Competition, F80 M3, F82 M4, F10/F90 M5, and more. Check your coolant cap ensuring that it is the same shape as seen in the product photos. Each kit comes with a Billet Charge Cooler Tank Cap Cover, and an Installation Instruction Card. This is a not a full cap replacement. The Billet Cap Cover affixes to the top of your factory coolant cap installing easily in minutes.
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URO - Corporate Logo
T#:29002182
Part#: 17137642160
Back Ordered
$ 80.81 USD
Free Shipping on orders $49 and up

Expansion tanks are susceptible to damage due to constant exposure to high ambient temperatures and chemical degradation. If your expansion tank is cracked, replacing it is crucial to prevent catastrophic engine damage from overheating.

Features:

Guaranteed fitment Precision-molded to OE dimensions for compatibility with original sensors and connections Quality materials resist engine heat and harsh cooling system environments Factory pressure-tested 24-Month Unlimited Mileage Warranty URO Parts offers more than 8,000 high-quality spare parts, many of which are specifically designed to replace factory BMW components. Their business was founded on the premise of producing parts that adhere to the highest standards of precision, materials, and workmanship. Each part is closely evaluated by a team of industry professionals to determine how to offer the best blend of durability, function, and price. If you're looking for quality replacement components at a reasonable price, look no further than URO Parts.

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Genuine BMW - Corporate Logo
T#:21637227
Part#: 17135A7BC90
In Stock
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 on orders $49 and up
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 on orders $49 and up
URO - Corporate Logo
T#:593040
Part#: 17113400017
Ships in 2 Business Days
$ 68.99 USD
Free Shipping on orders $49 and up
Secures the expansion tank to the radiator

Genuine BMW - Corporate Logo
T#:186538
Part#: 17137640515
In Stock
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
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

Includes the fluid level sensor. Allows for the reserve and overflow of coolant from heating and cooling expansion.

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.


Genuine BMW Expansion Tank -
This item fits the following BMW Chassis:
E82,E90,E92,E93

Fits BMW Engines including:
N55
 

 

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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
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Expansion Tank Cap - 1.4 Bar - E36 318i 323i 325i 328i M3
We Price Match - Give Us A Call or Chat!
Febi - Corporate Logo
T#:340717
Part#: 17111742232
In Stock
$ 24.99

This product was last offered at the strikethrough price on
06-18-2026

$ 15.99 USD
Free Shipping on orders $49 and up
$ 15.99 USD
Free Shipping on orders $49 and up

This expansion tank cap, from the E30 325is, is designed to give way at 20 PSI instead of 30 PSI, like the stock cap. In the event the system over-pressurizes, this cap should let go first, potentially saving your radiator, hoses, or other vital cooling system components. While there's no guarantee it will save your radiator, this small part could mean the difference between calling a tow service and making it home, and a little extra insurance never hurt. This cap is a high-quality aftermarket part from an OE supplier.

Fits the Following BMWs:

E36 318i 323i 325i 328i M3

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URO - Corporate Logo
T#:639293
Part#: 17137642158
In Stock
$ 86.99

This product was last offered at the strikethrough price on
03-09-2026

$ 55.99 USD
Limited Qty Sale
Free Shipping on orders $49 and up
$ 86.99

This product was last offered at the strikethrough price on
03-09-2026

$ 55.99 USD
Limited Qty Sale
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!
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Precision Raceworks - Corporate Logo
T#:38161689
Part#: 201-0393-BLU
In Stock
$ 109.99 USD
Free Shipping on orders $49 and up

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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URO - Corporate Logo
T#:379491
Part#: 61318360855
Ships in 2 Business Days
$ 12.99 USD
Free Shipping on orders $49 and up
$ 12.99 USD
Free Shipping on orders $49 and up
Monitors the coolant level in the expansion tank


URO - Corporate Logo
T#:4126643
Part#: 17137601948
Back Ordered
$ 69.99 USD
Free Shipping on orders $49 and up
URO Coolant Expansion Reservoir. Quality replacement Coolant tank for leaking or old Coolant parts.
Meyle Expansion Tank Cap
We Price Match - Give Us A Call or Chat!
Meyle - Corporate Logo
T#:579357
Part#: 3148009004
In Stock
Sale - Save 40% $ 14.99

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

$ 8.99 USD
Free Shipping on orders $49 and up
Sale - Save 40%
$ 14.99

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

$ 8.99 USD
Free Shipping on orders $49 and up
Replace worn or missing pieces.
Precision Raceworks Coolant Cap Bundle - Blue - Most BMWs from 2016 t...
Must Swap Pressure Relief Valve From PN #17117639021 to New Unit. Other Pressure Relief Valves Will Not Apply
Precision Raceworks - Corporate Logo
T#:47679258
Part#: 622-0291-BLU
Ships in 10 Business Days
New Item
$ 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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URO - Corporate Logo
T#:587219
Part#: 17137647283
Ships in 2 Business Days
$ 60.99 USD
Free Shipping on orders $49 and up

Rein - Corporate Logo
T#:555024
Part#: 17137647283
Ships in 2 Business Days
$ 118.99 USD
Free Shipping
$ 118.99 USD
Free Shipping

Replace your damaged expansion tank to prevent coolant loss or potential overheating issues.

his item fits the following BMW Chassis:
F01,F02,F06,F10,F12,F13

Fits BMW Engines including:
N54,N55,N57N

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Genuine BMW - Corporate Logo
T#:628106
Part#: 17138665638
In Stock
11% 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.

$ 30.99 USD
Free Shipping on orders $49 and up
11% 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.

$ 30.99 USD
Free Shipping on orders $49 and up
A failing expansion tank cap can compromise your entire cooling system, leading to lost pressure, fluid boil-off, and dangerous temperature spikes under load. This Genuine BMW Coolant Reservoir Cap restores factory pressure thresholds to keep your coolant boiling point elevated during spirited driving and track sessions.
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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
URO - Corporate Logo
T#:362009
Part#: 17111741167
Ships in 2 Business Days
$ 49.99 USD
Free Shipping on orders $49 and up
Does not include level sensor and cap

Febi - Corporate Logo
T#:377229
Part#: 17132754264
Ships in 1 Business Day
$ 11.99

This product was last offered at the strikethrough price on
08-12-2026

$ 9.17 USD
Free Shipping on orders $49 and up
$ 9.17 USD
Free Shipping on orders $49 and up
Replace the expansion tank cap for your MINI / BMW

Genuine BMW - Corporate Logo
T#:22514
Part#: 17112283345
Ships in 1-2 days
5% off MSRP $ 215.99

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

$ 205.99 USD
Free Shipping
5% off MSRP
$ 215.99

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

$ 205.99 USD
Free Shipping
This high quality Genuine BMW expansion tank is used on the S85 V10 engines, and is a common failure item. Be leary of competitors selling this part for less -- is it a Genuine BMW? Probably not. We only carry the Genuine BMW 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. 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. While replacing the expansion tank we recommend replacing the level sensor (sold below) as these are also common failure items.

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 BMWs:
2004-2010 E60 BMW M5
2004-2010 E63 BMW M6
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Enthusiast Bundles - Corporate Logo
T#:37419798
Part#: 008363LA02EB1KT
Ships on Nov 17, 2026
Sale - Save 24% $ 1,055.95

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

$ 799.04 USD
Free Shipping on orders $49 and up
Sale - Save 24%
$ 1,055.95

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

$ 799.04 USD
Free Shipping on orders $49 and up

Take your BMW’s cooling system to the next level with this Turner Motorsport Cooling Upgrade Kit. Featuring a Heavy-Duty Aluminum Expansion Tank and a Mechanical Thermostat Conversion Kit, this combo is engineered to deliver ultimate reliability and superior performance for M52TU/M54 engines. Say goodbye to the cooling system failures common in stock setups—Turner Motorsport has you covered.

Turner Motorsport M52TU/M54 Heavy-Duty Expansion Tank Kit

The Turner Motorsport Aluminum Expansion Tank is a premium upgrade designed to replace the fragile factory plastic tank, which is known to crack, leak, or even explode. Crafted for durability, this tank’s all-aluminum construction with wrinkle black powder coating ensures this is the last expansion tank you’ll ever need.

Why Upgrade? The factory plastic tanks on BMW M52TU/M54 engines are notorious for failure under heat and pressure. Avoid the risk of being stranded on the side of the road with a mess of coolant—Turner Motorsport’s aluminum expansion tank is built to withstand years of demanding use and intense heat cycles.

Key Features and Benefits:

Complete Kit: Includes Turner Aluminum Expansion Tank, coolant level sensor, expansion tank cap, and flared coolant pressure release line. OEM Fit & Capacity: Direct fit with no modifications, maintains stock coolant capacity and expansion volume. Baffled Design: Prevents air pockets during aggressive driving and ensures accurate coolant level readings. Premium Construction: TIG-welded 5052 aluminum with machined fittings for factory hose compatibility. Turner Motorsport M52TU/M54 Mechanical Thermostat Conversion Kit

Replace your problematic factory plastic thermostat housing with Turner Motorsport’s high-quality billet aluminum Thermostat Conversion Kit. This upgrade not only provides increased reliability but also allows for thermostat swaps to suit specific temperature requirements, making it ideal for daily drivers and track cars alike.

Why Make the Switch? The factory plastic thermostat housing with its built-in thermostat is prone to cracking and requires the whole unit to be replaced during maintenance. Turner’s conversion kit changes the game by providing a durable billet housing with a replaceable thermostat for flexibility and lower maintenance costs.

Key Features and Benefits:

Increased Reliability: Uses an M50/S50 mechanical thermostat, including an 80°C thermostat for enhanced cooling control. Customizable: Includes barbed hose connections for standard E46 M3 hoses and -16 ORB connections for custom hoses. Engineered to Last: CNC-machined from billet 6061 aluminum and black anodized for corrosion resistance. Enhanced Sealing: Features a Viton gasket for superior durability and sealing performance. Kit Includes:

6061 Billet Aluminum Thermostat Housing 80°C Mechanical Thermostat Thermostat Housing Gasket Thermostat Harness ECS Silicone E46 M3 Cooling Hoses Turner Motorsport Precision Engineering & Product Development

Every component in this cooling upgrade kit has been rigorously designed, engineered, and tested by Turner Motorsport’s Research and Development team. Using state-of-the-art technology such as FARO laser scanning, SolidWorks 3D modeling, and in-house rapid prototyping, Turner ensures that these products meet the highest standards of quality, precision, and durability.

Upgrade your BMW with confidence—Turner Motorsport is your partner in performance and reliability.

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Mahle-Behr - Corporate Logo
T#:340674
Part#: 17137542986
Ships in 1-2 days
$ 137.95

This product was last offered at the strikethrough price on
08-12-2026

$ 133.10 USD
Free Shipping
$ 133.10 USD
Free Shipping
This Behr OEM cooling system expansion tank / coolant reservoir is a direct replacement for the factory unit. Replace your cracked or leaking radiator expansion tank today.

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 BMWs:
2004-2010  E60 BMW  525i 525xi 530i 530xi 528i 528xi 528i xDrive 535i 535xi 535i xDrive 545i 550i
2004-2010  E63 BMW  645ci 650i
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Rein - Corporate Logo
T#:591959
Part#: 17111741167
Ships in 2 Business Days
$ 69.99 USD
Free Shipping
$ 69.99 USD
Free Shipping
Plastic has a limited lifespan - replace every 80,000 miles
Genuine BMW - Corporate Logo
T#:3026
Part#: 17112229114
In Stock
4% off MSRP $ 329.99

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

$ 315.99 USD
Free Shipping
4% off MSRP
$ 329.99

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

$ 315.99 USD
Free Shipping
This radiator expansion tank (coolant reservoir) is used on E39 M5 from 1999-2003. It is a common failure item. If you are overhauling your coolant system, now is the time to consider preventative replacing this 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 BMWs:
1999-2003 E39 BMW M5
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Genuine BMW - Corporate Logo
T#:377422
Part#: 17137640515KT
In Stock
$ 225.99

This product was last offered at the strikethrough price on
06-08-2026

$ 222.99 USD
Free Shipping
$ 222.99 USD
Free Shipping

URO - Corporate Logo
T#:36947225
Part#: 17135A6A031
Ships in 2 Business Days
$ 102.99 USD
Free Shipping on orders $49 and up
The coolant expansion tank in your vehicle provides a reservoir for excess fluid as it expands and contracts due to temperature changes. However, frequent exposure to these extreme fluctuations can cause the tank to crack or break over time. To maintain proper coolant levels within the cooling system, any damage to the tank—such as cracks, broken fittings, or damaged mounting points—requires immediate replacement.
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Genuine BMW - Corporate Logo
T#:376939
Part#: 17112229114KT
In Stock
$ 353.99 USD
Free Shipping
$ 353.99 USD
Free Shipping
Packaged by Turner - Corporate Logo
T#:338020
Part#: 17117573781
In Stock at Vendor
Sale - Save 2% $ 140.99

This product was last offered at the strikethrough price on
04-01-2026

Starting at $ 137.98 USD
Free Shipping
Sale - Save 2%
$ 140.99

This product was last offered at the strikethrough price on
04-01-2026

Starting at $ 137.98 USD
Free Shipping
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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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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Rein - Corporate Logo
T#:17704748
Part#: 17138677649
In Stock
$ 148.99

This product was last offered at the strikethrough price on
03-16-2026

$ 118.99 USD
Free Shipping on orders $49 and up
$ 118.99 USD
Free Shipping on orders $49 and up

Rein - Corporate Logo
T#:33946948
Part#: 17139846642
In Stock
$ 99.65 USD
Free Shipping on orders $49 and up

The Expansion Tank is an essential part of your vehicle’s cooling system, designed to accommodate the expansion of coolant as it heats up during engine operation. This high-quality tank helps regulate coolant pressure, preventing overheating and ensuring optimal engine performance. Built to meet or exceed OEM standards, this expansion tank is crafted from durable, heat-resistant materials to provide long-lasting reliability. It offers a direct fit for a wide range of European vehicles, ensuring easy installation.

  • Prevents Overheating: Manages coolant expansion to maintain consistent engine temperature.
  • Durable Construction: Made from premium, heat-resistant materials to ensure long-term durability.
  • OEM Quality Fit: Designed for a precise fit, meeting or exceeding original equipment specifications.
  • Leak-Proof Design: Provides a secure seal to prevent coolant loss and maintain system efficiency.
  • Easy Installation: Direct replacement part, compatible with a variety of European vehicle models.

Find the Rein Expansion Tank at Turner Motorsport for top-quality replacement parts and reliable performance.

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Rein - Corporate Logo
T#:39059266
Part#: 17135A6A030
In Stock
$ 86.99

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

$ 75.99 USD
Limited Qty Sale
Free Shipping on orders $49 and up
$ 86.99

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

$ 75.99 USD
Limited Qty Sale
Free Shipping on orders $49 and up
Coolant expansion tanks can crack over time, especially during services where they need to be removed. Replace your tank with a brand new tank to ensure your cooling system remains leak-free.
Rein - Corporate Logo
T#:584477
Part#: 17137647281
Ships in 4 Business Days
$ 71.99 USD
Free Shipping
$ 71.99 USD
Free Shipping
URO - Corporate Logo
T#:373592
Part#: 17132754264
In Stock
$ 8.19 USD
Free Shipping on orders $49 and up
Replace the expansion tank cap for your MINI / BMW to restore the seal of your cooling system


Rein - Corporate Logo
T#:46616024
Part#: EPK0141
In Stock
$ 97.99

This product was last offered at the strikethrough price on
06-01-2026

$ 87.99 USD
Limited Qty Sale
Free Shipping on orders $49 and up
$ 97.99

This product was last offered at the strikethrough price on
06-01-2026

$ 87.99 USD
Limited Qty Sale
Free Shipping on orders $49 and up
The coolant expansion tank provides a reservoir for excess coolant as it expands and contracts with temperature fluctuations. Constant exposure to these extreme changes can eventually cause the tank to crack or fail.
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Goldenwrench Supply Co - Corporate Logo
T#:641289
Part#: FXXCET-R
In Stock
$ 65.00 USD
Free Shipping
$ 65.00 USD
Free Shipping
Give the plain plastic factory coolant caps an upgrade with the brand new BLACKLINE Performance Coolant Expansion Tank Cap Cover from Goldenwrench. Each cap is CNC formed from T6 Aluminum and anodized in a limited release race inspired red color. All logos and decorations are finalized through a precision 3D milling process, machined into each cap for the ultimate premium finish. The BLACKLINE Performance Billet Coolant Expansion Tank Cap Cover will fit most BMW vehicles equipped with the N55, S55, S63, and S65 engine with the large coolant tank found in the following vehicles E90/E91/E92 M3 LCI, F22 M235i, F87 M2/M2 Competition, F80 M3, F82 M4, F10/F90 M5, and more (check your coolant cap ensuring that it is the same shape as seen in the product photos). Each kit comes with a Billet Coolant Expansion Tank Cap Cover, and an Installation Instruction Card. This is a not a full cap replacement. The Billet Cap Cover affixes to the top of your factory coolant cap installing easily in minutes.
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