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Mahle-Behr 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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Mahle-Behr - Corporate Logo
T#:350824
Part#: 17137640514
Ships in 1 Business Day
$ 142.99

This product was last offered at the strikethrough price on
02-20-2026

$ 130.99 USD
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$ 130.99 USD
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Upgrade your BMW's cooling system with the Turner Motorsport Mahle Coolant Expansion Tank. This essential component provides additional space for coolant expansion and contraction, ensuring optimal performance in varying temperatures. Designed to withstand drastic temperature changes, this expansion tank prevents coolant leaks and maintains proper coolant levels in your vehicle. Replace your damaged tank to keep your BMW's cooling system running smoothly.

Key Benefits:

  • Prevents coolant leaks and loss
  • Ensures proper coolant expansion and contraction
  • Durable construction for long-lasting performance
  • Direct replacement for damaged tanks
  • Compatible with various BMW models
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Mahle-Behr - Corporate Logo
T#:361568
Part#: 17111741167
Ships in 1 Business Day
$ 100.99

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

$ 97.99 USD
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$ 97.99 USD
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This radiator expansion tank (coolant reservoir) is used on E39 540i from 1997-2003 and E38 740i 740il 750il from 1995-2001. It is a common failure item. 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 OEM Hella tank will give you a long life-span and will put your worries to rest of possible failure and coolant loss.

Hella is a premium manufacturer that supplies automotive parts to numerous car brands across the world. Everything from electrical to mechanical genuine parts have been made and supplied directly to BMW before the vehicles ever leave the production floor. Their high quality, long lasting parts have made them a trusted brand chosen to help keep your BMW on the road for many years to come.

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!

This item fits the following BMWs:
1997-2003 E39 BMW 540i, 540i wagon
1995-2001 E38 BMW 740i 740il 750il
1990-1998 E31 BMW 840i 840ci 850i 850ci
2000-2003 E52 BMW Z8

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Mahle-Behr - Corporate Logo
T#:340674
Part#: 17137542986
In Stock at Vendor
$ 137.95 USD
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$ 137.95 USD
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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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Mahle-Behr - Corporate Logo
T#:592026
Part#: 17138570079
Ships in 1 Business Day
$ 139.00

This product was last offered at the strikethrough price on
03-20-2026

$ 103.99 USD
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$ 103.99 USD
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Includes level sensor

Mahle-Behr - Corporate Logo
T#:377924
Part#: 17137552546
Ships on Aug 28, 2026
$ 85.99 USD
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$ 85.99 USD
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Replace your cracked or faded tank
Mahle-Behr - Corporate Logo
T#:186486
Part#: 17137647713
Ships on Aug 28, 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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