BMW Coolant Expansion Tanks for BMW Z3 (1996-2002)

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On certain models, namely E36, E46, and E90, the factory BMW expansion tank is prone to either breaking at connection points or blowing apart altogether. If you're starting to feel like your expansion tank is on borrowed time, it's probably time to replace with either a direct OE replacement, or strengthen your cooling setup with an aluminum expansion tank - we offer numerous performance upgrades for your expansion tank. Especially if you're someone who likes to track your BMW, we recommend upgrading your expansion tank to avoid ruining your track day.
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Mahle-Behr - Corporate Logo
T#:2766
Part#: 17111742231
Ships in 4 Business Days
$ 20.99

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

$ 19.99 USD
Free Shipping on orders $49 and up
$ 19.99 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.

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:
1990-1991 E30 BMW 318i 318is 318ic
1992-1998 E36 BMW 318i 318is 318ic 323is 323ic 325i 325is 325ic 328i 328is M3
1999-2005 E46 BMW 323i 323ci 325i 325ci 325xi 328i 328ci 330i 330ci 330xi M3
1989-1995 E34 BMW 530i 535i 540i M5
1991-1995 E34 BMW 525i
1997-2003 E39 BMW 525i 528i 530i 540i M5
1989-1994 E32 BMW 735i 735il 740i 740il 750il
1995-2001 E38 BMW 740i 740il 750il
2002-2008 E65 BMW 745i 745li 750i 750li 760i 760li
1990-1998 E31 BMW 840i 840ci 850i 850ci 850csi
2004-2011 E83 BMW X3 2.5i X3 3.0i X3 3.0si
2000-2006 E53 BMW X5 30.0i X5 4.4i X5 4.6is X5 4.8is
1996-2002 Z3 BMW Z3 1.9 Z3 2.3 Z3 2.5i Z3 2.8 Z3 3.0i M Coupe M Roadster
2003-2008 E85 BMW Z4 2.5i Z4 3.0i Z4 3.0si M Roadster M Coupe
2000-2003 E52 BMW Z8 Z8 Alpina
2007+ E90 BMW 335i & 335xi
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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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Mahle-Behr - Corporate Logo
T#:341101
Part#: 17111723520
In Stock at Vendor
$ 97.62

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

$ 77.22 USD
Free Shipping on orders $49 and up
$ 77.22 USD
Free Shipping on orders $49 and up
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.

Rein - Corporate Logo
T#:591949
Part#: 17107514964
Back Ordered
$ 80.99 USD
Free Shipping
$ 80.99 USD
Free Shipping
Includes bleeder screw

Rein - Corporate Logo
T#:46616026
Part#: EPK0025
Back Ordered
$ 74.99 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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Mahle-Behr - Corporate Logo
T#:2765
Part#: 17107514964
In Stock
$ 121.99

This product was last offered at the strikethrough price on
07-23-2026

$ 89.99 USD
Free Shipping on orders $49 and up
$ 89.99 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. This is the OEM Behr part - not an aftermarket. We have found that the aftermarket coolant reservoirs fail easier than the OEM Behr part. 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.

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:
2000-2003 X5 BMW X5 4.4i X5 4.6is
1999-2002 Z3 BMW Z3 2.3 2.5i 2.8 3.0i

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Mahle-Behr - Corporate Logo
T#:363898
Part#: 17111712835
Ships on Sep 21, 2026
$ 20.99 USD
Free Shipping on orders $49 and up

This high quality Hella/BEHR brand expansion tank is used on M42, M44, M50, M52, engines, and is a common failure item on all E36 3 series with 4 cylinder engines (318i/is/ti/ic) 1990-1999, Z3 with 1.9 liter and E34 525i from 1989-1995. Hella/BEHR was the original equipment supplier to BMW, so you know the Hella/BEHR made expansion tank will be the highest quality available. Be leary of competitors selling this part for less -- is it a Hella/BEHR? Probably not. We only carry the Hella/BEHR brand expansion tank as it is the only one we use in our own BMWs.

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:
1990-1991 E30 BMW 318i 318is 318ic
1992-1998 E36 BMW 318i 318is 318ti 318ic
1989-1995 E34 BMW 525i
1996-1998 Z3 BMW Z3 1.9

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Rein - Corporate Logo
T#:46616014
Part#: EPK0012
Back Ordered
$ 29.99 USD
Free Shipping on orders $49 and up
The coolant expansion tank provides a place for excess fluid as coolant expands and contracts with temperature changes. Constant exposure to these extremes can cause the tank to crack, break, or suffer damage to its nipples or mounting points. To keep your cooling system sealed and functioning properly, any damaged tank should be replaced.
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