BMW Coolant Expansion Tanks for BMW 3 Series E30 (1984-1991)

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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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ECS - Corporate Logo
T#:363070
Part#: 003530ECS01A
In Stock
Sale - Save 25% $ 35.99

This product was last offered at the strikethrough price on
06-13-2026

$ 26.99 USD
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Sale - Save 25%
$ 35.99

This product was last offered at the strikethrough price on
06-13-2026

$ 26.99 USD
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Replace the flimsy plastic bleeder screw used in the coolant expansion tank or in one of the cooling system hoses with this high quality, durable, aluminum bleeder screw. The stock plastic screw can deform over time due to heat or even regular use. We have even seen the head of the screw snap off, leaving the threaded body stuck in the expansion tank. This aluminum screw will help to prevent sudden failure of the bleeder screw, which can result in immediate overheating of the car.

ECS Tuning's Aluminum Coolant Bleeder Screw replaces Genuine BMW Part Number 17111712788

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Mahle-Behr Coolant Expansion Tank - E30
For vehicles with production date from 09/1987
Mahle-Behr - Corporate Logo
T#:399336
Part#: 17111712641
In Stock at Vendor
$ 56.99 USD
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$ 56.99 USD
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Replace your cracked or faded expansion tank.
Mahle-Behr - Corporate Logo
T#:363898
Part#: 17111712835
Ships in 10 Business Days
$ 20.99 USD
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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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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
Free Shipping on orders $49 and up
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

Mahle-Behr - Corporate Logo
T#:2766
Part#: 17111742231
In Stock
$ 19.99 USD
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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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Bremmen Parts - Corporate Logo
T#:640140
Part#: 17111712788
In Stock
Sale - Save 39% $ 3.99

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

$ 2.44 USD
Free Shipping on orders $49 and up
Sale - Save 39%
$ 3.99

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

$ 2.44 USD
Free Shipping on orders $49 and up
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.

Mahle-Behr - Corporate Logo
T#:369633
Part#: 17111742232
Ships in 1 Business Day
$ 18.99 USD
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$ 18.99 USD
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This radiator expansion tank cap fits E30 325e 325es 325i 325is 325ix 325ic with M20 engine from 1988 . It is a common failure item. When this item fails, it cannot hold pressure which results in your BMW overheating. If you are overhauling your coolant system, now is the time to consider preventative replacing this cap. It is also referred to as the coolant reservoir cap.

This item fits the following BMWs:
1988-1991  E30 BMW  325e 325es 325i 325ic 325is 325ix
1989-1990  E34 BMW  525i with M20 engine
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Expansion Tank Cap
For vehicles with production date from 09/1987
MTC - Corporate Logo
T#:371228
Part#: 17111742232
Ships in 9 Business Days
$ 6.99 USD
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$ 6.99 USD
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1.4 Bar pressure. Older radiator caps being to lose their ability to hold pressure over time. Resulting in a lower boiling point for the coolant system.

ECS - Corporate Logo
T#:33412932
Part#: 61132359999
Ships in 6 Business Days
Sale - Save 25% $ 10.99

This product was last offered at the strikethrough price on
06-14-2026

$ 8.24 USD
Free Shipping on orders $49 and up
Sale - Save 25%
$ 10.99

This product was last offered at the strikethrough price on
06-14-2026

$ 8.24 USD
Free Shipping on orders $49 and up

Includes connector housing with terminals and seals. Commonly used for the coolant level sensor.

ECS Tuning replacement harness connectors include all necessary pins and wire seals for a complete harness repair. Whether you have a broken harness connector or need a complete wiring repair, we have the components you need.

Each connector includes an additional terminal in case one becomes lost or damaged during installation.

*OEM cross reference PN# 61132359999 - Commonly used for the coolant level sensor.

Please reference the original part number from the existing connector to confirm fitment, before ordering.

Suggested tools:

Suggested crimping pliers: T#387193
Wire De-pin tools:
12pc De-Pin Tool Set - T#386379
23pc De-Pin Tool Set - T#641943

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