BMW Coolant Expansion Tanks for BMW Z Series E85/6 (2003-2008)

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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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Bav Auto Expansion Tank Mounting Plate - E46 Non-M w/ Auto Trans
Bav Auto Expansion Tank Mounting Plate - E46 Non-M w/ Auto Trans ...
For vehicles with an automatic transmission only
Bavarian Autosport - Corporate Logo
T#:638089
Part#: 17111436251
In Stock
Sale - Save 20% $ 45.99

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

$ 36.79 USD
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Sale - Save 20%
$ 45.99

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

$ 36.79 USD
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This Bav Auto part is the mounting bracket from the radiator to the expansion tank on E46 3 series and E85/E86 Z4 with an Automatic Transmission. 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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Bremmen Parts Water Pipe Connector - E83, Z4
Bremmen Parts Water Pipe Connector - E83, Z4
Bremmen Parts - Corporate Logo
T#:1195932
Part#: 17112248409
Ships on Aug 7, 2026
Sale - Save 3% $ 31.61

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

$ 30.66 USD
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Sale - Save 3%
$ 31.61

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

$ 30.66 USD
Free Shipping on orders $49 and up
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Located underneath the expansion tank
Bav Auto Expansion Tank Cap - E36 E46 E34 E39 E32 E38 E65 X3 X5 Z4
Bav Auto Expansion Tank Cap - E36 E46 E34 E39 E32 E38 E65 X3 X5 Z4 ...
Bavarian Autosport - Corporate Logo
T#:640208
Part#: 17117639022
In Stock
Sale - Save 15% $ 13.99

This product was last offered at the strikethrough price on
06-03-2026

$ 11.89 USD
Free Shipping on orders $49 and up
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Sale - Save 15%
$ 13.99

This product was last offered at the strikethrough price on
06-03-2026

$ 11.89 USD
Free Shipping on orders $49 and up
Add to Wish List
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. 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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Bremmen Coolant Bleeder Screw - BMW E30 E36 E38 E39 E46 E83 E90 Z4
Bremmen Coolant Bleeder Screw - BMW E30 E36 E38 E39 E46 E83 E90 Z4 ...
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
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Sale - Save 39%
$ 3.99

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

$ 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.

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BMW Mini
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