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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ECS Tuning Aluminum Coolant Bleeder Screw
ECS Tuning Aluminum Coolant Bleeder Screw
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ECS - Corporate Logo
T#:363070
Part#: 003530ECS01A
In Stock
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This product was last offered at the strikethrough price on
06-13-2026

$ 26.99 USD
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$ 35.99

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$ 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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VTT Billet Coolant Reservoir Cap - Anodized Blue - Most BMWs 2006+ (E/F/G-Chassis)
VTT Billet Coolant Reservoir Cap - Anodized Blue - Most BMWs 2006+ (E...
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Vargas Turbo Technologies - Corporate Logo
T#:7530036
Part#: COOLANTCAPBLUE
In Stock
$ 79.99 USD
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$ 79.99 USD
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VTT is proud to offer their billet replacement for the factory plastic Coolant Reservoir cap. This cap does away with the weak plastic cap while adding some pop, and color to your engine bay. This coolant cap retains ALL of the factory provisions by simply allowing you to snap the factory pressure-relief into the new Billet Cap. VTT also designed these caps to complement their N5X Billet Oil caps, N5XBillet Oil filter housing caps, and Billet Power Steering cap, so all 4 will have the same design. These caps are offered in 4 colors – Red, Black, Blue, and Clear anodized Replaces Genuine BMW Reservoir Cap # 17117639020 Note: Fitment includes 99% of all BMW with a coolant Reservoir tank from the E series forward, meaning then fit even the brand New G8X M3/4 with the S58, all B58, etc. If your BMW is an E90 or newer this cap most likely will fit
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VTT Billet Coolant Reservoir Cap - Anodized Red - Most BMWs 2006+ (E/F/G-Chassis)
VTT Billet Coolant Reservoir Cap - Anodized Red - Most BMWs 2006+ (E/...
2X Entries Into Our F80 M3 Sweepstakes
Vargas Turbo Technologies - Corporate Logo
T#:7530034
Part#: COOLANTCAPRED
In Stock
$ 79.99 USD
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$ 79.99 USD
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VTT is proud to offer their billet replacement for the factory plastic Coolant Reservoir cap. This cap does away with the weak plastic cap while adding some pop, and color to your engine bay. This coolant cap retains ALL of the factory provisions by simply allowing you to snap the factory pressure-relief into the new Billet Cap. VTT also designed these caps to complement their N5X Billet Oil caps, N5XBillet Oil filter housing caps, and Billet Power Steering cap, so all 4 will have the same design. These caps are offered in 4 colors – Red, Black, Blue, and Clear anodized Replaces Genuine BMW Reservoir Cap # 17117639020 Note: Fitment includes 99% of all BMW with a coolant Reservoir tank from the E series forward, meaning then fit even the brand New G8X M3/4 with the S58, all B58, etc. If your BMW is an E90 or newer this cap most likely will fit
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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
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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
Free Shipping on orders $49 and up
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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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VTT Billet Coolant Reservoir Cap - Anodized Clear - Most BMWs 2006+ (E/F/G-Chassis)
VTT Billet Coolant Reservoir Cap - Anodized Clear - Most BMWs 2006+ (...
This coolant cap retains ALL of the factory provisions by simply allowing you to snap t...
2X Entries Into Our F80 M3 Sweepstakes
Vargas Turbo Technologies - Corporate Logo
T#:7530035
Part#: COOLANTCAPRAW
Ships in 3 Business Days
$ 78.99 USD
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$ 78.99 USD
Free Shipping
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VTT is proud to offer their billet replacement for the factory plastic Coolant Reservoir cap. This cap does away with the weak plastic cap while adding some pop, and color to your engine bay. This coolant cap retains ALL of the factory provisions by simply allowing you to snap the factory pressure-relief into the new Billet Cap. VTT also designed these caps to complement their N5X Billet Oil caps, N5XBillet Oil filter housing caps, and Billet Power Steering cap, so all 4 will have the same design. These caps are offered in 4 colors – Red, Black, Blue, and Clear anodized Replaces Genuine BMW Reservoir Cap # 17117639020 Note: Fitment includes 99% of all BMW with a coolant Reservoir tank from the E series forward, meaning then fit even the brand New G8X M3/4 with the S58, all B58, etc. If your BMW is an E90 or newer this cap most likely will fit
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MMX 90mm Billet Coolant Expansion Tank Cap | BMW
MMX 90mm Billet Coolant Expansion Tank Cap | BMW
MMX Performance - Corporate Logo
T#:29002094
Part#: MMR03-1502
Ships in 2 Business Days
$ 127.99 USD
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$ 127.99 USD
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The MMX Performance 90mm billet coolant expansion cap for BMWs has been designed from the ground up in the UK, from a solid piece of billet aluminum. Each cap was designed to directly replace the OE cap, not merely stuck in place. Fitment is for models with the matching OE (17 11 7 639 021) part number.
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VTT Billet Coolant Reservoir Cap - Anodized Black - Most BMWs 2006+ (E/F/G-Chassis)
VTT Billet Coolant Reservoir Cap - Anodized Black - Most BMWs 2006+ (...
2X Entries Into Our F80 M3 Sweepstakes
Vargas Turbo Technologies - Corporate Logo
T#:7530033
Part#: COOLANTCAPBLK
In Stock
$ 79.99 USD
Free Shipping
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$ 79.99 USD
Free Shipping
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VTT is proud to offer their billet replacement for the factory plastic Coolant Reservoir cap. This cap does away with the weak plastic cap while adding some pop, and color to your engine bay. This coolant cap retains ALL of the factory provisions by simply allowing you to snap the factory pressure-relief into the new Billet Cap. VTT also designed these caps to complement their N5X Billet Oil caps, N5XBillet Oil filter housing caps, and Billet Power Steering cap, so all 4 will have the same design. These caps are offered in 4 colors – Red, Black, Blue, and Clear anodized Replaces Genuine BMW Reservoir Cap # 17117639020 Note: Fitment includes 99% of all BMW with a coolant Reservoir tank from the E series forward, meaning then fit even the brand New G8X M3/4 with the S58, all B58, etc. If your BMW is an E90 or newer this cap most likely will fit
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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 ...
10X Entries Into Our F80 M3 Sweepstakes
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
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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. 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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2 Pin Connector
2 Pin Connector
10X Entries Into Our F80 M3 Sweepstakes
ECS - Corporate Logo
T#:33412932
Part#: 61132359999
In Stock
Sale - Save 25% $ 10.99

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

$ 8.24 USD
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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
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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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