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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Turner Motorsport HD Aluminum Coolant Expansion Tank Kit - M50/M52/S5...
For vehicles produced before 09/1998
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Turner Motorsport - Corporate Logo
T#:9998526
Part#: 008348LA01BKT
In Stock
Sale - Save 20% $ 423.99

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

$ 339.19 USD
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$ 423.99

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$ 339.19 USD
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Our Turner Motorsport's full aluminum expansion tank was designed and engineered in house to help with the weak point in your E36 cooling system. The coolant expansion tank goes through heat cycles over and over again from regular driving, it is important that your expansion tank is doing its job to retain coolant to keep your engine operating temperatures down and keep your engine bay clean. Not only is this a major upgrade but also a great maintenance item to replace. Our expansion tank was designed to fit the OEM hoses for an easy install and comes with all the upgraded items you will need for a clean install,

If your E36 needs a new expansion tank, make sure this is the last expansion tank you ever need to buy. Our coolant expansion tank has a full aluminum construction and wrinkle black powder coat for durability. Expansion tank kit comes with all the accessories you need to replace your expansion tank once, and never have to worry about it again.

Aluminum Coolant Expansion Tank Features:

- Maintains stock coolant capacity and expansion volume

- Designed to maintain OE coolant elevation, preventing air pockets

- Baffled tank ensures that air pockets cannot be introduced during aggressive driving and provides accurate coolant level reading

- Carefully designed bleed passage prevents the introduction of air as the engine cools

- Turner engraved internal fill level

- TIG welded 5052 aluminum construction

- All bungs are machined to fit factory hose ends

Kit contents:

Turner Aluminum Expansion Tank
Coolant level sensor
Expansion tank cap
Heavy duty bleeder screw
Flared coolant pressure release line
Hardware for installation

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ECS Tuning Aluminum Coolant Bleeder Screw
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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
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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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Bav Auto Coolant Expansion Tank - E36 E39 Z3 M50 M52 S50 S52 ...
For vehicles with production date up to 08/1998
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Bavarian Autosport - Corporate Logo
T#:638094
Part#: 17111723520
In Stock
Sale - Save 20% $ 39.99

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

$ 31.99 USD
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Sale - Save 20%
$ 39.99

This product was last offered at the strikethrough price on
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$ 31.99 USD
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Replace your old expansion tank to prevent potential failure or leaks. Includes a brand new coolant level sensor. 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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Coolant Expansion Tank
2X Entries Into Our F80 M3 Sweepstakes
Rein - Corporate Logo
T#:591949
Part#: 17107514964
Back Ordered
Sale - Save 5% $ 80.99

This product was last offered at the strikethrough price on
08-31-2026

$ 76.94 USD
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Includes bleeder screw

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
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Sale - Save 15%
$ 13.99

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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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Rein - Corporate Logo
T#:340541
Part#: 17111742231
Ships in 2 Business Days
Sale - Save 5% $ 17.99

This product was last offered at the strikethrough price on
08-31-2026

$ 17.09 USD
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Sale - Save 5%
$ 17.99

This product was last offered at the strikethrough price on
08-31-2026

$ 17.09 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.
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Meyle Expansion Tank Cap
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Meyle - Corporate Logo
T#:579357
Part#: 3148009004
In Stock
Sale - Save 40% $ 14.99

This product was last offered at the strikethrough price on
05-15-2026

$ 8.99 USD
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Replace worn or missing pieces.
BMW Expansion Tank With Cap - 17107514964
2X Entries Into Our F80 M3 Sweepstakes
Rein - Corporate Logo
T#:46616026
Part#: EPK0025
Ships in 4 Business Days
Sale - Save 6% $ 74.99

This product was last offered at the strikethrough price on
08-31-2026

$ 70.63 USD
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Sale - Save 6%
$ 74.99

This product was last offered at the strikethrough price on
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$ 70.63 USD
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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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Bremmen Parts - Corporate Logo
T#:640497
Part#: 17107514964
In Stock
Sale - Save 50% $ 63.99

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

$ 32.00 USD
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Sale - Save 50%
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This product was last offered at the strikethrough price on
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$ 32.00 USD
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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. 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
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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This product was last offered at the strikethrough price on
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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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Coolant Expansion Tank With Cap - 17111712835
2X Entries Into Our F80 M3 Sweepstakes
Rein - Corporate Logo
T#:46616014
Part#: EPK0012
Back Ordered
Sale - Save 8% $ 29.99

This product was last offered at the strikethrough price on
08-31-2026

$ 27.65 USD
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Sale - Save 8%
$ 29.99

This product was last offered at the strikethrough price on
08-31-2026

$ 27.65 USD
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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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