Find Parts That Fit Your Vehicle

BMW Coolant Expansion Tanks

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.
Sort By:

Turner Motorsport - Corporate Logo
T#:12806793
Part#: 008378LA02
In Stock
Sale - Save 20% $ 479.99

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

$ 383.99 USD
Free Shipping on orders $49 and up
Sale - Save 20%
$ 479.99

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

$ 383.99 USD
Free Shipping on orders $49 and up

Our Turner Motorsport's full aluminum expansion tank was designed and engineered in house to help with the weak point in your N52/N54 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 BMW 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.

Product 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

Show More Show Less
Turner Motorsport - Corporate Logo
T#:21735881
Part#: 053082LA01
In Stock
Sale - Save 25% $ 75.99

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

$ 56.99 USD
Free Shipping on orders $49 and up
Sale - Save 25%
$ 75.99

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

$ 56.99 USD
Free Shipping on orders $49 and up

Upgraded or replacement silicone heater hose for our N54 expansion tank relocation kits.

60" silicone performance coolant hose featuring a molded 90-degree bend for installs with space constraints.

Features and benefits:

Constructed of 4-Ply reinforced silicone for improved durability over the failure-prone rubber hoses.
Reduced thermal conductivity
Improved resistance to ozone and UV degradation for improved performance and durability.
Turner branded

Show More Show Less
Turner Motorsport - Corporate Logo
T#:568366
Part#: 021942TMS05
In Stock
Sale - Save 25% $ 26.99

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

$ 20.24 USD
Free Shipping on orders $49 and up
Sale - Save 25%
$ 26.99

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

$ 20.24 USD
Free Shipping on orders $49 and up
The E9X/ E8X N54 Expansion Tank Wire harness is perfect for those running a relocated coolant reservoir tank. This harness plugs right into the factory connector allowing you to extend the position of the sensor without the need to splice any wires.
Show More Show Less

Burger Motorsports - Corporate Logo
T#:38621407
Part#: BMS-TCBS
Back Ordered
$ 25.00 USD
Free Shipping on orders $49 and up
Replace your fragile OEM plastic coolant bleeder screw, which is prone to cracking and failure, with a premium titanium upgrade built for strength and style under the hood. Factory plastic components weaken over time due to constant heat cycles, leading to brittleness and potential failure. Our titanium replacement delivers superior durability, being twice as strong as aluminum yet 45% lighter than steel, ensuring unmatched resilience and long-term reliability for your coolant system. More than an upgrade, it’s a must-have for engine longevity. CNC-machined from solid titanium, each screw features a laser-etched Burger Motorsports logo and is hand-burned to create unique color patterns—no two are alike. A heavy-duty replacement O-ring is included for a perfect fit.
Show More Show Less

Mahle-Behr - Corporate Logo
T#:399336
Part#: 17111712641
In Stock at Vendor
$ 56.99 USD
Free Shipping on orders $49 and up
$ 56.99 USD
Free Shipping on orders $49 and up
Replace your cracked or faded expansion tank.
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.

Mahle-Behr - Corporate Logo
T#:1735
Part#: 17117573781
In Stock at Vendor
$ 100.99

This product was last offered at the strikethrough price on
04-01-2026

$ 96.99 USD
Free Shipping on orders $49 and up
$ 96.99 USD
Free Shipping on orders $49 and up
This coolant reservoir is for the non-M E46 3-series models from 1999-2006 (M3 takes a different expansion tank). 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 most recent expansion tank design from Hella-Behr, the OEM supplier to BMW. It replaces the original BMW part number 17137787039.

Other items to consider replacing at the same time are the radiator cap, coolant level sensor, lower radiator hose, coolant temp sensor in the lower hose, and the hose clamps. If your car has an automatic transmission you should also replace the oil cooler thermostat in the radiator frame, which is a common source for leaks.

This coolant expansion tank fits:

1999-2006 E46 3 series - 323i, 323Ci, 325i, 325Ci, 325xi, 328i, 328Ci, 330i, 330Ci & 330xi (**no M)
2004-2008 X3 SAV - X3 2.5, X3 3.0, X3 3.0si
2000-2005 X5 SAV - X5 3.0
Show More Show Less
Mahle-Behr - Corporate Logo
T#:399788
Part#: 17111719110
In Stock
$ 75.99

This product was last offered at the strikethrough price on
05-07-2026

$ 65.99 USD
Limited Qty Sale
Free Shipping on orders $49 and up
$ 75.99

This product was last offered at the strikethrough price on
05-07-2026

$ 65.99 USD
Limited Qty Sale
Free Shipping on orders $49 and up

Mahle-Behr - Corporate Logo
T#:2765
Part#: 17107514964
In Stock
$ 121.99

This product was last offered at the strikethrough price on
07-21-2026

$ 105.99 USD
Free Shipping on orders $49 and up
$ 105.99 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

Show More Show Less

Mahle-Behr - Corporate Logo
T#:363898
Part#: 17111712835
Ships in 10 Business Days
$ 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

Show More Show Less
Mahle-Behr - Corporate Logo
T#:7462
Part#: 17137501959
Ships in 1-2 days
$ 103.27 USD
Free Shipping on orders $49 and up

This high quality OEM Behr expansion tank is used on N62 V8 engines, and is a common failure item on X5's with V8 engines Be leary of competitors selling this part for less -- is it a Behr? Probably not. We only carry the Behr brand expansion tank as it is the only one we use in our own BMWs. If you are overhauling your coolant system, now is the time to consider preventative replacing this expansion tank. 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.

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:
2004-2006 E53 BMW X5 4.4i X5 4.8is

Show More Show Less


Mahle-Behr - Corporate Logo
T#:583983
Part#: 17137647284
Ships in 1-2 days
$ 98.99

This product was last offered at the strikethrough price on
05-07-2026

$ 95.99 USD
Free Shipping on orders $49 and up
$ 95.99 USD
Free Shipping on orders $49 and up
Replace your cracked tank
Mahle-Behr - Corporate Logo
T#:19450
Part#: 17107509071
Ships in 4 Business Days
$ 36.99 USD
Free Shipping on orders $49 and up
This high quality BEHR brand expansion tank is used on MINI Cooper R50 R52, and is a common failure item. BEHR was the original equipment supplier to BMW, so you know the BEHR made expansion tank will be the highest quality available. Be cautious of competitors selling this part for less -- is it a BEHR? Probably not. We only carry the BEHR brand expansion tank as it is the only one we use in our own MINIs. If you are overhauling your coolant system, now is the time to consider preventative replacing this expansion tank. These are known to go bad, causing a leak which can leave you stranded. 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.

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 MINIs:
2002-2006 R50 MINI MINI Cooper
2005-2008 R52 MINI MINI Cooper Convertible.
Show More Show Less
Mahle-Behr - Corporate Logo
T#:46488
Part#: 17137823626
Back Ordered
$ 67.99 USD
Free Shipping on orders $49 and up
This high-quality BEHR brand expansion tank is used on MINI Cooper R55 R56 and is a common failure item. BEHR was the original equipment supplier to BMW, so you know the BEHR made expansion tank will be the highest quality available. Be cautious of competitors selling this part for less -- is it a BEHR? Probably not. We only carry the BEHR brand expansion tank as it is the only one we use in our own MINIs. If you are overhauling your coolant system, now is the time to consider preventative replacing this expansion tank. These are known to go bad, causing a leak which can leave you stranded. 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 fewer 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.

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 MINIs:
2007+ R56 MINI MINI Cooper, MINI Cooper S
2007+ R55 MINI MINI Cooper Clubman, MINI Cooper S Clubman
2007+ R57 MINI MINI Cooper Convertible, MINI Cooper S Convertible,
2011+ R60 MINI MINI Cooper Countryman, MINI Cooper Countryman S


This item fits the following BMWs:
2015+ I01 BMW i3
2015+ I12 BMW i8
Show More Show Less

Mahle-Behr - Corporate Logo
T#:359934
Part#: 17111436381
Back Ordered
$ 57.51 USD
Free Shipping on orders $49 and up

This radiator expansion tank is used on E39 528i 525i 530i from 1999-2003. It is a common failure item. 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. OEM Hella/Behr brand.

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:
1999-2003 E39 BMW 525i 528i 530i

Show More Show Less

Mahle-Behr - Corporate Logo
T#:2766
Part#: 17111742231
In Stock
$ 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
Show More Show Less
Mahle-Behr - Corporate Logo
T#:369633
Part#: 17111742232
Ships in 1 Business Day
$ 18.99 USD
Free Shipping on orders $49 and up
$ 18.99 USD
Free Shipping on orders $49 and up
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
Show More Show Less