BMW Coolant Expansion Tanks for BMW 3 Series E46 (1999-2005)

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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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Coolant Expansion Tank - E46 (non-M), X3, X5 3.0
10X Entries Into Our F80 M3 Sweepstakes
Packaged by Turner - Corporate Logo
T#:338020
Part#: 17117573781
In Stock at Vendor
Sale - Save 9% $ 140.99

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

Starting at $ 128.98 USD
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Sale - Save 9%
$ 140.99

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

Starting at $ 128.98 USD
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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
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ECS Cooling System Refresh Kit - Level 1
10X Entries Into Our F80 M3 Sweepstakes
Packaged by Turner - Corporate Logo
T#:15677493
Part#: 11517527910-KT
In Stock
Sale - Save 4% $ 336.99

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

$ 324.43 USD
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Sale - Save 4%
$ 336.99

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

$ 324.43 USD
Free Shipping on orders $49 and up
Stop the problems before they arise. If you vehicle has 80,000 miles or more, replace all of these components to ensure that your vehicle stays healthy. To keep everything in top order, continue to replace these components at 80,000 mile intervals. Water pump failure, cracked plastic housings, and expansion tank leaks will not be a concern once all these problem parts are replaced. This kit was put together by Turner including the basic parts that need replaced. Water pump with metal impeller Fan switch Thermostat and thermostat housing Sealing gaskets Expansion tank with level sensor, clamp and cap 1 Gallon Coolant Upper & lower radiator hoses
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ECS Cooling System Refresh Kit - Level 2
10X Entries Into Our F80 M3 Sweepstakes
Packaged by Turner - Corporate Logo
T#:15677514
Part#: 11281706545-KT
In Stock
Sale - Save 3% $ 474.99

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

$ 460.24 USD
Free Shipping on orders $49 and up
Sale - Save 3%
$ 474.99

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

$ 460.24 USD
Free Shipping on orders $49 and up
Stop the problems before they arise. If your BMW has 80,000 miles or more, replace all of these components to ensure that your vehicle stays healthy. Avoid water pump failure, cracked thermostat housings, and expansion tank leaks, which all lead to overheating and subsequent damage. This kit was put together by Turner for a complete cooling system service. GEBA water pump with metal impeller ECS aluminum water pump pulley Fan switch Thermostat and thermostat housing Sealing gaskets Expansion tank with level sensor, clamp and cap 1 Gallon Coolant Upper & lower radiator hoses Accessory drive belts Radiator drain plug
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Cooling System Refresh Kit - Level 2
10X Entries Into Our F80 M3 Sweepstakes
Packaged by Turner - Corporate Logo
T#:15744066
Part#: 11287837898-KT
Ships on Dec 7, 2026
Sale - Save 26% $ 808.99

This product was last offered at the strikethrough price on
07-15-2026

$ 596.54 USD
Free Shipping on orders $49 and up
Sale - Save 26%
$ 808.99

This product was last offered at the strikethrough price on
07-15-2026

$ 596.54 USD
Free Shipping on orders $49 and up
BMW has been designing notoriously failure-prone cooling systems since the late 1980s. The coolant capacity in most BMW engines is not sufficient to accommodate any driving or overheating near red zone temperatures. After the gauge reaches this critical area, it is common for thousands of dollars in damage to occur. Stop the problems before they arise. If your vehicle has 80,000 miles or more, replace all of these components to ensure that your vehicle stays healthy. To keep everything in top order, continue to replace these components at 80,000 mile intervals. Water pump failure, cracked housings, and expansion tank leaks will not be a concern once all these problem parts are replaced. Saleri water pump with metal impeller ECS aluminum water pump pulley Fan switch Vaico Q+ thermostat - made in Germany! Sealing gaskets Expansion tank with level sensor, clamp and cap 1 Gallon Coolant Upper & lower radiator hoses Accessory drive belts Radiator drain plug
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Genuine BMW - Corporate Logo
T#:207187
Part#: 17117639022
In Stock
21% off MSRP $ 34.96

MSRP stands for Manufacturer's Suggested Retail Price. This is the suggested retail price provided by the manufacturer, supplier or seller.

$ 27.67 USD
Free Shipping on orders $49 and up
21% off MSRP
$ 34.96

MSRP stands for Manufacturer's Suggested Retail Price. This is the suggested retail price provided by the manufacturer, supplier or seller.

$ 27.67 USD
Free Shipping on orders $49 and up


Genuine BMW Radiator Cap - 2,0Bar
This item fits the following BMW Chassis:
E36 M3,E39 M5,E46 M3,E85 Z4M,E53 48IS,E36,E38,E39,E46,E53 X5,E65,E83 X3,E85 Z4,E86 Z4,F06,F10,F12,F13

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Genuine BMW - Corporate Logo
T#:360752
Part#: 17117573781
In Stock
$ 173.21 USD
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$ 173.21 USD
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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.
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Genuine BMW - Corporate Logo
T#:13185
Part#: 17112283344
In Stock
7% off MSRP $ 215.23

MSRP stands for Manufacturer's Suggested Retail Price. This is the suggested retail price provided by the manufacturer, supplier or seller.

$ 199.98 USD
Free Shipping
7% off MSRP
$ 215.23

MSRP stands for Manufacturer's Suggested Retail Price. This is the suggested retail price provided by the manufacturer, supplier or seller.

$ 199.98 USD
Free Shipping
This radiator coolant reservoir/expansion tank for E46 M3 is a common failure item as the plastic weakens over time and stress crack will lead to coolant leaks. If your car has over 80k miles and hasn't had one of these replaced, we highly recommend it during your next major service. We have found that the aftermarket coolant reservoirs fail easier than the original BMW piece so we only offer the BMW type on this part.

When doing any sort of repair or maintenance there is no replacement for genuine factory parts. Turner Motorsport carries the Genuine BMW brand with pride and has the parts you need to complete your next project with confidence.

This item fits the following BMWs:
2001-2006 E46 BMW M3
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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

$ 87.99 USD
Free Shipping on orders $49 and up
$ 87.99 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
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Meyle Coolant Expansion Tank - E53 X5, E46 M52/54, E83 X3
5X Entries Into Our F80 M3 Sweepstakes
We Price Match - Give Us A Call or Chat!
Meyle - Corporate Logo
T#:369184
Part#: 17117573781
In Stock
$ 66.99 USD
Free Shipping on orders $49 and up

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.

Other items to consider replacing at the same time are the radiator cap, coolant level sensor, lower radiator hose, coolant temp sensor, 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.

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!

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Rein Coolant Expansion Tank - E46, E53, E83
2X Entries Into Our F80 M3 Sweepstakes
Rein - Corporate Logo
T#:402141
Part#: 17117573781
In Stock
$ 76.39 USD
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$ 76.39 USD
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Includes cap and level sensor
URO Coolant Expansion Tank - BMW E46 M3
2X Entries Into Our F80 M3 Sweepstakes
URO - Corporate Logo
T#:48608189
Part#: 17112283344
Ships in 1 Business Day
$ 155.99 USD
Free Shipping on orders $49 and up
​This radiator coolant reservoir/expansion tank for E46 M3 is a common failure item as the plastic weakens and cracks, causing coolant leaks. If your E46 M3 has over 80k miles and still has the original expansion tank, we highly recommend replacing it during your next major service.
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Coolant Expansion Tank - E53 E46 E83 M52 M54
2X Entries Into Our F80 M3 Sweepstakes
URO - Corporate Logo
T#:373103
Part#: 17137787039
Ships in 1 Business Day
$ 45.99 USD
Free Shipping on orders $49 and up
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.
Show More Show Less


Genuine BMW - Corporate Logo
T#:374557
Part#: 17117573781OEKT
In Stock
$ 273.99 USD
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$ 273.99 USD
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The expansion tank in your BMW is a vital component of the cooling system, and because of the constant abuse from heat and temperature changes, it often fails. This kit contains all of the basic items needed for a tank replacement.
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Expansion Tank Mounting Bracket - E46 - Manual Trans
For vehicles with manual transmission only
Genuine BMW - Corporate Logo
T#:13180
Part#: 17111436250
Ships in 3 Business Days
2% off MSRP $ 134.99

MSRP stands for Manufacturer's Suggested Retail Price. This is the suggested retail price provided by the manufacturer, supplier or seller.

$ 131.99 USD
Free Shipping
2% off MSRP
$ 134.99

MSRP stands for Manufacturer's Suggested Retail Price. This is the suggested retail price provided by the manufacturer, supplier or seller.

$ 131.99 USD
Free Shipping
This Genuine BMW part is the mounting bracket from the radiator to the expansion tank on E46 3 series Manual Transmission.

When doing any sort of repair or maintenance there is no replacement for genuine factory parts. Turner Motorsport carries the Genuine BMW brand with pride and has the parts you need to complete your next project with confidence.​

This item fits the following BMWs:
1999-2005 E46 BMW 323i 323ci 325i 325ci 325xi 328i 328ci 330i 330ci 330xi
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Genuine BMW - Corporate Logo
T#:46115
Part#: 17121719356
Ships in 5 Business Days
3% off MSRP $ 31.99

MSRP stands for Manufacturer's Suggested Retail Price. This is the suggested retail price provided by the manufacturer, supplier or seller.

$ 30.99 USD
Free Shipping on orders $49 and up
3% off MSRP
$ 31.99

MSRP stands for Manufacturer's Suggested Retail Price. This is the suggested retail price provided by the manufacturer, supplier or seller.

$ 30.99 USD
Free Shipping on orders $49 and up


Genuine BMW Cap
This item fits the following BMW Chassis:
E46 M3,E30,E46

Fits BMW Engines including:
M20,S54,S62


Expansion Tank Mounting Plate
2X Entries Into Our F80 M3 Sweepstakes
Rein - Corporate Logo
T#:402140
Part#: 17111436250
In Stock
$ 70.99 USD
Free Shipping
$ 70.99 USD
Free Shipping

Expansion Tank Retaining Plate
For vehicles with automatic transmission only
2X Entries Into Our F80 M3 Sweepstakes
URO - Corporate Logo
T#:362912
Part#: 17111436251
Ships in 1 Business Day
$ 53.99 USD
Free Shipping on orders $49 and up
$ 53.99 USD
Free Shipping on orders $49 and up
Mounts to the side of the radiator for retaining the expansion tank
Expansion Tank Mounting Bracket - E46 E85 Z4 - Auto Trans
For vehicles with automatic transmission only
Genuine BMW - Corporate Logo
T#:12560
Part#: 17111436251
In Stock
Sale - Save 51% $ 205.99

MSRP stands for Manufacturer's Suggested Retail Price. This is the suggested retail price provided by the manufacturer, supplier or seller.

$ 101.32 USD
Free Shipping
Sale - Save 51%
$ 205.99

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

$ 101.32 USD
Free Shipping
This Genuine BMW part is the mounting bracket from the radiator to the expansion tank on E46 3 series and E85/E86 Z4 with Automatic Transmission.

When doing any sort of repair or maintenance there is no replacement for genuine factory parts. Turner Motorsport carries the Genuine BMW brand with pride and has the parts you need to complete your next project with confidence.

This item fits the following BMWs:
1999-2005 E46 BMW 323i 323ci 325i 325ci 325xi 328i 328ci 330i 330ci 330xi
2003-2008 E85 BMW Z4 2.5i Z4 3.0i Z4 3.0si
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Expansion Tank Mounting Plate
2X Entries Into Our F80 M3 Sweepstakes
URO - Corporate Logo
T#:584756
Part#: 17111436250
Ships in 1 Business Day
$ 49.99 USD
Free Shipping on orders $49 and up
Replace your broken mounting plate to keep your expansion tank secure and prevent leaks.
Rein Expansion Tank Mounting Plate - E46, Z4
For vehicles with automatic transmission only
2X Entries Into Our F80 M3 Sweepstakes
Rein - Corporate Logo
T#:402139
Part#: 17111436251
Ships in 1 Business Day
$ 80.99 USD
Free Shipping
$ 80.99 USD
Free Shipping
Mounts to the side of the radiator for retaining the expansion tank

Bremmen Parts - Corporate Logo
T#:640140
Part#: 17111712788
Ships on Sep 16, 2026
$ 3.99 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#:2766
Part#: 17111742231
Ships in 3 Business Days
$ 20.99

This product was last offered at the strikethrough price on
08-13-2026

$ 19.99 USD
Free Shipping on orders $49 and up
$ 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
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Meyle Expansion Tank Cap
5X Entries Into Our F80 M3 Sweepstakes
We Price Match - Give Us A Call or Chat!
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
Free Shipping on orders $49 and up
Sale - Save 40%
$ 14.99

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

$ 8.99 USD
Free Shipping on orders $49 and up
Replace worn or missing pieces.
Rein - Corporate Logo
T#:340541
Part#: 17111742231
Ships in 1 Business Day
$ 17.99 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.
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Expansion Tank Mounting Clamp
2X Entries Into Our F80 M3 Sweepstakes
URO - Corporate Logo
T#:591954
Part#: 17111707777
Ships in 1 Business Day
$ 6.99 USD
Free Shipping on orders $49 and up
Locks the expansion tank into the mounting plate via the large hole in the bottom of the tank
Genuine BMW - Corporate Logo
T#:380426
Part#: 17117573781OEKT1
Ships in 3 Business Days
$ 589.99

This product was last offered at the strikethrough price on
07-10-2026

$ 499.99 USD
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$ 499.99 USD
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Fluid Level Sensor
5X Entries Into Our F80 M3 Sweepstakes
We Price Match - Give Us A Call or Chat!
Meyle - Corporate Logo
T#:5973204
Part#: 17117546548
Ships on Sep 16, 2026
$ 13.99 USD
Free Shipping on orders $49 and up
MEYLE-ORIGINAL: True to OE fluid level sensor. Used in multiple locations. Wulf Gaertner Autoparts AG manufactures and markets automotive spare parts under its MEYLE brand. Since its foundation in 1958, Wulf Gaertner Autoparts has been an owner-operated, unlisted family business on the aftermarket scene. Since 1995, Wulf Gaertner Autoparts AG has been manufacturing and trading under its MEYLE brand. They pride themselves on top-grade quality-tested spare parts for passenger cars, vans and commercial vehicles. Comparable OE Cross Reference - 17117546548
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