BMW Coolant Expansion Tanks

Coolant Expansion Tank - E46 (non-M), X3, X5 3.0

T#:338020

Part#: 17117573781

In Stock at Vendor

Sale - Save 2% $ 140.99

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

Starting at $ 137.98 USD

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Sale - Save 2%

$ 140.99

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

Starting at $ 137.98 USD

Add to Wish List

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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OEM Coolant Expansion Tanks Kit - F22/23 F3X B48 B58

T#:27605427

Part#: 17138677649TKT

In Stock at Vendor

Sale - Save 5% $ 208.99

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

$ 198.66 USD

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Sale - Save 5%

$ 208.99

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

$ 198.66 USD

Add to Wish List

Genuine BMW expansion tanks have a bad habit of failing after a few years. This has primarily been caused by the plastic construction of the expansion tanks. After enough heat cycles, the plastic becomes brittle and can crack, causing coolant to leak out and air to enter the coolant system. If a failing expansion tank is not addressed soon enough, the coolant loss can lead to an overheating engine. This kit includes two brand new high quality expansion tanks and caps

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Coolant Expansion Tank - E36/E39/Z3 6 cylinder 1992-1998

T#:338018

Part#: 17111723520

In Stock at Vendor

$ 97.99

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

Starting at $ 77.22 USD

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Starting at $ 77.22 USD

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This high quality BEHR brand expansion tank is used on M50, M52, S50 and S52 engines, and is a common failure item on all E36 3 series with 6 cylinder engines (325/328/323 and M3) 1992-1999, Z3 with 2.8 liter, MZ3 Roadster/Coupe (S52), and E39 528i from 1997-1998. BEHR was the original equipment supplier to BMW, so you know the BEHR made expansion tank will be the highest quality available. 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. 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.

Need a new coolant level sensor too? If your coolant level sender is bad, your on board computer will constantly display a "low coolant" message (unless your coolant is actually low...). If you're replacing your expansion tank, now is a great time to replace this failure prone sensor. If you want a new coolant level sensor, simply choose from the option below. Because there are different sensors for different year/model BMWs, please be as specific as possible when you give us your car info during checkout (model, year, production date). Thanks!

This item fits the following BMWs:
1992-1998 E36 BMW 323ic 325i 325is 325ic 328i 328is 328ic M3
1997-1998 E39 BMW 528i
1997-1998 Z3 BMW Z3 2.8
1998-2000 Z3 BMW M Roadster M Coupe (S52)

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Expansion Tank Replacement Kit - E60 M5,E63 M6

T#:584232

Part#: 17112283345KT

In Stock

$ 249.99 USD

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$ 249.99 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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Cooling System Refresh Kit - Level 2 - E9x, E82, E88, Z4

T#:42099868

Part#: 11537558523TKT

Back Ordered

Sale - Save 19% $ 829.99

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

$ 671.10 USD

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Sale - Save 19%

$ 829.99

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

$ 671.10 USD

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Keep your BMW running at the proper temperature and avoid costly engine repairs with the Cooling System Refresh Kit, the complete maintenance solution trusted by enthusiasts and professionals alike.

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N54 Billet 90 Degree Coolant Tank Fitting

T#:12184492

Part#: VTT-COOLANT-90-1

In Stock

$ 37.99 USD

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$ 37.99 USD

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Enhance the flexibility of your BMW's coolant system with the Vargas Turbo Technologies 90-Degree Coolant Tank Fitting. Ideal for applications such as single turbo setups or forward-facing intake manifolds, this fitting provides extra clearance and versatile hose routing options.

Key Benefits:

Allows hose to run straight down, increasing clearance
Made of durable 6061-T6 aluminum for long-lasting performance
Anodized black finish for enhanced durability and corrosion resistance
Includes fitting and clamp for easy installation

Upgrade your BMW's coolant system with the Vargas Turbo Technologies 90-Degree Coolant Tank Fitting for improved performance and versatility.

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VTT Billet Coolant Reservoir Cap - Anodized Blue - Most BMWs 2006+ (E...

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/...

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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VTT Billet Coolant Reservoir Cap - Anodized Clear - Most BMWs 2006+ (...

T#:7530035

Part#: COOLANTCAPRAW

Ships in 6 Business Days

$ 78.99 USD

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$ 78.99 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 Black - Most BMWs 2006+ (...

T#:7530033

Part#: COOLANTCAPBLK

Back Ordered

$ 79.99 USD

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Qty

$ 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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Vargas Expansion Tank Coolant Hose - Blue - BMW B58 F2X F3X

T#:51848504

Part#: VTT-B58-CEBLUE

Ships on Aug 6, 2026

$ 59.99 USD

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$ 59.99 USD

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Elevate your BMW's engine bay while safeguarding your cooling system with the VTT B58 Expansion Tank Hose in Blue.

Vargas Upgraded Silicone Upper Vent Hose - Black - BMW N54 E8X/E9X ...

T#:52164880

Part#: N54CLVTBLKO

Ships on Aug 6, 2026

$ 54.99 USD

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$ 54.99 USD

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The VTT N54 Upper Vent Hose is a critical upgrade for any BMW enthusiast looking to eliminate the weakest links in their cooling system.

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SELECT YOUR BMW

Coolant Expansion Tank - E46 (non-M), X3, X5 3.0

OEM Coolant Expansion Tanks Kit - F22/23 F3X B48 B58

Coolant Expansion Tank - E36/E39/Z3 6 cylinder 1992-1998

Expansion Tank Replacement Kit - E60 M5,E63 M6

Cooling System Refresh Kit - Level 2 - E9x, E82, E88, Z4

N54 Billet 90 Degree Coolant Tank Fitting

Key Benefits:

VTT Billet Coolant Reservoir Cap - Anodized Blue - Most BMWs 2006+ (E...

VTT Billet Coolant Reservoir Cap - Anodized Red - Most BMWs 2006+ (E/...

VTT Billet Coolant Reservoir Cap - Anodized Clear - Most BMWs 2006+ (...

VTT Billet Coolant Reservoir Cap - Anodized Black - Most BMWs 2006+ (...

Vargas Expansion Tank Coolant Hose - Blue - BMW B58 F2X F3X

Vargas Upgraded Silicone Upper Vent Hose - Black - BMW N54 E8X/E9X ...

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