BMW Coolant Expansion Tanks

Expansion Tank Replacement Kit

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T#:15744017

Part#: N524ECSTNKKT-KT

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10-20-2026

$ 100.95 USD

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The coolant expansion tank in your vehicle gives additional fluid a place to go after expansion and contraction from temperature change. Because it is subjected to such drastic changes on a regular basis, it can often crack or break. You want to keep all the coolant in your vehicle in the cooling system. If your tank has experienced damage such as cracking, nipples breaking off, or mounting point damage, you will need to replace it. The kit includes: Expansion tank with level sensor URO expansion tank cap Genuine BMW expansion tank grommet Genuine BMW mounting bolts

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

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T#:338020

Part#: 17117573781

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Starting at $ 123.98 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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OEM Coolant Expansion Tanks Kit - F22/23 F3X B48 B58

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T#:27605427

Part#: 17138677649TKT

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05-03-2026

$ 202.62 USD

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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

10X Entries Into Our F80 M3 Sweepstakes

T#:338018

Part#: 17111723520

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$ 99.99

This product was last offered at the strikethrough price on
10-22-2026

Starting at $ 63.18 USD

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Starting at $ 63.18 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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ECS Cooling System Refresh Kit - Level 1

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T#:15677493

Part#: 11517527910-KT

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$ 323.65 USD

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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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Expansion Tank Replacement Kit - E60 M5,E63 M6

10X Entries Into Our F80 M3 Sweepstakes

T#:584232

Part#: 17112283345KT

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$ 250.99 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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ECS Cooling System Refresh Kit - Level 2

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T#:15677514

Part#: 11281706545-KT

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Sale - Save 3% $ 474.99

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05-03-2026

$ 460.17 USD

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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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N52 ECS Cooling System Refresh Kit - E8x E9x

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T#:59440849

Part#: TWTRPMPPIEBRPRKT

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$ 665.99 USD

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Be sure your cooling system is up to the task

ECS Cooling System Refresh Kit - Level 2

10X Entries Into Our F80 M3 Sweepstakes

T#:15710821

Part#: 17137607482-KT

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10-13-2026

$ 736.19 USD

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As your mileage increases, so does wear and tear on your engine's cooling components. Cooling system components live a rough life, going through extreme temperature changes and being exposed to the elements. A cooling system failure can, and probably will leave you stranded. Included in this kit Water pump with new bolts Thermostat & housing Expansion tank with level sensor Expansion tank cap 1 Gallon of OEM Coolant Waterpump & thermostat hoses Upper and lower radiator hoses Accessory belt

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Cooling System Refresh Kit - Level 2

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T#:15744066

Part#: 11287837898-KT

Ships on Dec 18, 2026

Sale - Save 3% $ 808.99

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

$ 786.20 USD

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

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T#:42099868

Part#: 11537558523TKT

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05-03-2026

$ 667.28 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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Automatic Transmission Thermostat Kit

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T#:57122955

Part#: 17111438819KT2

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This product was last offered at the strikethrough price on
10-19-2026

$ 91.86 USD

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Keeping your E53 X5 automatic transmission cool is essential for longevity and peak performance. The factory transmission thermostat circuit relies on plastic housings and o-ring seals that deteriorate over time. When the transmission thermostat fails or it's mounting assembly cracks, coolant loss follows putting your transmission at risk of overheating under load.

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Cooling System Refresh Kit - Level 2

10X Entries Into Our F80 M3 Sweepstakes

T#:15677500

Part#: 82141467704-KT

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$ 669.06 USD

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As your mileage increases, so does wear and tear on your engine's cooling components. Cooling system components live a rough life, going through extreme temperature changes and being exposed to the elements. A cooling system failure can, and probably will leave you stranded. For automatic transmission (or DCT) vehicles only This kit includes: Thermostat with mounting hardware 1 gallon of BMW coolant Water pump with mounting hardware Primary cooling system hoses and radiator hose gasket, and bleeder screw Expansion tank with cap Accessory belt

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Engine Coolant Expansion Tank

10X Entries Into Our F80 M3 Sweepstakes

T#:30729009

Part#: 17138677649

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$ 75.59 USD

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Coolant Expansion Tank

10X Entries Into Our F80 M3 Sweepstakes

T#:36032353

Part#: 17111741167

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$ 51.84 USD

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Coolant Expansion Tank - 17111436381

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T#:36303285

Part#: 17111436381

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$ 40.00 USD

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BMW E39 Coolant Expansion Tank is an essential component designed to maintain the proper coolant level in your vehicle's cooling system. Manufactured with high-quality materials, this expansion tank ensures reliable performance and durability, preventing engine overheating by accommodating the expansion of coolant as it heats up. The kit includes a level sensor and cap, providing everything needed for a seamless installation. This expansion tank is specifically engineered to meet the exact specifications of your BMW E39, offering a perfect fit and optimal functionality.

Complete Kit: Includes level sensor and cap for easy installation. High-Quality Construction: Built with durable materials for long-lasting performance. Prevents Overheating: Helps manage coolant expansion, ensuring engine protection. Exact Fit: Designed to meet the precise specifications of your BMW E39. Enhanced Reliability: Ensures proper coolant level maintenance for optimal cooling system function.

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Bav Auto Coolant Expansion Tank - E53 X5, Z3 2.3 2.5i 2.8 3.0i ...

10X Entries Into Our F80 M3 Sweepstakes

T#:640497

Part#: 17107514964

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09-16-2026

$ 55.24 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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Coolant Expansion Tank

10X Entries Into Our F80 M3 Sweepstakes

T#:30728965

Part#: 17137823626

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$ 38.34 USD

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Coolant Expansion Tank W/O Cap

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T#:639188

Part#: 17137529273

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$ 32.94 USD

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Bremmen Parts Water Pipe Connector - E83, Z4

10X Entries Into Our F80 M3 Sweepstakes

T#:1195932

Part#: 17112248409

Ships on Nov 10, 2026

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$ 30.66 USD

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Located underneath the expansion tank

Coolant Expansion Tank Cap

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T#:36032339

Part#: 17117639020

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09-17-2026

$ 11.99 USD

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Bremmen Coolant Bleeder Screw - BMW E30 E36 E38 E39 E46 E83 E90 Z4 ...

10X Entries Into Our F80 M3 Sweepstakes

T#:640140

Part#: 17111712788

Ships on Dec 16, 2026

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09-02-2026

$ 2.44 USD

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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.

Coolant Level Sensor

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T#:30728984

Part#: 61311378320

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$ 15.29 USD

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Coolant Expansion Tank - With Cap

10X Entries Into Our F80 M3 Sweepstakes

T#:55497428

Part#: 17137640514

Ships on Nov 10, 2026

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10-08-2026

$ 62.99 USD

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Coolant Expansion Tank

10X Entries Into Our F80 M3 Sweepstakes

T#:45723154

Part#: 17137642158

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$ 50.99 USD

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E30 Coolant Expansion Tank

10X Entries Into Our F80 M3 Sweepstakes

T#:57507437

Part#: 17111712641

Ships on Jan 11, 2027

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10-21-2026

$ 46.99 USD

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Coolant Expansion Tank

10X Entries Into Our F80 M3 Sweepstakes

T#:53044121

Part#: 17137601948

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$ 67.49 USD

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MINI F5X F6X Expansion Tank

10X Entries Into Our F80 M3 Sweepstakes

T#:28138156

Part#: 17137617362

Special Order: No Guaranteed ETA

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$ 77.51 USD

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MINI F5X F6X Expansion Tank

For Mini owners looking to maintain optimal engine performance, the MINI F5X F6X Expansion Tank is an essential component. This expansion tank ensures proper cooling system functionality, preventing overheating and potential engine damage. Crafted with high-quality materials, it guarantees durability and reliability for long-term use, providing peace of mind to Mini enthusiasts.

Ensures proper cooling system functionality
Prevents overheating and potential engine damage
Crafted with high-quality materials for durability
Provides peace of mind to Mini enthusiasts

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SELECT YOUR BMW

Expansion Tank Replacement Kit

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

ECS Cooling System Refresh Kit - Level 1

Expansion Tank Replacement Kit - E60 M5,E63 M6

ECS Cooling System Refresh Kit - Level 2

N52 ECS Cooling System Refresh Kit - E8x E9x

ECS Cooling System Refresh Kit - Level 2

Cooling System Refresh Kit - Level 2

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

Automatic Transmission Thermostat Kit

Cooling System Refresh Kit - Level 2

Engine Coolant Expansion Tank

Coolant Expansion Tank

Coolant Expansion Tank - 17111436381

Bav Auto Coolant Expansion Tank - E53 X5, Z3 2.3 2.5i 2.8 3.0i ...

Coolant Expansion Tank

Coolant Expansion Tank W/O Cap

Bremmen Parts Water Pipe Connector - E83, Z4

Coolant Expansion Tank Cap

Bremmen Coolant Bleeder Screw - BMW E30 E36 E38 E39 E46 E83 E90 Z4 ...

Coolant Level Sensor

Coolant Expansion Tank - With Cap

Coolant Expansion Tank

E30 Coolant Expansion Tank

Coolant Expansion Tank

MINI F5X F6X Expansion Tank

MINI F5X F6X Expansion Tank

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