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BMW Coolant Expansion Tank

128 items

Coolant expansion tank cracks can cause leaks, low coolant warnings, and overheating. Replace a worn reservoir tank with A-Premium and keep your cooling system protected.

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ÜRO Parts 17137543003 Engine Coolant ReservoirÜRO Parts 17137543003 Engine Coolant Reservoir
ÜRO PartsPart # 17137543003
ÜRO Parts 17137543003 Engine Coolant Reservoir
32 Reviews
$75.99
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3-year warranty
90 days free return
Fits 2007-2008 BMW Alpina B7, 2006-2008 BMW 750i, 2006-2008 BMW 750Li, 2004-2006 BMW 760i, 2003-2008 BMW 760Li, 2002-2005 BMW 745i, 2002-2005 BMW 745Li
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: BMW
Item LocatedUnited States
Quantity1
Part interchange
17137543003, 17138600275, 17137647713, 17137543003, 603-259, EPT0021, EPK0021, V20-1216, 
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item #1000ZL6Q
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ÜRO Parts 17111723520 Engine Coolant Reservoir
ÜRO PartsPart # 17111723520
ÜRO Parts 17111723520 Engine Coolant Reservoir
32 Reviews
$36.99
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3-year warranty
90 days free return
Fits 1999-1999 BMW 528i, 1998-2000 BMW Z3, 1998-1999 BMW 323i, 1998-1999 BMW 323is, 1998-1998 BMW 528i, 1998-1998 BMW Z3, 1997-1997 BMW 528i, 1997-1997 BMW Z3, 1996-1999 BMW 328i, 1996-1999 BMW 328is, 1995-1999 BMW M3, 1992-1995 BMW 325i, 1992-1995 BMW 325is
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: BMW
Item LocatedUnited States
Quantity1
Part interchange
17111723520, 17111723520, 376705401, 376888411, 603-281, EPT0026, V20-0083, URO-001487
item #1000ZKQS
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ÜRO Parts 17137787039 Engine Coolant Reservoir
ÜRO PartsPart # 17137787039
ÜRO Parts 17137787039 Engine Coolant Reservoir
32 Reviews
$51.99
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3-year warranty
90 days free return
Fits 2008-2010 BMW X3, 2006-2007 BMW X3, 2004-2006 BMW 325Ci, 2004-2005 BMW X3, 2003-2003 BMW 325Ci, 2001-2006 BMW 330Ci, 2001-2006 BMW X5, 2001-2005 BMW 325i, 2001-2005 BMW 325xi, 2001-2005 BMW 330i, 2001-2005 BMW 330xi, 2001-2002 BMW 325Ci, 2000-2000 BMW 323Ci, 2000-2000 BMW 328Ci, 1999-2000 BMW 323i, 1999-2000 BMW 328i
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: BMW
Item LocatedUnited States
Quantity1
ColorBlack
Part interchange
17137787039, 17137787039, 17117573781, 17111436413, 17132247553, 603-535, EPK0018, EPT0018, 
...View more
item #1000ZEA9
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ÜRO Parts 17111741167 Engine Coolant Reservoir
ÜRO PartsPart # 17111741167
ÜRO Parts 17111741167 Engine Coolant Reservoir
32 Reviews
$58.99
Edit ZIP code
3-year warranty
90 days free return
Fits 2003-2003 BMW Z8, 1997-2003 BMW 540i, 1997-2001 BMW 740i, 1995-2001 BMW 740iL, 1995-2001 BMW 750iL, 1995-1995 BMW 740i, 1994-1997 BMW 840Ci, 1994-1995 BMW 850CSi, 1993-1997 BMW 850Ci, 1991-1992 BMW 850i
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: BMW
Item LocatedUnited States
Quantity1
Part interchange
17111741167, 17111723071, 17111741167, 376705431, 603-537, EPK0013, EPT0013, Z49007, 
...View more
item #1000ZHKQ
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ÜRO Parts 17138677649 Engine Coolant Reservoir, Radiator
ÜRO PartsPart # 17138677649
ÜRO Parts 17138677649 Engine Coolant Reservoir, Radiator
32 Reviews
$101.99
Low stock: Only 4 left
Edit ZIP code
3-year warranty
90 days free return
Fits 2021-2021 BMW 230i, 2021-2021 BMW 230i xDrive, 2019-2019 BMW 330i xDrive, 2017-2021 BMW M240i, 2017-2021 BMW M240i xDrive, 2017-2020 BMW 230i, 2017-2020 BMW 230i xDrive, 2017-2020 BMW 430i, 2017-2020 BMW 430i Gran Coupe, 2017-2020 BMW 430i xDrive, 2017-2020 BMW 430i xDrive Gran Coupe, 2017-2020 BMW 440i, 2017-2020 BMW 440i Gran Coupe, 2017-2020 BMW 440i xDrive, 2017-2020 BMW 440i xDrive Gran Coupe, 2017-2019 BMW 330i GT xDrive, 2017-2019 BMW 340i GT xDrive, 2017-2018 BMW 330i, 2017-2018 BMW 330i xDrive, 2017-2018 BMW 340i
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: BMW
Item LocatedUnited States
Quantity1
Installation PositionRadiator
Part interchange
17138677649, 17138677649, 17138617044, 188339, 3142230020, EPT0235, V205117, URO-018046
item #1000ZP3R
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ÜRO Parts 17138093924 Engine Coolant Reservoir, Radiator
ÜRO PartsPart # 17138093924
ÜRO Parts 17138093924 Engine Coolant Reservoir, Radiator
32 Reviews
$106.99
Low stock: Only 4 left
Edit ZIP code
3-year warranty
90 days free return
Fits 2023-2024 BMW M2, 2021-2024 BMW M3, 2021-2024 BMW M4
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: BMW
Item LocatedUnited States
Quantity1
Installation PositionRadiator
Part interchange
17138093924, 17138093924, URO-021597
item #1000ZH8C
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ÜRO Parts 17137647281 Engine Coolant Reservoir
ÜRO PartsPart # 17137647281
ÜRO Parts 17137647281 Engine Coolant Reservoir
32 Reviews
$65.99
Edit ZIP code
3-year warranty
90 days free return
Fits 2015-2019 BMW Alpina B6 xDrive Gran Coupe, 2013-2019 BMW 650i Gran Coupe, 2013-2019 BMW 650i xDrive Gran Coupe, 2012-2018 BMW 650i, 2012-2018 BMW 650i xDrive, 2011-2016 BMW 550i, 2011-2016 BMW 550i xDrive, 2011-2015 BMW Alpina B7, 2011-2015 BMW Alpina B7 xDrive, 2011-2015 BMW Alpina B7L, 2011-2015 BMW Alpina B7L xDrive, 2011-2013 BMW X5, 2010-2017 BMW 550i GT xDrive, 2010-2015 BMW 550i GT, 2010-2015 BMW 750i xDrive, 2010-2015 BMW 750Li xDrive, 2010-2015 BMW 760Li, 2009-2015 BMW 750i, 2009-2015 BMW 750Li, 2009-2014 BMW X6
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: BMW
Item LocatedUnited States
Quantity1
MaterialPlastic
ColorBlack
item #1000ZNPK
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ÜRO Parts 17111712835 Engine Coolant Reservoir
ÜRO PartsPart # 17111712835
ÜRO Parts 17111712835 Engine Coolant Reservoir
32 Reviews
$27.99
Edit ZIP code
3-year warranty
90 days free return
Fits 1997-1998 BMW Z3, 1996-1996 BMW Z3, 1995-1999 BMW 318ti, 1993-1993 BMW 525iT, 1991-1998 BMW 318i, 1991-1997 BMW 318is, 1989-1995 BMW 525i
Add Trim and Engine info to ensure a guaranteed fit
Vehicle: BMW
Item LocatedUnited States
Quantity1
Part interchange
17111712835, 17111712835, EPT0012, V20-0577, URO-001485
item #1000ZL8D
Show less
Page 7 of 7

Shop coolant expansion tanks and engine coolant reservoirs by vehicle. The right tank gives heated coolant room to expand and provides a place to monitor the level, but layouts differ across cooling systems. Use the year, make, model, engine, and product notes to compare tank shape, hose ports, mounting points, and included components before ordering. Never open the cooling system while the engine is hot.

What Does a Coolant Expansion Tank Do?

As coolant warms, its volume increases. Depending on the vehicle's design, an expansion tank or reservoir receives the changing coolant volume and helps the system maintain the correct operating level. Many tanks have MIN/MAX or COLD-FILL marks so the level can be checked without opening the system. The tank is only one part of the cooling circuit; the radiator, water pump, thermostat, hoses, cap, and coolant passages must also work correctly.

Expansion Tank vs. Coolant Reservoir Terminology

Catalogs may use coolant expansion tank, engine coolant reservoir tank, overflow tank, recovery tank, or surge tank for similar-looking parts. They are not always identical. A pressurized expansion or surge tank may use a pressure cap and connect directly to the circulating system, while an overflow bottle may receive coolant through a small hose from the radiator. Match the original configuration rather than relying on the name alone.

Signs of a Cracked or Leaking Tank

Inspect the coolant reservoir tank when you notice a low-coolant warning, a level that keeps dropping, overheating, or coolant odor under the hood. Possible evidence includes cracks, damp seams, staining or dried residue, damaged hose necks, loose connections, and leakage around the cap. These symptoms do not prove the tank itself has failed; radiator hoses, the water pump, thermostat housing, radiator, or other cooling-system components may also leak. Diagnose the source before replacing parts.

Cap, Sensor, Hose, and Fitment Checks

Start with the A-Premium vehicle selector and confirm the year, make, model, engine, trim, and any transmission notes in the listing. Compare the original tank's shape, mounting points, hose connections, fill markings, and OE or interchange numbers. Product configurations vary: some tanks include a cap, level sensor, hose, bracket, or mounting plate, while others require original components to be transferred or purchased separately. Read the Kit Parts Included field and product notes before checkout.

Safe Inspection and Replacement Considerations

Work only after the engine has cooled completely. Never remove an engine coolant reservoir cap while the engine is running or hot because the system may be pressurized. Follow vehicle-specific service information for draining, installation, refilling, and bleeding, and use the coolant specification in the owner's manual. After service, inspect the connections and monitor the cold level. If overheating continues, coolant drops again, or the repair exceeds your experience, stop driving and have the system professionally diagnosed.

FAQ

Do coolant expansion tanks include the cap and level sensor?

Not always. A-Premium listings show tanks with different combinations of caps, level sensors, hoses, brackets, and mounting plates. Check the title, product notes, and Kit Parts Included field for the exact item you are considering.

Are a coolant expansion tank and an overflow reservoir the same thing?

They may describe the same general category, but the actual system can be pressurized or non-pressurized and may route coolant differently. Match the original tank, connections, cap arrangement, and vehicle fitment instead of choosing by terminology alone.

What are common signs of a leaking coolant reservoir?

Cracks, wet seams, dried coolant residue, leaks near the cap or hose necks, repeated low-coolant warnings, and an unexplained falling level are common clues. Because other cooling parts can cause the same symptoms, confirm the leak source first.

Does falling coolant level always mean the expansion tank has failed?

No. The tank, cap, hoses, radiator, water pump, thermostat housing, heater circuit, and internal engine leaks can all contribute to coolant loss. Inspect and diagnose the entire system before replacing a part.

When can I safely open the cooling system?

Park on level ground, switch the engine off, and wait until it is completely cold. Never remove the coolant reservoir cap while the engine is running or hot. Follow the vehicle's specified checking procedure.

Related Blogs

The Role of the Expansion Tank in Automobile Cooling Systems

The car coolant expansion tank is a vital component that accommodates fluid volume changes, maintains proper pressure, and removes air bubbles, ensuring efficient cooling system operation through a pressurized air pocket and durable construction.

Jul 21, 2026

The Need-to-Know Guide on Expansion Tank Replacement

A car expansion tank stores excess coolant, accommodating fluid expansion as the engine heats up. Replacing a malfunctioning expansion tank is essential to avoid overheating, pressure issues, and consequential engine damage in the vehicle.

Jul 21, 2026