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Heating and Cooling› Overflow Tanks and Catch Cans

MTC

Coolant Expansion Tank

$52.95 $47.66 Save $5.29

SKU: 17117573781

Special Order
Special Order
Ships in 4–6 weeks
Free Shipping over $200
$100 Minimum Order
30 Days Return
INSTALL DIFFICULTY
DIY PRO SHOP

Easy — 1–2 hours

Overview

It provides the necessary volume for coolant to safely expand and contract as temperatures fluctuate during engine operation.
Show original supplier description
The MTC coolant expansion tank serves as a critical component for your BMW's cooling system, offering a reliable solution for replacing aged or leaking original units. By providing the proper space for coolant to expand and contract during heat cycles, this reservoir helps prevent cooling system failure and maintains optimal operating temperatures. This replacement part is designed for compatibility with various BMW E46 models, including the 323Ci, 323i, 325Ci, 325i, 325xi, 328Ci, and 328i, as well as select E83 X3 and E53 X5 3.0L models. Please note that the expansion tank typically does not include the cap or coolant, which may be required for a complete system refresh. As with most cooling system maintenance, it is recommended to inspect surrounding components such as radiator hoses and sensors during installation to ensure the entire system functions correctly.

Product descriptions are provided by our supplier partners and may not always be perfectly accurate. Not sure this fits? or call (760) 282-4645 and we’ll verify before you order.

Fitment

Fitment Guaranteed

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Log your build in the MOTORMIA app and we’ll guarantee this part fits your exact setup — or your money back, return shipping covered.

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Specifications

BrandMTC
Part Number17117573781
CategoryHeating and Cooling
5,000+ Trusted brands
1M+ Enthusiasts
5M+ Parts sold
(760) 282-4645 hello@motormia.co

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Returns & Fitment

Built for enthusiasts. Every order is backed by our 30 day return window on eligible items. Unused and uninstalled products may be returned with approved RMA and no restocking fees when received in new condition. Orders placed through the MOTORMIA app with a complete build qualify for our Fitment Guarantee — free return shipping if the part doesn’t fit your exact setup. The guarantee covers fit only; installation must follow manufacturer instructions, and we recommend a qualified shop for parts marked Difficulty 4–5.

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Shipping

Orders are processed in 1–3 business days. In stock parts ship promptly from our partner network. Special-order items either aren’t currently stocked or are built to your spec — expect 4–6 weeks. If a part goes on backorder while your order is in the queue, we’ll reach out and work through discounted alternatives together.

Free shipping over $200 in the continental US. Alaska, Hawaii, U.S. territories (Puerto Rico, U.S. Virgin Islands, Guam, American Samoa, and the Northern Mariana Islands), and international orders carry surcharges — most appear at checkout. Some exceptions (LTL freight, or suppliers who quote freight only after we place the order) won’t. In those cases we’ll reach out with the exact charge before your order moves forward.

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