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MMX Performance

Shop Creeper

$151.00

SKU: MMR03-1502

In Stock
In Stock
Ships by Sep 13
Free Shipping over $200
$100 Minimum Order
30 Days Return
INSTALL DIFFICULTY
DIY PRO SHOP

Beginner — under 30 min

Overview

The MMX Performance BMW Billet Coolant Expansion Cap is a direct OE replacement for your BMW's plastic coolant cap. It is precision-engineered from 6061 aerospace-grade aluminum for improved durability and heat resistance. The cap features advanced 5-axis CNC machining for a precise fit and a gloss black anodized finish for corrosion resistance and a refined look.
Show original supplier description
The MMX Performance BMW Billet Coolant Expansion Cap offers a significant upgrade over the factory plastic unit, addressing potential degradation from heat cycles and sealing issues. This cap is a true OE replacement, machined from a solid block of 6061 aerospace-grade aluminum for superior strength and long-term reliability. Its robust construction is enhanced by advanced 5-axis CNC machining, ensuring a precise fit and finish. The cap comes complete with pre-installed OE-spec internals, including a pressure valve, internal spring, and a Viton O-ring seal, eliminating the need to transfer components from your old cap. This plug-and-play installation, combined with an improved grip design for easier handling, makes servicing your cooling system more confident and straightforward. The gloss black anodized finish not only provides excellent corrosion resistance but also adds a refined, OEM+ aesthetic to your engine bay. Available in both 60mm (replacing OE part number 17117639024) and 90mm (replacing OE part number 17117639021) fitments, it's crucial to confirm the correct size or OE part number on your existing cap before purchase. This billet expansion cap is designed and tested in the United Kingdom and comes with a 1-year manufacturer warranty.

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

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Specifications

BrandMMX Performance
Part NumberMMR03-1502
CategoryTools
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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