Upgrade your cooling system with this billet aluminum coolant expansion tank cap, designed as a direct replacement for aging factory plastic caps commonly found on BMW models. Over time, plastic caps can weaken, discolor, or fail under pressure—this upgraded aluminum cap provides a more durable and refined solution.

Why Upgrade Your Coolant Cap?

As vehicles age, cooling system components are exposed to constant heat cycles and pressure. Replacing the expansion tank cap helps maintain proper system pressure, reduces the risk of leaks, and restores confidence in your cooling system.

Key Features:

• CNC-machined billet aluminum construction for long-term durability
• Anodized surface finish for corrosion resistance and a clean engine bay look
• Direct replacement design with no modifications required
• Rated for proper cooling system pressure (2.0 bar)
• Ideal maintenance upgrade for older BMW cooling systems

Specifications:

• Condition: Brand New
• Product Type: Coolant Expansion Tank Cap
• Material: Aluminum Alloy
• Surface Finish: Anodized
• Maximum Pressure Rating: 2.0 Bar
• OEM Reference Numbers: 17111742231, 17110152374, 17111712492, 17111712669, 17117639022

Fitment:

• BMW 3 Series E36 (1992–1998)
• BMW 3 Series E46 (1999–2005)
• BMW 5 Series E39 (1995–2004)
• BMW X3 E83 (2003–2006)
• BMW X5 E53 (2000–2006)
• BMW Z4 E85 / E86 (2003–2005)

Installation Notes:

• Direct fit replacement for factory expansion tank cap
• No tools or modifications required
• Recommended as part of routine cooling system maintenance

What’s Included:

• 1x Billet Aluminum Coolant Expansion Tank Cap

Built for Longevity:

This aluminum expansion tank cap is a simple yet effective upgrade that enhances durability while maintaining proper cooling system pressure—perfect for enthusiasts who want reliability without sacrificing OEM fitment.