Turner F8X S55 Heavy Duty Aluminum Expansion Tank Kit

Most modern BMWs are notorious for cooling system issues, often leaving owners stranded or causing irreversible engine damage if they fail. The coolant expansion tank is at the heart of these issues—a crucial component that holds hot engine coolant under high pressure. Unfortunately, BMW manufactured the factory F8X expansion tanks out of plastic. After years of exposure to high temperatures and chemical-laden antifreeze, the plastic degrades, eventually weakening enough to rupture. 

With this failure in mind, Turner's team of BMW enthusiasts set out to develop the ultimate solution for F8X M2, M3, and M4 owners: a robust expansion tank that is built to last! Constructed from durable 5052 TIG-welded aluminum, this tank withstands high temperatures and pressures without deteriorating over time. Unlike the OEM molded plastic tank, this alternative is not prone to cracking, leaking, or weakening. With the Turner Motorsport Aluminum Expansion Tank Kit, you'll never experience expansion tank failure again!

To ensure precise fitment, 3D CAD modeling was utilized to design an upgraded tank that installs just like the factory unit. All bungs, nipples, and fittings are precision-machined for a reliable seal with factory hose ends. Unlike other aftermarket coolant reservoirs, this tank retains the factory coolant capacity and features a laser-cut Turner logo plate at the top of the tank to provide an exact level for filling. Additionally, internal baffles were implemented to prevent fluid cavitation inside the expansion tank. This ensures air pockets are not introduced to the cooling system and prevents false coolant level warnings during performance driving. 

Designed for both high-performance builds and daily drivers, the tank features a premium wrinkle black powder coat for a sleek "OEM+" look. This durable finish goes beyond style—it prevents corrosion for long-lasting reliability. In addition to the expansion tank, this kit also features a silicone overflow hose, a high-quality level sensor, and an OE expansion tank cap to ensure a comprehensive cooling system service. Don't let the problematic factory expansion tank leave you stranded—upgrade your S55-equipped BMW and drive with confidence!

FEATURES

• Durable 5052 TIG-Welded Aluminum Construction ensures long-term reliability and prevents expansion tank failure.
• A premium wrinkle black powder coat finish offers a show-ready "OEM+" appearance while preventing corrosion.
• A laser-cut aluminum Turner logo plate provides a clear and accurate fill level indicator. 
• Unique internal baffles prevent the introduction of air pockets during performance driving.
• All external bungs and fittings are precision-machined to fit factory hose ends, providing a leak-free seal. 
• Includes proprietary coolant level sensor and wiring harness adapter for plug-and-play, CEL-free functionality.

KIT CONTENTS

• Turner Motorsport Aluminum Expansion Tank
• Silicone Coolant Overflow Hose
• 6mm Nipple Fitting
• Expansion Tank Cap
• Coolant Level Sensor
• Coolant Level Sensor Wiring Harness Adapter

INSTALLATION

The team at Turner Motorsport has assembled a start-to-finish installation guide, including detailed instructions on removing your factory components. To learn more, click the PDF under the "INSTALLATION" tab above.