New E9x M3 Heavy Duty Aluminum Expansion Tank Kit
Most modern BMWs are notorious for their cooling system issues, often leaving owners stranded or causing irreversible engine damage in the event of failure. At the heart of these issues is the coolant expansion tank, a crucial component responsible for holding hot engine coolant under high pressure. Unfortunately, BMW chose to manufacture the factory E90 M3 expansion tank 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 E90 M3 owners: a robust expansion tank 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, Turner's alternative is not prone to cracking, leaking, or weakening. With Turner's Heavy Duty 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 E90 M3 and drive with confidence!
The last expansion tank you'll ever need!
For Your E9x M3
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Ships on Aug 26, 2026
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Ships on Nov 3, 2026