BMW Cooling System Parts & Accessories for BMW E90 M3 S65 4.0L

BMW is well-known for its problematic cooling systems, which are often a catalyst for irreversible engine damage and a hefty repair bill. The coolant expansion tank, a crucial component responsible for holding hot engine coolant under high pressure, is a common cause of cooling system issues. Unfortunately, BMW chose to manufacture the factory E90 M3 expansion tank out of plastic. After years of exposure to high coolant temperatures, ambient engine bay heat, and chemical-rich antifreeze, the plastic degrades, eventually weakening enough to fail catastrophically.

With this issue in mind, our team of BMW enthusiasts engineered the ultimate cooling system upgrade for E90 M3 owners: a heavy-duty expansion tank built to last! Crafted from durable 5052 TIG-welded aluminum, this tank resists high temperatures and pressures without degrading over time. Unlike the fragile OEM plastic tank, Turner’s design eliminates the risk of cracking, leaking, or failure. Upgrade to our Heavy Duty Aluminum Expansion Tank Kit and say goodbye to expansion tank issues for good!

To guarantee exact fitment, the upgraded tank was designed using advanced 3D CAD modeling. All bungs, nipples, and fittings are precision-machined to ensure a secure seal with factory hose ends. Unlike other aftermarket options, this tank maintains the factory coolant capacity and includes our laser-cut logo plate at the top, providing an accurate fill level. Internal baffles are incorporated to prevent fluid cavitation, eliminating air pockets in the cooling system and avoiding false coolant level warnings during spirited driving.

Engineered for high-performance builds and daily drivers alike, this expansion tank boasts a premium wrinkle black powder coat finish for a clean "OEM+" aesthetic. This tough coating not only enhances appearance but also protects against corrosion for long-term durability. The kit includes a silicone overflow hose, a high-quality level sensor, and an OE expansion tank cap, offering a complete cooling system upgrade. Avoid the risks of the factory expansion tank—upgrade your E46 M3 today and drive with confidence!

Features & Benefits:

Durable 5052 TIG-Welded Aluminum Construction: Ensures long-term reliability and eliminates expansion tank failure.
Premium Wrinkle Black Powder Coat Finish: Offers an "OEM+" appearance while preventing corrosion.
Factory Coolant Capacity Retention: Maintains the same coolant level as the original design.
Laser-Cut Turner Logo Plate: Provides a clear and accurate fill level indicator.
Internal Baffles: Prevent the introduction of air pockets during high-performance driving.
Precision-Machined External Bungs and Fittings: Ensure a perfect fit for factory hose connections.
Kit Includes:

Turner Motorsport Aluminum Expansion Tank
Performance Silicone Coolant Overflow Hose
Expansion Tank Cap
Billet coolant bleeder screw
Coolant Level Sensor
Product Development:

Our Heavy Duty Aluminum Expansion Tank was designed, engineered, tested, and quality inspected by our Research & Development team. Our development process includes leading-edge product technology: FARO laser scanning for reverse engineering and quality inspection, SolidWorks 3D CAD modeling, rapid prototyping utilizing our in-house 3D printer, and rigorous long-term product testing.

Installation:

- Click HERE for Installation Instructions -

Tired of dealing with brittle, dry-rotted rubber hoses? Whether you're refreshing your cooling system or replacing aging components, this ECS Silicone Radiator Coolant Hose Set is the ultimate upgrade. Designed for durability, performance, and a factory-perfect fit, these premium silicone hoses outperform standard rubber in every way.

Why Choose Silicone Over Rubber?

Made from heavy-duty, reinforced 4-ply fluorosilicone, ECS hoses withstand extreme temperatures and pressures far beyond OEM rubber hoses. Engineered to resist oil, fuel, and electrochemical degradation, these hoses are tested for continuous operation at 250°F and over 45 psi, delivering superior reliability, reduced turbulence, and improved coolant flow.

Key Benefits:

Direct OE Fitment – Perfectly molded to factory specifications for seamless installation on your S65-equipped E9X M3. Enhanced Durability – Heat-resistant silicone prevents cracking, swelling, and deterioration over time. Superior Cooling Performance – Smoother internal passageways improve coolant flow and system efficiency. Pre-installed Quick-Connect Fittings – Hassle-free installation with OEM-style connectors. Premium Hardware Included – Comes with German-style stainless steel worm-drive hose clamps for a secure fit. Kit Includes:

Upper Radiator Hose Lower Radiator Hose Pre-Installed Factory "Quick-Connect" Flanges (4) Stainless Steel Worm-Drive Hose Clamps (4) Replaces OEM Part Numbers: 11537838214 & 11537840661.