BMW F80 M3 S55 3.0L

Whether your S55-equipped BMW serves as a daily driver or track car, keeping temperatures cool is critical. While most enthusiasts focus on upgrading the radiator and water-to-air intercooler systems, the engine oil cooler is an overlooked yet critical component.

New for the F8X-generation M2, M3, and M4 is a low-slung, horizontally mounted oil cooler designed to harness underbody aerodynamics. By placing the cooler in a low-pressure zone, this design enhances airflow efficiency and achieves sustainable oil temperatures for stock and street-driven cars. However, the compact core is quickly overwhelmed on modified or track-driven vehicles. Its exposed mounting position also leaves it highly susceptible to impact damage, so a minor scrape or piece of road debris can mean a costly full replacement. If you’re already replacing your oil cooler, it’s the perfect time to upgrade!

Our engineering team set out to solve the shortcomings of the factory design by developing a larger, higher-capacity core that delivers measurable gains in thermal stability. With a 7% increase in core thickness over OEM, this upgraded unit enhances airflow through the cooler and helps maintain lower, more consistent oil temperatures under sustained load. Thanks to its robust bar-and-plate core, precision-formed sheet metal end tanks, and durable 5052 aluminum construction, it’s built to withstand the harsh realities of real-world performance driving.

Replaces OEM part numbers 17212284540 and 17214802333.

Features:

High-efficiency bar-and-plate core for superior heat dissipation Fully TIG-welded 5052 aluminum end tanks Retains OEM rubber mounting for vibration-isolated, factory-style fitment Black painted finish with laser-etched Turner logo Designed as a direct-fit replacement and upgrade for S55-equipped F8X vehicles Design:

7% thicker core (30mm vs 28mm) for increased thermal capacity 6.5% increase in finned area (104,000 mm² vs 97,650 mm²) for better cooling Compatible with the Turner Motorsport skid plate kit (ES#3448772, ES#3247792) for complete protection Product Development:

Our High Performance Aluminum Heat Exchanger was designed, engineered, tested, and quality inspected by our Research and Development team in our Wadsworth, Ohio, facility. We strive for the highest level of precision and quality through leading-edge product development technology, including 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.

BMWs are well-known for their problematic cooling systems, which are often the cause of 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 F8X 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 F80 M3, F82/F83 M4, and F87 M2 Competition owners: a heavy-duty expansion tank that is 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, our 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 S55-equipped BMW 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. Proprietary Coolant Level Sensor with Wiring Harness Adapter: Provides a plug-and-play, CEL-free functionality. Kit Includes:

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

Upgrade your stock oil cooler thermostat for improved performance. Swap your factory 110-degree Celsius thermostat for a new 70-degree Celsius version for faster oil flow and extended temperature control. With oil temperatures reaching 230 degrees Fahrenheit by the time your factory thermostat opens, initiating oil flow at lower temperatures proves more effective than attempting to cool down already elevated temperatures.

Utilizing a factory-style thermostat, this upgrade can be used in all weather conditions and allows your engine to warm up properly, unlike thermostat bypass kits.

Kit contents:​

Lower temperature thermostat - 70c (158F) vs Factory 110c (230F)
Low temp thermostat spring