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This product was last offered at the strikethrough price on
06-14-2026
This product was last offered at the strikethrough price on
06-14-2026
BMWs are well-known for their 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 E46 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 E46 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 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.
Ditch your failure-prone plastic end tanks and increase cooling capacity by 25%—all without modifying your core support or accompanying shrouds. This Performance Triple-Pass Radiator is the ULTIMATE cooling system upgrade for your S54-equipped BMW!
The E46 M3 is a masterclass in German engineering. Harboring six independent throttle bodies, infinitely variable dual-VANOS, and an 8,000 RPM redline, the S54 is practically a racing engine for the road. Unfortunately, the engine's motorsport pedigree didn't quite make it to the cooling system. The OEM radiator, while superior to its non-M counterpart, struggles to keep coolant temperature in check under sustained high-RPM conditions. Heat soak, elevated operating temperatures, and component fatigue are all too familiar to M3 owners who track their S54 regularly.
To solve this problem, we teamed up with CSF Race, a global leader in high-performance cooling solutions with over five decades of industry experience. Together, we developed the CSFxTurner Triple-Pass Radiator: a high-performance, no-compromise solution built to meet the cooling demands of track-day warriors.
Part Design:
CSF-Exclusive "B-Tube" Technology Unlike conventional "O-tube" designs, CSF’s patented B-tube structure increases wall strength while creating a more efficient flow path. This alone accounts for a 15% increase in cooling capacity over an OE "o-tube" radiator! Triple-Pass Core Design As the name suggests, this unique structure forces coolant through the core three times before exit, resulting in a substantial temperature delta across the radiator core. Two-Row Compact Structure This radiator was designed with precise fitment in mind. While total tube count and size are increased, the overall radiator dimensions stay the same as OE, ensuring a drop-in fit with zero modifications required. 25% Increase in Cooling Capacity All of the above design features translate to a massive 25% cooling increase over the stock radiator! Features & Performance Benefits:
Direct-fit upgrade—no modifications required! Accepts all OEM attachments via CNC-machined "Quick-Connect" hose ends and accessory mounting provisions TIG-welded aluminum construction provides increased durability An all-aluminum drain plug replaces the weak OE plastic unit, ensuring seamless functionality for the life of the radiator Increased cooling efficiency for high-performance and racing use Designed and tested by Turner Motorsport in collaboration with CSF Race
When it comes time to replace your thermostat, be sure you have everything you need. This kit includes everything you need to replace your thermostat, including the thermostat.
Kit includes:
This item fits the following BMWs:
2001-2006 E46 BMW M3
This product was last offered at the strikethrough price on
03-31-2026
This product was last offered at the strikethrough price on
07-09-2026
This product was last offered at the strikethrough price on
07-09-2026
Due to weak rubber and plastic construction, vital cooling system parts are prone to premature failure. Key components, such as radiator hoses, the thermostat, and the expansion tank are particularly prone to cracks, leaks, and catastrophic failure, which can lead to overheating and potentially severe engine damage. Fortunately, our team of experts has assembled this kit of high-performance alternatives and high-quality OE replacement components, both tailored to safeguard your cooling system from failure and increase cooling system capability.
Our Level 3 High-Performance Cooling System Service Kit is the ultimate solution for ensuring long-term reliability and enhanced cooling performance. Each component in this comprehensive kit has been carefully selected by our team of enthusiasts to address common failure points and provide a robust, performance-oriented upgrade for your vehicle. By replacing aging factory parts with premium, high-performance alternatives, you’ll optimize cooling efficiency and safeguard your engine from the stress of overheating.
Our all-inclusive "Level 3" High-Performance Cooling System Service Kit includes:
CSFxTurner Performance Triple-Pass Aluminum Radiator Turner Motorsport Heavy Duty Aluminum Expansion Tank ECS Silicone Radiator Hoses ECS Aluminum Water Pump Pulley Wahler Thermostat (80°C) Bremmen Aluminum Water Pump Bremmen Parts Auxiliary Fan Switch Continental Accessory Belt ECS Kevlar-Reinforced A/C Compressor Drive Belt Genuine BMW Water Pump O-Ring Genuine BMW Water Pump Bolts Genuine BMW G48 Antifreeze (1 Gallon) Redline Water Wetter Performance Coolant Additive (12 oz.)
Just like the rest of your vehicle's major systems, the cooling system must also be addressed periodically to ensure proper cooling and component reliability. Plastic and rubber components become brittle and prone to splitting or cracking after long periods of heating and cooling cycles, especially in colder climates! The coolant itself can degrade or become contaminated, leading to potential corrosion or freezing issues. Finally, thermostats and sensors can fail completely, preventing proper cooling and/or coolant temperature readings to become inaccurate.
To make sure you are not left stranded on the side of the road with an overheated engine, we have put together this Basic Cooling System Service kit. This kit contains all of the most-likely-to-fail components, giving you peace of mind knowing your engine will continue to run cool for another 60,000+ miles.
See kit contents below for all included components.
This product was last offered at the strikethrough price on
07-09-2026
As the E46 M3 gets on in years and mileage, the cooling system will be one of the areas that needs the most attention. We have packaged all of the major cooling components into one overhaul kit:
We have found that the E46 M3 can develop inconvenient cooling issues, even on daily driven street cars. While the infamous radiator and water pump failures of the E36 are a thing of the past, the E46 M3 still has its own complications. The best approach to avoid bigger problems is preventative maintenance. We recommend replacing the water pump before 80,000 miles and the radiator before 100,000 miles. By addressing these problem areas before a failure, you will save yourself a larger repair bill in the future.
In addition to the standard cooling package items above, there are several other cooling-related components that may make sense to do at the same time:
This cooling overhaul package fits:
2001-2006 E46 BMW M3
Just like the rest of your vehicle's major systems, the cooling system must also be addressed periodically to ensure proper cooling and component reliability. Plastic and rubber components become brittle and prone to splitting or cracking after long periods of heating and cooling cycles, especially in colder climates! The coolant itself can degrade or become contaminated, leading to potential corrosion or freezing issues. Finally, thermostats and sensors can fail completely, preventing proper cooling and/or coolant temperature readings to become inaccurate.
To make sure you are not left stranded on the side of the road with an overheated engine, we have put together this Basic Cooling System Service kit. This kit contains all of the most-likely-to-fail components, giving you peace of mind knowing your engine will continue to run cool for another 60,000+ miles.
See kit contents below for all included components.
This product was last offered at the strikethrough price on
07-09-2026
This product was last offered at the strikethrough price on
07-09-2026
If you plan to drive your BMW aggressively on the track, it is important that you upgrade your cooling system to avoid overheating. To ensure your BMW keeps cool on the track, we have built out our new High Performance Cooling System Upgrade kits. Featured in this kit is everything you will need to redo your cooling system from top to bottom with OEM components, with select stock components swapped out for the high performance alternative! This kit includes a high performance Mishimoto Radiator for significantly better cooling than the stock radiator and full aluminum construction that won't crack from long term heat cycling, and a Genuine BMW Motorsport 55*C thermostat, for lower temperature operation and increased cooling of the engine.
Additional items included in this kit:
This product was last offered at the strikethrough price on
06-13-2026
This product was last offered at the strikethrough price on
06-13-2026
MSRP stands for Manufacturer's Suggested Retail Price. This is the suggested retail price provided by the manufacturer, supplier or seller.
MSRP stands for Manufacturer's Suggested Retail Price. This is the suggested retail price provided by the manufacturer, supplier or seller.