BMW Cooling System Parts & Accessories

Our Turner Motorsport's full aluminum expansion tank was designed and engineered in house to help with the weak point in your E46 cooling system. The coolant expansion tank goes through heat cycles over and over again from regular driving, it is important that your expansion tank is doing its job to retain coolant to keep your engine operating temperatures down and keep your engine bay clean. Not only is this a major upgrade but also a great maintenance item to replace. Our expansion tank was designed to fit the OEM hoses for an easy install and comes with all the upgraded items you will need for a clean install.

If your BMW needs a new expansion tank, make sure this is the last expansion tank you ever need to buy. Our coolant expansion tank has a full aluminum construction and wrinkle black powder coat for durability. Expansion tank kit comes with all the accessories you need to replace your expansion tank once, and never have to worry about it again.

Product Features:

Maintains stock coolant capacity and expansion volume
Designed to maintain OE coolant elevation, preventing air pockets
Baffled tank ensures that air pockets cannot be introduced during aggressive driving and provides accurate coolant level reading
Carefully designed bleed passage prevents the introduction of air as the engine cools
Turner engraved internal fill level
TIG welded 5052 aluminum construction
All bungs are machined to fit factory hose ends
Kit contents:

Turner Aluminum Expansion Tank
Coolant level sensor
Expansion tank cap
Flared coolant pressure release line
Hardware for installation
Product Development:

Turner expansion tanks are designed, engineered, tested and quality inspected by our Research and Development team at Turner. Nothing but 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.

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 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 E9X N55 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 E82/88 and E90/92/93 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 N55-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. Kit Includes:

Turner Motorsport Aluminum Expansion Tank Performance Silicone Coolant Overflow Hose Aluminum Coolant Bleeder Screw Ball Stud 6mm Fitting 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.

Installation:

To aid in the installation process, we've assembled a start-to-finish installation guide, including detailed instructions on removing your factory cooling expansion tank and associated components.

Click HERE for Installation Instructions

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

Track-tested and street-ready. the ULTIMATE cooling system upgrade for your N54 or N55!

Ditch your failure-prone plastic end tanks and increase cooling capacity by 25%, all without modifying your core support or accompanying shrouds. The CSFxTurner Performance Triple-Pass Radiator is the best cooling system upgrade for your N54/N55-equipped BMW!

The BMW 135i and 335i deliver serious performance straight from the factory, thanks to the twin-turbocharged N54 and single-turbo N55 engines. With strong midrange torque, high-revving capabilities, and proven tuning potential, these engines punch well above their weight. However, while the powertrain excels, the factory cooling system often falls short, especially under sustained boost or track conditions. Heat soak, rising coolant temps, and long-term thermal stress are common issues for enthusiasts pushing their N54 or N55 hard, making a performance radiator an essential upgrade for reliability and consistency.

Recognizing the critical need for increased cooling capacity, the team at Turner Motorsport partnered with CSF Race, world leaders in high-performance cooling systems with over 50 years of experience. The result is an Upgraded Performance Radiator: a high-performance, motorsport-grade upgrade engineered to keep your N54/N55 cooler and on the track for longer.

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!
Dual Core Design
2-Row 42mm Core (Dual Core) Featuring CSF's Exclusive B-Tube Technology
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 & 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
Aluminum drain plug
Designed and tested by Turner Motorsport in collaboration with CSF Race
Backed by the Turner Lifetime Replacement Program
Every unit features precision CNC-machined brackets and OE-style connections for a seamless, drop-in installation using factory or aftermarket hoses. Whether you're building a track weapon or a high-horsepower street car, this Turner x CSF radiator is the cooling solution your N54 or N55 needs to perform reliably under pressure. All backed by the Turner Lifetime Replacement Program.

The 6-speed Getrag 420G transmission, found in the European E36 M3 Evolution and E46 M3, has become an increasingly popular swap amongst E36 owners. Its increased strength, longevity, and overdrive sixth gear make it a great choice for both track cars and daily drivers. Unfortunately, many of the components needed to complete this transplant have become hard to source. Despite increased demand from enthusiasts, BMW has blocked the sale of European E36 M3 parts into North America.

Recognizing this issue, we set out to develop a replacement for the unavailable, 420G-specific transmission crossbrace. Our initial investigation revealed that the factory cast aluminum construction was failure-prone, so durable 5GA 1018 steel was chosen to provide a lasting upgrade. The Turner Motorsport Heavy-Duty Transmission Crossmember is finished in a brilliant silver powder coat to resist corrosion and maximize appearance. Despite being much stronger than the factory crossmember, our design is dimensionally identical, ensuring a perfect fit with your six-speed swap.

Design:

Manufactured from durable 5GA 1018 steel - much stronger than OEM cast aluminum construction Finished in brilliant silver powder coating for maximum corrosion resistance Steel gussets are welded to the main bracket for added strength and power-holding capability Integrated locating dowels prevent bushing rotation and ensure proper alignment under load Dimensionally identical to the OEM part - fully compatible with OE-style bushings and factory hardware Features & Benefits:

Direct replacement for Genuine European BMW part number 23702227892 Finished in brilliant silver powder coating for maximum corrosion resistance Retains factory mounting points and driveline geometry for hassle-free installation Product Development:

Our Heavy Duty Transmission Crossmember was designed, engineered, tested, and quality inspected by our Research and Development team. We strive for nothing but 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.

Tired of dealing with brittle, dry-rotted rubber hoses? Whether you're refreshing your cooling system or replacing aging components, our 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, Turner Motorsport 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.

Replaces OEM Part Numbers: 11537848501 & 11537848502. Can be used with your factory connectors.

BMWs are well-known for their problematic cooling systems, which often lead to irreversible engine damage and hefty repair bills. The coolant expansion tank—a crucial component that holds hot engine coolant under high pressure—is a common cause of cooling system issues. Unfortunately, BMW chose to manufacture the factory E30 expansion tank out of plastic. After decades 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 E30 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 E30 today and drive with confidence!

OEM Replacement Upper Radiator Hose for E46 3 series (Not M3).

This lower radiator hose fits the following BMWs: 
1999-2000 E46 3 Series Sedan/Wagon - 323i & 328i 
1999-2000 E46 3 Series Coupe/Conbertible - 323Ci & 328Ci 
2001-2005 E46 3 Series Sedan/Wagon - 325i, 325xi, 330i, 330xi 
2001-2006 E46 3 Series Coupe/Convertible - 325Ci, 330Ci