BMW Cooling System Parts & Accessories for BMW 1 Series

Our Turner Motorsport's full aluminum expansion tank was designed and engineered in house to help with the weak point in your N52/N54 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
Heavy duty bleeder screw
Flared coolant pressure release line
Hardware for installation

Upgraded or replacement silicone heater hose for our N54 expansion tank relocation kits.

60" silicone performance coolant hose featuring a molded 90-degree bend for installs with space constraints.

Features and benefits:

Constructed of 4-Ply reinforced silicone for improved durability over the failure-prone rubber hoses.
Reduced thermal conductivity
Improved resistance to ozone and UV degradation for improved performance and durability.
Turner branded

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.