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

This packages covers the major components you would install along with a new water pump or thermostat. On the N54 cars (135i, 335i, 535i) the water pump and theremostat are mounted together. In fact, to get to the thermostat, BMW expects you to remove the water pump. This package covers the whole job. With the electric water pump now an integral part of the efficiency and performance of the engine, staying on top of its maintenance and replacement is the smart thing to do.

Our water pump/thermostat overhaul includes:

• OEM VDO electric water pump, p/n 11517588885 or 11517632426
• OEM mounting screws for water pump (set of 3), p/n 11517602123
• OEM Behr thermostat, p/n 11537549476
• Original BMW connecting hose from thermostat to water pump, p/n 11537545665
• Original BMW hose clamps for hose (x 2)
  
• BUY AS A PACKAGE AND SAVE $$!
  
  The water pump on the N54 engine has more cooling responsibilities than ever before. Not only must it provide cooling for the engine, but it's also pumping fluid used to cool the turbocharger oil and automatic transmission oil. The good news is that the pump only works when, and only as much, as it needs to. The engine computer dictates how much fluid needs to be pumped through the system depending on the load. That means the system can actually stop the pump when warmer temperatures are needed. No longer is the pump spinning all the time from an engine-driven belt. The bad news is that it's now an electrical part, so a failure is usually immediate and with no warning. And if the electronics are at fault, there is no way to rebuild or repair it. Fortunately, the engine computer will force a shut down or reduce power if a problem occurs, preventing catastrophic engine damage.
  
  How to avoid a water pump failure in the future? Replacing the water pump as part of a regular interval schedule will ensure you always have a functioning pump in place. Since this technology is relatively new for BMW, therefore the lifecycle of the pump isn't yet known, we have been recommending replacement every 80-100k miles. This package of OE/OEM parts covers everything with Original BMW coolant offered to finish off the job. A proper bleeding procedure must be followed with the new electric pump.
  
  This water pump package fits the following BMWs with the N54 engine:
  2007-2010 E60 BMW 535i 535xi 535i xDrive
  2008-2010 E82 BMW 135i
  2011-2012 E82 BMW 1M Coupe
  2006-2010 E90 BMW 335i 335xi 335i xDrive - Sedan
  2007-2010 E92 BMW 335i 335is 335xi 335i xDrive - Coupe
  2007-2010 E93 BMW 335i - Convertible

The water pumps in these BMW models are known for failure near 80,000 miles is a very common issue often times leaving the owner stranded. This kit provides a single stop for water pump and thermostat replacement needs to save the search and get you back on the road.

Kit includes:

• OEM Wahler Thermostat
• OEM VDO Electric Water Pump
• Genuine BMW Antifreeze/Coolant
• OEM VDO Mounting hardware required for both the thermostat and water pump

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.

CSF is one of the premier cooling product specialists available on the market thanks to designs such as their High Performance Aluminum Radiators. Using a single pass designed core, this radiator gives you all the cooling you could ever need. Paired with these radiators are CNC machined brackets and corrosion resistant hardware that allow final installation to have a same as stock fitment! This enables you to have much higher cooling without having to cut away any metal or delete any important components just for the sake of lower coolant temperatures. 

Features:

• Two-row, triple-pass design radiator core
• CNC machined mounting brackets
• All needed hardware included
• Hand polished aluminum with a mirror-like finish
• Stock fitment prevents modification to engine bay

Fits the following BMWs:
2007-2011 E82/E88 BMW 135i, 1 M Coupe with automatic transmission
2006-2012 E9X BMW 335i/is with automatic transmission
2009+ E89 BMW Z4 30i 35i/is

Upgrade your BMW's cooling system with the Turner Motorsport Mahle Coolant Expansion Tank. This essential component provides additional space for coolant expansion and contraction, ensuring optimal performance in varying temperatures. Designed to withstand drastic temperature changes, this expansion tank prevents coolant leaks and maintains proper coolant levels in your vehicle. Replace your damaged tank to keep your BMW's cooling system running smoothly.

Key Benefits:

• Prevents coolant leaks and loss
• Ensures proper coolant expansion and contraction
• Durable construction for long-lasting performance
• Direct replacement for damaged tanks
• Compatible with various BMW models

CSF is one of the premier cooling product specialists available on the market thanks to designs such as their High Performance Aluminum Radiators. Using a single pass designed core, this radiator gives you all the cooling you could ever need. Paired with these radiators are CNC machined brackets and corrosion resistant hardware that allow final installation to have a same as stock fitment! This enables you to have much higher cooling without having to cut away any metal or delete any important components just for the sake of lower coolant temperatures. 

Features:

• Two-row, triple-pass design radiator core
• CNC machined mounting brackets
• All needed hardware included
• Hand polished aluminum with a mirror-like finish
• Stock fitment prevents modification to engine bay

Fits the following BMWs:
2007-2011 E82/E88 BMW 135i, 1 M Coupe with manual transmission
2006-2012 BMW 335i/is with manual transmission

Enhance the flexibility of your BMW's coolant system with the Vargas Turbo Technologies 90-Degree Coolant Tank Fitting. Ideal for applications such as single turbo setups or forward-facing intake manifolds, this fitting provides extra clearance and versatile hose routing options.

Key Benefits:

• Allows hose to run straight down, increasing clearance
• Made of durable 6061-T6 aluminum for long-lasting performance
• Anodized black finish for enhanced durability and corrosion resistance
• Includes fitting and clamp for easy installation

Upgrade your BMW's coolant system with the Vargas Turbo Technologies 90-Degree Coolant Tank Fitting for improved performance and versatility.

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. 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: 17127531579 & 17127564478

This is the upper radiator hose that goes from the engine to the top of the radiator with either N51 or N52 enigne.

This item fits the following BMWs:
2008+ E82 BMW 128i
2006-2011 E90 BMW 325i 325xi 328i 328xi 328i xDrive 330i 330xi - Sedan
2006-2012 E91 BMW 325xi 328i 328xi 328i xDrive - Wagon
2007-2013 E92 BMW 328i 328xi 328i xDrive - Coupe
2007-2013 E93 BMW 328i Convertible
2009+ Z4 BMW Z4 sDrive30i