BMW Coolant Expansion Tanks

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.

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.

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

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

BMW N47 N55 Expansion Tank from Turner Motorsport is a high-quality replacement designed to address issues with cracked or damaged coolant expansion tanks. Engineered for durability and performance, this expansion tank ensures reliable cooling system function.

• Durable Construction: Built to withstand high temperatures and pressure, ensuring long-term reliability.
• Direct Replacement: Engineered as a precise fit for BMW N47 and N55 engines, making installation straightforward and hassle-free.
• Enhanced Cooling Efficiency: Maintains optimal coolant levels and pressure for effective engine cooling.
• High-Quality Materials: Manufactured from premium materials to resist cracking and leaks.

• Features a billet radiator-style neck for enhanced durability
• Resolves expansion tank issues with a solid, built-in mount
• Eliminates worries about separating and leaking plastic tanks
• Perfectly complements Canton Racing 77-272 MINI power steering tank

The coolant expansion tank provides hot coolant with a place to travel, preventing pressure buildup within your cooling system. On many BMWs, this component is constructed from plastic. While cheap to replace and manufacture, a failed cooling tank can cause costly engine damage.

With this issue in mind, Moroso designed a high-quality replacement. Featuring TIG welded, 100% aluminum construction, this tank is sure to outperform it's factory counterpart.

Features:

Key Benefits:

Direct bolt-in replacement for stock, 2 piece plastic tank Fabricated Aluminum for strength, factory tanks fail after repeated high heat situations & age Features billet aluminum mounting tab/bleeder assembly for strength and precision No cutting of factory hoses is required and accepts the factory clip-on hose Moroso part (63324) racing radiator cap included; operates in the same pressure range as the factory cap Moroso radiator cap mounts to a billet aluminum neck that will not strip out like plastic threaded necks This aluminum tank can be polished, chromed, powder coated or left as-is

The coolant expansion tank provides hot coolant with a place to travel, preventing pressure buildup within your cooling system. On many BMWs, this component is constructed from plastic. While cheap to replace and manufacture, a failed cooling tank can cause costly engine damage.

With this issue in mind, Moroso designed a high-quality replacement. Featuring TIG welded, 100% aluminum construction, this tank is sure to outperform it's factory counterpart.

Features:

Bolt-in replacement for stock cracked or discolored tanks Fabricated aluminum Features billet aluminum filler neck and integrated sight glass to monitor coolant level Can be polished, painted, powder coated or left as-is Moroso radiator cap (63320) included

Take your BMW’s cooling system to the next level with this Turner Motorsport Cooling Upgrade Kit. Featuring a Heavy-Duty Aluminum Expansion Tank and a Mechanical Thermostat Conversion Kit, this combo is engineered to deliver ultimate reliability and superior performance for M52TU/M54 engines. Say goodbye to the cooling system failures common in stock setups—Turner Motorsport has you covered.

Turner Motorsport M52TU/M54 Heavy-Duty Expansion Tank Kit

The Turner Motorsport Aluminum Expansion Tank is a premium upgrade designed to replace the fragile factory plastic tank, which is known to crack, leak, or even explode. Crafted for durability, this tank’s all-aluminum construction with wrinkle black powder coating ensures this is the last expansion tank you’ll ever need.

Why Upgrade? The factory plastic tanks on BMW M52TU/M54 engines are notorious for failure under heat and pressure. Avoid the risk of being stranded on the side of the road with a mess of coolant—Turner Motorsport’s aluminum expansion tank is built to withstand years of demanding use and intense heat cycles.

Key Features and Benefits:

Complete Kit: Includes Turner Aluminum Expansion Tank, coolant level sensor, expansion tank cap, and flared coolant pressure release line. OEM Fit & Capacity: Direct fit with no modifications, maintains stock coolant capacity and expansion volume. Baffled Design: Prevents air pockets during aggressive driving and ensures accurate coolant level readings. Premium Construction: TIG-welded 5052 aluminum with machined fittings for factory hose compatibility. Turner Motorsport M52TU/M54 Mechanical Thermostat Conversion Kit

Replace your problematic factory plastic thermostat housing with Turner Motorsport’s high-quality billet aluminum Thermostat Conversion Kit. This upgrade not only provides increased reliability but also allows for thermostat swaps to suit specific temperature requirements, making it ideal for daily drivers and track cars alike.

Why Make the Switch? The factory plastic thermostat housing with its built-in thermostat is prone to cracking and requires the whole unit to be replaced during maintenance. Turner’s conversion kit changes the game by providing a durable billet housing with a replaceable thermostat for flexibility and lower maintenance costs.

Key Features and Benefits:

Increased Reliability: Uses an M50/S50 mechanical thermostat, including an 80°C thermostat for enhanced cooling control. Customizable: Includes barbed hose connections for standard E46 M3 hoses and -16 ORB connections for custom hoses. Engineered to Last: CNC-machined from billet 6061 aluminum and black anodized for corrosion resistance. Enhanced Sealing: Features a Viton gasket for superior durability and sealing performance. Kit Includes:

6061 Billet Aluminum Thermostat Housing 80°C Mechanical Thermostat Thermostat Housing Gasket Thermostat Harness ECS Silicone E46 M3 Cooling Hoses Turner Motorsport Precision Engineering & Product Development

Every component in this cooling upgrade kit has been rigorously designed, engineered, and tested by Turner Motorsport’s Research and Development team. Using state-of-the-art technology such as FARO laser scanning, SolidWorks 3D modeling, and in-house rapid prototyping, Turner ensures that these products meet the highest standards of quality, precision, and durability.

Upgrade your BMW with confidence—Turner Motorsport is your partner in performance and reliability.