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

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.)

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:

• radiator
• water pump
• thermostat
• radiator hoses and clamps
• gaskets and o-rings

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:

• Original BMW coolant
• fan clutch
• main serpentine belt and A/C belt
• Turner Power Pulley Kit (because now is the perfect time!)

This cooling overhaul package fits:
2001-2006 E46 BMW M3
 

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:

• ECS Tuning Silicone Replacement Coolant Hoses - For increased reliability over stock rubber hoses
• ECS Tuning Heavy Duty Aluminum Bleeder Screw
• OEM Expansion Tank, Cap, and Level Sensor
• OEM Belts, Tensioners, and Pulleys
• OEM Auxiliary Fan Switch
• Genuine BMW Hardware for Easy Installation
• ECS Tuning Aluminum Water Pump Pulley - For increased reliability over the stock composite pulley

Replace the flimsy plastic bleeder screw used in the coolant expansion tank or in one of the cooling system hoses with this high quality, durable, aluminum bleeder screw. The stock plastic screw can deform over time due to heat or even regular use. We have even seen the head of the screw snap off, leaving the threaded body stuck in the expansion tank. This aluminum screw will help to prevent sudden failure of the bleeder screw, which can result in immediate overheating of the car.

ECS Tuning's Aluminum Coolant Bleeder Screw replaces Genuine BMW Part Number 17111712788

Replace your cracked or leaking radiator hose to prevent further leaks and potentially catastrophic failure. This hose replaces the Upper radiator hose that connects the thermostat housing to the radiator.

This Upper Radiator Hose fits the following BMWs:
2001-2006 E46 3 Series M3, M3 Convertible

This OEM Hella/Mahle-Behr engine fan clutch fits BMW E46 M3, Z3 M Roadster, M Coupe 2001-2002, E34 535i & M5, and E32 735i 735il. Made to the same or higher standards of quality as the genuine part, ensuring proper fan control and cooling. Failed fan clutches can result in overheating due to the fan not spinning fast enough to deal with excess heat or can cause poor engine performance when a clutch has locked up causing the fan to be fully engaged permanently.

Hella is a premium manufacturer that supplies automotive parts to numerous car brands across the world. Everything from electrical to mechanical genuine parts have been made and supplied directly to BMW before the vehicles ever leave the production floor. Their high quality, long lasting parts have made them a trusted brand chosen to help keep your BMW on the road for many years to come.

As a leading source of high performance BMW parts and accessories since 1993, we at Turner Motorsport are honored to be the go-to supplier for tens of thousands of enthusiasts the world over. With over two decades of parts, service, and racing experience under our belt, we provide only quality performance and replacement parts.  All of our performance parts are those we would (and do!) install and run on our own cars, as well as replacement parts that are Genuine BMW or from OEM manufacturers. We only offer parts we know you can trust to perform!

This item fits the following BMWs:
2001-2006 E46 BMW M3
1989-1993 E34 BMW 535i M5
1988-1992 E32 BMW 735i 735il
2001-2002 Z3 BMW M Roadster M Roadster

The ECS Exact-fit water line is a perfect upgrade if you're tired of dealing with brittle failure prone parts under your hood. The reinforced fluorosilicone hose has been pre-formed to route the same way your stock line did so you can maintain that clean factory installed appearance. Upgrading the line fitting with a billet aluminum piece eliminates the failure prone plastic fitting giving your cooling system strength.

Included:

Aluminum fitting

• Material: 6061-T6 Aluminum - MIL-A-8625F Type II Class 2 black anodized for superior corrosion resistance and strength
• Single-piece design avoiding additional interfaces that may cause leaks
• Matches OEM style connection to upper coolant hose

Silicone hose

• Material: Black Reinforced Fluorosilicone Lined Coolant Safe Silicone
• Pre-formed hose to ensure OEM style routing and appearance
• Can maintain the use of your stock retaining clips to route the hose in identical locations (due to slight variations in silicone the retainer on the expansion tank may not fit)
• Pressure tested to ensure 2X operating pressures to ensure reliability

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The BMW E30 / E36 / E46 Offset Lower Radiator Mounts are designed to provide enhanced support and positioning for the radiator in BMW models, specifically the E30, E36, and E46. These mounts are a practical upgrade for vehicles that require extra clearance, especially when using aftermarket or larger radiators in performance builds.

Key Features:

1. Offset Design for Increased Clearance:

   • The offset configuration of these mounts offers additional room, making them ideal for accommodating larger radiators or custom cooling setups. This ensures proper fitment, especially in high-performance or modified vehicles.

2. Stable and Secure Mounting:

   • These mounts provide firm support to keep the radiator securely in place, preventing unwanted movement or vibration, which is crucial for maintaining the cooling system’s efficiency during intense driving conditions.

3. Durability and Heat Resistance:

   • Built from high-quality, heat-resistant materials, these mounts are designed to withstand the rigors of both daily driving and track use. They ensure long-lasting performance even under high temperatures and stress.

4. Optimized Cooling Performance:

   • By ensuring the radiator is properly aligned and secured, these mounts help maximize the cooling system's performance. Proper positioning allows for efficient airflow through the radiator, which is vital for preventing overheating during demanding driving situations.

5. Easy Installation:

   • These offset radiator mounts are designed as a direct-fit replacement, making installation simple and straightforward. They are compatible with the BMW E30, E36, and E46, allowing for an easy upgrade to support larger or performance-focused radiators.

6. Perfect for Modified and Performance Builds:

   • Whether you're upgrading to a high-capacity radiator or modifying your vehicle for improved performance, these mounts offer the extra flexibility and stability needed for customized setups.

Benefits of Upgrading or Replacing:

• Extra Clearance for Larger Radiators: The offset design allows for better fitment, especially when upgrading to a larger or aftermarket radiator.
• Prevents Vibration and Damage: These mounts reduce the risk of damage caused by vibration or radiator movement, ensuring longer-lasting performance.
• Enhanced Cooling Efficiency: Properly securing the radiator ensures that it can work at peak efficiency, leading to better cooling performance during high-demand driving.

In summary, the BMW E30 / E36 / E46 Offset Lower Radiator Mounts are an excellent choice for enthusiasts looking to upgrade their cooling system or accommodate a larger radiator. Their durable construction, ease of installation, and offset design make them a valuable addition for performance builds or maintaining cooling system reliability in modified BMWs.