BMW Cooling System Parts & Accessories for BMW E90 M3 S65 4.0L

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The cooling system is arguably the weakest point in numerous BMWs. If you drive an aging BMW or plan on taking your car to the track like we do, we recommend beefing up your cooling system before going to the track. Generally, the main components in your cooling system that are prone to failure include the following: expansion tank, factory hoses, water pump, thermostat, fan (especially if your vehicle comes factory with a clutch fan), and radiator. Factory BMW expansion tanks are plastic and prone to either breaking off at connection points or combusting. As factory rubber hoses age they either crack or break over time - we offer silicone cooling hose upgrades for most applications to avoid future failures. If you have an older vehicle, your water pump likely comes from the factory with a plastic impeller - we offer upgraded water pumps with metal impellers that are far more reliable. Newer model BMWs utilize electric water pumps - BMW spent millions of dollars engineering these water pumps, but they fail so often that we recommend replacing at 60,000 mile service intervals to avoid being stranded on the side of the road. In terms of thermostats, we offer various upgraded thermostats for racing applications. If your BMW utilizes a clutch fan from the factory, we have several options available in terms of universal electric fans - we recommend replacing these to avoid sending brittle plastic fan blades through your hood. For radiators, we recommend swapping out your radiator for one that does not use plastic connection points like your factory radiator.

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S65 Heavy Duty Aluminum Expansion Tank Kit - E9x M3
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Turner Motorsport - Corporate Logo
T#:36981082
Part#: 054921LA02
Ships in 7 Business Days
Sale - Save 15% $ 458.99

This product was last offered at the strikethrough price on
06-14-2026

$ 390.99 USD
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Sale - Save 15%
$ 458.99

This product was last offered at the strikethrough price on
06-14-2026

$ 390.99 USD
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BMW is well-known for its 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 E90 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 E90 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
Billet coolant bleeder screw
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:

- Click HERE for Installation Instructions -

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OEM Style Hose Clamps
10X Entries Into Our F80 M3 Sweepstakes
Turner Motorsport - Corporate Logo
T#:338927
Part#: HOSE-CLAMPS
In Stock
Sale - Save 3% $ 3.99

This product was last offered at the strikethrough price on
06-13-2026

Starting at $ 3.87 USD
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Sale - Save 3%
$ 3.99

This product was last offered at the strikethrough price on
06-13-2026

Starting at $ 3.87 USD
Free Shipping on orders $49 and up
Hose clamps for radiator hoses, coolant hoses, vacuum hoses, or intake hoses. These hose clamps are the same style as your OEM hoses with a smooth inside band to prevent cutting into the hose material.
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Coolant Vacuum Purge & Refill Tool Set
10X Entries Into Our F80 M3 Sweepstakes
Schwaben - Corporate Logo
T#:402498
Part#: 024948SCH01A
In Stock
Sale - Save 22% $ 115.99

This product was last offered at the strikethrough price on
05-03-2026

$ 89.99 USD
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Sale - Save 22%
$ 115.99

This product was last offered at the strikethrough price on
05-03-2026

$ 89.99 USD
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The Schwaben Coolant Vacuum Fill Tool ensures no air pockets get into your cooling system while you're replacing your coolant - intended for use to refill your cooling system, not for removal. Can be used with Schwaben fluid extractors or with shop air - standard air compressor with a minimum rating of 90 PSI (6.2 bar). Includes all fittings and adapters necessary for use, with a molded storage case to keep your Schwaben Vacuum Fill Tool pristine for future use.
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Schwaben Coolant Refill/Air Purge Tool
10X Entries Into Our F80 M3 Sweepstakes
Schwaben - Corporate Logo
T#:362940
Part#: 003466SCH01
In Stock
Sale - Save 20% $ 112.99

This product was last offered at the strikethrough price on
09-29-2026

$ 90.39 USD
Free Shipping on orders $49 and up
Sale - Save 20%
$ 112.99

This product was last offered at the strikethrough price on
09-29-2026

$ 90.39 USD
Free Shipping on orders $49 and up
When it comes to BMW's we all know the weak point is commonly in the cooling system, many models proving hard to bleed the air pockets out after the refresh. The coolant refill tool solves this problem, ensuring that you get an air pocket free fill. The entire task is as simple as draining the system like normal, reinstalling the drain plugs and hooking the tool up to your refill location. The reason this tool works so well is due to the venturi valve, it converts air pressure from the compressor to vacuum inside the cooling system, then with a twist of a valve sucks coolant right into the system using the vacuum pressure.
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Schwaben Locking Hose Clamp Pliers
10X Entries Into Our F80 M3 Sweepstakes
Schwaben - Corporate Logo
T#:377131
Part#: 004170SCH01A
Ships on Oct 28, 2026
$ 63.99

This product was last offered at the strikethrough price on
05-02-2026

$ 57.99 USD
Free Shipping on orders $49 and up
$ 57.99 USD
Free Shipping on orders $49 and up
These pliers feature a spring loaded clamp with a 24" cable and will lock onto the clamp and hold open for easy removal. These pliers are designed to remove metal or plastic self-tightening hose clamps with diameters from 11/16" to 2-1/2" ( 18 to 54mm).
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Radiator Pressure Tester Kit
10X Entries Into Our F80 M3 Sweepstakes
Schwaben - Corporate Logo
T#:391482
Part#: 014710SCH01A
In Stock
Sale - Save 25% $ 205.99

MSRP stands for Manufacturer's Suggested Retail Price. This is the suggested retail price provided by the manufacturer, supplier or seller.

$ 154.49 USD
Free Shipping on orders $49 and up
Sale - Save 25%
$ 205.99

This product was last offered at the strikethrough price on
05-03-2026

$ 154.49 USD
Free Shipping on orders $49 and up
Are you refreshing your coolant system or having issues with coolant loss? An easy way to test your system for leaks and ensure you're able to maintain pressure without coolant loss is the Schwaben Cooling System Pressure Tester Kit.
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Schwaben Locking Hose Pinch-Off Pliers
10X Entries Into Our F80 M3 Sweepstakes
Schwaben - Corporate Logo
T#:379950
Part#: 009787SCH01A
In Stock
Sale - Save 15% $ 39.99

This product was last offered at the strikethrough price on
05-02-2026

$ 33.99 USD
Free Shipping on orders $49 and up
Sale - Save 15%
$ 39.99

This product was last offered at the strikethrough price on
05-02-2026

$ 33.99 USD
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Schwaben Locking Hose Pinch-Off Pliers have adequate clamping force to effectively seal large or pressurized cooling system hoses. These pliers are ideal for clamping shut most hoses, ensuring reliability in your automotive tasks. With swivel jaws, they provide even clamping force, making them a versatile tool for various applications.

  • Adequate clamping force for large or pressurized hoses
  • Ideal for clamping shut most hoses
  • Swivel jaws ensure even clamping force
  • Versatile tool for automotive maintenance

WARNING: This product contains chemicals known to the state of California to cause cancer, birth defects, and/or reproductive harm. For more information, visit http://www.p65warnings.ca.gov.

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Gear Wrench - Corporate Logo
T#:387079
Part#: KDT3977
Ships in 2 Business Days
$ 53.99 USD
Free Shipping on orders $49 and up
This tool is a variation of our popular 3976 Flat Band Hose Clamp Pliers and features 45º jaws with swivel tips to grip at any angle and pliers that latch securely in position.

Schwaben Radiator/ Intercooler Fin Comb
10X Entries Into Our F80 M3 Sweepstakes
Schwaben - Corporate Logo
T#:384260
Part#: 015326SCH01A
In Stock
Sale - Save 29% $ 20.99

This product was last offered at the strikethrough price on
05-02-2026

$ 14.99 USD
Free Shipping on orders $49 and up
Sale - Save 29%
$ 20.99

This product was last offered at the strikethrough price on
05-02-2026

$ 14.99 USD
Free Shipping on orders $49 and up
Straighten bent fins in heat exchangers like radiators, condensers, and intercoolers obstruct air flow and reduce heat transfer. Paper-thin fins are easily bent, even by slight pressure.