BMW Cooling System Parts & Accessories for BMW E93 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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Radiator Lower Support & Bushing Kit
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Genuine BMW - Corporate Logo
T#:55317651
Part#: 171178RLSKT
Ships in 1 Business Day
New Item
$ 56.33 USD
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Keep your cooling system locked down on the street and the track with the Turner Motorsports Radiator Lower Support & Bushing Kit.
Vargas Coolant Hose Upgrade Kit - Black - BMW E9X M3
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Vargas Turbo Technologies - Corporate Logo
T#:52164951
Part#: S65COOLFULLBLK
Ships in 10 Business Days
New Item
$ 524.99 USD
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$ 524.99 USD
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Upgrade your BMW E9X M3’s engine bay and cooling reliability simultaneously with the Vargas Turbo Technologies S65 Billet/Silicone Full Hose Kit.
Hose Clamp 2 5/16" - 3 1/4" - priced each
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ECS - Corporate Logo
T#:376806
Part#: 54155K23
Ships in 1 day
$ 4.99 USD
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Hose Clamp 2 5/16" - 3 1/4"

Ensure secure hose connections with the Hose Clamp 2 5/16" - 3 1/4", a versatile and reliable solution for various applications. Crafted from durable materials, this clamp offers superior strength and corrosion resistance. Its adjustable design allows for a snug fit, reducing the risk of leaks and ensuring optimal performance. Upgrade your hose connections with the precision and reliability of the Hose Clamp 2 5/16" - 3 1/4".

  • Versatile and reliable solution for various applications
  • Superior strength and corrosion resistance
  • Adjustable design for a snug fit
  • Reduces risk of leaks for optimal performance
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O-RING
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Victor Reinz - Corporate Logo
T#:580584
Part#: C32348
In Stock
$ 3.99

This product was last offered at the strikethrough price on
05-07-2026

$ 2.99 USD
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$ 2.99 USD
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Anti-Freeze Tester
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CTA Tools - Corporate Logo
T#:641679
Part#: CTAA195
Ships on Jul 27, 2026
$ 9.98 USD
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Tests all ethylene glycol solutions with radiator hot or cold
2 Pin Connector
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ECS - Corporate Logo
T#:33412932
Part#: 61132359999
Ships on Jul 28, 2026
Sale - Save 25% $ 10.99

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

$ 8.24 USD
Free Shipping on orders $49 and up
Sale - Save 25%
$ 10.99

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

$ 8.24 USD
Free Shipping on orders $49 and up

Includes connector housing with terminals and seals. Commonly used for the coolant level sensor.

ECS Tuning replacement harness connectors include all necessary pins and wire seals for a complete harness repair. Whether you have a broken harness connector or need a complete wiring repair, we have the components you need.

Each connector includes an additional terminal in case one becomes lost or damaged during installation.

*OEM cross reference PN# 61132359999 - Commonly used for the coolant level sensor.

Please reference the original part number from the existing connector to confirm fitment, before ordering.

Suggested tools:

Suggested crimping pliers: T#387193
Wire De-pin tools:
12pc De-Pin Tool Set - T#386379
23pc De-Pin Tool Set - T#641943

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Bav Auto Temperature Sensor - BMW E39 E46 E9X E60 F01/02
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Bavarian Autosport - Corporate Logo
T#:639833
Part#: 13621433076
In Stock
Sale - Save 20% $ 14.99

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

$ 11.99 USD
Free Shipping on orders $49 and up
Sale - Save 20%
$ 14.99

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

$ 11.99 USD
Free Shipping on orders $49 and up
This is the coolant temperature sensor used in many BMW models from the late-1990s to the mid-2010s. The engine computer relies on the coolant temp to set the fuel mapping for the engine. As the car warms up the computer changes the fuel mixture. If your car is running a bit rich (too much fuel) it could be because this sensor is failing and not sending the correct info to the computer. This sensor is located in a variety of places depending on the engine. But it's one of those easy replacement items 'while you're in there' when doing a water pump or thermostat replacement. From 1974 to 2019, Bavarian Autosport was one of the premier vendors for BMW and MINI auto parts. We are happy to preserve the Bav Auto legacy by continuing to carry their high-quality products into the future. All Bav Auto parts will remain unchanged in design and sourced from the same OEM suppliers to ensure long-lasting reliability. We trust these parts, accessories, and upgrades so confidently that we back every Bavarian Autosport branded component with a 2-year warranty.
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Fluid Level Sensor
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We Price Match - Give Us A Call or Chat!
Meyle - Corporate Logo
T#:5973204
Part#: 17117546548
Special Order: No Guaranteed ETA
$ 13.99 USD
Free Shipping on orders $49 and up
MEYLE-ORIGINAL: True to OE fluid level sensor. Used in multiple locations. Wulf Gaertner Autoparts AG manufactures and markets automotive spare parts under its MEYLE brand. Since its foundation in 1958, Wulf Gaertner Autoparts has been an owner-operated, unlisted family business on the aftermarket scene. Since 1995, Wulf Gaertner Autoparts AG has been manufacturing and trading under its MEYLE brand. They pride themselves on top-grade quality-tested spare parts for passenger cars, vans and commercial vehicles. Comparable OE Cross Reference - 17117546548
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Moroso Aluminum Coolant Expansion Tank
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Moroso - Corporate Logo
T#:29666104
Part#: 63850
In Stock at Vendor
$ 586.00 USD
Free Shipping on orders $49 and up

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 Included is a Moroso (63324) racing radiator cap that 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 Can be polished, chromed, or powder coated or left as-is

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Radiator Support Bracket
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2X Entries For Our G87 M2 Sweepstakes! We Price Match - Give Us A Call or Chat!
Rein - Corporate Logo
T#:14122755
Part#: 17117514402
Special Order: No Guaranteed ETA
$ 8.99 USD
Free Shipping on orders $49 and up
Mounts to top of radiator bracket, 2 per vehicle.
Meistersatz Temperature Sensor
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Meistersatz - Corporate Logo
T#:379740
Part#: 13621433076
Ships in 3 Business Days
$ 15.99 USD
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Monitors coolant / oil temperature