BMW Cooling System Parts & Accessories for BMW E46 M3 S54 (1999-2005)

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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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Meyle Expansion Tank Cap
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Meyle - Corporate Logo
T#:579357
Part#: 3148009004
In Stock
Sale - Save 40% $ 14.99

This product was last offered at the strikethrough price on
05-15-2026

$ 8.99 USD
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$ 14.99

This product was last offered at the strikethrough price on
05-15-2026

$ 8.99 USD
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Replace worn or missing pieces.
Febi Temperature Sensor
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Febi - Corporate Logo
T#:340711
Part#: 13621433076
In Stock at Vendor
$ 17.99

This product was last offered at the strikethrough price on
06-22-2026

$ 16.99 USD
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$ 16.99 USD
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Monitors coolant / oil temperature
40-60mm 3/8"/9mm Band Hose Clamp
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ECS - Corporate Logo
T#:341280
Part#: 003402ECS06A-08
In Stock
Sale - Save 25% $ 3.99

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

$ 2.99 USD
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$ 3.99

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

$ 2.99 USD
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ECS Tuning 304 Stainless Steel Hose Clamps

Revolutionize your car maintenance with ECS Tuning's premium 304 stainless steel hose clamps. Eliminate dealership delays and inflated prices! These German-style clamps utilize T-bolts for hassle-free diameter adjustment. With various band widths available, these durable clamps ensure reliability without the hefty cost. Experience dealership-quality products at affordable rates, exclusively at ECS Tuning.

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Temperature Sensor
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URO - Corporate Logo
T#:37892090
Part#: 13621433076
In Stock
$ 10.34 USD
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Temperature sensor for monitoring coolant and oil

Genuine BMW Engine O-ring S54 3.2L 11537830709
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Genuine BMW - Corporate Logo
T#:13012
Part#: 11537830709
In Stock
$ 6.99 USD
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Ensure your BMW remains leak-free by replacing all associated O-Rings when replacing the water pump. If experiencing leaks, inspect these rings for wear and tear. This O-Ring is specifically used on the return pipe to the thermostat housing.

  • Prevents leaks for enhanced car performance
  • Essential for maintaining a leak-free system
  • Inspects and replaces worn O-Rings for optimal functionality
  • Compatible with BMW models for hassle-free installation
GENUINE BMW O-RING:11709521.--

This item fits the following BMWs:
BMW M Series - M3, M3 Convertible
BMW Z Series - Z4 M Coupe, Z4 M Roadster

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Genuine BMW O-Ring - Priced Each
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Genuine BMW - Corporate Logo
T#:367933
Part#: 17222245358
In Stock
$ 3.99 USD
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Upgrade your BMW's oil or transmission cooling system with the Turner Motorsport Genuine O-Ring, part number 17222245358. This high-quality O-ring is designed to provide a reliable seal, ensuring optimal performance and preventing leaks in your BMW's vital systems. Additionally, it is compatible with MINI applications, where it is commonly used on the end of the parking brake cable.

  • Genuine BMW part for guaranteed quality and compatibility
  • Prevents leaks in the oil and transmission cooling systems
  • Ensures optimal performance of vital components
  • Compatible with MINI applications for versatile use
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Bremmen Auxiliary Fan Temperature Switch - E46 E39 E9X E60 E70 E53 ...
Mounted in upper radiator hose, controls operation of auxiliary fan
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Bremmen Parts - Corporate Logo
T#:640141
Part#: 13621433077
In Stock
Sale - Save 20% $ 20.99

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

$ 16.79 USD
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$ 20.99

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

$ 16.79 USD
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The auxiliary fan switch activates the auxiliary cooling fan to provide additional cooling under high heat loads, and when the car is stationary
OEM Rein Expansion Tank Cap - BMW E32 E34 E36 E38 E39 E46 & More ...
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Rein - Corporate Logo
T#:340541
Part#: 17111742231
In Stock
$ 17.99 USD
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This radiator expansion tank cap is used most BMW's from 1991-2006. It is a common failure item. When this item fails, it cannot hold pressure which results in your BMW overheating. If you are overhauling your coolant system, now is the time to consider preventative replacing this cap. It is also referred to as the coolant reservoir cap.
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Genuine BMW Coolant Bleeder Screw 17111712788
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Genuine BMW - Corporate Logo
T#:7432
Part#: 17111712788
In Stock
$ 5.94 USD
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This is the Genuine BMW Coolant bleeder screw. We recommend a heavy duty Aluminum replacement from ECS Tuning if you do not want to replace this part again when it fails.


Genuine BMW Vent Screw
This item fits the following BMW Chassis:
E36 M3,E46 M3,E85 Z4M,E53 48IS,E30,E34,E36,E38,E39,E46,E53 X5 X5,E83 X3,E85 Z4,E86 Z4,E90
 

 

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1/2"/12mm Band Hose Clamp - 25-40mm - Priced Each
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ECS - Corporate Logo
T#:385425
Part#: 003402ECS05A-06
In Stock
Sale - Save 25% $ 4.99

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

$ 3.74 USD
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Sale - Save 25%
$ 4.99

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

$ 3.74 USD
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Upgrade Your BMW Maintenance with Stainless Steel Hose Clamps from ECS Tuning

ECS Tuning introduces premium full stainless steel hose clamps, offering superior quality and convenience for your BMW maintenance. Avoid dealership delays and overpricing by choosing from a selection of band widths, ensuring you receive top-quality hose clamps without overpaying.

Key Benefits:

  • Premium full stainless steel hose clamps
  • Various band widths for enhanced convenience
  • High-quality alternative to dealership pricing
  • Readily available stock eliminates waiting time
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60-80mm 1/2"/12mm Band Hose Clamp
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ECS - Corporate Logo
T#:377836
Part#: 003402ECS05A-10
In Stock
Sale - Save 25% $ 6.99

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

$ 5.24 USD
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Sale - Save 25%
$ 6.99

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

$ 5.24 USD
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ECS Tuning Stainless Steel Hose Clamps for BMW

Upgrade your BMW's hose clamps with ECS Tuning Stainless Steel Hose Clamps, designed for convenience and durability. Say goodbye to long waits and overpriced dealership clamps. With various band widths available, these stainless steel clamps ensure a secure fit for your vehicle's hoses.

Benefits:

  • Convenient replacement for worn-out hose clamps
  • Made of durable stainless steel for long-lasting performance
  • Available in various band widths for versatile use
  • Affordable alternative to dealership pricing
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Schwaben 32mm / 36mm Fan Clutch and Oil Filter Cap Open-End Wrench ...
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Schwaben - Corporate Logo
T#:361021
Part#: DO-3236
In Stock
Sale - Save 25% $ 25.99

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

$ 19.49 USD
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$ 25.99

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

$ 19.49 USD
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Why buy two tools when you can get one that will do many jobs like this open end wrench? It is great for removing and installing the fan clutch and plastic oil filter cap. Also works great for removing and installing the VAN0S solenoid on M50 engine family. Use the same tools the Turner Motorsport tech's use!

Features:

  • Made of Chrome Vanadium Steel for strength
  • 32/36mm open end sides

 

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