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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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Auxiliary Fan Switch O-Ring

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T#:377077

Part#: 13621433077S

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$ 0.88 USD

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$ 0.88 USD

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Now you can just replace the o-ring instead of the whole switch

70-90mm 3/8"/9mm Band Hose Clamp

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T#:363017

Part#: 003402ECS06A-11

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$ 5.24 USD

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Upgrade your BMW with ECS Tuning's Stainless Steel Hose Clamps, designed for convenience and durability. With various band widths and German-style T-bolts, these clamps offer easy adjustment to your required diameter. Say goodbye to dealer pricing and enjoy the quality you love at ECS Tuning.

Full stainless steel construction
Various band widths available
German-style T-bolts for easy adjustment
Convenient solution for hose clamp replacement

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90-110mm 3/8"/9mm Band Hose Clamp

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T#:341281

Part#: 003402ECS06A-13

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05-02-2026

$ 4.19 USD

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ECS Tuning 304 Stainless Steel Hose Clamps

Once again, ECS Tuning has found a way to make life easier for working on your car. Need new hose clamps but don't want to wait to order it from the dealership or pay more than you should for a hose clamp? That's where we come in! These are full 304 stainless steel hose clamps with various band widths for your convenience. They are German style using T-bolts to adjust in size to your required diameter. Never pay dealer pricing again, but still get the quality you love here at ECS Tuning.

Made from high-quality 304 stainless steel for durability
German-style design with T-bolts allows for easy size adjustment
Various band widths for versatile use
Avoid dealership pricing without compromising on quality
Perfect for BMW enthusiasts seeking affordable yet reliable hose clamps

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Band Hose Clamp | 12-20mm 3/8"/9mm

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T#:304266

Part#: 003402ECS06A-03

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$ 3.74 USD

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Secure hoses in your BMW effortlessly with the ECS 3/8" / 9mm Band Hose Clamp (12-20mm). Specifically designed for BMW models, this clamp ensures a snug fit and reliable hold for hoses measuring between 12mm to 20mm. Crafted with durable materials, these clamps provide exceptional resistance against leaks and are ideal for various automotive applications. Upgrade your BMW's hose security with these reliable ECS hose clamps.

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BMW Brass Coolant Bleeder Screw - Priced Each

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T#:587673

Part#: 17111712788PRM

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$ 5.75

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02-25-2026

$ 5.35 USD

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Having an operational bleeder screw for your coolant system assures that when service is performed, all air pockets are removed. Having air pockets in your coolant system prevents your system from functioning properly. Your heat may not work as well and there is the potential for engine overheating if the air pocket is trapped behind the thermostat. Be sure that all of the air is bled out of your system with a new bleeder screw.

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Genuine BMW Hose Clamp 07129952104

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T#:6533

Part#: 07129952104

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$ 3.99 USD

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GENUINE BMW HOSE CLAMP 07129952104

Bav Auto Expansion Tank Cap - E36 E46 E34 E39 E32 E38 E65 X3 X5 Z4 ...

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T#:640208

Part#: 17117639022

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06-03-2026

$ 11.89 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. 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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Fan Delete Nut

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T#:3459

Part#: 11511310640

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$ 17.99 USD

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This BMW Motorsport part was designed for BMW touring car racing. This reverse thread nut covers the ugly exposed stud when you remove your engine fan and fan clutch. This simple part cleans up the look of an engine with the fan removed. Fits most BMW models. COOL!

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Red Line Water Wetter Heat Transfer Agent

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T#:3607

Part#: 1-WW-12Z

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$ 15.99 USD

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Water Wetter is a unique wetting agent for cooling systems which reduces coolant temperatures by as much as 30*F. This liquid product can be used to provide rust and corrosion protection in plain water for racing engines, which provides much better heat transfer properties than glycol-based antifreeze. Or it can be added to new or used antifreeze to improve the heat transfer of ethylene and propylene glycol systems. Designed for modern aluminum, cast iron, copper, brass, and bronze systems.

We have been using RedLine Oil in our street cars and race cars for years. Hands-down, it is the Number One brand of high performance lubricant for BMWs.

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Bremmen Coolant Bleeder Screw - BMW E30 E36 E38 E39 E46 E83 E90 Z4 ...

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T#:640140

Part#: 17111712788

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$ 2.44 USD

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Plastic bleeder screw for cooling system is used to bleed air that would otherwise create an air pocket and lead to overheating. Includes o-ring seal.

OEM Behr Coolant Expansion Tank Cap - E36 E46 E34 E39 E32 E38 E65 X3 ...

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T#:2766

Part#: 17111742231

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$ 19.99 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.

Hailing from Stuttgart, Mahle-Behr specializes in automotive cooling systems. From air conditioning to engine cooling M-B has you covered with OE-quality replacement parts.

This item fits the following BMWs:
1990-1991 E30 BMW 318i 318is 318ic
1992-1998 E36 BMW 318i 318is 318ic 323is 323ic 325i 325is 325ic 328i 328is M3
1999-2005 E46 BMW 323i 323ci 325i 325ci 325xi 328i 328ci 330i 330ci 330xi M3
1989-1995 E34 BMW 530i 535i 540i M5
1991-1995 E34 BMW 525i
1997-2003 E39 BMW 525i 528i 530i 540i M5
1989-1994 E32 BMW 735i 735il 740i 740il 750il
1995-2001 E38 BMW 740i 740il 750il
2002-2008 E65 BMW 745i 745li 750i 750li 760i 760li
1990-1998 E31 BMW 840i 840ci 850i 850ci 850csi
2004-2011 E83 BMW X3 2.5i X3 3.0i X3 3.0si
2000-2006 E53 BMW X5 30.0i X5 4.4i X5 4.6is X5 4.8is
1996-2002 Z3 BMW Z3 1.9 Z3 2.3 Z3 2.5i Z3 2.8 Z3 3.0i M Coupe M Roadster
2003-2008 E85 BMW Z4 2.5i Z4 3.0i Z4 3.0si M Roadster M Coupe
2000-2003 E52 BMW Z8 Z8 Alpina
2007+ E90 BMW 335i & 335xi

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SPAL Fan Mounting Bracket - E30 E36 E46

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T#:584502

Part#: 30130011

In Stock

84% off MSRP $ 78.99

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

$ 12.99 USD

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84% off MSRP

$ 78.99

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

$ 12.99 USD

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Securely mount your fan in place to reduce movement and increase rigidity.

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