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BMW Cooling System Parts & Accessories for BMW 3 Series E46 (1999-2005)

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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OEM Nissens Radiator - Automatic - E46, Z4

For vehicles with automatic transmission only

T#:362222

Part#: 17119071519

In Stock

$ 173.39

This product was last offered at the strikethrough price on
06-02-2026

$ 165.05 USD

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$ 165.05 USD

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The cooling system is a weak point on any E46. Many cars develop issues in as few as 50,000 miles.

Overheating an inline 6 engine almost always results in large repair bill, and sometimes a warped cylinder head.

Replace yours with a high-quality OEM Nissens radiator to prevent further issues and potential overheating.

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Rein Coolant Expansion Tank - E46, E53, E83

2X Entries For Our G87 M2 Sweepstakes! We Price Match - Give Us A Call or Chat!

T#:402141

Part#: 17117573781

In Stock

$ 76.39 USD

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$ 76.39 USD

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Includes cap and level sensor

Active Autowerke Sport Fan Clutch - E36 E46

T#:397219

Part#: 14-010

Ships in 2 Business Days

5% off MSRP $ 259.00

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

$ 246.99 USD

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5% off MSRP

$ 259.00

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

$ 246.99 USD

Add to Wish List

When you push your powerplant, thermodynamics push right back. The toll of high performance is higher heat load – and many stock components begin to complain. But Active Autowerke has you covered - this upgraded fan clutch increases viscous coupling of cooling fan blade speed to water pump speed, yielding increased airflow through the radiator for more efficient cooling. A simple, yet wonderful, thing.

This product fits the following BMWs:
1992-1999 E36 323i 325i 328i 330i M3
1998-2006 E46 323i 325i 328i 330i M3

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