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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MTC - Corporate Logo
T#:361005
Part#: 17111178412
Back Ordered
$ 2.03 USD
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This is the small lower rubber mount that goes on the bottom of the radiator. These mounts sit down into mount 17111723337. Fits left or right side - priced each
Meistersatz - Corporate Logo
T#:379740
Part#: 13621433076
Ships in 3 Business Days
$ 15.99 USD
Free Shipping on orders $49 and up
Monitors coolant / oil temperature
Auxiliary Fan Switch
Mounted in upper radiator hose, controls operation of auxiliary fan
URO - Corporate Logo
T#:376847
Part#: 13621433077
Ships in 1 Business Day
$ 10.99 USD
Free Shipping on orders $49 and up
$ 10.99 USD
Free Shipping on orders $49 and up
Comes with related o-ring

URO - Corporate Logo
T#:56977984
Part#: 17117514402
Back Ordered
New Item
$ 6.99 USD
Free Shipping on orders $49 and up
Maintain cooling system stability under spirited street driving and hard track use with this URO Parts replacement upper radiator mount bracket.

Rein - Corporate Logo
T#:46719180
Part#: CHK0376R
Back Ordered
$ 43.99 USD
Free Shipping on orders $49 and up
Keep your cooling system sealed, strong, and ready for anything with this Rein radiator hose kit—your all-in-one fix for cracked, leaking, or worn factory hoses. Years of heat, pressure, and age can cause rubber to weaken, split, or swell, setting the stage for coolant leaks and potential overheating. Rein hoses are engineered to meet or exceed OEM standards, built from premium, heat-resistant materials that can take on extreme temperatures and system pressures without faltering. Each hose features factory-correct bends, fittings, and diameters for an exact, hassle-free installation—no cutting or forcing required. Whether you’re tackling a full cooling system refresh or chasing down a small coolant leak, this Rein kit provides everything needed to restore confidence and performance under the hood. Why choose this Rein radiator hose kit: Factory-level precision – Direct-fit replacements that deliver OEM-quality reliability. Built to last – Resists cracking, swelling, and chemical damage from daily heat cycling. Confidence restored – Prevents coolant loss, overheating, and on-road breakdowns. All-in-one upgrade – Includes upper and lower hoses for a complete system refresh. If keeping your BMW’s cooling system running tight and trouble-free is the goal, Rein brings the dependable quality and fitment you can count on—engineered to perform just like factory, mile after mile.
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