BMW Cooling System Parts & Accessories for BMW E21 320i M10 1.8L

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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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BMW Fan Clutch Wrench Set - CTA
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CTA Tools - Corporate Logo
T#:640926
Part#: CTAA886L
In Stock
$ 52.17 USD
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32mm Wrench removes the lock nuts on the thermo-viscous fan, while the other holds the water pump pulley while loosening the radiator fan
Achilles Motorsport OBD1-to-OBD2 Coolant Hose Adapter - BMW M52 S52 E...
For models with a OBD2 24v Swap (M5X, S5X engines) only!
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Achilles Motorsports - Corporate Logo
T#:1150775
Part#: 11-AM-CHCAP-OBD1
Ships in 3 Business Days
$ 54.99 USD
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$ 54.99 USD
Free Shipping on orders $49 and up
OBD2 to OBD1 Conversion Coolant Hose Adapter for E36 M52 & S52 Engines Replaces the metal pipe from the OBD2 engines with a hose adapter that allows the installation of a normal OBD1 coolant hose. This is useful when converting an OBD2 Engine to OBD1, or when swapping OBD2 engines into a car that is originally OBD1 (like an E30). The simple kit comes complete with the necessary 2 O-rings, extended bolt, Nylon Lock Nut & washers to make this a quick install. No need to wait! It is also completely reversible!
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Fan Clutch Wrench - 32mm
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CTA Tools - Corporate Logo
T#:641760
Part#: CTAA878
Ships on Jul 28, 2026
$ 23.57 USD
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Use to remove and install Fan Clutch Assemblies when replacing Water Pumps or doing other Engine Services

Anti-Freeze Tester
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CTA Tools - Corporate Logo
T#:641679
Part#: CTAA195
Ships on Jul 28, 2026
$ 9.98 USD
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Tests all ethylene glycol solutions with radiator hot or cold