CSF BMW Auxiliary Radiators w/ Rock Guards

The auxiliary radiators are the pair of small coolers tucked behind the front bumper, and on the F8X they pull double duty: the right side feeds the charge air cooling system and the left side handles engine cooling. They do fine from the factory, but they are also a decade into their life on most of these cars, with bent and clogged fins and brittle plastic mounting pods that crack. This CSF unit replaces the OE radiator with a 2 row 42mm core using CSF's B tube design, and because CSF folded the old plastic mounting pod into the radiator body itself, the core is about 7 percent larger and the tanks hold roughly 10 percent more volume than stock.

It is 100 percent aluminum and TIG welded, with aluminum mounting pins and brackets that hold up far better than the brittle OE plastic. The radiator is a true drop in fit that mounts in the factory location and uses the OEM quick connect lines, and a detachable rock guard ships with it to keep stones and track debris from puncturing the core, which is one of the more common ways the stock units fail and dump coolant. The black finish keeps it discreet behind the grilles.

One thing to know before ordering: these are sold individually, and a full car uses two, one per side. Because the two sides serve different systems, you can also upgrade just one if you are chasing a specific problem: the right side for charge air temps, the left side for engine coolant temps. It fits the S55 powered F8X cars, covering the F80 M3, the F82 and F83 M4, and the F87 M2 Competition and CS. Each radiator is leak and pressure tested before it ships.

FITMENT

- F87 M2C (Competition Only)

- F80 M3

- F82 / F83 M4