CSF Racing Race-Spec Dual Pass Oil CoolerBMW E46 M3 E39 M5 Race Spec Dual Pass Oil Cooler While the E46 M3 and E39 M5 come with a factory oil cooler, it was obviously not designed for high performance driving. Just a few minutes on the track quickly shows how inadequate the factory cooler is. Dangerously high oil temperatures can lead to serious damage to your engine and need to be addressed. CSF and Rogue Engineering teamed up to create an oil cooler that could stand up to the rigors of