My 330i 2018 bmw has a cracked in the oil housing unit. This is due to bmw putting plastic parts instead of aluminum. After researching this I found thousand of people complaining about the sane thing. The car overheats and sometimes the oil gets mixed into the coolsnt system b causes more damage. This seems to happen on cars with mileage between 60-70 on engines B46, B48 n B58z