Still attempting to ascertain how gas is entering the crankcase of this car. I bought this 500SEL a year ago. It sat for about 2 years without being run. I purged the fuel tank, installed a new fuel pump and fuel filter, changed the plugs and lastly, the oil. I noticed then , upon initial oil drainage, that it appeared fuel was mixed with the oil, but didnt think much of it. After fixing a major vaccum leak, I got the car to run and idle!!!. Then, as I had the air cleaner removed, gas began to gush out of the air cleaner hose!! ( pass. side valve cover). I checked the fuel press. regulator, and it seems ok, I dont know if the cold start valve is stuck open if this would result in this symptom. Any ideas???? Maybe the fuel distributor is leaking into the intake somehow?? Someone here I'm sure has a good educated guess. Thanks! Dave