Merz '84 500SEL
 

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

I still cant fathom how fuel can come out of where you describe. Are you sure that there is not a leak in a fuel line near injector #4 which is in close proximity to the air cleaner hose?. Did you pull the hose off the valve cover? Does fuel still come shooting out without the hose? What you describe seems impossible to me.

If the fuel distributor was leaking, the fuel would go down the intake manufold and be burned. Pull the right side valve cover and have a look inside. If fuel is comming from inside the valve cover you might get a clue.

What was causing the major vacuum leak?

I'm absolutely sure that fuel was pouring out of the air cleaner hose as the square peg fits in the square hole. Nowhere else my friend!! The vaccum leak was a 1/2 in diameter hose leading to the cold start valve that had a crack in it. Yes maybe I'll pull the valve cover, but it seems futile. When I finally determine the problem I'll let you know what it was. Thanks Dave

The fuel has to have "puddled" in that hose(in the "L" turn of it) from the top and "gushed" back due to positive crankcase pressure when engine was started, because it CAN"T pump with gas from the bottom (unless the laws of physics have been suspended). It's possible? enough gas is back flowing into the air cleaner housing from a defective cold start valve/warm up regulator or fuel distributor to partially fill this hose and make it appear to originate there when back pressure blows it out on start-up?

Im really curious now. Let me know what you find.