suck or blow

[Opposedodie]

I was working on my mustang today and where the oil spout is on the left hand valve cover there is a outlet that went to the throttle body, well I think I forgot to hook it up and put my finger over it while the engine was running and it was sucking pretty hard .. I thought it was supposed to blow air out? I hooked it up to the throttle body and restarted my car and blew the dipstick out on a test drive ... Oil everywhere... Well unhooked it and added a quart of oil and don't really know what to do with it ... What is this supposed to do suck air in or blow it out? The engine only has about 700 miles on it...

 

[mob]

The tube that goes to the throttle body to the valve cover is supposed to suck air into the engine. The crankcase pressure escapes out of the PCV valve. The problem with this is when you have a supercharger instead of the engine sucking air, the supercharger is now pushing air into the crankcase, and that air has to escape somewhere....too much air to just be sucked through the PCV valve so it blows out the next weakest spot, usually the PCV valve will come out first, lucky for you it was only the dipstick and not an important seal. A temporary fix would be to just cap the line that goes to the throttle body and put a breather filter on the valve cover. You dont want to just cap it because you need to get some air going into the engine.