Quick question, the crank case pressure is building up and blowing oil from the sump(its had a new one to try solve this but still does it now and its properly sealed when it goes back on), now what would cause this? the oil cap is coming off, but its not coming off with high pressure, and when you take it off, it still runs!

Oil pissed out the d/v when driving and dropping down to 3rd from 4th....
Piston rings gone?