Actually Jordan, that's not quite right in this engine, if it was a single cylinder engine, then you're right. But with 4 pistons, each 180 degrees apart, theoreticly(sp) each piston will fill and/or displace the movement of its' opposite. I wish someone with a real fresh engine could put a gage in the oil filler hole and see just how much cranckcase pressure, if any, is generated by an engine at idle. That would be a great benchmark to see if, in fact the rings or valve guides are worn sufficiently to cause problems. Like blow oil out the sealing surfaces of the various gaskets. All that being said, with the engine at idle and the PCV system working, with max vacuum at idle and the small orifice in the intake manifold, would there be any pressure in the crankcase at all? I don't know, but it appears the pic that opeldean has, shows an excessive amount of pressure at idle. JMTCW