Quote Originally Posted by ricki_kalsi View Post
So burning oil does not have anything to do with Piston ring being loose / Worn? - only the PVC valve?
It does have to do with the piston ring and bores with worn. What happens is that the combustion gases at high pressure pass between the piston ring and wall (called blowby) and get into the crankcase. The combustion gas causes the crankcase to have higher pressure, which then is released by the PCV valve back into the intake manifold. If you have this problem, then usually the pressure is enough to cause even a new PCV valve to open. So in this situation, replacing the PCV valve won't solve the entire problem, but can help partially.

The amount of oil burnt depends on the amount of gas being released by the PCV into the intake manifold and that in turn is affected by a weak/worn PCV valve spring and worn piston rings and bores.