What year engine? What is the oil pressure at idle? The movement of the part that supplies the oil is not a problem, my 55-59 235 does the same thing. Air to move the potential clog is a temp fix. Pull the rocker arm off. Keep all the parts in order, clean and clear it then put it back on. Adjust the valves, not too hard, see the tech tips. You might consider the bypass filter it does help. You have probably cleared most of the crud out with the oil you have used so finish the job and let the rockers live a good long time.
