hey, i took off my valve cover today, because for a while i had a slight ticking sound on start up, not all the time but once in a while. i read in another post about pushing down on the rockers to see if there was a bad lifter, but nothing moved there. but i can turn the pushrods in a complete circle with every thing tightend down, except 2 pushrods. is this normal? or is it something i should look into. and if so how would you fix this problem. thanks