Ever since the Mellon oil pump after a oil change in my truck the oil pressure is good. Alittle over 40psi at idle warm then I go out and floor it a few times and it will idle around 33psi. It will idle there until the next oil change and then do the same thing, if I change the filter right after I take it out and beat on it bam back to 40's. The oil filters look good when I take them off. And I've tried different brands fram, mobile 1, ect. They all do the same thing . Is it possible I'm collapsing them on the inside from to much suction?