i have a vw scirocco 16v. it has 175000 miles on it. when i did a compression test on it when it was cold it tested at 25psi. but when i got warmed up and i started to drive it the oil light comes on and when i test it again it's at 5-9psi. does anyone know what might be he problem. the bottom end isn't clicking. do i need a oil pump or rod bearings?