I have a 2003 Mustang GT. One day the motor randomly started knocking and i believe it to be upper valve train noise i hooked a mechanical gauge up to it and its reading anywhere from 6psi to 12 psi when it is supposed to have around 40. I called around and a lot of people i asked said it was the oil pump, so i replaced that and the knocking quieted down quite a bit so i started driving it again and after a 60 mile trip i brought it home. The next morning the car stalled after about a tenth of a mile of driving and when i started it it seemed like it was struggling to start. Also when it stalled i lost all power, power steering, etc. It stalled a couple more times on the way home. Now it always makes a very loud knocking sound. Last weekend i pulled the engine, flipped it and removed the oil pan and looked at all of the bearings. All of the main bearings were in good shape, but two of the rod bearings were badly damaged. Also i found a piece of paper or something in the bottom of the oil pan when i removed it. So im wondering if the paper was clogging up the vent and restricting the oil flow and that is what was causing it. Now im facing the choice of whether or not i should have it rebuilt or buy a used engine because i dont know how much damage the rest of the engine has. i would appreciate any input thanks.