[mueller944s2]

The story was I was doing a lot of long distance driving and at a stoplight (luckily next to my house) it started making a knocking noise and the oil pressure dropped to 1. I towed it home and found the oil was really low. I check it persistantly but this was weird, it never drinks that much. I pulled off the belt cover and everything is good in there. Pulled off the valve cover and chain tensioner and valve springs are good. Changed the oil and there was a tiny bit of copper at the bottom, but not much at all (bearings). I was told a lifter might've collapsed so I ran it for 5 minutes and the knocking got a little better but not much. The oil pressure cold is 4 which is lower than normal and I was also told that the relief valve might be stuck which would cause the low oil pressure and keep a lifter from getting enough oil. Using a stethoscope I can't hear anything inside the engine, and the sound is coming from the head area.