E a lifter.So this guy I know bought this truck. 97. 4.6 .....intake gasket was blown. Fixed that then when I drained the oil nothing but sludge came out. I filled it back up with 5w20. Started it and it made an engine noise. Sounded like a rod maybe. So I pulled the front diff and the pan.....more sludge. I checked all the rod bearings and two of the mains. Looked ok. Like they had 100000 miles on them. But no spun bearings and visually looked good. I cleaned the pickup tube and the pan. Thinking it was just clogged up with sludge. More fresh oil in it and it still has a knock noise. It's as loud from the top as it is from the bottom. I am at a lost. What could it be?. Started pulling injector plugs and noticed when one is unplugged it makes no noticeable difference. Could a bad injector cause a knock like a rod. Could it be something in the top end. I know its an ohc motor so not a lifter.

 

Sounds like a bearing problem. That sludge is probably everywhere

 

Pulled the valve cover and a rocker had came compleatly off. Don't know how that could of happened. I loosened cam and slid it back in. Buttoned motor up and it still was loud for a few minutes but finally got quiet. I guess the finally got the oil through.