Some of the things you run across, even from other mechanics.
'99 Alero with the 3.4L.
Some other mechanic told him the engine was locked up.
Checked the oil, over full with gas. Glad it wouldn't fire off.
Drained it out, fresh oil, cranked it. Dead cylinder on number one. Pulled the valve cover, cause the 3.1/3.4's have rocker issues. Sure enough the needles on the intake rocker seized and the pushrod went through the rocker.