Grinding, " diesel " noise under valve covers

dadsbee said
Probably the "bingo" right there, converter to flex plate bolt head(s) hitting the dust cover..

All.of a sudden? After 12 years? Or maybe I never noticed it. I may be chasing ghosts. I seem to remember some.noise, but that was after the RE dizzy... am I freaking out over nothing? Or did timing wipe my bottom end?