Grinding, " diesel " noise under valve covers

it was just a wild guess as to being a possible culprit. The only way to make sure the lever is still tight on its pivot pin or that there’s not something amiss on the mechanicals is to remove and inspect it even though it still pumps. Doubtful it is the issue but you never know
Hey, it's 2 screws and 2 bolts. So rip it off there, and wiggle the lever?