Grinding noise in park?

Like maybe one of the bolts has come loose?
I suppose I could remove inspection cover and check.
Look over the flex plate carefully too. You really can see where it bolts to the crankshaft. if the potside bolts are tight and the plate isn't cracked where it bolts to the converter lugs, Upi can start it up and listen for the noise in park. Safety first. On a hoist at a shop or on heavy jack stands with the wheels blocked.