Taurus grinding on start up

My 02 Taurus occasionally makes a metallic grinding noise when I attempt to start it–same type of noise as when you turn the key when the car’s already running. Wait a minute, then it starts OK. It just started doing this a few months ago, with about 140k miles. I’ve found a discussion of this online, but no solution that works. One person got a new starter, but it didn’t help. Any ideas what to do? Thanks in advance…

The noise might be caused from a worn starter drive gear or from damaged gear teeth on the flex plate or both. The only thing that can be done at this point is pull the starter and check for damaged teeth on the starter and/or flex plate.

Tester