Under the car, remove the starter inspection plate and see if you can move the starter gear back and forth with your finger. I had one go bad on a 99 L36, and when you turn in one direction, inertia flings the starter gear against the flexplate. It bounces back and forth and makes helluva racket that draws lots of attention! That would be the return spring getting lazy on the starter drive, so replacing the whole thing is the fix. Do it before the starter ring on the flexplate gets all chipped up, if you find thats the problem.
