Kind of a raspy ticking, only when rolling. Speed doesn't really matter, slow or fast. Thought it might be throw out bearing but is lubed and pressing clutch pedal makes no difference in sound. kind of sounds like something loose in closed driveshaft perhaps. Slight tapping and also sounds like something rubbing then it sounds like something comes loose and makes bad noise and noise goes away for a minute or two and starts again.
I double checked the air compressor to be sure it is not engaged. Put it on jacks and pulled floorboards and ran in place but can not identify exact location by sound or feel. Odd!