Hi Rick,
Before you send it back to Lionel, if you have a compressor blow air down the stack
with 20 PSI pressure, after that take the engine off the track and (yes) shake it like you would shake a rattle spray paint can. The fan motor might have landed on a dead spot.
If you don't have a compressor just blow down the hole as hard as you can, try this before sending it in for repair. Since you did a reset three times you will have to reprogram the engine again.
Hope this helps,
Alex