I had one of these in my grandson's set- the motor died (started growling) during the second Christmas. These motors are very small (but a new one is only $18 from Lionel - probably less if you did some research.)
I replaced it w/ a LionChief Plus Pacific. Cost more than the set!! But a much better loco. (Later replaced the motor on the PA Flyer, and use it as as switcher on my layout.)
Mike