I just purchased my Econo 1 Leisure Line Stove (pre-owned) and so far so good...until a few days ago. The convection fan is rattling BAD. It is very loud, it sounds like the fan is gonna fly right out of the cage!! I think it may be the motor bearings. Has anyone encountered this problem before? Are new motors costly? It looks like it would be a nightmare to get to the motor. The fan is enclosed in the hopper with rivets!!! It looks like I would have to take the hopper off all together to work on it. Any suggestions?