I can understand your concern. If the noise is actually coming from the motor, it could be a weak motor and could be a sign it’s going out. A good check will be to spin the blower wheel and see if it starts to run. This would indicate a weak capacitor. You must be very careful spinning the blower, so your fingers do not get caught. Another check would be to see if, there is voltage to the motor, when you hear this noise. Be very careful making this voltage check. There should not be any voltage to the motor until it starts. If there is voltage (120 volts) and the motor is not running, then it will be a defective motor. If there is no voltage there while you hear the noise, I suspect the vent (inducer) motor is the source of the noise. It will come on before the blower starts. This would be normal. I hope this helps you. Thank you for using Manage My Life.
If you do not feel confident repairing this problem yourself, then you can have it repaired at your home by a Sears technician. Here is a link for the website:
Sears Home Services
: Be sure to disconnect the appliance before performing any troubleshooting procedures. If you are not comfortable with doing any voltage checks or repairs that might be recommended, please contact a local service provider for repairs. Be aware that there could be sharp edges inside the appliance that could cause cuts or other injuries to yourself or others.