We have Amana 80, an older model (20+ years likely) furnace (in the basement). My wife told me it is was not working right -making some noise (like trying hrad- humming) during the day . I smelled a burnt oil/cable smell. I checked the rooms for a fire and found nothing but realized it was coming from the vents. I checked the furnace. It will ignite and burn the gas for 2-3 min and stop. It will continue humming and try again... As it tries (humming) further it sends the smell to the two rooms (not all of the house).

What do you think it may be?
Some reading says it may be the on/off capacitor for the fan
Some says the motor on h fan may be gone
Any comments?
Thanks
Toni