My furnace, when the motor first turns on, makes a really loud vibrating noise. It seems like the blowers start, the noise lessens in volume. It has been loud for a number of weeks, and finally yesterday I went downstairs to see if anything was loose, but didn't see anything. Any thought from anyone? I could use some help. Would really like to try and fix this myself, and not have to call a service tech. Thanks.

By the way - it is a Carrier Model 58STA / 58STX. I have seen some people talking about a loose squirrel cage. Could that be a culprit?

(quote){I have seen some people talking about a loose squirrel cage. Could that be a culprit?}
Yes it very possible, does the noise/vibration never stop? Just quiets down a little
Could be that a fin in the squirrel cage has broken,or a weight for balancing has come off,in which case the cage will need to be replaced