There could be dirt and/or something loose that fell into the blower motor. Also, when these motors begin to fail, they'll often make weird noises when you turn the controls on high.
The only way to check is to remove the blower motor and check it out.
If you intend on doing this yourself, let me know and I'll walk you through the procedure. If you just want info for dealing with a shop, I can help with that as well.
Monday, November 15th, 2010 AT 2:58 PM