Ok, I got off of work today and started my car. (97 Civic EX) I left and about five minutes later I hear a horrible humming sound coming from behind the glovebox area. I pushed the clutch in and turned off the engine, the noise stopped. I started it again and it started making this little squealing, squeaking noise. Something like a cricket would make. Could this be a sign of a heater core going out? Any suggestions on this? Thanks,
Chad

 

^^

 

Are you sure some rat is not under there somewhere.

 

Blower motor bearing, or if it changes with throttle, an air leak in the intake plumbing.