anyone ever heard a chirping noise after leaving your heat on for a little while and then turning the fan down a couple of notches? It seem to happen whenever i have the heat on for about ten to fifteen minutes and then turn the heat down a little. After turning it down it makes this annoying cricket chirping sound until either i've driven for maybe an hour or until i turn the heat off. Anyone know what the heck that is? this is on a 2000 a6 4.2l

 

sounds like the bearings in the fan either need lubrication or they're starting to go bad. it's easy to get to, all you have to do is take off the glovebox and you can look right at it. just take off the little access cover in the center and give it'll a little squirt of wd-40 and see if that takes care of it.

 

Check out this tech article on how to repair the blower motor: http://www.audiworld.com/tech/elec132.shtml