Hey, just another little thing goin on with my car (other stuff here http://www.ultimatesubaru.org/forum/showthread.php?t=50654) most of the time right when I turn on the defrost there is this mid pitched whining, thought it mught be the electric fan kicking on and rubbing against something but I don't think thats it, I made sure ther isn't anything even remotely close to the fun to rub. The noise doesn't last more than maybe 20 or 30 seconds then it stops and comes back randomly if I leave the defrost on, usually turning it off then on again makes it stop. Could it be the AC pump or something else. Anyone else dealt with this?

Most likely the fan motor bearings. Sometimes they can be lubed and will stop making noise for a while. But some motors can't be lubed. All you can do is try.

will that happen specifically on defrost? all other settings don't have the same noise, it's kinda wierd. :-\

I had mouse condos in my heating ducts. Took me a looong while to pick out the Mickey and friends doings. All was well except for a noise on high, then from out of nowhere, a full fall leaf came flying out of the duct!

With fan motors, when the bearings wear, the rotating parts (armature) can start to vibrate under certain conditions. I had one that whined only in right turns. So when you set the system on defrost it might just right amount of load on the motor to make it whine. But I wouldn't rule out a leaf either. My 69 Chevy truck likes to pull that one all the time.

I had mouse condos in my heating ducts. Took me a looong while to pick out the Mickey and friends doings. All was well except for a noise on high, then from out of nowhere, a full fall leaf came flying out of the duct!

I have actually had a problem several times with the exact same thing - I am still not sure if I got it all out of the ducts. I think I actually saw a rather funny TSB on it - don't remember the title, but it seems as though the coweling is wide enough to allow vermin in - I know some people use screening to prevent further problems.

 

Another note - make sure the fan itself is clean of debris - I had a loud noise and no air - dropped the fan assy out, and it was full of junk.

 

Worse case scenario - pull a fan from the JY!!

 

Good Luck

thanks, there was alot of debris (mainly leaves) on the vents I cleared it off when I started driving the car. we'll see though, it's a really loud noise, i don't think a leaf would make that much noise. i'm thinking more on the lines of bearings, though fan speed doesn't seem to effect the sound at all. Is there a vacuum system related to directing fins for air flow, or for turning the A?C compressor on or off ( I think on defrost the car runs the air through the compressor to dry it). just some of my own ideas, correct me where I'm wrong.

the air direction fins in the dash are vacuum actuated, and the A/C compressor does run for defrost - if the A/C system isn't charged, unplug the blue wire to the compressor to prevent it from seizing

 

Good Luck