I have had a GE Profile Bottom-Freezer refrigerator for about 2 years now. I've never had a single issue with it until recently. It seems like when the fan hits a certain speed it starts resonating. It sounds like someone is blowing into one of those old candy whistles slowly but steadily and it's loud enough that it wakes me up at night. Of course, when the fan hits a high speed the resonating howling/whistling sound goes away. I tried the empty-the-ice-tray trick but that did nothing.
Some other things I've noticed (Although I can't tell if it's just me being hyper-aware now).
- The freezer, while set to 0 degrees, seems to go up to around 8 degrees and hover around 4 degrees. Again, this could be a defrost cycle.
- The refrigerator, while it does have the correct temp (37 degrees), it seems to have more humidity. I've also noticed little ice-beads around the vent in the back of the refrigerator. This may also be because I can't keep my head out of the freezer area looking for the whistle.