I just took my 05 4.4 in today. Strange noise is predominant when I make a turn under power like when I idle ;) throught the stop sign near my house then turn and give it a little gas. NOise seems to only occur when I'm turning (differential??) so I'll see what the dealer comes up with.

looks like the whinning noise is a miracle for all of us :)
I think, it could be due to antifreeze - it is not as liquid as required anymore and try to replace it
it could be the heater fan itself altough...:confused: