This same problem has been happening to me for the past 3 months, I thought it was the transmision, but I was noticing that the WHINE was following the BOOST PSI. So I called the PSD GOD at St. George Ford 435-674-3200 Dave. He told me to remove the Air Filter Inlet from the TURBO, then see if you can move the turbo shaft in and out if it moves more than 10mils then pull out your wallet, then see if you can move the turbo shaft up and down side to side if it moves more than 10mils then pull out your wallet. THIS IS WHAT I DID AND IT ALL MOVED. A NEW garrett ball bearing turbo that is ported and polished with an 88mmCompressor wheel will cost $1100. This turbo will bolt up to existing equipment.
IF THIS IS THE PROBLEM CALL: JOHN WOOD 760-356-9421