Also having lots of trouble with my 2008 F450. The radiator had already been replaced but the ongoing problem is the loss of power. The check engine light comes on and when you push the gas pedal the truck is bogging down and not moving. At times it shakes and I have to take my foot off the gas. It has been to the dealer 3 times and is currently there. They have said now it is the lower turbo unit. My truck has had this problem since 15k miles and only has 46k miles now.
My brother had the same truck with the same issue, although he has since moved on to another vehicle.
Anybody else having the loss of power problem?