2005 6.0 making weird noise when started
 

My 2005 6.0 that is stock started making like a whistle sound when I turn the truck on. Only when the engine is cold. It some time one or two whistles like a solenoid is blowing off. The truck is a daily driver for work and every so often I haul a trailer with a heavy load. I don't abuse it. Has anyone had this problem and may direct me to what the problem may be. Also some times I'm driving down the highway and my truck loses power and boost gauge drops to zero and then comes right back up after a few seconds go by. Could it be the actuator which controls the unison ring inside the turbo? Thank you in advance.