I have a 07 F 250 with 39480 miles on it and it's starting to act up. Once in a while, when I start out, there will be a loud roar, and no power, no boost. I've had it into the shop twice (different dealerships). The first time it was a Saturday and they didn't have a diesel tech on duty. They put it on the computer and couldn't anything except that it needed a couple of flash updates. The second time they told me that they couldn't "duplicate the problem". Thursday I drove for 2 hrs, 65-70 mph, stopped for about 30 minutes and it did it again no power, it lasted for about 5 miles then picked up. The return trip didn't have any problems. I stopped at the dealership again on the way home and they said it sounds like the turbo.
Is there anything I can do? Any advise? I'm suppose to start a 10 day vacation pulling my RV through the mountains of NC and VA and it has me a little more than worried...