POSSIBLE TURBO LEAK

[akburns]

I HAVE A 1999 SUPERDUTY F350 4 x 4 CREW CAB DUALLY THAT I BOUGHT NEW AND ABOUT 1 MONTH AGO IT STARTED MAKING A AIR LEAD SOUND FROM THE ENGINE AREA WHEN FIRST RUN IN THE MORNING AFTER GOING ABOUT 1/2 MILE UNTIL ABOUT 4 MILES THEN RUNS FINE. THIS HAPPENS WHENEVER THE VEHICLE IS STARTED COLD WHETHER IT IS PLUGGED IN OR NOT. WHEN I PUT MY FOOT IN IT, IT STOPS UNTIL I LET OFF. I LOOSE POWER WHEN THIS IS HAPPENING.

[JustStroked01]

Sounds like your Exhaust back pressure valve for warming the truck up when its cold. Don't worry about it unless it starts to stick on for excessive amounts of time.