I'm lost???please help

[Ryno250]

Im very new to the powerstroke and diesel world all together so I have no idea whats wrong with my truck.... I have a 99 f-250, powerstroke, manule tranny, 70,000 miles. When I start the truck in the morning cold or not it sounds like theres an air hose blowing under it. It will continue to do this on and off for about thirty minutes or so driving or not. When this occurs I basically have no power. I plugged it in and no codes...also no check engine light or anything of the sort. PLEASE HELP

[purduefarmboy460]

Sounds like you might be describing the exhaust valve opening up to let the air around the turbo in cold weather, that is a normal function of the strokers to warm the engine and you are losing power because the turbo isn't building boost... just a thought, it might be something else, but that sounds like it.

[f250powerstrokeman]

i agree with farmboy if this happens in cold weather its 9 times outta 10 the back pressure valve and if its cold enough it will kick on when you are driving down the road also its a great idea from ford cause we all know how the older powerstrokes like to run cold in cold weather keeps the heat nice and warm

[00powerstrokin]

i have a 2000 powerstroke and mine does the same thing but it rarely stops doing it. if i run it hard for a few minutes it will stop. after another few minutes it will start doing it again. it is really annoying and i lose a ton of power. i got a exhaust back pressure sensor code, so i replaced it but it still does it. i dont know what to do.