i have a 2002 f350 7.3 dsl...the problem is when the truck warms up around 200 to 225 f the truck sounds like i have a huge cam in it its like im power breaking at a dead stop......when i take off from a light she smoothes out and she still has plenty of power. when the engine is cold she purrs like a kitten. What gives?i have tried to research the problem but too no end any ideas? Thanks for your time..... Joseph

 

Not that it helps your situation but I had a gasser do that almost pushed me into an intersection. I had to slam it in neutral really quick. Scared the crap out of me, turns out the throttle plate stuck.

I'd look for something like that a stuck gas pedal, linkage etc.

 

What weight and how old is the oil?

Mine will do this if I beat the crap out of it on high mileage oil. The oil sheers down and gets to thin, an oil change always cures it.

 

10/40 rotilla h/d oil just changed 200 miles ago

 

thanks
everyone