light grey/white smoke when decelerating is usually a sign of cavitation on the cylinder wall... looks like your engine is starting its last leg... thankfully mine does not smoke what so ever that way..

if I get 50-100K out of this truck (paid only 1500$) I will more than happy!

>Hey "91F250DSL - Patrick Bureau" you mentioned piston
>compression at every 100k miles. I've got an F250 7.3l
>diesel with 218000 miles and it smokes after 3 hrs driving
>when I let off the accelerator. Smoke is light gray/white.
>Could this indicate rings or valves need replacing?
>
>Thanks
>DieselSteve