I am wandering whats the problem with my truck.. here lately i have realy noticed that the valves or lifters ar clattering like crazy in the mid to upper rpm range.. like when it gets to 1500 or so they start.. and now i am noticeing alot of power loss when i am driven the other day i turned my box up just playen around and it didnt realy run that much better than when it was on the 40 hp setting.... I drive pretty conservative most of the time and have been noticeing that it is not smoken alot of black..its sort of a light grey.... i had a guy tell me that it might be a injector going south??? i havent had my valves set and its just turned the 183k mile mark..... sorry for such a long post ...........

 

Valves need to be adjusted thats where I'd start.