I have always thought that this new dually I bought has more engine noise than my 96 or 99 had. Today I rode in a guys 01 and his was very quiet. My other 2 trucks were strait piped, so maybe I just couldn't hear the engine noise. My question is do the valves need adjusted, am I running too much timing, or is it just a little tired at 220,000 miles? Maybe I just need to cut the muffler off.

 

a valve adjustment couldn't hurt any, all it requires is a little time. The valve cover gasket is even reusable as long as you don't damage it and clean it up good. Could also be that your injectors are starting to get weak too (especially with that kinda mileage on them). The springs in them weaken over time,thus lowering the pop off pressures and the tips get worn and gummed up, giving a less than optimal spray pattern. Doing injectors and valve adjustment would be kinda the same as a tune up on a gas engine.

 

afoulk,
This truck smokes a good bit for a close to stock Cummins, could that be related to the mileage on the injectors as well? It runs very well, just a little smokey when rpm's are low.