Is there any specific mileage or is it necessary to run an overhead rocker/valve adjustment on the 7.3 PSD?

 

My 7.3 has progressively lost mileage down to about 12-13 mpg hwy and seems to have a bit more engine noise. (sounds like injectors or rockers, not sure) Engine has plenty of power. Just want to head off any future problems if some PM is neccessary.

 

7.3's have hydraulic lifters.

No adjustments.

Pop

 

Moved to 7.3L section for future reference on valve adjustments.