I have a vibration at idle that goes away when the rpm comes up. Thought it was a bad injector but I replaced them and it didn't fix my problem. Other than the vibration the truck seems to run strong, any suggestions to what this might be would be great. 2000 2500 4x4 Quad cab.

 

Try tightening the motor mounts. Also check the trans mount. Which trans? If its a manual, check the clutch.

 

Its a 5 speed and it does not matter if the clutch is in or out, I filled the filter housing with sea foam and it went away until it got back in to the pure diesel fuel.

 

could be injectors then. Possibly caused by a VP going south, but maybe not. Kind of hard to diagnose. Is there any knocking or other noises associated with the vibration?

 

no knocking or any other sign of problems, just this little shake. Cant be an injector, the new set would be at least a little different wouldn't it?

 

If you can get a hold of someone, or own a diagnostic program, turn off cylinders one by one and see if you can find the one that is misfiring. Maybe you have a leaky injector or a bad copper seal, or a particle under the seal that stayed there when injectors were changed?