When I'm at idle it will fluctuate 10rpm sometimes.I can also hear a sort of a ticking but not really loud on the top towards the front of the engine.When I'm going down the road that's when you can definitely feel and hear fast vibration.On a second and off a second even when I'm off the throttle coasting it feels like it a longer vibration and noise.I guess I'm going to pull the top off this engine and check valve clearance.Any suggestions what it might be or had the same problem please let me know.Thanks in advance
If you go down the road and kick it in neutral with engine idling does it vibrate the same. How long have you had the truck. Is the engine sounds changing. 2250 make terrible sounds from the front left top side of engine. Sounds like valve train is destroying its self. No ticking just really loud and violent sounding.
Check engine mounts, fuel pump pressure because you mentioned it drops rpm at idle and runs rough. Any codes logged on the ECM?
Also what engine do you have or what is the year and make of your truck..If 871 or older engine may be actuators