Just bought this truck with 78,000 miles in it. its in supperb condition got it from car max. it,s a 8 cylinder 4.8 always had ford f150. I notice the engine has a little jump in it. took it to a dodge dealer they put it in there computer and did a complete diagnostic on it no code came up throttle body was super clean spark plugs is new, filter is new. but I still feel that vibration in the engine like if it was jumping you can see the antenna skaking from the vibration has anyone had this same proplem or is this the way the engine sopost to run

 

Is it a jump or a slight quiver?

 

depending on the gas you are running could be a slight burp in the system, being winter blend gas now, most of the trucks tend to run a little funny

 

Printman,

Does this happen at idle? Do the RPM's fluctuate when this happens?

 

just to keep it going, my truck seems to have this issue... rpms a bit shaky, and it is like a quiver, just like somthing is a-miss in the engine. Not a conisistent idle.

 

While the causes could be different it would seem that a rpm fluctuating at idle would be plug,coil, or fuel delivery concern. If it is a vibration with a steady rpm it would point to more of a mount or a pulley wobble cause. Even if plugs are new you should make sure they are the correct application for the vehicle and that none of them have a crack in them.