I just bought an 2006 f150 4x4 with a 5.4l 3valve, and this morning when I pulled into work it was idling Rough as I let off the gas and rolled into my parking spot. No check engine light or nothing, just when it's in gear Rpm is at 600-700 and vibrating. When I shifted it into neutral or park it went away and the engine ran smooth. According to the oil pressure gauge I've got good flow. I was told from the dealer that they replaced the cam phasers, timing chain and put new spark plugs in it. Anyone know what the issue is here?

 

it may not go away in park, just no load on the motor so you cant feel it... If problem gets bad enough you will get a code to narrow down the location.. could be a COP (coil on the plug), or could be something with the phasers or air flow sensor, etc.