So I have a very strange and hard to pinpoint problem. Occasionally when starting my f350 when it is warm, when the engine rpm comes down after the start up it will start skipping almost? It sounds like someone opening the door on a throttle body very quickly and closing it again. Almost like tapping the throttle but my rpm never moves. This never happens on a cold start and when it does happen the oil is always warm. That being said one time while I was idling in a parking lot it started doing while I was just sitting there. Also if you just drive it or press the accelerator and hold it at about 1000 rpm for like 5 seconds then let go it stops. I have no idea what this could be as it doesn't sound like any of the normal problems 6.0s have. Any help is appreciated.