This is the first V8 F150 i have had, so it may sound like a dumb question. I noticed a real rough idle on the truck when it gets to normal opearting temperature. The thing is, it is only every so often it does this. I could be sitting at a stop light or in park and it will idle rough. the next time i drive the truck it idles smooth. I think i have it narrowed to three things....egr, a coil, fuel filter. Has anyone else had this kind of issue?

 

Actually the idle is usually rough almost to the point it feels like a miss. If you get a tuner you can actually up the idle speed to help with this miss like feel. Also getting solid coil wires seems to help too.

 

Just change my fuel filter this morning. It make a big different on idle. It sounded like a cam phase problem before filter change and now it sounded like a normal ford V8. After removing of the filter, clean fuel comes out one end of the filter and BROWN color fuel comes out the other end. Open up the filter, the filter element is totally dark brown. I just got my f-150 with 136k last month. Looked like the filter never been change. It is an original Ford part. It also needs a special tool to remove the filter.

 

Could be a number of things. Has it ever had the spark plugs changed? The o2 sensors?

How many miles on it?

I would start with plugs and maybe cops and a fuel filter.