I have a 99 Expedition, 5.4 Triton, 2wd, that runs very rough. It did this a year ago and I took it to a shop. Their nifty little laptop showed that cyl. #1 was dropping out and it was a bad coil. This time the “check engine” light came on so I had it read at a parts store and their scanner showed that cyl. #6 was misfiring. A coil was only about $40 so I put one in. I knew which one was #6 from my repair book. I had battery disconnected so computer will reset. Everything went fine but the miss is still there. Any idea what the next step could be? I thinking about replacing the fuel filter. I did but that was about 1 or 2 years ago. Is it time for a new filter? Might as well.
Let me knoe what you come up with. Thanks so much for your time.
JP#3
Three Possibilities: Fuel problem–possible there is a clogged fuel injector to this cylinder (if this vehicle has individual injectors). Spark problem–bad plug, wire, or coil. Compression problem–bad valve or piston rings.
Is there any smoke (blue or white?), oil usage, coolant usage, etc?
well, at start up there was a bluish smoke. my 1 ton ford van does it too. both do not seem to consume more than the usual amount of oil. oil level only seems to get low when it gets close to the next change, consumption is that slow.
thats really all i know at this point. i may have to take it in to get it fixed. i’ve lost the desire to work on cars, especially newer ones. everything on this 5.4 is so tight and even worse on my E350 work van that also has a 5.4.
thanks for your input.