Cody Hall
Member
Okay, reporting back. I have now been driving the Expedition for a week and I am confident it's been resolved, at least the bulk of the misfires, as the CEL is no longer coming on or flashing when accelerating. It is running great now!
I went back and pulled #4 plug and coil and did a detailed inspection. First thing I noticed was carbon tracking on the spark plug! Upon further inspection, I could also see where the spark was jumping to the aluminum head as there was an obvious black spot. Apparently I did not properly apply the dialelectric grease as it was gobbed all over the metal end of the spark plug and deep down in the coil spring. With the dielectric grease being an insulator, obviously this was causing an issue allowing the spark to take an alternate path. When I had placed dielectric grease on originally, I had mistakenly just gobbed the grease on the coil boot end and pushed the boot over the spark plug upon reassembly. A rookie mistake on my part I know. Lesson learned
So I ended up cleaning the plugs back off, replaced the coil boots, properly applied dielectric grease to the porcelain on the spark plug only, as well as a little on the inside end of the boot, and made sure that the spark path remained free of dielectric grease. I repeated this exercise for all 6 cylinders. It now runs like a champion, at least 99% better than it was!
Now a question I have for the group - if Forscan records 1 or 2 misfires after driving for 2 hours (including warm up), is this a cause for concern still? Obviously every once in a I am still getting a couple misfires, just not sure if this is somewhat expected or not?
I went back and pulled #4 plug and coil and did a detailed inspection. First thing I noticed was carbon tracking on the spark plug! Upon further inspection, I could also see where the spark was jumping to the aluminum head as there was an obvious black spot. Apparently I did not properly apply the dialelectric grease as it was gobbed all over the metal end of the spark plug and deep down in the coil spring. With the dielectric grease being an insulator, obviously this was causing an issue allowing the spark to take an alternate path. When I had placed dielectric grease on originally, I had mistakenly just gobbed the grease on the coil boot end and pushed the boot over the spark plug upon reassembly. A rookie mistake on my part I know. Lesson learned
So I ended up cleaning the plugs back off, replaced the coil boots, properly applied dielectric grease to the porcelain on the spark plug only, as well as a little on the inside end of the boot, and made sure that the spark path remained free of dielectric grease. I repeated this exercise for all 6 cylinders. It now runs like a champion, at least 99% better than it was!
Now a question I have for the group - if Forscan records 1 or 2 misfires after driving for 2 hours (including warm up), is this a cause for concern still? Obviously every once in a I am still getting a couple misfires, just not sure if this is somewhat expected or not?
