I have a 2005 Lariat and it has 155k miles. I bought it with 40k but have not changed the plugs as I was not aware of the plug issue. Just found out about it and was preparing to get them done. Running sea-foam in the tank and at 80mph the number 2 cylinder (and others) began to misfire. The engine shut down and after 5 minutes started back up again. FYI, for a week or so the timing seemed to be retarded back.

Took it to the Dealership and they confirmed a code for the #2 cylinder but also said the compression was low and they recommended a new engine. I am skeptical. This truck has highway miles only and has had oil changes every 3 to 5k miles! Always ran great. Right now it is running ok.

Thoughts?

 

Well, number two is still misfiring. Now gotta figure out why.Changed plugs and cop for that cylinder. Still missing bad. So bad that the engine shakes bad when driving. Guess its time to pull the head.