I have a 2006 F250 with 41,800 miles on it. It started up with a tick about two weeks ago after I changed the oil and then a misfire with quick acceleration then good till between 55-60mph and misses again. Scanner isn’t picking it up but I can feel it. I replaced cheap filter with the Motor Craft OEM and changed out the Castrol MagnaTec 5w20 for the Motor Craft 5w20 night before last. Still have miss and ticking from passenger side that persists with acceleration although much quieter since I changed to Motor Craft. I figure roller follower or lash adjuster for that but don’t think that’s the cause of misfire. This truck has had oil changes every 3,000 miles and recommended services at every mileage marker since it left the lot by the gentleman I bought it from with records to verify besides the one I recently did myself. I’ve ordered plugs and will do that here in a few days but any other thoughts anyone may have to what may be causing the misfire in a rig with this low of miles would be appreciated.

 

Is it possible the tick and misfire are two different issues?

The tick often happens at startup because an exhaust manifold seal is starting to fail, and when the engine heats up and expands the manifold seats properly- after a while the manifold will not seat after the engine warms up.

Also, most shops recommend substituting 5-20 to 5-30 for the 5.4 3v engine.

Finally- I suspect you may have the original spark plugs with only 41k miles. Change them ASAP. They have a design flaw, and can break apart while running the engine and take out a cylinder by dropping metal from the plug into the cylinder (ask me how I know).

I think changing the plugs is a good place to start as they need to be replaced anyways.

 

MikeKerr thank you for you thoughts.

Since my original post I have pulled the throttle body and cleaned it checked the MAF which looks like it’s brand new I bought a stethoscope and listened to different spots on the engine and I have some noise that I believe is lash related on cylinders 2 and 6 but there is a very clear ticking coming from the intake manifold area when I pure the scope near where the injectors are it is most noticeable. I have looked at all of the exhaust manifold bolts and they are all there but it wouldn’t hurt to change the gaskets anyways I will do that. I should be getting the new plugs in the mail today and intend to change them this weekend. I also ordered new valve lash adjusters and roller followers and figure I will change any that I find that are bad or even suspect while I’m at it. I will update the post with my results.

 

I thought a few years ago I had na exhaust leak (tick) but spent hours and just could not ID the specific location...took it to my favorite muffler shop....agreed but again, just couldn't ID the location.....I then found it....I had a spark plug that was loose by about 1/4 of a turn...….

 

Now at 42,236 miles Took it to the dealership it was originally purchased from they kept it a week changed the plugs and oil claim they couldn’t recreate the noise. Say they removed drivers side valve cover no sludge and that everything looked good. Cost me $600.00 to have them do plugs and an oil change way I see it. I drove it less than 20 miles before I noticed sound again. Took it back the next day insisted they figure it out the service guy agreed there was excessive engine noise. 8 hrs later they call me and tell me the dealerships service foreman trace the ticking to cylinder 1 but that he doesn’t feel it warrants further inspection that it’s normal engine noise and that it’s not hurting anything.
It’s now been 24 hours since I picked it up again and now it’s no longer a ticking its a very apparent tap tap tap and to add to it all my rear differential is leaking and wasn’t when I dropped it off not sure how that happens seeing as it has nothing to do with what it was there for unless it was a result of the “full point inspection” they claim to have done and checked the diff in the green good to go category.
I bought followers and rollers and the spring compression tool I’m just going to do the job myself. Between what I paid them and the cost of a rental car for a week I’m out almost $900 for new plugs and the same problem only worse. Merry Xmas to me!