My daily driver is a 2007 F150 4wd. It has the 5.4 3 valve motor in it and just shy of 69k miles. I moved my son back to collage on Sunday and used the truck to do so. I bought fuel on our way out of town. About a half hour into the hour and half drive the truck began to stumble / shutter / jerk / buck. The automatic transmission still seemed to have power. It is not a brake, front end, U joint issue, it has something to do with the motor but the check engine light has never come on. The truck cooled down while we unloaded it and it ran fine for the first half hour and then began to act up again. Drove the truck to work Monday and the truck began to act up within about 10 minutes. This is what I've done so far in order to correct the problem.

-Thought perhaps I had a coil going bad because I've had similar issues with the 2000 F250 and it turned out to be a coil. All new coils from Summit.
-All new plugs and yes they are a pain in the rear. Three broke off including of course #8 and that one with the electrode still in it.

Started back up with the same problem so then:

-Fresh gas
-Cleaned mass air flow sensor
-Cleaned and re-oiled the K&N air filter
-Ran Sea Foam in the tank
-Replaced the fuel filter

Started up again, slight improvement but not by much. Not to sure where to go from here. I am thinking perhaps the fuel pump but not sure. Did not mind doing what I've done so far because it was routine maintenance that needed done anyways; but I would like to avoid replacing a bunch of parts that I don't need to.

Any thoughts would be appreciated! Thanks.

 

If it only happens when moving then I would pull the rear e-brakes out and ream the pivot. Many threads - search on my name as I know I posted on it years ago.

 

I've checked the brakes all the way around when I get to my destination just in case it could be a brake problem. They don't seem to be getting hot, would this type of problem warm up the rear rotors? Also I should of included in the initial post that it will also bog down under heavy acceleration, almost as if the motor wants to fall flat on it's face. Fuel milage has also gone down from mid 15 mpg to roughly 13.8 mpg.

 

Rotors did not get hot.
This thread describes symptoms https://www.ford-trucks.com/forums/6...ing-brake.html

This is how I fixed it https://www.ford-trucks.com/forums/8...ake-drums.html


I suggest you apply e-brake, ensure it works on both sides. Release e-brake, spin both wheel. Pry both lever arm (on the backside) to ensure they are fully released. Drive truck without reapplying the e-brake and see if the problem is gone.

 

Mine had a simular issue. Ended up being the variable valve timing sensors.

 

Well, here is the update. Checked out the barking breaks and they are in good working order. Just to be sure I pulled the rotors and ended up finding a leaking axle seal. Funny how a $9 seal will cost you $100 in fluid! Also changed the transmission filter and topped off with fresh fluid as well as a bottle of Lucas. No change I still have the same problem, sure with the darn thing would throw a check engine light.

 

Mine never threw a code either. It would just shake and make a horrible noise towing at lower speeds up hill.

 

Thanks for the update. Do you have any pending codes?

 

Not sure what a pending code is please explain.

 

Some codes will immediately trigger the MIL. Other codes will be stored as pending until the computer has validated (reoccurrence) and then triggers the MIL.
So you may have a stored code even when the MIL is off. Any code reader can check.

 

There are really a lot of potential causes - everything from a clogged cat to the Fuel Pump Driver Module and plenty more. You're going to have to keep testing/checking or have it diagnosed at a shop. It possibly could be nothing more than corrosion or a loose connection at a sensor.

 

Update, today I was able to use a very basic scanner. No codes, or pending codes. I'll try to get access to a better scanner.

 

If there are no pending codes then it is hard to imagine that it is an engine problem.
Although post 7 says similar symptoms yet no codes so maybe cam sensor problem.
IIRC the transmission has a separate control system and only trips the MIL when they become major.
It might be worth while for you to describe the latest example of your symptoms (I find that trouble shooting often helps to sharpen the description.)

 

I want to attach myself to this thread. I have some of the same sort of shuttering going on with my "new to me" 2008 F150. Mine shutters slightly at about 40 to 50 MPH when I'm lightly trying to accelerate. I haven't towed anything yet to see if some more pronounced will show up then.

I found this video:
I have 102K on mine and don't know if plugs have been changed.

 

yeah, i'm thinking VCT solenoid(s). are the symptoms only at lower rpms?