I have a 2008 F-150 V8 5.4 flex with 105k miles and I bought it used not long ago. I've noticed slightly one other time in lower speeds that sometimes behaves strangely when coasting and then applying the gas pedal. Well, today on the highway I was coasting as I was catching up to traffic and it did it much more distinctly and slightly jerky but it only lasted for a few seconds and didn't do it again. I'm looking for ideas on what this might be. Thanks.

 

I have a similar issue with my truck and the jerking but mine is the reverse it happens when I get on the gas to get up to speed. Mine issue is a random miss so I plan to change out plugs before too long just need the free time to do it.


Do you have any more history behind the truck that might help us some?

 

Yes, this is actually what I meant, going from coasting to pressing the gas pedal. I was a little concerned today because I could actually hear it along with the jerky moving.

 

Have you plugs been changed out?

 

I haven't changed them.

 

Well I can not say for sure but it sounds similar to my problem. You might have a code in your computer and just didn't notice the flashing CEL. You might want to check that out and see if you have anything.

 

I looked for any flashing but nothing. How buried are the plugs on this truck?

 

Well the plugs are another issue all together. they can be done but be prepared to spend a few hours doing it they are not much fun. You will need a special tool called a Lisle tool just in case the plugs break off which most do. To get the back ones pulling the computer is recommend to make it easier. I would also run some sea foam through the motor one or two times before trying to remove them to help loose the carbon build up some. I also recommend using only Motorcraft plugs to go back with as many people have had issues with other plugs in these engines. Also do forget the anti seize on the plugs to keep them from breaking the second time they are changed.

 

You know I just thought about something. Its possible that the previous owner changed the plugs out and broke one so he left it in the truck rather then getting it out and that could be causing your issue. But that i think would throw a code fairly quickly but its still possibly.

 

Sounds like fun. I found another thread that sounds alot like what mine is doing. Guess I need to replace the plugs.

2005 5.4 XLT - engine rough/jerking between 40-60mph - Ford F150 Forum

 

Run a search on here and you can pick up some good tips. Its not impossible but its a bit of a pain.

Good luck!