I have an '07 F-150 5.4L. Truck has around 96,000 miles. As the truck cruises between 40-50mph (most often around 45mph) the truck jerks/stutters repeatedly until accelerating or decelerating slightly. This does not happen every time the vehicle increases in speed between 40-50mph, however. Just sometimes. It does seem to happen much more when pulling a boat or trailer. I am wondering, does this sound like an engine issue (missing, etc) or a transmission issue? Thanks in advance for any and all input

 

I believe that is about the speed where the transmission wants to shift into overdrive, so I would guess that the transmission is where I would look first. How long has it been since the fluid was changed?

 

I'm thinking COP's or plugs

 

I just wanted to chime in and say I'm experiencing the same issues (2000 F150 5.4L) but wanted to add that mine also does it stopped at a light in D. Like the OP said it also does it when very lightly holding the throttle steady at 40-50mph.

Does that change the probable diagnosis any? I was thinking stall converter and something to do with old or bad ATF fluids.

Thanks.

 

Throw a trans in it and when that doesn't fix it look for faulty ignition components.

 

sounds like my problem, i have a 2004 fx4 5.4 supercab couple months after getting it i always felt a jurk when comeing out of first gear i though it was the rear end. next thing i knew i was with out a tranny. i would get it checked before you are on the side of the road. when the tranny goes shes gone.

 

Mine is doing the same (2007, XLT 5.4L). It seems as if it sputters when I am trying to accelerate. It has gotten worse to where now it does it when I take off but going up a hill or ramp. Didn't think about the tranny, because it seemed more like a sputtering problem, but I'll look into the tranny also.

 

My 07 5.4 with 173,000 Mi would do the same thing at 40-50 mph and it was the spark plugs now it drives smoothly

 

Definatley sounds like plugs

 

Mine had a slight shutter when I would goose it passing on the highway and I switched out the rear end fluid with royal purple. Not a cheap fix but it worked! Just a thought.