Hello Gents. I am hoping to get some help here. I have a 2006 f150 5.4l, and I have developed a problem. It seems the my truck has started to skip, or "pulsate" when I am accelerating. If I really get on the gas the "pulsate" goes away. This only seems to happen around 45-50 mph. Now this is where it gets weird. I have no check engine light on, and I have checked to make sure my light is working. I brought it to a garage and they told me something about Fords having a misfire issue that sometimes doesn't trigger a check engine light. . . . . now idk about that because every misfire I have seen triggers a check engine light, but I had them replace the spark plugs anyways. And it didn't fix my problem. At this point the only thing I can think of is possibly tranny, but I was hoping to get some insight from you guys before I spend a ton of money on tranny work. Any type of input on this will be greatly appreciated. Please let me know thanks.

 

Have you checked or replaced your coils on the plugs?

 

I have not yet, but if a coil pack was bad wouldn't it trigger my check engine light?

 

Not necessarily. On mine I had the stumble like you describe, i had a couple bad coils, no check engine lights.

 

Thanks I will look into this and see if it solves my issue. I'll repost when I get an answer.

 

I also had this same problem. mine started to misfire and "pulsate" under light acceleration at highway speeds and then got worse after weeks and started doing it more often. when i would accelerate hard it would go away. i also had NO check engine light for the first couple weeks. I took it to a friend who owns his own shop and he checked it out and said it was the common rail valve. I also had him replace the spark plugs and coil packs since the whole intake manifold was coming off. but it fixed me problem and ran great after that. no problems since! i would suggest looking into that.

 

Thanks. this is the first I have heard of that, I will investigate this.

 

Change all coils. Use only Moto Craft , expensive but aftermarket is dicey. Rock Auto best price.

 

second the rock auto suggestion

 

Had same exact issue and it was just the plugs. No issues since changed.

 

Same here. Just changed plugs and problem went away. From what I've read about problems others have had I've been lucky, 115 thousand miles plus and so far so good.

 

Did you find/fix the issue?