I am the original owner of a 2003 F250 Super Duty 6.0L. I have had all the required work that has ever needed to be done to it, including replacing the entire wiring harness and some work on the turbo this last September. Over the last few weeks I have noticed it sputtering when going between 45-55MPH up a hill. It only does this when I'm going at a steady speed. It starts fine and accelerates fine, but if I'm going a steady speed up a hill 45-55MPH I notice the sputtering. I've had almost all my work done by the dealership and just had it in last week for this, but they have told me there is nothing wrong, but knowing my truck, I know there is. Does anyone know what could be causing this? There are no check engine lights on or anything.

 

Might want to have a moderator move this to the 6.0L forum.

Any way to get some live readings from it? Maybe while it's doing it? Does it go away when you increase throttle?

 

Moved to 6.0L Power Stroke Diesel forum.

Welcome to FTE crisk.

 

Thanks Redford for moving this to the 6.0 Forum. Much appreciated!

 

Thanks amdriven2liv for your recommending this get thread get moved to the 6.0 Forum.


To answer your question about going away when I increase the throttle, yes it does go away. The truck accelerates fine, it's only when I'm in that 45-55mph at a steady speed that it does it. I'm also noticing that it does it on flat surfaces too now, not just up hill. Do you think it could be an injector going out? That is about the only thing to the engine I haven't had done. I have 180,000 miles on the truck now.

 

I'm experiencing the same thing which I believe is known as overdrive stumble and from what I understand, it's injector(s) related.

 

Thanks PowerLines. I had a feeling it might be related to the injectors.

 

I had this type of issue on my late build 04. (I'm not saying it is the exact same thing as yours, but this is what mine did.) At about 55mph it would, as my wife called it, "woof". It would do this a couple times, and a little smoke would come out with each "woof". Flat ground, just running up the highway. Step on the throttle, it would go away. It also did it while towing my TT, flat ground or up hill.

I couldn't see anything on my Scangauge II that would make me say. "Oh, it's the ......."

No codes were thrown.

So, I thought that just maybe the EGR valve was getting weak. Thus opening for a second under certain conditions. Well, on this trip with the trailer over to Central Oregon, I stopped in at the Ford dealer and paid too much for an EGR valve and installed it at the campground the next day.

The woof went away. Hasn't been back. That was nearly three years ago.

 

That's funny! Mine did the same thing. It was okay under light load, but as soon as I started to go uphill around 45MPH or so, Woof, Woof, Woof...
Each Woof was accompanied by a big black puff of smoke. I remember seeing some guy behind me laughing.

Anyway, in my case it was the FICM.

I replaced the FICM and all was fixed.

 

I have the same symptoms under load towing my trailer or pulling a large hill unloaded. Would get the woof, woof and black smoke with each one. Getting into the peddle or backing off would stop it. My buddy who is a ford diesel mech said the most common thing is the egr valve. I replaced mine last week. I will be towing next week and hopefully this solved the issue.

 

Yeah, I've replaced the EGR coller, valve, FICM, you name it. It's not really a woof I'm gettin with mine or black smoke, just he sputtering between 45-55MPH. I've noticed over the last couple days I don't even have to be going up hill anymore. It's not as noticeable as when I'm going up hill, but still noticeable.

 

I agree you likely have an injector going south, I would get the codes read, you can have pending codes and not have a check engine light.

 

I have also had the "woof" you are describing. It was also sometimes accompanied by black or white smoke. Did it every now and then at random times. Finally got worse, woof at times, other times driving down the road the engine got quiet and boost dropped to 0 then would come back. At a stoplight one morning I had a dead pedal. Limped it to ford, bad egr valve. Watched the mechanic pull the valve and it was damp and covered in soot. Had the egr deleted and opted for studs while at it. No woof or smoke since.

 

Thanks guys for all the replies and input. It's much appreciated. I have an appointment this Friday with a pretty reputable diesel shop (not going back to the dealership). I'll let them know what you all think it might be as well as let you all know what the results turn out to be.

 

hey Mustang 309, I forgot to mention in a previous reply that the Ford Dealership did check the codes when I had to them a couple weeks ago for the problem and they told me all the codes checked out fine.