engine "chugging" under light load

[cruiserwy]

On vacation for the week and truck is acting up a bit. Approx 45 mph while lightly on the throttle to maintain speed, the engine will make a chugging sound and starts "pulsing". It idles fine and runs great under load. Pulled camper 400miles yesterday and it ran great, except for the issue I just described. Any ideas on what it could be?

Thanks in advance.

[cruiserwy]

Took the truck to the dealer in bozeman mt. this morning, mechanic said the turbo is going bad.

[prairiedawg]

My problem is the same. Took it in for a contaminated fluid and the mech changed Nox sensor and module. Went for road test and the fluttering got worse. He then changed the turbo (kit) throttle body and solenoid. Still doing the same thing. Lost power and you can't even spin the tires. It's been 1 week today. If they can't find out what the problem is by Friday, Ford is getting the keys back. Not sure what I will get next.

[cruiserwy]

Did the dealer rebuild the turbo? Truck is at my local dealer now. They called me Tuesday morning and said a new turbo was on the way and it will be ready on Monday.

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[cjf250sd11]

Mine has been fluttering occasionally particularly on decel now surging under light loads exactly as you described. Please keep us updated.

I have a Job1 '11 build so I know they have made improvements to the turbo that is std on all '12 models.

[prairiedawg]

I got my truck back and works great. The turbo was shot and they replaced the kit. The flutter was still there and after extensive testing the mechanic couldn't pin point the problem. Himself and the tech some how realized that the wrong data was downloaded into the ECM for my truck. It actually had software loaded for a F450. The flutter and turbo surge is gone. I can spin the tires and the limited slip kicks in on pavement. I hooked up my 5th which weights 12000 and pulls strong and doesn't miss a beat.

[jesilvas]

Good to hear that they are learning and seem to be doing well.

[cruiserwy]

Had my truck back for less than a week, still has the same symptoms as before. Called and talked to the dealers service manager, he is going to have a mechanic waiting for me at 5 this evening to go for a test drive.

[elk1]

I have just had my turbo changed and ecm updated and still have the same chugging problem at low lugging. Not impressed i don't think ford knows whats the issue. No incovenance to them there not with out a truck!!!

[algz06]

mine is doing the same. started at 2000 miles. called ford and its a known problem and they dont have a fix.