SkiSmuggs

Since new my 2011 Ecoboost has pulsed/bucked when under load towing up hill even if only a slight grade. I replaced my plugs for the 2nd time when my 17000 mile plugs started missing on cylinder 4 according to Torque Pro. I am on a new trip and still get the missing feel, but after 2 days on the road, no misses are recorded on any cylinder and it pulls on ramps like a beast. It is only while trying to maintain speed uphill that it does it. New plugs are gapped at. 028 vs. 031 for the last set.
Any ideas about what the problem might be?

itguy08

6th gear only? If so, there is a TSB and updated programming to make it go away.

HCFX2013

Does it also make an audible "clunk, clunk" noise? If so, my old Eco did the same thing and nothing fixed it.

vozaday

The odd tune will cause a weird pulsation like that. Kinda like the torque converter doesn't know what to do. But I do remember seeing a TSB for a transmission module that fixed this problem

SkiSmuggs

It does it in fourth and fifth as well. Punch it and it takes off with strong power, but just trying to maintain speed uphill, it pulses and bucks. It has done it with multiple tunes as I just confirmed with a 5-Star tune.

nemosdad

SkiSmuggs my 2011 eco did this as well. Around 55 to 60mph going up a long hill and just enough gas to maintain speed.
Mine wouldn't buck per say but you could feel a miss. Once hooked up to my trailer it was a different story. Hooked up, it was jarring both up and down hills at 55.

Checked my plug gaps and they were all over the place. Regapped, still bucked. Went in for the tsb and the problem went away and hasn't returned.

MadocHandyman

What grade fuel do you run Ski? Mine does the same but it's minimized greatly with running 91 octane ethanol free. Can just barely feel it and it's very infrequent
Not sure what could be going on there but it is a huge difference from running 87 with 10% ethanol.

SkiSmuggs

I haven't run 87 since January when I made a permanent switch to 91/93, usually Mobile. But a 9500 lb trailer will accentuate even minor problems.

BoostedFx

I know that there is a TSB to fix this issue, that said does anyone have the TSB #? I would like to have it as back up when I take my truck into the dealership. They aren't exactly on top of things regarding TSB updates and I know they won't be able to recreate it cause it only happens to me while driving on the interstate and going up a hill. Having proof will be a 100% back up to my claim.

FordService

I'll look into this further, SkiSmuggs, although getting in contact with your local dealership is your first step toward reaching the best resolution. What's your current odometer reading?

Are you experiencing a similar issue? I understand your concern regarding the recreation of the symptom, although I do suggest taking a technician on a drive regardless. Please send along some details about your concern, including your model year and current mileage; I'll check my resources and see how to best assist.

Brittany