F150 3rd-4th gear hesitation

Hey guys - I've been all over google. Opinions are like assholes. That said, I know there's some Ford people here, and I trust more of you guys knowing vehicles than a lot of other places I read.

2012 F150 Ecoboost, about 93K miles... It has started, lately, hesitating/lagging/missing/whatever you want to call it sporadically between 2nd and 4th gear, from around 25MPH up to about 45MPH. It doesn't jump or shudder, like it is mechanically jammed. But more like it feels on a bike when you're in too high a gear and it just lugs a bit.

I don't so much have a loss of power, as I can still do highway speeds. I have noticed my gas mileage is a little lower lately too. It does not shudder or shift hard like I might expect with a mechanical transmission issue.

I've checked/replaced plugs (all brand new), I've looked at the air system (brand new filter), I've attempted pulling codes (no error codes). It has done it on more than one tank of gas, so I'm not sure its bad gas. I did throw some SeaFoam in this last tank to see if maybe if cleaned up fuel system gunk or something.

I'm down to about 4 ideas:

1. Intercooler is a known issue. The way people describe the intercooler problem, they get a lag or even a complete drop in power as the truck goes into limp mode. I've only had that happen once a few years ago. Hasn't happened again. That said, intercooler has always been suspect in the back of my mind.

2. Code issue that needs to be updated? I've heard people say the computer might require updates? If so, is anyone aware of an update for what I've described? I'm trying to find reliable TSB info for my year/model.

3. Transmission? It doesn't feel like what I'd consider a transmission issue, but then again, I'm not a mechanic that sees these problems all the time.

4. Timing? I've read there's a timing chain stretch issue. I don't know if this happens without an engine light though. As I said, no codes.

If I need to take it to dealer, I will. I'm just trying to avoid a $2K car repair bill while I'm looking for a new job.

 

Following
I'm at 133k 2010 and feels like clutch is slipping or trans can't get into gear unless I let off periodically in the low gears

 

I have this exact same issue with my 2006 Grand Cherokee. From my research at the time, it's almost certainly a transmission issue.

The third to fourth gear stuttering is the telltale sign (again, going by memory).

 

If you hammer it from a stop and run it through the gears, does it act differently in 1st and 2nd than it does in 3rd(aside from revving quicker due to gearing of course)? If you're cruising along in OD and squeeze it a little, does the converter unlock(rpm jump a few hundred) or stay low and that could be the sluggishness?

 

Good question. The difference in the two scenarios is exactly why I'm leaning away from transmission. If I do a jackrabbit start (not even hammering, just aggressive take off) and go through the gears up to 70-80mph, it seems fine. But, if I'm driving neighborhood speeds, or driving more conservatively, that's when I notice it more. I wish I could describe it better. If I give it gas, it goes, but if I'm maintaining the same level of throttle - 2nd/3rd/4th gear it'll sort of buck/miss/hesistate... Umm.... The more I think about it, its sort of like how a dirty carb on a dirtbike acts from time to time...

Maybe a fuel system issue? Funny, in all of my research, fuel hasn't come up one time.

It doesn't shift hard or feel like its delayed going into the next gear at all.

 

I'm dealing with a stumble on my 170k mile excursion that may be the same issue you are having.

Light load hesitation in between 1500-2000 rpm. I'm putting a set of plug coils on it. I'd recommend the same. $50/coil from Ford or $70 for a set of ten on amazon...

 

I started to do this the other day when I was switching out plugs. I didn't because they were $45 each at Autozone. I'll probably order a set on amazon today just to rule that out, in case I have to take it do the dealer.

What I read was that it should throw a code if one of the COPs goes bad, but I guess if its like a pre-failure/intermittent, it might not be enough to force the code yet.

 

You'd think you would get a misfire code if it was a coil, but it is a Ford....

 

I know - if it was GM, I'd have made this post 40K miles ago.

 

I'm thinking the spark is breaking down on the secondary side of the coil and is intermittent which is why it may not throw a code.

I may cuss myself for not using FoMoCo coils but at $50/pop x 10 coils I'll try my luck with the knock offs...

 

Looked at the trans fluid?

 

I have the same truck. My transmission complaint is downshifting from 5th to 4th at slow speeds. There is a definite clunk. I do have a tuner so the shifts points are slightly harder so that may contribute. I now manually shift it so it stays in 4th until speeds pick up again.
I changed the trans fluid with Mercon LV and also installed an aluminum pan that has a drain plug and holds 3 qts more fluid. It didn't change the shifting but I did it as routine maintenance. I would definitely change the fluid if you haven't already at those miles. There's some good youtubes from fordtechmakuloco. There's no traditional dipstick that you access from the engine compartment. It's underneath next to the cat.
Did you drill the intercooler yet?
Adding a catch can might be another good investment since its a direct injection engine. You might have carbon buildup on the intake valve that's affecting performance. To my knowledge the only way to fix it is to remove the heads, putting a catch can in will help keep it from getting worse. I empty mine weekly. You should see the stuff that comes out of it in the winter months.

 

I couldn't find a link with coils as cheap as you mentioned. Mine is an ecoboost (6 cylinder) and I'm not sure it uses the same coils.

 

Yeah - I can't go nuts because I'm looking for a job, but I just recently learned about the catch can - which sucks. If I'd known about it, I'd have done it years ago. I'll do it as soon as I can... $400 for a catch can seems steep, but also seems to be the going rate.

I thought about drilling the intercooler, but if that's the fix, I'm likely better off just replacing the damn thing. The TSB about the intercooler didn't come out until my truck was already out of warranty, so I didn't get a free replacement like some people.

I've got, easily, $2K or more in things I need/want to do just to make it last longer, not even performance gains.

 

Next on the list after the new coils arrive. Just in case.

 

RE: catch can. Get one that works on boost and vacuum. It's surprising how often the engine is on boost.

 

Find your Ford part number then search that on Amazon. That's how I found mine.

I still haven't put them in yet...

 

Do the plugs on the back first while you are rested.

Coils and plugs did the trick. Plugs were shot with about 50000 miles on them and the driver rear plug looked like it had seen some water in the hole.

Test drive showed no stumbling in the exact area where the defect was pretty common. Same road same speed. Light throttle load between 1500-2000rpm.