Shudder / Shaking Misfire Under Load - not spark plugs

89 no solution

Well after a 4 and a half hour trip each way to/from Chicago using 89 fuel, I can say it's just as noticeable as with 93.

Jerry

Update: My dealer called to tell me they finally heard back from Ford engineers. Ford wants them to perform a whole battery of different tests, which tells me Ford has no idea what is wrong. We're working out a time that I can get a loaner car so they can keep my Mustang a couple of days to do all the tests. I'll update afterwards.

Thanks for keeping the thread updated.

The dealer finally has my car now and is supposed to keep it until they get this figured out. I hope it is not a long wait and that they really do figure it out.

Can't wait to hear what they find. I replaced coils on mine just so I can say it's not them.

After reading some of the F150 & SHO forums last night regarding similar symptoms, I pulled my cold side hose and checked for moisture or oily residue. Found nothing. However, I did find that the throttle had some carbon like buildup. So I opened the throttle blade and cleaned that up with some MAF cleaner. I also, pulled the MAP sensor and found it to be oily and dirty. I cleaned it with MAF cleaner.

On my drive in this morning the problem seemed to be gone. I'm not calling it fixed yet. I will be driving to NC this weekend through the Smokey's. If it acts fine then I will say one of those two things impacted it in a positive manner.

Thanks for the news. I can only wish it is something this simple; let us know how it goes after your trip.

RedEcoJet said:

Can't wait to hear what they find. I replaced coils on mine just so I can say it's not them.

After reading some of the F150 & SHO forums last night regarding similar symptoms, I pulled my cold side hose and checked for moisture or oily residue. Found nothing. However, I did find that the throttle had some carbon like buildup. So I opened the throttle blade and cleaned that up with some MAF cleaner. I also, pulled the MAP sensor and found it to be oily and dirty. I cleaned it with MAF cleaner.

On my drive in this morning the problem seemed to be gone. I'm not calling it fixed yet. I will be driving to NC this weekend through the Smokey's. If it acts fine then I will say one of those two things impacted it in a positive manner.

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RE: oily residue, do you have a CAI with an oil bath air filter? I've heard of similar issues in other CAI equipped Ecoboost engines before (not Mustangs).

Also, if this is the issue, makes you wonder what the intake valves look like...was hoping my dealer would borescope the intake to look at the valves when I took mine in

GJarrett said:

Thanks for the news. I can only wish it is something this simple; let us know how it goes after your trip.

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I'll know pretty quickly once I get in the mountains. I put about 100 miles on her today without a hint of the shudder/mis I was getting before.

Update for the day: got a call, Ford engineers instructed my dealer to install me a new dual-mass flywheel. I have no idea what that means and need to learn about what a dual-mass flywheel is and why it would cause this... or if this is the first step of them throwing parts at this.

FYI I do know about flywheels oldskool, but am not up to date on dual-mass new flywheel stuff. I guess a flywheel isn't simply a flywheel nowadays, but an old fart can learn new things when he has to.

EDIT: just researched this, and it could indeed be the problem if the dual mass flywheel failed, would explain a lot of the symptoms I am experiencing. Dual mass flywheels are mostly used in diesels to control vibration at low rpm under high torque loads, which is exactly what I am experiencing. That, along with the discovery that an imbalance condition can cause a misfire, completes the scenario. I am hopeful that this may indeed be it and that a fix is in the works.

Stay tuned...

Ran pretty good to NC. Not perfect but 80%. I think I will buy a new T-MAP sensor when I get home. It wasn't annoying like before, just felt it every now and then. Even then it was less noticable.

Jerry

Good to read. I also wiped mine off with some paper for now. It was a bit oily but that's normal, I'd say, with the stock pcv system. Car feels a bit smoother. Don't forget that there's the second map(?) / temp. sensor in the intercooler. Not sure what effect that might have in all of this.

RedEcoJet said:

Ran pretty good to NC. Not perfect but 80%. I think I will buy a new T-MAP sensor when I get home. It wasn't annoying like before, just felt it every now and then. Even then it was less noticable.

Jerry

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Are both of the MAP Sensors a Temperature type MAP Sensor? Does anyone have any documentation that can prove that? I looked to the Big G and could not find anything except for from one vendor and the vendor is not FORD.:ford:

jrock said:

Are both of the MAP Sensors a Temperature type MAP Sensor? Does anyone have any documentation that can prove that? I looked to the Big G and could not find anything except for from one vendor and the vendor is not FORD.:ford:

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I'm not sure, but when I looked up replacements on the Internet, none of the images looked like mine. Maybe there is an improved design. My engine was built in January 2014. I think I will stop at the Ford dealership and see if there is a difference. Mine had a carbon like buildup on it as well as some oily residue.

This is the intake manifold one: BV6Z9F479A
This is the intercooler one: AG9Z9F479B

Wonder if this is related:

https://www.mustang6g.com/forums/showthread.php?t=100140

Apparently, still some field failures happening....