Troubleshooting Question

[DavidMcmillan]

My auto service days are long past, so I humbly call on the OSA experts with a somewhat puzzling question. One of our vehicles is a 2013 ford edge, 3.5 L 6 cyl, with about 140,000 miles. Under moderate acceleration there is a bit of a stuttering that seems like a plug issue, clogged fuel line, something. It isn’t noticeable under stronger acceleration. One ford dealer was unable to diagnose.

Now, the real question of this post. The issue is less noticeable when using higher octane gas.

Any thoughts?

 

[swampratt]

Did you change the spark plugs yet?

Even if you did I have seen many of the twin turbo Fords need a tighter gap than the factory recommends .
Larger created misfires.

The higher octane kind of makes me think carbon build up issues.
May be due for a BG system combustion chamber cleaner

 

[DavidMcmillan]

Yes, I forgot to mention plugs were changed out earlier this summer.

I hadn’t thought of a BG effort. I may be able to accomplish that this week. Certainly worth a shot.

Thank You!

 

[Mr.Glock]

Manual or Automatic? If Automatic, could be Torque Convertor shudder. Transmission ever been serviced?

But if a higher octane really affects, then spark where Swampratt is suggesting.

 

[swampratt]

Did the issue start shortly after the plug change?
The spark plug gap on that vehicle is excessive in my book and a good way to stress the coils.

 

[DavidMcmillan]

Auto. Transmission was also on my thoughts. This has been in the family since new, the last four years it has been with one of the grandsons at college. Son-in-law had transmission serviced at the beginning of that usage.

 

[DavidMcmillan]

The issue was present before the plug change, I had those replaced when I got involved earlier this summer.

 

[dlbleak]

I know it’s only 140k but you might have a flow test done on the exhaust to rule out a clogged catalytic converter

 

[DavidMcmillan]

I have run a couple of cat cleaner doses and really didn’t notice any change.

 

[SoonerP226]

Under moderate acceleration there is a bit of a stuttering

Moderate/light throttle acceleration hesitation/stumbling is a classic symptom of coils that are on their way out. If they weren’t changed when the plugs were done, they probably need to be done. Personally, I do the plugs and coils as a unit—you have to pull the coils to pull the plugs, so it’s just as easy to put new coils in with the new plugs.

FWIW, my truck got well over 100K miles (I want to say it was closer to 150K) on the factory plugs and coils, but the new (OEM) coils started stuttering after something like 30K miles. The replacements for the second set are still going strong.