Ford V10 shutter/ misfire only in overdrive diagnosed/ fixed

[K-9_HANDLER]

Thought I would share my experience with this and what I found incase other folks have a similar issue and want a possible resolution. Several weeks ago truck started what I would describe as a shutter or misfire. Its the excursion in my sig picture. Truck has around 100K. Plugs and boots replaced 4K ago by me. The symptom would only appear when in OD between 40-50 mph and 12-1600 rpm when going up a slight incline with light acceleration. If I pressed more on the gas forcing a downshift problem went away. Problem not exhibited any other time.
No CEL light on and when hooked to scanner no codes were current or none pending. Decided to chase a possible cylinder misfire. I didnt think it was tranny related as the rpms didnt fluctuate when truck was symptomatic. Also didnt think it was the torque converter ( was hoping it wasnt).
Hate just throwing parts at a problem so I had to isolate cylinders to figure which if any were misfiring as I was not going to buy 10 coils ($400) and hope for the best. On my scanner went into mode 6 diagnostic monitor tests. In there I used test $53. It gave me a list of all 10 cylinders and any misfires sensed. Sure enough they all had 0 except #2 and #7. #2 had over 800 and #7 had 1020.
Replaced coils/ boots/ plugs in those two cylinders with new Motorcraft units.Pulled plugs looked great, what gives I thought. Been driving it and problem appears fixed.
So why no CEL light or code? Why did electrodes on pulled misfire plugs look ideal? Well I did some digging around on the net and apparently when in OD the air/fuel mix is leaned which requires more voltage to ignite. Marginal failing coil cant supply enough and a miss occurs. Miss only occurs then and not during other driving conditions so the percentage of misses never gets to the threshold to throw a hard fault/ code. Other folks on here with more knowledge can probably explain this better then me.
Hope this helps someone. Total repair cost me under $100 could have been much worse.

[bid_time]

K-9 HANDLER wrote:
... On my scanner went into mode 6 diagnostic monitor tests. In there I used test $53....

Where can I find a list of "$xx" codes for the mode 6 tests for my 2002 V10? When I read the manual for my scanner it says "Refer to Vehicle Service Manual for Tests ID's" and I don't have a vehicle service manual. So I would think they must be available somewhere on the web, but I can't find them, anyone know where I can find them?

[_40Fan]

Fords are the worst at setting a misfire code. Honestly, if you own a Ford and have a Win 7 laptop, buy a $125 cloned VCM-II. Nothing beats a dealership scan tool when chasing misfires. It would have taken 2 seconds after it started missing to know which cylinder it was.

Need help setting it up after purchase, let me know.

[Wes_Tausend]

...

Thanks for the info, guys. This makes a lot of sense. I think I may have experienced a miss on my V10 Excursion at times. With ten cylinders, a V9 can be rather subtle. If I recall, it seemed to occur during moderate cruise rather than hard hard-pull, a weird scene. Now I know what to look for.

Wes
...

[dodge_guy]

You are not getting a code because some SD trucks don't have full OBDII diagnostics! My X is one of them. I don't have misfire monitors, downstream O2's that monitor the cats, or an EGR monitor. That is how it was built. Almost anything with a GVWR over 8601lbs has Federal emissions. Cali trucks and a couple other states have Cali emissions with more stringent requirements.

[K-9_HANDLER]

Yak wrote:
Mode 6 is a wonderful tool. You have to have so many misfires on one cyl before you set a light but I don't understand why it didn't set a p0300, random misfire. As a Ford tech I prefer OEM coils, depending on the brand, too many issues with after market coils. Most of the time I get,"my mechanic replaced all the plugs and coils but it still misses"

I love Mode 6. I couldnt understand not getting a code either. In $53 cylinder #7 had the comment "HI" after the misfire count. At 800 misfires #2 still said "OK".

As a side note my average MPGs are creeping up on the trucks computer after making the repair.

[Yak]

Mode 6 is a wonderful tool. You have to have so many misfires on one cyl before you set a light but I don't understand why it didn't set a p0300, random misfire. As a Ford tech I prefer OEM coils, depending on the brand, too many issues with after market coils. Most of the time I get,"my mechanic replaced all the plugs and coils but it still misses"

[jerem0621]

My V10 F350 had an identical problem...same fix...new coils solved the problem.

When I pulled the coils I had six of them that had visible cracks in the coil body... Here is a pic...As far as I know..my V10 is the only modular posted with these cracks.

I think the dually was a fleet truck with lots of idle hours on it.




Thanks!

Jeremiah

[dodge_guy]

Glad to here you got it. I carry 2 spare coils with me, for this exact reason.

The plugs are very easy to change. They will not break. On early Tritons up to 01 you have to becareful when installing them so you don't pull out the 3 threads they have. 02 and up have about 5 or 6 threads. The breaking plug issue was on the 3 valves. And I'm not sure if that was all Tritons or just a certain engine.

[K-9_HANDLER]

Cougarnewbie wrote:
How tough was it to change out the 10 plugs? I've read that they are tough to break loose and easy to break. The dealer wants $600 to do it, if they don't break any.
Thanks

I sent you a PM.

[Cougarnewbie]

How tough was it to change out the 10 plugs? I've read that they are tough to break loose and easy to break. The dealer wants $600 to do it, if they don't break any.
Thanks

[K-9_HANDLER]

Mine X is a 2001. Scanner I have is an inexpensive Accutron Accuscanner plus. If a scanner has the 10 modes of OBDII it should do the $53 test.

[Sam_Spade]

One should always suspect spark problems, most likely a HV leak to ground, when a miss occurs only under extra load.

[CloudDriver]

What scanner are you using for these tests?

[Desert_Captain]

K-9, Good info thanks for sharing. What year is your V-10?