Check the plug. I chased a #8 misfire for far too long believing the plug was good because the dealer just changed all 8. I finally went back to troubleshooting 101, pulled the plug and found the ground strap missing. Replaced the plug and all was well. Bottom line, don't discount simple solutions.
Cylinder 5 misfire even with new coil !
- Thread starter pennyanguy
- Start date
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Tim Deater
Member
I struggled with figuring out what cylinder from a missfire code as well recently, mine was due to water getting up where it was not supposed to be from me being a little crazy with the water hose after making a mess changing a water pump. I could never really nail down a for sure answer, but it seems that the OBDII code is telling you it is the 5th cylinder in the firing order, not cylinder order on the engine. So I think that would be the second one from the front on the drivers side. I think the firing order is 1-3-7-2-6-5-4-8 I ended up cleaning and drying out all of mine and found water in a few of them. Again, I don't know for sure, and I bet there are a lot of smarter people here that would know that.
07navi
Full Access Members
All those modular engines have holes where the plugs are, water can easily get in there and cause shorts, I always put heavy grease around the tops of the boots to help keep it out when changing plugs.
Definitely check the spark plug to make sure it is fine, then swap coil pack with another one. A brand new coil pack can be doa in the box. I had this happen on our old '06 Expy. Happened while on a long distance trip. Went to Napa (Sat & no dealership open in the area) and got an aftermarket one. Put it in, seemed fine, then within 10 miles, started misfiring. Went to next exit & another Napa. They gave me another one, and that one worked perfect.
My experience with aftermarket VS OEM coil packs is that the aftermarket ones tend to not last as long as OEM. For the price difference, I bought aftermarket then just replaced them if it went bad "prematurely." Only happened on a couple of them out of 8.
pennyanguy
Active Member
Update...
So as I said, 200 miles maybe since all plugs were replaced, so the coincidence to me was the glaring thing... I gave a half hearted attempt at switching plugs, but they were in there pretty good and I did not want to give the mechanic an excuse if I did something so I brought it to them this morning... 5 minutes later he comes back sheepishly... bad plug.. they switched plugs first (cause I told him I already did the coils) and the misfire moved with the plug... so.. half an hour to wait for another plug to come in... and all is good. I asked why the plugs were so tite... he said they torque them to 35ft/lbs... thats the spec... seems high to me... but they are in there already, and now I know what I am looking at and why the plugs supposedly break so often
Gotta say... DUMB design FORD... why the long shank and double electrode hoop... just looks like something that will be troublesome.
So, Mech showed me the bad plug.. it was a motorcraft... so he obviously put in Ford parts (good?) , and it was clean so not old plugs with 100K miles on them... I am naturally distrustful of mechanics but I am starting to grudgingly accept this guy may be decent... expensive but decent.
So last question for all you great folks who took the time to comment... Is there a better plug to replace the Motorcrafts with? Is anything less "break prone"? Should I do that now? or soon? or should I look at another plug change at say 50K miles instead of 100K.. At the rate I drive this truck... that would probably be 5-7 years.
So as I said, 200 miles maybe since all plugs were replaced, so the coincidence to me was the glaring thing... I gave a half hearted attempt at switching plugs, but they were in there pretty good and I did not want to give the mechanic an excuse if I did something so I brought it to them this morning... 5 minutes later he comes back sheepishly... bad plug.. they switched plugs first (cause I told him I already did the coils) and the misfire moved with the plug... so.. half an hour to wait for another plug to come in... and all is good. I asked why the plugs were so tite... he said they torque them to 35ft/lbs... thats the spec... seems high to me... but they are in there already, and now I know what I am looking at and why the plugs supposedly break so often
Gotta say... DUMB design FORD... why the long shank and double electrode hoop... just looks like something that will be troublesome.
So, Mech showed me the bad plug.. it was a motorcraft... so he obviously put in Ford parts (good?) , and it was clean so not old plugs with 100K miles on them... I am naturally distrustful of mechanics but I am starting to grudgingly accept this guy may be decent... expensive but decent.
So last question for all you great folks who took the time to comment... Is there a better plug to replace the Motorcrafts with? Is anything less "break prone"? Should I do that now? or soon? or should I look at another plug change at say 50K miles instead of 100K.. At the rate I drive this truck... that would probably be 5-7 years.
07navi
Full Access Members
Only the original plugs broke, and don't wait 100k to change any plug.,,,,,,,,,,,yes use mtrcrft
