2014 Expedition Misfired twice

[Crixus12]

I agree, I change mine every 30k miles but that's just me. They are like tires, they start wearing out from day one.

Do you change the plugs and boots that often or just the plugs?

 

[vincentrose]

Yep, I purchased a 2014 in August, and it was doing the same thing to me. Floor it, Check engine flashes, Stored misfire code, (I think in Cylinder 1&2). New plugs cured the problem. Old plugs were so worn out, some of them had a gap 1/8 inch to 1/4 inch wide, its a wonder they were firing at all. 8 new plugs later, purrs like a kitten, and roars like a lion when you floor it!!!

 

[07navi]

Do you change the plugs and boots that often or just the plugs?

Just the plugs and any boot that is shot which is usually none. I'm a "if it ain't broke don't fix it" kinda' guy and it has served me well. I also keep the plugs holes immaculate with a wood dowel, cloth, solvent, and drill setup. Dirty/wet plug holes are hard on boots.

 

[JamaicaJoe]

I had the dealer change my plugs only at 45K , a pricey endeavor that did not include the boots. A while later I had misfires again until I replaced the boots. You are not saving money by ignoring the boots. The COP s I would leave alone unless I have a misfire with new plugs and boots. You can swap the COP easy enough to test it.

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[JamaicaJoe]

Yep, I purchased a 2014 in August, and it was doing the same thing to me. Floor it, Check engine flashes, Stored misfire code, (I think in Cylinder 1&2). New plugs cured the problem. Old plugs were so worn out, some of them had a gap 1/8 inch to 1/4 inch wide, its a wonder they were firing at all. 8 new plugs later, purrs like a kitten, and roars like a lion when you floor it!!!

The only reason those bad plugs fire at all is because each ignition sequence is something like 6 strikes of HV. So if the first does not take, 5 more sparks in a row. Of course the timing is delayed.

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[07navi]

The only reason those bad plugs fire at all is because each ignition sequence is something like 6 strikes of HV. So if the first does not take, 5 more sparks in a row. Of course the timing is delayed.

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??????????

 

[07navi]

I had the dealer change my plugs only at 45K , a pricey endeavor that did not include the boots. A while later I had misfires again until I replaced the boots. You are not saving money by ignoring the boots. The COP s I would leave alone unless I have a misfire with new plugs and boots. You can swap the COP easy enough to test it.

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Me? I check them and reuse them if good and never had a problem doing that.

 

[Gumbyalso]

I have an '11 XLT plus and a 2000 EB with the 5.4, both owned since new. The '11 5.4 is 3V and the '00 is 2V. I change the plugs every 100K on the '00 and have changed coils once at 300,000. The plugs have never been an issue but 300,000 was stretching the coils. It started having issues going uphill. It has 327,000 on it now with no issues. I changed the plugs on the '11 at 110,000 which is when I think the book calls for it. When I pulled the plugs they didn't look like they needed to be changed. I changed them anyway because I'd already bought the new plugs. I use the OEM plugs. The '11 has 197,000 on it now. I will change the plugs again at 220,000 and maybe do the coils then too. I've never had a problem with these platinum plugs. It's much easier to change the plugs on the '11 than on the '00 because of clearance issues. It took me 45 minutes to change the plugs on the '11.

 

[Thunderbirdsport]

I changed the plugs on a '99 5.0 exploder one day, customer was waiting while I did it. I jacked it up enough to unload the suspension so as to get to the plugs through the wheel well. Easy peasy. Took half an hour or so. She was amazed that someone would jack up a car to change the spark plugs. Better than laying on top of it, getting a back ache, and getting scratched all to heck.

 

[Swede252]

Plugs. Old plugs cause misfiring issues.
That’s all.