2014 Expedition Misfired twice

[Crixus12]

Hey there.

Ive had my 2014 Expedition EL since it was new and I am just approaching 90,000 miles.

Twice in the past two years (maybe three years) when I would accelerate (hate to say, peddle to the metal) while merging uphill on a ramp, same spot both times, my car would not exceed about 35mph and the check engine would flash, putting me in limp mode practically for about 1 minute. Then it will drive normally and can’t replicate it. Light goes away but with a garage scanner there is a stored misfire code in cylinder 8. Not sure if this matters but I believe both times it was about sub 40F and the car was only about 3-5 minutes warmed up/running. As of now. No stores codes since I last cleared it.

I’m only about 7k miles away from the manufactures recommendation to replace all plugs (which I will replace with all new boots as well, bought from RockAuto- all Motorcraft brand).

My question is should I be concerned at all about cylinder 8 or the ignition coil? As mentioned, this hasn’t occurred since. Any other thoughts?

Thanks for the help!

 

[bloodhound]

Hey there.

Ive had my 2014 Expedition EL since it was new and I am just approaching 90miles.

Twice in the past two years (maybe three years) when I would accelerate (hate to say, peddle to the metal) while merging uphill on a ramp, same spot both times, my car would not exceed about 35mph and the check engine would flash, putting me in limp mode practically for about 1 minute. Then it will drive normally and can’t replicate it. Light goes away but with a garage scanner there is a stored misfire code in cylinder 8. Not sure if this matters but I believe both times it was about sub 40F and the car was only about 3-5 minutes warmed up/running. As of now. No stores codes since I last cleared it.

I’m only about 7k miles away from the manufactures recommendation to replace all plugs (which I will replace with all new boots as well, bought from RockAuto- all Motorcraft brand).

My question is should I be concerned at all about cylinder 8 or the ignition coil? As mentioned, this hasn’t occurred since. Any other thoughts?

Thanks for the help!

Presumably you mean 90,000 miles. Your plugs are worn, which caused a misfire under load in cylinder 8.

 

[07navi]

I would replace the plugs now and see how it goes. (Bloodhound beat me to it by seconds). Just the pugs and make sure all the boots are good and the plug holes are clean.

 

[Crixus12]

Presumably you mean 90,000 miles. Your plugs are worn, which caused a misfire under load in cylinder 8.

Edited. Thanks for catching that!
Perfect. Just didn’t want to ignore something else. Thanks for the response.

 

[JamaicaJoe]

Just change all the plugs and the boots. The coil might be fine. If you still get a misfire on that same coil, change it. You might mark that coil in case the mechanic mixes it up with another.

You can't get more than 45K on plugs despite what Ford claims. It is a myth.

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[07navi]

Just change all the plugs and the boots. The coil might be fine. If you still get a misfire on that same coil, change it. You might mark that coil in case the mechanic mixes it up with another.

You can't get more than 45K on plugs despite what Ford claims. It is a myth.

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

 

[JamaicaJoe]

If I were the OP I would not be giving full throttle at freezing temps with only a few minutes of warm up.

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[Trainmaster]

Yep, change the plugs. And flooring the thing isn't what you should be doing.

 

[Thunderbirdsport]

Mine just did the same thing last night, for the first time. New plugs today, we'll see what results. Been noting a drop in MPGs, figured it was the bigger tires. Not so sure that the size increase is going to cause a loss of 5 MPG though...

So like I said, I'm gonna do new plugs in a bit. Freezing rain today so may as well do something under a roof.

 

[Crixus12]

If I were the OP I would not be giving full throttle at freezing temps with only a few minutes of warm up.

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I 100% agree. Bad judgement that day while in a rush.

 

[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.