Spark plug issue, how prolific?

[Cam Driven]

Hi all,

We are looking for a used Expedition around the 2002 to 2006 vintage and the zooming spark-plug issue keeps popping up.

How bad was/is it?
Is there a percentage of the vehicles produced for each problem year?
I see repair-guys on YT stating "I have replaced lots/hundreds/thousands," or "this is my 140th repair kit," etc.

How concerned should we be when looking at vehicles?

Thanks

 

[Rockclutch]

Hi Cam

Plenty of folks on here have WAY more knowledge of this than I do.
My understanding is that the 5.4 3V had this issue but the 5.4 2V did not. Something about very shallow thread depth on the 3 valve heads.

My 04 is the 2V edition and I have had no issues with the plugs at all over the 100+ k miles I've driven.

I was always advised to steer clear of the 3V.

Phil


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[TobyU]

They all had issues. The 3 valve for the early years use a 2 piece plug that snapped off during removal. Then they went to one piece. Will have to search for date. Many on here know it by heart.
The 2v more 5.4 than 4.6 had 3-4 threads in the head and that is not really enough to hold a spark plug.
Then they had a low torque spec for the plug so they loosened up and blew out often damaging the threads on the way out since there wasn't any more down in there.
They changed to torque sped to like 22-24ft lbs DON'T quote me on this. Go look it up but I think I am close. I don't torque plugs. I use a 3/8 ratchet and go pretty darn tight. I worry more about me stripping the threads from over tightening than them coming out.

 

[JExpedition07]

Hi Cam

Plenty of folks on here have WAY more knowledge of this than I do.
My understanding is that the 5.4 3V had this issue but the 5.4 2V did not. Something about very shallow thread depth on the 3 valve heads.

My 04 is the 2V edition and I have had no issues with the plugs at all over the 100+ k miles I've driven.

I was always advised to steer clear of the 3V.

Phil


Sent from my LG-H872 using Tapatalk

It’s opposite, the 3V engines have a lot more threads in the head than the 2V, the 2V are the ones that pop out randomly.

 

[Rockclutch]

It’s opposite, the 3V engines have a lot more threads in the head than the 2V, the 2V are the ones that pop out randomly.

Thanks! Learn something new every day[emoji41]

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[jeff kushner]

My first 2 Expys did not have two-piece plugs. From my recollection, 06-08 maybe?

jeff

 

[David Kuchler]

I have an 06, and replaced plugs and COPS, the plugs all came out with no issues, and they appeared to be original, (2 piece)
Pure luck id guess, I replaced with the newer 1 piece, and seems all is good in that department.
I am having the occasional rattle issue cam phaser, vvt, or some darn thing, cant seem to solve it, so it will either explode, or not, this seems to be causing a Whicked gas mileage issue along the way, typically around 10 to 12 on the highway, when I first got the truck, prior to any work besides air cleaner replacement and new oil, I did get 18 on a couple tanks in a row, since then, and after a ton of parts, 12 is good as it gets.
replaced, vvt, cops, sparks plugs, driver module fuel pump, fuel pump, mass air flow, fuel pressure sensor, one cam phaser, computer, seems only gotten worse since,


on another note, I have an issue when first starting when heater comes on, aint freeze is coming into cab and fogging windows for first 20 minutes of running then goes away, don't see any leaks, and not loosing any fluid to speak, maybe half a gallon in 2 months, of driving at most.
anyone ever have this occur, and what did it take to fix it??????

 

[parkerdoug383]

Hi Cam

Plenty of folks on here have WAY more knowledge of this than I do.
My understanding is that the 5.4 3V had this issue but the 5.4 2V did not. Something about very shallow thread depth on the 3 valve heads.

My 04 is the 2V edition and I have had no issues with the plugs at all over the 100+ k miles I've driven.

I was always advised to steer clear of the 3V.

Phil


Sent from my LG-H872 using Tapatalk

It wasn't shallow threads those were on the first gen ones. It was exactly the opposite on the 05's and up they used a 2 piece plug which welded itself to the top end they often break on removal from what I understand it's a devestating repair job

 

[JExpedition07]

I did the spark plugs on my last 2007 with (0) issues and did them on the current 2007 with (0) issues.