5.4 three valve sparkplugs

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Bamamav

Well-known member
Joined
Mar 29, 2012
Messages
6,171
Location
Berry, Alabama
Got a 05 Expedition with the 3 valve 5.4, had a "mechanic" put a new set of Motorcraft plugs in it about last November. These are the infamous ones that are known to break off in the head, so I didn't trust myself to change them. So, about a month ago, had a misfire start, I figured a bad coil, replaced it, nope, pulled the plug, no electrode on it! Figured it was a fluke, a bad one got through, took it back to O'reilly's and got them to replace it, 2 year warranty, no big deal. Put it in, everything was hunky dory. Then last week, another misfire, different cylinder. Ordered a couple of coils and a plug from Rock Auto, waited on it to come in. Put a coil on Thursday, still a miss, so pulled the plug , it to had lost the electrode. Put the new plug in and the new coil, good to go again.....

Wife drove it about 30 miles, ck engine light back on, another misfire! This time, it was the plug next to that one. So Sat, I went and got a warranty replacement on the other one I had just taken out, and bought a spare, just in case...

In my internet searches, I found out if the plugs aren't properly torqued down, it allows extra air to pe pulled into the cylinder and lean the mixture, torching the plug. The last plug was finger tight! I didn't even have to use the ratchet to break it loose! So, for chits and giggles, I checked a couple more of them, both turned a quarter turn. Apparently the "mechanic" just snugged them down, never torquing them.

The two I haven't checked are a mofo to get to, I'm hoping they are tight enough. Going to run it and see, if they do go bad I will man up and do them, but I dread the heck out of it. Good thing is they all have came out real good and screwed back in good, so I don't fear breaking one as bad, t's just all the stuff in the way making access almost impossible. Stupid design with half the engine under the damn cowl like that!

Took a couple of hours, laying on my belly across the fender and radiator to do them, just killed my day.
 
If engineers had to work on the area of their's, they wouldn't design such stupid stuff.
I feel our pain. The NOX sensor went out on my 2014 Ram diesel last month and after taking the wheel, fender well, clipping half dozen zip ties I finally got to the box where it took another 2.5 hours to get two small bolts and two lager mounting bolts off just to be able to unplug the dang thang.
It is so far back against the engine and such a small hole ya can just barely reach in there to work.
They could have just as easily mounted it on the frame.
 
I hate this crap. Hate, HATE, HATE.

I hope my old "White Elephant" (1996) lives as long as I do, because I can work on it easily. When the wife's 2010 turd needs to be flushed, I'll be shopping hard for something much older.

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First time I did plugs on a 5.4 I was wincing every turn of the ratchet. Didn't have any broken, but a lot if screeching. Next time I was a little more cocky because I got off easy the first time. Broke 3 and had to use the crush-a-plug tool to dig them out. I was amazed each time how much better they ran after the plug change though. Great motor, as long as you don't have to replace the plugs. Or timing chains. Or, cam phasers, or . . . . ;)
 
First time I did plugs on a 5.4 I was wincing every turn of the ratchet. Didn't have any broken, but a lot if screeching. Next time I was a little more cocky because I got off easy the first time. Broke 3 and had to use the crush-a-plug tool to dig them out. I was amazed each time how much better they ran after the plug change though. Great motor, as long as you don't have to replace the plugs. Or timing chains. Or, cam phasers, or . . . . ;)

Shhhhhhhhh!!! Don’t start talking about those other things!:D
Ours has 165000 on it, I’m hoping to double that before anything like the chains or phasers come up.

He said ours came out easy, and he did use antizeize on them, so that helped I’m sure. But being only finger tight is way too loose!

Dr C., I’ve been thinking that way about my 99 F150 5.4. It’s got 165000 on it,too, and I did the plugs on it last year. I was as nervous as a long tailed cat in a room full of rocking chairs, those don’t break off, they strip the threads out of the heads. More better ideas, using only 4 threads in the heads to hold them in:eek:. I thought about going to a 96 or earlier with a Windsor, but realized my truck is now 21 years old....a 96 would be 24 years old! Not many still around in any kind of shape.
 
I had to Google your plugs, Bama... what a retarded design! Some engineers need to be beaten about the head and shoulders, mostly the head. :mad:

My '96 has 180K miles on it. It's a 6.5T diesel and I expect it to go 300K at least. My wife would still be driving her '96 Blazer if my son didn't crash it. It had 100K on it. :(

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Iv'e got the 4.6, went through the tear dropping the spark plug hole thing, major pia.
 

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I had to Google your plugs, Bama... what a retarded design! Some engineers need to be beaten about the head and shoulders, mostly the head. :mad:

My '96 has 180K miles on it. It's a 6.5T diesel and I expect it to go 300K at least. My wife would still be driving her '96 Blazer if my son didn't crash it. It had 100K on it. :(

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180k on the diesel? When was the last time you changed the spark plugs on that? :p
Also, now that it's getting warmer, don't forget to reverse the battery cables so the AC will come on and not the heat.
 
180k on the diesel? When was the last time you changed the spark plugs on that? :p
Also, now that it's getting warmer, don't forget to reverse the battery cables so the AC will come on and not the heat.

Glow plugs. Never again if I have anything to say about it.

I sometimes drive it backwards to rewind the odometer. :rolleyes:

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