I am now part of the spit out spark plug club. Wife's Expy spit the #5 plug on friday. We were leaving town on a 200 mile trip and stopped for gas. Upon restarting the truck she popped. Sounded like a old Farmall tractor! We have had the truck about four months. Luckily the plug appears to have just backed out. Threads on plug were good and as far as I could tell the threads in the head looked good. Went ahead and bought a new plug and coil because it broke the old coil. New plug went right in. I have been reading about how the plugs should be checked for proper torque but have been putting off doing it. Well they have all been checked now! Anyway it gave me a good excuse to pay the extra to drive the Ex. Got 14.3 mpg at 65! Fixed Expy when we got home so life is good again. John

 

You got EXTREMELY lucky the threads in you cylinder head weren't ruined!

Go buy a lottery ticket! LOL!

Stewart

 

I forgot to mention #2 plug I removed with just my fingers on the extention. There couldn't have been one or two threads holding it in. Maybe I will go buy that lottery ticket! John

 

Is it possible for the plugs to back out like that if they had been installed
with the proper torque? or in this case did the last person to install thje plugs forget to tighten them?

 

After having launched a plug in my Lightning a few years back, I got in the habit of checking them every 6 months or so.

I once found two of the plugs only finger tight, I'm sure on the way to working loose enough to pop.

I stopped being lazy after that and started torquing them properly and I haven't had one single problem with the plugs, nor have I found them loose ever since.

Based on my experience, and the experience of my fellow L owners who also torque their plugs, I feel safe in saying you should have zero problems with a properly torqued spark plug.

Stewart

 

I know its a little late to be asking this but I want to make sure I didn't screwup. How many inch pounds are there in a foot pound? I searched and didn't find anything excact but i assume that there are 12 in lbs to 1 foot lb. John

 

You are correct. 12 inch pounds per 1 foot pound.

Stewart

 

I have a silly question- If a plug is backing out, don't you notice the truck is not running correctly? I mean I know it has 10 cyl and all but does a check engine light or rough idle not happen?
Just wondering..
Thnaks!!
Beth

 

In this case it was on my wifes 5.4 Expedition and the truck was running excellent. I stopped and filled up with gas and when I started the truck back up POP!! There was no check engine light because I shut it off immediately. Somehow I knew what is was. I am just glad it happened close to home and not in the middle of no where. John

 

WOW!! I had no idea it happened in expy's as well. Why did ford make the plug holes so shallow? Sorry I have a diesel, just trying to learn a little..

Thnaks
Beth

 

It happens to all the modular engines from Ford.

The 4.6, the 5.4, and the 6.8L Triton engines. And not just the truck engines, it happens to the Mustangs too. It wasn't until 2003, when Ford started putting more than 4 threads per plug hole in the cylinder heads that the plugs became less problematic.

That's why I referenced my Lightning (it has a 5.4L) when I posted in this thread, because you KNOW I have a PSD in my Excursion, Beth!

As for it running rough, I can't answer for the V10's, but my Lightning didn't run any rougher. The only tell-tale give-away that commonly occurs is what sounds like an exhaust leak developing. And when you get out of the vehicle to check it out, all you hear is a ticking noise, which shouldn't be confused with the injector tick you can hear on Lightnings, and I would assume other vehicles too.

Those with plugs won't have any problems at all if they check them every-so-often, as well as change the plugs when the engine is warm-to-the-touch, torquing them down to Ford specs.

Stewart

 

Thanks for the info!! interesting...........I have friends looking for a new truck, they LOVE mine but wanted to know a little more about the gasser. I keep telling them it's better to glow then spark!! LOL Really, I think they would be happy with either one....

 

That is a case of the plug backing out of the hole until it pops. Iv'e seen it happen even with Iron heads.

The threads are still there, thankfully. You don't have to do any herculean repairs.

The problem with the 2001 and earlier modular heads is that they do not have enough threads in the head to hold. 3 threads instead of 5 in the newer heads, 2002 and newer.

The threads would fatigue, and then the plug would pop out of the hole, leaving no threads at all in the hole.

The only fixes for that type of damage are to replace the head, (expensive) put in a Heli-coil (doesn't last long) or put in a Time-sert steel sleeve insert. (permanent repair and better than original)

I have now put in a total of 29 Time-serts inserts in different vehicles. Each one of them a PITA and about an hour and a half of time.

 

I disagree. There are way too many of my Lightning brethren who have experienced this problem, and it starts when the plug starts to loosen and back out.

As the plug backs out, the lack of threads, and the fact they are aluminum, allow the plug to be launched. The threads do not fatigue and fail first, allowing the plug to launch.

If that were the case, then there would be more plug launches in Lightnings than any other vehicle because of the higher cylinder pressures we have, due to the different boost levels we all drive with. Boost levels and engine pressures do not cause the plugs to launch any more frequently in the Gen 2 Lightnings when compared to the 4.6L Mustangs or the 6.8L Super Duties, so thread fatigue is not the issue.

Also, one of the tell-tale signs that can happen (doesn't necessarily mean it will) prior to a plug launch is a ticking sound, which some describe as an exhaust leak when the hood is closed and they are inside the vehicle. That ticking sound is the threads of the plug ticking against the threads of the cylinder head as they come loose.

Because the heads only have 4 threads per hole, if not torqued properly, the plug can start to loosen and back out until it eventually backs all the way out, or it's launched.

With the new cylinder heads starting in '03 (some of the early '03's still have the 4 threads), Ford began putting 8+ threads per cylinder hole in the heads, which gives a wider margin of error when installing plugs, because let's face it, until this started happening, I don't think there were too many mechanics (shade tree or professional) that were torquing spark plugs when installed.

Stewart

 

To bad you can't safety wire the plugs some how.... You know like we have to do for racing on bolts and oil pan and stuff... This is an interesting thread and I don't even have spark plugs!!
Beth