The v10 has somewhere in the range of 80k miles on it. We were about 15 miles from our destination when the EX dropped a gear on the interstate the rpms jumped up like it always dose no big deal right?

But it wasn't ok it banged and then it was real loud like a exhaust gasket went out. There was a significant loss in power. We went to get it looked at, it turns out that the back passenger side plug worked its way out.

The gap was pushed together, coil broken, and some more plastic stuff was broken. The threads on the plug looked good so we didnt figure there was any damage.

We came back (2 1/2 hour drive) it ran fine with the new plug in it. It ran fine.

So that brings me to a few questions. If it happend on one cilender when is it going to happen to the others?

What could have caused this other than they are prone to it?

Why would the gap be more or less crushed, could the piston have hit it?

What kind of long term damage has been done?

Thank you very much. Anything anyone would like to add is very welcome. Me or my dad might have some more questions for you all cause this newer technology is way out of our leage.

 

OK, a few things.

The gap is pushed down because it was rattling around on top of the hole. The intake stroke will suck it down, the compression stroke will push it up, and the intake will suck it back down again. So, the gap is crushed.

When you put the new plug in it, it torqued down correctly?

Second:

By 2005, you have the long-thread heads in the X (2-valve V10). It is very rare for this to happen.

You should go through all the other plugs and make sure the threads in the heads are good, and that they are torqued down correctly.

Was the old plug very rusty? Or clean?

 

the plug wasnt clean but it wasnt rusty either. It was just black on the spark end. So it has 2 valve? I figured it would be a 3v. But that is a bummer that it is rare. I didnt know ours was one of the fixed ones. Thank makes me a little more concerned. What are the plugs supposed to be torqued to? Thanks

 

Are you the original owner? If so have the plugs ever been changed? You see where the answer to this question will take you.
Now, who knows the correct torque for the pugs?
V-10s went to the 3 valve heads in 05.

 

The Excursion, and the E-series (vans) are all 2-valve, even 2005 and later.

Torque is 14ft/lbs on the later engines, at least, that's what I remember finding when I researched it last time.

That's what I used on my short-thread-head 2001 V10

 

We are the original owners, plugs have never been touched. Im not getting a great feeling about this the more i think about it. But where do we go from here?

 

Huh, I wished i would have realized that earlier. Because we were going to turbo it because we figured it was a 3v and we couldn't get a supercharger for it. The custom turbo was way to expensive at a quoted 15k lol.

But good to know what it is now.

Thanks for the Torque to by the way. Ill try and find a torque wrench some where and check out the plugs.

Hope you guys have some ideas cause im drawing blanks. Once again thank you guys.

 

It's weird that the plug tightened down and stayed there after it escaped once already

Usually the threads are gone. Totally gone.

If it were me, I'd check the threads with an inspection mirror and see how they look. If they are still there, reinstall the plug with some anti-seize and leave it.

If not, get a Timesert insert installed and keep an eye on the rest of the plugs.

This is one of the ONLY later-year V10's we've heard of having a plug issue.

The only thing I can think of is it was improperly torqued down at the factory, although Ford went through great pains to make sure that didn't happen after 2000 or so.

Here's what I have on the plug issue and when (and what) Ford did what they did to try to correct it.

2005 is pretty late in the game.

December 1996 - 4.6L 4V alignment feature added
February 1997 - 4.6L 2V head alignment feature added
September 2000 - WEP (Windsor Engine Plant) 2V head alignment feature modified (4.6/5.4/6.8)
November 2002 - WEP introduced long thread heads on 2V (all)
May 2003 - REP (Romeo Engine Plant) introduced long-thread heads on 4V 4.6 and 5.4
November 2003 - REP introduced long-thread heads on 2V and modified alignment feature

In 1999, and 2001, an interim fix was done for a cross-threading issue.
Original process:

Step 1 - Zero torque spark plug (air tool)
Step 2 - Torque to 16-20Nm final torque (DC Run down), monitor at 6-12Nm, and final torque must be reached within 0-360 degrees.

New process (addressed the possibility of applying installation torque for more than 25 degrees of rotation)
Step 1 - Zero torque spark plug (air tool)
Step 2 - Torque to 16-20Nm final torque (DC Run down) start monitor at 6-12Nm, and final torque must be reached within 3-25 degrees.

Another action to address cross-threading was the addition of an alignment feature to lead the plug into the hole.

 

I will double check the threads. But I checked the plug and none of the threads were messed up.

Yah the fact that i couldnt find any thing on here about newer v10 plug issues really kind of worried me. No that you said this is one of the only ones makes me even more uneasy. Ill be sure and have that checked out so it dosnt happen again.

Thanks yet again sir

 

The plugs are steel, and the cylinder head aluminum. Aluminum is much, much softer, so the head is more likely to have thread damage.

 

oh, ****. Thats not good. it has been sitting sense it got back, ill get it check as soon as possible.