Spark Plug WTF... Am I an idiot

[billschroeder5842]

Before you read (or judge) I've had over a dozen Chargers/Roadrunners in my life...

As preventative maintenance, I went to pop out the #1 plug to inspect. I popped off the plug boot and found that the spark plug was loose---finger tight at best as I backed it out without any wrenches.,

Feeling curious I checked the rest and found 7/8 were loose--real loose.

I changed the spark plug about 3000 miles ago and thought I did the correct tightness--I've changed plugs dozens of times before.

While I could have absolutely screwed this one up, absent me being an idiot, what would cause the plugs to back out like this?

Thanks!

[c00nhunterjoe]

Simple error when you installed and didnt snug them enough, defective washers, dirt in threads? Its not typical for them all to loosen up like that. I would just just them again after a week of driving to be sure and not sweat it.

[stripedelete]

Don't know.  But don't feel bad.  I had the same thing with my boat two weeks ago.

One plug (#8?).  It practically fell out.  It was a routine tune-up and was running like a charm.  I have no idea how.  

[Ghoste]

Don't know what would cause it, but I do subscribe to the notion of retightening after a short drive past the first install.

[myk]

Gotta be careful with loose plugs especially if you have aluminum heads.  I hear that the looseness of the plugs will not only pop them out but destroy the threads on the way out as they vibrate loose.  This happened to me on my Mustang 4.6L, and I ended up having to rethread the heads...

[billschroeder5842]

Thanks all--I feel like less of an idiot.

I retighten and will drive for a bit and recheck.

Now I know to keep and eye on this one!

[flyinlow]

Two things I can think of :

1.)  Aluminum crush gaskets where not heat treated/made right? Originally tighten correctly, then the heat got to the gasket, lost some of its strength and the plug is now loose.   

2.)  You are an idiot. Welcome to the club, we have all gotten distracted working on cars.

[Dino]

Two things I can think of :

1.)  Aluminum crush gaskets where not heat treated/made right? Originally tighten correctly, then the heat got to the gasket, lost some of its strength and the plug is now loose.   

2.)  You are an idiot. Welcome to the club, we have all gotten distracted working on cars.

I recently had to pull a spark plug and it felt a bit looser than it should be so now I make it a point to retighten them after the first drive.  I actually retighten just about anything I touched after it has run for a while.  Better safe than sorry.   

[Ghoste]

I always do too, most shop manuals instruct you to do that anyway, install-tighten-test drive-retighten.

[c00nhunterjoe]

Same thing with header and intake bolts.

[Charger RT]

beer has been known to alter torque.
Tim

[69wannabe]

Gotta be careful with loose plugs especially if you have aluminum heads.  I hear that the looseness of the plugs will not only pop them out but destroy the threads on the way out as they vibrate loose.  This happened to me on my Mustang 4.6L, and I ended up having to rethread the heads...

The 4.6 and 5.4's for several years were bad about blowing the spark plugs out of the heads from the aluminum being weak from what I have read. We have several of ford work van's that I have had to put heli-coils in because of this where I work. Seems like 97-03 were the years this was a problem but i'm not a big fan of the modular engines so i'm really not 100% sure. I know the kit I use is the Trition big-sert repair kit and it works flawlessly. Thank goodness when a spark plug gets loose on a cast iron head it usually is just loose and doesn't blow out. On a small block the socket maybe binding against the head and giving the false feeling that the spark plug is tight. I haven't had that problem with a big block I don't think but I think that is possible on a small block.

[Bandit72]

beer has been known to alter torque.
Tim

Yours too?!?!?