5.7 Hemi spark plug question

[Ronsant]

For any Chrysler/Dodge mechanics- I just changed the plugs on my 2006 Magnum. It was running rough when under acceleration, and I found a code for a misfire in cylinder #4, but no check engine light had come on.
These 2 plugs are from the same cylinder, and both are damaged and oily.
(Aside, Dodge dealer used iridium plugs instead of recommended copper plugs)
What would cause that type of damage to those plugs ?

Am I looking at replacing a spark plug tube seal, or more serious than that?

Thanks

 

[AandPDan]

Can't tell but is the electrode complete on both of the plugs?
Foreign object ingested? How is the air filter.

 

[f355spider]

I would suspect an ignition issue on that cylinder (coil). If that prong came off (or did it erode away?), that can cause damage to the intake or exhaust valves. Hopefully it exited the cylinder without causing damage to the valve seat or valve...and is probably lodged in the catalytic convertor...but that shouldn't be a big deal.

Might want to do a compression and leakdown test.

 

[Ronsant]

Can't tell but is the electrode complete on both of the plugs?
Foreign object ingested? How is the air filter.

Ground electrode is gone on one, and center electrode is gone on both.
Air filter is clean and relatively new.

 

[Rand]

at this point besides using a borescope on it.. put in fresh plugs and see what happens?

 

[Ronsant]

I would suspect an ignition issue on that cylinder (coil). If that prong came off (or did it erode away?), that can cause damage to the intake or exhaust valves. Hopefully it exited the cylinder without causing damage to the valve seat or valve...and is probably lodged in the catalytic convertor...but that shouldn't be a big deal.

Might want to do a compression and leakdown test.

Yes, I assumed that the ground electrode got spit out the exhaust valve.

 

[Ronsant]

at this point besides using a borescope on it.. put in fresh plugs and see what happens?

I installed the new plugs today and went for a short ride. Seems OK. I clears the misfire code and will take it for a longer ride tomorrow where I can warm it up and get on it a bit.
I don’t recall ever seeing a plug with the center electrode missing.
The plug tubes on that cylinder were very oily as well.

 

[slacktide_bitog]

Maybe a spark plug tube seal leak, valve cover gasket, possible coil problem

If those plugs were installed at the dealer, they're less likely to be counterfeit, I hope

 

[Ronsant]

Maybe a spark plug tube seal leak, valve cover gasket, possible coil problem

If those plugs were installed at the dealer, they're less likely to be counterfeit, I hope

Dealer did them about 40k miles go. Weird that they installed iridium. I went with NGK standard plugs and will plan on 30K replacement.

I’ll need to read up on the plug tube seals. Hopefully not too difficult.

 

[clinebarger]

The seals are just figure 8 looking gaskets that fit into the Valve Cover.

 

[Ronsant]

The seals are just figure 8 looking gaskets that fit into the Valve Cover.

Ordered Fel-Pro kit from rock auto. Looks like the passenger side is gonna be a poopshow to r&r

 

[OVERKILL]

I suppose it's possible that sufficient oil was making its way into that cylinder to cause detonation, thus damaging both those plugs, but I'd be looking to run a borescope on that cylinder, because the metal had to go somewhere and that doesn't look good.

Regarding why the dealership used Iridium plugs? I'm assuming because the later HEMI's spec'd precious metal tipped plugs and this recommendation has likely been back-spec'd to the older HEMI's.

 

[Ronsant]

Got the valve cover gaskets changed. Pass side is a huge PIA. Can’t come in straight with the cover, too much crap in the way.
First attempt had a leak where I couldn’t even see it. Bottom rear corner. Must have hit the gasket on a rocker arm while trying to get it on. Not wanting to ever do this again.
Plugs and coil are clean.

 

[maw_76]

It just dawned on me that I have about 50k on my current set of NGK old school coppers. I swapped out the original ones around 60k (to be honest with ya they didn't look all that bad), but since this past winter my gas mileage isn't where it used to be. I'm debating whether I throw the same plugs in there or an iridium of some sort? What's the general consensus? It's a '12 Ram w/5.7.

 

[dogememe]

Why would you use copper plugs in 2025?

Iridium might cost 3x as much but it also lasts 3x as long lol. And while I’ve never changed plugs on a Hemi, I can’t imagine it being fun given there are 16 of them!

 

[Skippy722]

Why would you use copper plugs in 2025?

Iridium might cost 3x as much but it also lasts 3x as long lol. And while I’ve never changed plugs on a Hemi, I can’t imagine it being fun given there are 16 of them!

A lot of people STILL use them. I was told on a fb group if I put anything than copper plugs into my hemi (2011’s came with copper plugs!) a black hole would open, my hemi would obliterate itself on start up, etc.

It ran perfect on auto lite iridium’s.

 

[Ronsant]

The factory recommended is copper core every 30K miles for my 2006 5.7.

I’m not sure if better plugs would extend the intervals. Must be a reason that the factory recommended what they did. Newer 5.7 have different cylinder heads, so the rec might be different.

 

[maw_76]

Yeah, it's my understanding they switched to an iridium in '13, but I believe they updated the coils. Sounds like at least 1 vote for Autolite Iridium's.

 

[maw_76]

Actually, I put those Autolite Iridium's in my Honda a number of years ago. I can't say I've ever had an issue with them and that was 75,000 miles ago.

 

[HemiBenny]

Why would you use copper plugs in 2025?

Iridium might cost 3x as much but it also lasts 3x as long lol. And while I’ve never changed plugs on a Hemi, I can’t imagine it being fun given there are 16 of them!

My 2011 Ram came with Copper plugs, and that's what goes back in. She runs great on these plugs.
The plugs on a Hemi aren't difficult to change out if you have a 5/8" swivel spark plug socket. I have the Gearwrench 80546, and it makes life easy doing this job. It helps prevent side torquing the plugs and breaking them during installation, as well as making the job of removing the plugs in the rear easier.
I like that they get changed out every 30k, it keeps them from getting seized up in the head so much. It also gives me the chance to inspect the plugs that come out and everything else in the general area while I'm in there. (I'm weird that way)

So far, everything has been fine, and all is good. It may all go to hell tomorrow, but today, all good!