Mis-fire Cylinder #2...now #2 and #3

[doulos4jc]

You do understand the porcelain dosent just drop on its own free will.

I'm sure it had a perfectly legitimate reason to fail. If it was just to piss me off, it worked.

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[doulos4jc]

Seriously, I'd love to hear some WAG's on why it went boom. (Wild a$$ guesses)

 

[4bangin]

No engine damage?

 

[doulos4jc]

No engine damage?

None as far as I can tell...new plugs and it's running great.

 

[perfweld]

They must not be a very good plug if they just separate like that for no reason, my guess would be detonation. Id change brands anyways, not something id want to deal with.

 

[5.0yote]

Bad plug...very bad plug

That looks like an overheating issue either a pre-detonation or lean condition followed by the plug's insulator cracking under heat.

With two misfire situations I would not put my money on faulty plug.

 

[4bangin]

Whos your tuner?

 

[doulos4jc]

Whos your tuner?

SCT, Unleashed

 

[dgc333]

Could be a lot of things, but the very most likely cause would be detonation.

Don't know if you can say detonation is the most likely cause. The plug could have had a hair line crack when it was install from being dropped or gapped that propagated over time until it failed.

If there was detonation you should be able to see fine bits of aluminum on the insulator.

 

[Spoolin]

I had this same problem and its was none of the problems stated above. It ended up being the caps that screw into the top of the plug had a little play in them causing a lot of misfires. I was trying everything to fix the problem and Adam recomended that I check the tips to see if they were loose. It seemed normal because they had play but weren't like falling off. I tightened all 4 and all missing went away.

 

[doulos4jc]

I had this same problem and its was none of the problems stated above. It ended up being the caps that screw into the top of the plug had a little play in them causing a lot of misfires. I was trying everything to fix the problem and Adam recomended that I check the tips to see if they were loose. It seemed normal because they had play but weren't like falling off. I tightened all 4 and all missing went away.

Driving today...new plugs and another CEL. P0303 again. Definitely will tighten up those caps and connectors.

 

[Spoolin]

Driving today...new plugs and another CEL. P0303 again. Definitely will tighten up those caps and connectors.

I'm about 100% sure that's it cause I replaced the ones I was getting codes for misfiring and the problem came back in like 20 miles. A big headache, I don't think I'll be purchasing densos again lol

 

[doulos4jc]

Just checked old densos, two had loose caps including the one that failed.

 

[TEXAS HEAT]

It seems like I've heard that some users of Denso's having issues with the electrodes breaking off. I've personally only ran them once in my Mazdaspeed before switching to NGK then Autolite Iridiums which I learned are the same plug. Having said that, I did purchase a set of Denso's from Adam, but I haven't installed them yet.

 

[Slow89]

almost ALL vendors and other big mustang names on here won't touch Densos for what it's worth.

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