spark plug pictures diagnostic thread

[gotyourgoat]

Have a spark plug? Take a picture of it. Share it here.

Explain why it looks the way it does or ask why it looks the way it does.

 

[gotyourgoat]

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Oil fouling. My valve stem seals are not good.

 

[Shorty81]

Just pulled these out. Very happy with how they looked. The old BBC is happy. Very consistant.

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[Slow build jim]

What plugs are you running in big block?

 

[Goldie Driver]

#6 & # 8 plugs after around 4K. Presumably weak piston rings from being right beside the EGR.

Could be bad valve stem seals, but since it smokes until warmed up, AND my hot rod mechanics told me the passenger bank is the weak side, I suspect it is not the better of the 2 possibilities.

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[78C10BigTen]

Just pulled these out. Very happy with how they looked. The old BBC is happy. Very consistant.

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Mmm oktoberfest!

 

[Charlie]

Mine smoked at start up. #7 plug was fouling. Got the valve stems replaced, no more issues.

 

[AuroraGirl]

Lean condition.
Also mismatched gaps
Also a bad coil to cap wire. The nub on coil is worn down so it arcs it over time probably not strongest spark

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[Backfoot100]

#6 is oil fouled after 5k miles. Had some smoke on startup since I owned it. Compression test is 165-175 across the board. Very happy with that.

Just finishing complete valve seal replacement with all positive seals. Factory seals were rock hard. Surprised this is the only plug that looked like this. All the rest looked perfect.

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Guess I'll see if that fixes it.

 

[Snoots]

#6 is oil fouled after 5k miles. Had some smoke on startup since I owned it. Compression test is 165-175 across the board. Very happy with that.

Just finishing complete valve seal replacement with all positive seals. Factory seals were rock hard. Surprised this is the only plug that looked like this. All the rest looked perfect.

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Guess I'll see if that fixes it.

Take it out to I-16 and blow the gunk out.