Rust colored spots on sparkplugs. Pictures

[horizontalkev]

Spark plugs are almost new with 100 miles on them. Are these brown spots from some type of additive? Other than that the color shows a nicely running AF ratio Im assuming correct? The far right spark plug has oil on the upper threads so a new valve cover gasket is on order. Thanks turners

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[DSM1G90]

Remember: If you're using 91 plus octane in any vehicle, there is so much junk additives in that fuel to raise the octane.

In doing so, that is what you're seeing on the plugs-the residue of all of the additives that resides on your plugs.

And this also goes for ones using lesser octane fuels-can't get away from it.

When lead was the additive to increase octane, plugs would really get coated, but not it's all chemical based.

They look normal and the A/F is just right - not too hot and not too cold.

Put them back in and happy (safe) driving.

-DSM

 

[horizontalkev]

I did use Gumouts "All in one" cleaner on my last fill up maybe that's where it came from. Then again I do live in the Midwest and we have crappy 91 pumps. Thanks Dsmers. One less worry