Spark Plug Check/Opinions

[Propflux01]

Plugs came out of a 2007 Santa Fe 2.7L. #2 was misfiring, I pulled the easy three (2,4,6) plugs and the #2 looked like this. What might cause this on the insulator that the others do not have? just from the misfire, or something wrong with this plug itself? I have replacement coils. Plugs have about 50K on them engine has 175K.

 

[clinebarger]

If the coil is weak.....The coloration of the insulator could be from abnormal combustion.

 

[Linctex]

Those plugs are all fine.

I also suspect a bad coil on the misfiring cylinder... NOT the plugs.

 

[WyrTwister]

Coil on plug ? If so , try swapping the coils & see if the misfire changes to another cylinder .

If it has plug wires , swap them too if they are long enough .

Were it me , I would install new plugs ( again ) and save those for emergency use .

Make sure the injectors are securely plugged in .

Best of luck ,

 

[Mad_Hatter]

I'd say from the misfiring. Swap plugs and see what happens.The other 2 plugs are in great shape.

 

[Propflux01]

Well, all six are getting new coils, needed or not. I just wanted to make sure the plugs were still serviceable.

 

[Kawiguy454]

...if theyre coilovers remember the dielectric grease on the boots. A misfire can happen if the coil-over is shorting/tracking across the boot. the color would indicate its not firing hot/right.