Diagnose my spark plugs please

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Jan 23, 2014
Not sure if they are normal or is this a sign that the engine is running lean or hot? They are about 10,000 miles. NKG Iridium
Need more info: Engine , plug heat range, application, useage? They look a tad hot - but I see no glazed metals on the combustion shell face or glased GND strap which would indicate overly hot. But, you seem to have moisture and evidence of corona discharge around the outer insulator.
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They look pretty good other than they are probably one heat range too cold for your engine. The last pic you posted shows a good view of the grounding strap, and the point where the plating changes color should ideally be at the center of the strap bend. If the point it changes is too close to the tip, the plug is too cold. Inversely, if the color changes closer to the threads you're running a plug that's too hot.
They look fine. They should be fine for another 60k miles. I wouldn't leave any spark plug in for 100k but there are some that do. Good luck!
Being that these are Irridium IX plugs, they won't be good for 100k like their Laser Irridium brothers. These are more like a 30k to 50k plug.
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