My 2010 limited has 105k miles. I just did the 2nd plug change. One plug on the left bank looks different than the others. The 2 pics are the same plug from 2 sides. One side has a tan color., the other side looks like the rest of the other plugs. I could use some feedback on what could be going on in that cylinder.
I did find oil inside one plug hole on the right bank that will require valve cover removal to replace plug seals

Attached Images

   

Both plugs looks normal to me. The tanned plug shows signs of being more worn. The tanned color is normal for a normally worn plug. The other plug almost looks much newer as it’s less tanned and slightly less wear on the electrode.

Otherwise no signs of wet/dry fouling, erosion, deposits, overheating or other “bad” conditions.

I need to repeat: the 2 pic's are of the same plug taken from each side. It's odd to me that one side has the tan color and the other side does not.

No, I read that in your original post. I’m standing with the tanning color being a normal but worn plug condition. As I said, it almost appears as if the bottom plug is newer. So, I agree it’s strange they are so drastically different.

My main point is neither plug condition in an isolated analysis is abnormal. No obvious signs of wet/dry oil/fuell fouling, erosion, overheating, melting, deposits (from coolant) etc..

If you don’t have any other symptoms like coolant or oil loss and so on, I wouldn’t be concerned with the result. It could well be that the bank with the more tanned plug is the hottest running cylinder due to the coolant path.

Plugs often come in packs of 4. Could it be one pack was actually counterfeit (2 of the 6 from previous change)? This is a documented issue.

Those are my visual observations. Did you measure the gaps?

Which driver’s side spark plug was this #6? Probably just need an Italian tune up.

Plug gap was similar on all the plugs - low .040's

Back cylinder left bank