sethmccauley

I always run ethanol free 92, have a catch can installed, change oil regularly. These were SP-550 which I replaced with a set of SP-580. The gaps were all almost exactly .30 but seems like quite a bit of carbon build up. I’ve seen others post photos after 60k-80k and they’ve got a nice light brown. What could be causing this? They all look almost identical. My only thought is I have MSD red coil packs that I installed at the same time as these plugs, possibly that could be the issue? I also got a 5 star tune which I run on the 91 octane tow setting, but I’ve only had the tune for about 3k miles. 2018 3.5 liter

HacksawMark

From Google;
Carbon fouling happens when the car's air and fuel mixture is too rich, which means the proportion of fuel is too high. It results in incomplete combustion, leaving behind a carbon buildup on the spark plug's firing end. Simply put, carbon fouling is a symptom of a fuel problem, not a spark plug problem.

SpencerPJ

I've never seen that on a stock set-up at those miles. I have seen tuners sometimes recommend different plugs and heat ranges, I would start by asking 5 star for their opinion.

Bluegrass

A look at the Long Term Fuel Trim tables for both banks may show them shifted lean (negative) to verify the condition.
The shift negative is the Ox Sensors detecting to much fuel in the exhaust and commands the program to meter less fuel.(shifted Lean).
If it cannot, excess unburnt fuel as carbon deposits, can result as incomplete combustion.
A lack of air flow or air restriction can do the same.
The program can only account for these changes over a limited amount of range. +/- 25% shifting range.
Plugs to cold in heat range can also look like a rich mixture condition. Your plug Nose Ceramic is black with carbon fluff.
The fuel tables may have been Richened up with the Tune.
When tune and changes are made, you have to re-look at the results from scratch and understand what is happening.
The coils did not do any good in the scheme of things. How they work is another lengthy story, and not the cause or you would have had misfires.
A combination of these could also have occurred.
Good luck.

WVMoose

iTrader: (2)

" I also got a 5 star tune which I run on the 91 octane tow setting,"

Ask your tuner. Although they are a fan favorite here, they dont follow up after the sale, they state you only have to datalog if you have issues, and so forth. Id work with them to do some datalogging and see what they say.

bud150

The plugs look rich, probably from running at idle, soot there is just idle I believe. Did you pull the plug cold?
If so then that could be the reason considering you have a tune. The real color tell is on the insulator. Like someone said ,contact your tuner and see what they have to say.

babock

Whenever I want to do a plug read, I get the engine up to operating temp while driving… not idling…and get it to a place I can turn it off with minimal idling time. Once engine cools to warm, I pull the plugs and look at them then.

SSellers

Looks a little rich but if you're going to change them every 30k not really a huge deal. I'd be more concerned if just one or two looked off. It would take a little work but you could put them back in, put the stock tune back in, and check them after a few hundred miles to see if they clean up. Since you said you put them in about 30k ago how'd the last ones look?

They're right.... depending on when you pull them can have some effect on how they look. Once had a friend get a new bike (had EFI) and he was showing it off to everyone. A few start ups and revs later the plugs fouled out so bad it wouldn't start.

Champion:
Black, dry soot on the electrodes and insulator tip indicates a carbon-fouled plug. This can be caused by a dirty air filter, excessive driving at low speeds, too rich of a fuel/air mixture or idling your vehicle for too long.