Bad Spark Plugs?
 

I just changed my own spark plugs, and it seems they are Carbon fouled.
Even though, they been changed at 50k miles after one of the coils failed.

Would these cause damage to any of my engine parts?
Knock sensor? and coils?

Just curious...

Have you made some aftermarket changes to the engine? How about a tune?

While these plugs aren't as pristine as one might expect, with the exception of #4, they don't look bad. You're hoping for minimal black carbon build up and for the ceramic surrounding (insulating) the center pin to be a nice tan color.

I don't think you ever find that on a modern FI, DI, VVT engine. They're just trying to be frugal with fuel and burning it hot, so you get some blackening around the edges and the center ceramic is more white (lean mixture) than tan.
As I said, it does look like #4 is either burning cooler or getting a richer mixture of fuel. Is that the plug with a bad coil? That would explain its appearance perfectly.

I don't think the condition on these plugs would cause any harm to the other components you mentioned. I think you are good to go! :nod:

On review I've got to say those pics do show a nice tan hue on the center insulators, with a little extra black on #4.

I changed my spark plugs at 105,000 miles. Yours look way worse than mine did.



One on the left is old, right is new.


I'd backtrack. Start with the fuel. I run only 91 and do the occasional Chevron Techron Complete Fuel Cleaner. I try and stick to either Shell or Chevron. If neither are available, choose another fuel that's a race team (Valero, 76, Texaco).



I'd check the coilovers and make sure they look good.



With the spark plugs, make sure they're torqued correctly. Think it's like 18.



If you don't run the car hard, it might be beneficial to drive it like you stole it every now and then. A buddy and I believe that performance cars need to be run hard to keep the parts working properly.

The car is running rich from all the start stop in traffic I reckon... most likely thats the cause since i only use premium 98 octane fuel all the time, with additives from time to time.

Yeah yours is way better.........and the life of the spark plug i had should've lasted longer... which was a shame.

I have a feeling i should put back the stock inlet with the baffle to reduce the amount of carbon my car is making from oil.

I use 98 octane Fuel.

Normal wear on those plugs.
Stock tune I'm assuming?

Spark plugs don't look to bad.

But to me it looks like you are burning some oil.

How is your oil level?

As long as the fuel trims are not maxed out negative, then you are not running rich. But you would need to log the car to see what the fuel trims are doing in real-time. But running rich is a relative term. A car is only running rich if the fuel trims are unable to pull enough fuel to keep the car at stoich. + or - 5% on the on the long term fuel trims would be fine. The car is able to add or pull fuel as needed to keep stoich. Its only if you are putting in too much fuel and the PCM is at the limit of what it can pull out, that you'd actually be "running rich".

The car uses the MAF as well as the o2 sensors to measure the car's air flow, and in turn calculate its fuel needs. I'd start by cleaning your MAF with the MAF spray cleaner and I'd think about replacing the o2 sensors.

Also unless you are modded, skip the 98 octane fuel. 93 is more than fine for a stock SS/RS.

He is in Israel, I believe they use a different rating system and their 98 is our 93.
I agree with cleaning the MAF and replacing the front O2 sensor, they do wear out.

OP's plugs look pretty good. I think the photo is a little underexposed because the camera is adjusting for the wooden background.
Most of the world uses RON (research octane number). USA uses AON (average octane number, (R+M)/2 as the pumps say).
RON-5=AON

If I had one dirty plug like that, I would run a compression check.

Catch can will help. Pull the intake manifold and you will likely see oil residue coming from the PCV. That oil eventually makes its way to the cylinders.

Edit*

I see you have a 4cyl turbo. Check to make sure the turbo isn't leaking oil.

I would expect all plugs to look about the same. Your bottom one in the photo does not. Appears your car is 2.0L turbo 4? Is so plugs suggested by GM in USA market are 12681659 not the number on your used plugs? You mention plugs were replaced once at 50K, so how may miles on plugs in photos?

Good pickup.
I can't accurately make out the full number on either the plugs or the box from the posted photos.