Hi, was having an issue with my 2010 ss and searched but found no definitive answers yet.
Was hoping the family here could help so here goes,
I think I have an issue with #1 injector sumtimes pouring fuel into the cylinder. I read something about white seals but didnt get a good understanding of what exact issue they cause. All my turbo cars go dead lean during full deceleration but not the cobalt and it will sometimes spew smoke while at idle, after decel and back to throttle and then sometimes its like its brand new. I dont think its a tune issue since it seems to be isolated to 1 cylinder going by the ash deposits only on that 1 plug. Thanks for listening an nice to meet you all.

 

Black smoke? Do you have any modifications or a tune? How many miles do you have? The DI turbo Cobalts are known to have issues with valve coking and could be part of your problem if you are higher mileage and have never cleaned your valves.

 

Yes fuel smoke, car has 94k on it. 3" zzp exhaust, injen intake pipe, cold & hot pipes aftermarket(cant remember brand atm) turbosmart recirc valve.
Know about the di valve coking but how do you suppose it could cause excessive amounts of raw fuel to enter the cylinder?
Does your cobalt dead lean as you decel?
Thx

 

I don't have a turbo cobalt but I could imagine a restriction of air could cause rich fuel mixture. My Cobalt does utilize deceleration fuel cutoff though yes. You could also have a faulty injector but I really don't know enough about DI injectors to speculate on that. When you pull your plug in the suspect cylinder is it wet and smell like fuel?

 

With all due respect, I think you are chasing what isnt there already.
#1 cylinder is being flooded for some reason.
Ash deposits only on #1 plug.
What is the talk about white seals in the injectors? Im assuming they are what holds the fuel behind the pintle in the injector yes? Car runs flawless except during orignal said times and only every now and then does this happen.... No cel well other than when seafoam spray soaked the wideband o2 and killed it lol...

 

Just trying to help you diagnose if your cylinder actually is flooding because of a faulty injector. Having an ashy spark plug isn't necessarily evidence of flooding neither is black smoke. Just means you are running rich for some reason which could be a number of things. #1 spark plug having deposits with the other three looking ordinary does indicate a combustion difference in cylinder #1. If that cylinder is the only cylinder running rich it could be a compression problem due to cylinder or head, and airflow problem in the head, or like you said an injector over-fueling for some reason though I don't know how likely that is. If your injector is over-fueling due to an internal leak I would think your spark plug would be a little wet and smell like fuel after letting the car idle, you may have misfires at idle and partial throttle, and maybe even rising oil level from fuel washing down the cylinder walls leaking into the crank case but those are just guesses. I have never actually witnessed a leaky or stuck injector in action.