2013 Tahoe - Spark plug needed replacement after 8k miles

[expredator]

Basically what the title says. Got a P0301 code 8000 miles ago and replaced the first spark plug. Solved the issue and everything was great until yesterday when the engine light started flashing and the car drove super rough. Checked the codes, got a P0300 and P0301. Took the first spark plug out that I had replaced and it looked roasted/burned. Replaced it, cleared codes and everything is fine now and the car drives great. What I don't understand is that I thought spark plugs last 50k miles and up. So why did this one go bad after only 8k miles? I bought AC Delco spark plugs both times (41-162).

 

[blackelky]

Wires? Maybe

 

[mattbta]

Where did you purchase these?

 

[iamdub]

Basically what the title says. Got a P0301 code 8000 miles ago and replaced the first spark plug. Solved the issue and everything was great until yesterday when the engine light started flashing and the car drove super rough. Checked the codes, got a P0300 and P0301. Took the first spark plug out that I had replaced and it looked roasted/burned. Replaced it, cleared codes and everything is fine now and the car drives great. What I don't understand is that I thought spark plugs last 50k miles and up. So why did this one go bad after only 8k miles? I bought AC Delco spark plugs both times (41-162).

Got a deal on them plugs? Like, half price compared to the auto parts stores? My bet is you didn't actually buy AC Delco plugs, but super crappy knock-offs sold through Amazon and ebay.

 

[expredator]

I bought then both times at a regular price ($12) at local auto stores. Yesterday at an OReilly, the time before cant remember, but most likely Autozone or OReilly. Yesterday at least I made sure it said AC Delco on it, so no sure why they should be of such poor quality.

About the wires, FWIW I did the water spray test yesterday, and saw no sparks. Again, changing the spark plug back then and yesterday completely fixed the issue, which made me believe that it's the spark plug.

I guess, the consensus is that the first time around I must have gotten a ****** product? Anything else that could be going on?

 

[iamdub]

I bought then both times at a regular price ($12) at local auto stores. Yesterday at an OReilly, the time before cant remember, but most likely Autozone or OReilly. Yesterday at least I made sure it said AC Delco on it, so no sure why they should be of such poor quality.

About the wires, FWIW I did the water spray test yesterday, and saw no sparks. Again, changing the spark plug back then and yesterday completely fixed the issue, which made me believe that it's the spark plug.

I guess, the consensus is that the first time around I must have gotten a ****** product? Anything else that could be going on?

The knock-offs say "AC Delco" and really look legit. But, you can see obvious differences when compared side by side to the genuine ones. Coming from a parts store, they should be genuine. I really hope the fakes haven't infiltrated the supply to the reliable sources now.

Still, Iridium spark plugs should last well over 100K miles. I'd check the others. If they're worn, take 'em back. If they're fine, including the new one, it could just be that you got a defective genuine plug.

I'm quick to suspect counterfeits because so many people buy "great deals" anywhere they can and the the cheap plugs have become so prevalent. What they can do to an engine is too scary to take lightly. I'm glad you bought from [what should be] a reliable source and hope you just got a super rare defect but all is well now.

 

[swathdiver]

What is the compression on that cylinder? Is the injector delivering as much fuel as the others?

Check the resistance on the wires, supposed to be between 397 and 1337 ohms. Somewhere in the 800s with OE wires is the norm.

Put in a new plug and inspect every six months or so.

 

[randeez]

did you inspect all the plugs and only 1 looked like that? or you only took out and swapped the "first one"?

 

[Fless]

did you inspect all the plugs and only 1 looked like that? or you only took out and swapped the "first one"?

^^^ This. What do the other plugs look like?

 

[expredator]

did you inspect all the plugs and only 1 looked like that? or you only took out and swapped the "first one"?

I have not. I saw the p0301 code and went for plug #1, which seems to have resolved the issue. Why do you suspect the other spark plugs? Should I inspect them even though the first appears to have been the culprit?