Random Misfire after Overheating 2013Yukon Denali 6.2L

[solli5pack]

I would say definitely get a scanner and find out what cyl or cyl's are misfiring and then start planning next steps after that.

 

[13UpInSmoke]

Ok so finally got around to hooking up the tech2 to watch misfire & these are the pics I took from today. Cylinder 1 seems the biggest culprit. Not sure if that's what's causing the occasional misfire from the others. Weird thought that I took a 6 hour drive to Atlanta sitting in traffic for a few hours & nothing happened. Truck ran great there & back. But as soon as Im driving back around town the misfire will randomly pop up. So the 9000 were when I started logging today, & ended with the 12000. Its weird though that it does it for a minute or 2 then back to normal & runs fine

Guess Ill get in there with a camera & see what I can see this week

 

[13UpInSmoke]

Ok so I swapped coils with #1 &. #3 and the misfire followed the coil. So new coils. Should I just replace the one or do them all? And do I go with like an accel or granatelli vs stock if replacing all?

 

[j91z28d1]

Ok so I swapped coils with #1 &. #3 and the misfire followed the coil. So new coils. Should I just replace the one or do them all? And do I go with like an accel or granatelli vs stock if replacing all?

when I bought my truck it had one replaced. I think it's ok to just do one.

I think probably oem would be the best from rock auto, that's the standard recommendation but I've had horrible luck with oem gm parts being no better than anything else lately.

good luck!

 

[13UpInSmoke]

I grabbed a car quest premium coil from advance auto real quick. Swapped it in & so far today running the rest of my errands it seems to be running pretty well again. I also grabbed a other set of plugs but may wait until I do the cam in the near future & swap them in if the coil fixes my misfire

 

[petethepug]

Nice detective work. I’ll betcha the coil didn’t like getting sprayed with coolant when the heater hose went.