2015 Tahoe..Misfire

[OR VietVet]

Ok. When they did the push rod and rocker did the plugs get changed at the same time? If not I would expect that the plug could have been partially fouled and may need changed now plus, most people change the plugs at 100k miles anyway, so change them all. Plus, as far as you know, the misfire is on another cylinder. Plus, when they diagnosed the previous misfire they may have swapped some plug wires to see if the misfire would follow a bad wire and the wire could have been damaged. Do you have any DTC's? Does this current misfire feel like the saame misfire as before, meaning it feels like just one cylinder?

 

[BigWolf504]

I'm goin to change the plugs and see if that helps

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[BigWolf504]

Code

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[OR VietVet]

I would do the wires at the same time. You could even swap the wire to another cylinder and see if misfire follows it. Also, post pics of the NUMBERED plugs.

 

[89Suburban]

I know. Been here since Nov. 2018 and you can tell he is frustrated. I can wait him out though.

Good man.

 

[OR VietVet]

What I don't understand is if the work was done 2k miles ago, why not go back there and see if under warranty.

 

[BigWolf504]

It still is I was wondering if anyone else was having this problem

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[Doubeleive]

It still is I was wondering if anyone else was having this problem

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plenty of people have had a misfire on cyl 7, for a variety of reasons, there is no common denominator here.
could be bad spark plug, spark plug wire, coil pack, coil pack wire harness, fuel injector, fuel injector wire harness, internal engine damage, could even be the ecm or ecm wire harness and maybe a couple other things I am missing. you will need to see a mechanic.

 

[89Suburban]

CHECK THE SPARK PLUG.

And be careful doing so because it is hard to get to and easy to cross thread trying to put back in.

 

[Christian80]

Code

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If cylinder 7 is one of the cylinders that is part of the DOD system you may want to look at a colapsed lifter or broken valve spring or just a sticky valve from carbon deposits. Check compression in that cylinder and/or do a valve leakdown test.