2017 6.2 GMC Sierra cylinder 1 misfire

[Manuel Gomez$]

Anyone have trouble with a 2017 6.2 cylinder 1 misfire. Already changed all spark plugs and wires. Also changed fuel injector 1.

[CamGTP]

You need to do a compression and leak down test.

 

Cylinder one is a AFM/DoD cylinder, there could be a problem with that.

[Manuel Gomez$]

Yes no compression...so going to open it up.

[CamGTP]

If you are lucky it's just the lifter that failed and it caused no damage to the camshaft lobe.

[Manuel Gomez$]

They checked the lifters and they were good. I'll double check them again tomorrow. 

[CamGTP]

If the rocker is loose, the lifter could be collapsed and that would explain the no compression on that cylinder.

 

Worst case is that you have a hole in the piston, broken ring lands or a failed head gasket. Either way to me the cylinder head is coming off.

[Manuel Gomez$]

Could be that.

[Lsgun1]

That is weird, doesn't look like the piston broke but like it was manufactured wrong. Everything in the head looked good and no other pistons look like that?

[Manuel Gomez$]

All other pistons looked good everything in the head is good. Going to replace # 1 piston and all rings.