Keith179

No, no oil came running out of it or anything like that

It only pools overnight. I can let it sit after running at temp for 4 or 5 hours and when it re starts there’s no smoke or misfire. I also find it strange it’s only on cyl 8 if it’s a pcv issue. When looking around with the bore scope the best I could it seemed like it was coming from above, but I had also run the truck prior (needed to pull it in the shop)

I’m out of ideas on this truck. 2020 Silverado 1500. 5.3 135,000 miles. Has a p0308 and p050d codes. Smokes From exhaust when cold. Compression test passed. New plugs, wires and coil on cyl 8. Same issue. New coil on 8, no change. Replaced injectors, no change. Bore scope showed oil pooled on the piston after sitting overnight. Pulled head and had machine shop check it out. No cracks. Stem seals looked good, replaced anyways. He also ground valve seats. Put it all back together and still have the same issue. Bore scope shows oil on the piston again. Leaning towards maybe a cracked ring but unsure. Cylinder looked good when the head was off, no scoring or scratches. Any ideas on what else I should look for? Appreciate the help