So, my engine threw a rod and bit the dust. I replaced it with a used engine that sounds good but is blowing smoke. I get a big puff at start up and a lot of smoke when accelerating. I dropped the exhaust and determied it was coming form the drivers side. I think the head gasket is good (no oil/coolant mixing, block test didn't show any exhaust gases,...). Did a compression test. All cylinders are around 160psi on my gauge but cylinder 6 is at 185 psi. Tested each cylinder 3 times. Cylinder 6 builds to 185 and then it leaks down rather quickly. When I pulled the tester out it had oil all over it and around it. So, does this sound like valve seals or valve stuck open or does it sound more like a ring issue. Just need to decide if I'm pulling the motor and returning it or if I could get by with replacing some valve seals.