I bought a PI 4.6L engine for parts. The seller said it burns oil on #5, and I have seen videos of it (litteraly spits oil out the exhaust). Compression was perfect hot and cold (210 and within 3 psi across all), no water in the oil. On teardown, the headgasket appeared fine (hard to tell since it is a multilayer steel gasket). The cylinders looked fine. What I did see, is oil in the #5 intake port, and of course a black plug and wet exhaust on that cylinder. So why would there be oil in head? Nothing before the valve stem is wet, but it got a new valve stem seal. It looks as if the oil is coming from a casting line that runs from the intake valve towards the valve stem? BTW, the engine only has 28k and was pulled from a wrecked car. Possible the impact cracked the head?