I noticed my truck has some oil above the starter. Thought it might have been the turbo return tube so I cleaned everything really good and checked again. Just in case, I went ahead and changed the o-rings out. Still has a small leak. I’m almost thinking I might have an internal leak and it cutting through the upper valve cover gasket. What are symptoms of an internal leak? I run a scan gauge so I have a way of troubleshooting to an extent. Truck is completely stock except for exhaust work. Any help would be much appreciated.