I recently took the turbo off of my GN because I had a little bit of smoke coming out of the exhaust. My Turbo Builder noted that the oil seal was bad but also the bearings had issues and the wheel had rubbed on the housing. When I was changing the oil, for about 1 second, I saw what looked like gray oil coming out. It then cleared up and changed to the regular color of oil. What do you think this could indicate?