When I was cleaning out the EGR valve (removing all carbon etc) I noticed quite a bit of oil on the inside of the inlet pipe. This made the carbon soft and sticky..... I assume this oil originates from possibly the turbo seals? Currently not putting an excessive amount of oil in. Performance & economy have improved since cleaning. Question is: Has anyone else noticed this when cleaning out the EGR valve? Should I be concerned that it is burning a bit of oil his way?