Hello dear community, I am facing a problem with the following engine where I don’t know any more. Motor is the 642.858 350 CDI 4Matic from the end of 2011 with around 150,000 KM. In the city hardly noticeable, but on the highway 1-1.5 liters already after 500KM are guaranteed to be gone, at 120 to maximum 160-180 km/h. Error codes none. Particle filters were already replaced new oil coolers new the entire charging air tract was expanded, was also some oil inside, cleaned, all seals new and w Crankcase ventilation new original part turbocharger (overhaul) piston rings or valve shaft seals is said, but wouldn’t it have to have 1-1.5 liters of oil in the stand after a tank filling? Would be happy about every experience value, am really despairing.