Movano A 2.5 DTI with 115hp from 2003 absorbs engine oil after turbo change.

Hello together, I am at the moment massively baffled and happy that my engine is still spinning. I drove about 600 km and at the same time the whole engine with engine oil at the top/off. Of course hardly anything was in the tub :/ In partial load everything is actually good, but as soon as it only slightly uphill with charge you have to pass the accelerator a bit and then a gigantic soot cloud begins to develop. Logically everything is much too fat, until the performance even decreases, then must Now the question to the experts – at first I thought of a non-closing AGR. But where does the whole oil come from? The turbocharger comes from a renowned glass palace and was repaired there, actually impossible since the over the wave loses oil. It already dripped from the normal running let some oil out of the hose of the suction nozzle. Is there anything not with the oil ventilation nic How can I test this best? So far I exclude a leak of the revised loader. Since the engine oil has also spread extensively on the top and the exhaust side. Does anyone know advice?