Too Auto mech, i agree, and give him credit, but engines will loose up to 1 qt per changed, caused by wear, risidue leaks,the extreme of what was recommended so too much, do as he said adout checking warranty, and get the field repair on the cs vent system done, if its determined turbo is bad, replace it,if what tech was saying about pulling oil into combustion chamber was true ,you would be losing a lot more oil, check another dealer, or foreign repair shop. take care