Fiat Doblo 1.9 JTD loses extremely oil

Hello guys and girls I have a little problem with my friend’s box. It’s a Fiat Doblo, BJ 2001, 1.9 JTD, 63 HP and 225000. We bought the car 2 weeks ago from Private, who had driven the Dicken only 2 weeks. They had no idea of cars and although the Doblo has fresh TÜV, the complete front axle – i.e., carrying joints, cathedral bearings and track rod heads on both sides – was not only over, but completely on the Ar… (at d d) I would like to thank the professional Tüvmann Well, we did that in any case and now a completely new mistake brewed up: After the Doblo was finished, we drove with him as a pack car (so he was also well loaded) to the JDM meeting, from us 750 km a distance. And quickly noticed that the good not only consumes oil, but oil FRISST!!! When we were back home (i.e. about 1500 km) we had a little more than 10 liters of refilled. ! It’s a good thing that he doesn’t really eat oil now, because the typical blue smoke doesn’t come out of the exhaust, so I looked under it today. Oil drops can be seen on the gearbox, but I don’t think that the 10 liters make up, right??? Oil pan and drain screw are completely dry. I’ve just cleaned everything up and then I want to see where it comes from, but maybe one of you already had this problem or experience? say and wish you dear greetings from the sunny Eifel! Greetings, Vreni