Hello everyone, I am also new here, I am a mechanic and the question you ask me is to look at it step by step.
1º Check if that turbo carries water cooling pipes such as the Opel Corsa TD, the Toyota Hilux TD etc. (It looks quickly if it carries two finite tubes, they are oil and if it carries four it is that two are the oil and two are the water)
if the turbo fucked and carry four tubes, you would notice it because it mixes water - oil, and by white smoke (burnt oil x escape by accelerating strong) and separately because it seriously decreases the blow pressure and therefore the air filling of the engine is lower and the car would not walk the car.
2nd Assuming that is not the cause, it would be necessary to go to button. For this, the check is easy, remove the expansion vessel cap with the cold engine and you make a cap that has a tub or a way like the wheels of the cars to be able to put compressed air ever at more than 1kg/cm2 this will simulate the hot water pressure conditions. When doing this, the sleeves are going to put hard as stones. After putting pressure on the circuit for a couple of minutes, you let the air escape through the cap gently, as if you will loosen the hot cap.
If you do not have this material, a simpler test but a little less reliable, is to put the water of the cold engine, put the cap, start, heat it and keep it about 2000 to 2500 for 5 or 6 minutes. Carefully and a cloth not to burn you press the engine water sleeves, if you notice that they are so hard that you cannot almost deck them is that they have a lot of pressure and that is because you have compression leaks to the cooling circuit, and of course water to the cylinders. After doing this, you stop and let it cool, and you check the water level again.
If you check that the water drops from level after doing this is that somewhere it has gone. And logically with the cold engine, the water does not evaporate so you start looking for the loss, if you do not see that the water has come out, it is that it has sneaked into the cylinders, either through the Board of Culata or because you have a fissure in the butt.
In any case, it would play the cylinder head, (workshop task) and take it to check and plan (rectifying work)
with the raised cylinder head, it is carefully observed and the seat surface of the cylinder head is cleaned in the block, the state in which the butt joint remained, (because it is the cause of your breakdown) is checked and visually it is appreciated where the water is escaped.
In addition to that, it will be seen that in one or several engine cylinders there is no finite soot of the diesel, but hard carbonilla or there is nothing and are clean. If so, you are seeing the site where the engine water was going.
It looks like a "Bricomania" program

I hope I have helped you.
All the best.