Hi, I hope all of you are doing well..!!! I have a Bmw 525i 1992 E34 with M50B25 engine, I´m having problems with the bleeding of my cooling system, Few days later after I do it, the coolant level goes down, and when I open the bleed screw, the level goes up again, and if I let him like that maybe in 2 weeks or less the car overheats!!.. what is happening?? please I need your help, I hope it is not a crack in the cylinder head or a little hole in head gasket, because I do not see any presence of milky oil..... thank You!!