Something was wrong with the coolingsystem, I suspected it was the thermostat as the bottom of the radiator didn't get really warm. The fans didn't kick in aswell, it got worse and worse to the point where I had to do something:
so I orderd a new thermostat with a lower temp setting(80°C vs 87°C), when taking this apart and testing the old thermostat it became clear that i didn't fully opened. So I replaced the thermostat with the newer, colder type (bit of a pita because of PAS pump). New G12 coolant was added and voila, result:
perfect.