Hello! Have an Audi 100 C3 Quattro Bj 1988 Mot.: NF the following problem: My heater/heat exchanger had a hair crack. Good how great it is to change that I don’t need to tell you anyway. So the new heat exchanger is only inside I have hardly a heating power now… Just so much that you can’t see your own breath anymore. Now my question to you, can or must I air the cooler somehow!? If so how is it best?? With us it currently has between -5 °C and -10°C and on Sunday we want to ride in an ice race. Speak fast help would be great. I thank you already in advance! Greetings Dominic