pretty white...are you using a koyo??? and do or have you treid water wetter??
edit: just saw a koyo,i think in the pics....are ur rad fans coming on?
air in the lines?
bad thermostat?
bad water pump?
maybe try some air ducting to create more airflow THRU the rad....i had nx cooling probs before...but i had takin out my ac looooong before so idk what could make it differnt...all i can think is that the ac compresse and water pump have somthing going on,ones messin up the other...