now i have this 09 bluebird 6.7 cummins was doing a general service on it and noticed the antifreeze was kinda milky i did a block test and it passed that i drained the radiator and the coolant was clean so i scratched my head lol now the the tank is full of it almost looks like white foam now the driver never complained about overheat or anything like i said was just doing a general servive so anyways i put my coolant flush machine on it and for the most part the coolant that came out looked pretty good but again the tank was full of some kinda white foam i took it off and cleaned it out and put freah antifreeze in it and am gonna keep my eye on it but anyone ever see such a thing???????