14liter,Detroit 60 515,egr ugly fixed,south Texas intermodal hauling, so my truck coolant sensor was giving me trouble in hills loaded and empty flush the radiator, using 50/50 pink sca ready stuff, then I cleaned the cac,radiator with air and water, it worked a lot better for about week then my heater core gave out cracked I bypass it then couple days later my sleeper goes out also bypass it currently working normal I guess still around 210 idle hot220 maybe temperature down here is over 100 every day just wondering if anyone knows or symptoms of both heater cores going out????????