I keep changing thermostat. Flushed the system. Car still runs hot when driving

or you have a blown head gasket. we went through this issues with a 2007 dodge nitro and we changed everything under the sun for overheating, thermostat, hoses, radiator and still same issues, had to send in for a motor to be rebuilt and send to engine shop and put the heads back together and redo all gaskets, so forth. it had a blown head gasket.