Both upper and lower hose get hot, heater core hoses are at the same temp. Its wierd, after flushing the cooling system, the heater began to work,, almost seems like the core is plugged. The coolant condition was very poor, thats why I blew out the core with air. But I drove the car for 20 min. and the heat stopped. I sqweezed the upper hose a few times, and started to get heat for about 4or5 minutes. then it blew cold air again. HELP HELP