I have a subaru legacy 1990 overheating, automatic, all wheel drive. I have changed the thermostat 3 times, water pump, timing belt, got timing reset, filled system and bled, blown out the heater core and put in an expensive head gasket sealer all to still overheating after 15 mins of driving. I am at a loss. The bottom radiator hose stays cool, I don't know if that's normal. Please give me an idea as this is my kids car and we need another 6 months out of it if possible. Changed all the above and still overheating I don't know what to do now. The overflow bottle fills up overflows and then sucks back in after it cools down. Also the heat will blow hot and then go cold before it starts to overheat.