I'm also running around crazzy for over a month to resolve this heat problem. I started with radiator fluid flush, bleed radiator, engine oil flush, and just today I replaced the thermostat. and still doesn't work at all. I already spent over $300. Tomorrow I'm having heater coil under the dashboard replace, its going to cost me $500, I hope it works. Otherwise, I'll wait for summer to sell this crap off.