can anyone please help me with this one? i have a 98' monte carlo ls with no heat. thermostat seems fine, theupper radiator house feels pressurized so i know it's closing + engine temperature looks ok according to the gauge. i feel nothing inside but cold air. when i toggle heat-cool driver\passengercontrols it sounds like the flapper is moving although i should mention that the heater mode switch doesn't seem to switch properly to front dash vents, windshield and floor works fine. when i let the car heat up and grab the heater corehoses the return doesn't even seem warm. is the heater core clogged?? if so am i taking the dash off to get to this bugger?