4 heater blowing cold air only from heater even Thank you for choosing just answer for your query.Yes, i can help you. Does the engine temperature gauge get up to normal operating temperature?It should be ralph lauren UK straight up, or half way.If not the thermostat is stuck open or opening to soon and must be replaced.This is a common occurrence on this year model. If the engine temperature is correct your symptoms are consistent with a plugged heat exchanger or heater core.There is no valve in this system to restrict coolant flow to the heater core.There is the possibility of the water pump impeller coming loose and slipping, but this is usually associated with an overheat condition. The coolant for this vehicle should be pink in color, if other coolant is mixed, the reaction could well cause the contamination to plug the heater core. The core of the heater core is not only a group of tubes, but the tubes are fi ... Read more »