How do you get your temp. Above 140 degrees, no heat coming out and put in new thermostat, no help. Tried putting cardboard in front of radiator, no help. Called about getting radiator flushed, but they want vehicle up to temp. With thermostat opening, back to square one, cannot get up to temp.
Do you live in an extremely cold region? What degree thermostat are you using? Do the heater hoses get hot? You may need to use an infra red temp detector, to double check the temp gage. Does the heater core get hot? Blower motor works?