Just checked the 08 Lt heater.
I do not think the heater core is plugged. Warmed the engine to about 140F as indicated on the Data Information Center.
Both inlet and return lines to the heater core were about 120F (quite warm) while the radiator's lower and upper hose were still cool to the touch.
On the inside, one of the 2 blend door motors( drivers side console side) was not operating. This was the temperature blend door.
I removed & opened the actuator and bent the contacts a bit, just enough to increase their contact pressure, then reassembled.
The actuator now works. After reinstalling, i noticed one of the white blend door levers is not connected also there is no air from dash center registers.
History of this car states the prior owner had purchaced one actuator from RockAuto....both of these actuators appear to habe been removed & replaced before.
Is there an assembly guide or diagram for this area of the HVAC blend doors? From the parts diagram on gmparts 08 chevy cobalt, interior, heater: the white plastic part looks like a lever as shown as item 6
Well Suckcess & failure.
suckcess i found the problem,
Failure in that the shaft to the blend door motor is broken worse, its MIA.....
Poo now for some creative machining.
Last edited by 1966tbird; 12-14-2016 at 01:30 PM.