Originally Posted by Durdeydolla
Bleeded system and attached loose vacuum hose, fixed vent flow but still not blowing hot air. If temp guage goes to 185 then its luke warm at stand still but if I drice it gets cold again. Checked my mix its 50/50, new thermostat and heater core, idk its driving me crazy cuz its so simple but I cant put my finger on it
Could be a bad thermostat even if it's new. Could also be a water pump issue or heater core. I would disconnect the heater hoses and force water through one of them with a garden hose and see how it flows. This will also help flush it out a bit but more importantly it will give you an idea how well water is moving through it. You also need to check how well the water pump is working. After you get the heater hoses hooked back up, back the radiator cap off to the first stage where it's loose but won't come off. This will not allow the system to build any pressure. Start the car and let it come up to operating temp and slowly remove the radiator cap and look inside. If the coolant is not moving, you have a problem with the water pump or possibly the radiator itself is plugged up. The coolant should be circulating anytime the motor is running and the thermostat is open.