I have heat at an idle but no heat while driving
My car has 130000 miles.
My car has a manual transmission.
Hi there. From the description you have provided and assuming this was not a problem, prior to changing the antifreeze leads me to believe, there is air trapped inside the heater core. Sometimes, the air will purge on its own, and all you have to do is add more antifreeze to the radiator with engine cold. Sometimes, it is necessary to purge the air. This requires experience to purge the air. If, this was a problem before the antifreeze change. It could be, a faulty (stuck open) engine thermostat. I recommend your vehicle’s no heat while driving be diagnosed and repaired by a certified technician from YourMechanic.