'08 impala, strange thing happening with heating

(posting for a friend)

Air only blows out hot when the car is moving.

So idle, no heat? If you bring the rpm's up to say 2500, do you get heat?

If yes, then you could have a restriction in the heater core(partially plugged), but more likely, you have an air pocket that is restricting flow, caused by a coolant leak......Check the vehicle's coolant level when cold....

ethanaw,

I am sorry your friend is having this concern. If your friend decides they would like to have their GM dealership look further into this concern, they can always reach out to us via private message. Please be sure to include name, VIN, address, and phone number.

Erica Tiffany
GM Customer Care

Was the thermostat checked? Is the engine temp higher than normal?
Check for line restrictions?