During the winter the vehicle does not produce heat. There is a knocking sound from under the dash and only cold air comes out of all the vents. When it was 20 degrees out I measure 35 degree air out the vents over the couse of an hour drive. The car has been to the dealer multiple times for this issues. They have acknowledged the problem and have tried replaing different parts but the problem still occurs. It's very cold in the car when it's below freezing outside and it's difficult to clear the windows of fog, frost, and snow with no heat. The HVAC system will make the knocking sound when turing on the car and sometimes when driving also. Trying to adjust the temperature will sometimes trigger the noise. I feel the knocking sound and lack of hear are related.

- Hanover, MA, USA