I don't know if everyone's tired of ac questions, but I've got a quick one. My ac works great in the city, going slow speeds. When I get on the freeway, it works only a little bit, like warm air is getting into the system somewhere and mixing with the cold. I've tried it with the lever on re-circulated air and fresh air and it doesn't make a difference. My engine temp has also been pretty consistent, both city and freeway. Has anyone else had this problem?