Mitsubishi Repair: 2007 Mitsbishi outlander, radiator cap, mitsbishi

Question
My Mitsubishi Outlander blows old air in the winter time when i'm idling at a stop light.  My dearler tells me that the vehicle is idling too slow yet he has not been able to fix this probem.  I say "bullshit" I have had numerous vehicles (between my husband and I 15) we have never experienced a vehicle blowing cold air cause it was idling too slow.  Do you have any thoughts?  
ps  Are you aware of any TSB from Mitsubishi on this problem?
looking forward to your reply.
Thank you!!

Answer
Sandra: Look I have not worked on such a new car has your's. But still that does not make a lot of sense to me. It is like your dealership has no idea what is going on with your car so they have threw this out at you. Maybe thinking as a woman you would think that is how things work. Sorry but most shops and dealerships do not treat women very good. There are some that do right well but for the most part no. Being the car only does it when idling at a stop light so that the engine is slowing down, I would be checking the water pump as it moves the water around the engine. I would check the drive belt as it might not be a tight as it should be, so not moving the water pump fast enough when at idling.Repair manual says to also check the timing on the engine too as an idea. Maybe you need a hotter thermostat in your car. Check the radiator cap, not maintaining proper pressure. There are some idea for you to check or get your dealership to check. Again I have not worked on such a new car as your's. But I can not believe it is all that much different when it comes to heat than an older car. You could have the computer checked there is a coolant sensor which could be weak too. Also how is the coolant in the car? Hope one of these helps you. Also you could go up on line and check recalls for your car; there might be something. Just type recalls for 2007 Mitsubishi and see what comes up.But no I know of none but then I don't work on much on these newer cars. Sorry. God bless: Linda