The reason the problem is worse at idle is because at speed more air is naturally being forced through the radiator.
The other possibility is that the engine started running hot, and its heatsoaking the condenser, affecting the AC.
Robert has it covered. Just want to add you need to check the antifreeze when the motor is cold before driving the car or you might blow the head gasket from overheating the motor. If the antifreeze is low it would be better to pay a tow bill rather than drive it and cause damage that will cost over $2,500.
If you know nothing, take it to a reliable mechanic.
Read the car handbook to see what you should check on your car every week or so - coolant levels, oil levels and so on.
If your temperature gauge is going up significantly while parked or stopped for longer periods of time you're best bet is to have your thermostat looked at. But I agree with David bring it to a mechanic, and tell him what's going on. Ask them to look around and mention that it could be your thermostat. Again, they're mechanics they know more than I do lol.
Ok so lemme preface this question by saying that i know NOTHING about cars or car maintainence, even though i know i should /.\ So i have a 2005 kia rio. never had problems with it before but for awhile my ac stopped blowing cool air. all it does is blow hot air. it seems cooler when driving but in park or at a red light the air seems warmer. and now the other problem is that my car keeps going up to "hot" on the hot/cold spectrum thing. it seems to happen when im in park or at as stop sign as well so i hate driving it esp cuz i live in az in 100°+ weather. and the steering wheel even locked up on me once. it was in park with the warm ac on and i tried starting the engine up and the wheel wouldnt move and couldnt pull out the parking space then i noticed it was at hot so i turned it off for awhile. please help as to why this is happening. i get stressed even driving down the street cuz i dont want itto stop on me in the intersection. thanks!
