OK my car always blew air that wasnt as cold as it should be. I recently had the system evac/recharged, and it seemed to blow colder but only for a couple of days. Now it is back to that warm air. Also, when i turn the car on on cold morning, the a/c makes a loud whining noise for about 15-30 seconds. Do I need a new compressor or what?
for miami's heat

 

sounds like a possible leak. Can you take it back to the place that charged it, tell them the situation? Maybe they'll test it for a leak?

 

probably leak, all those o-rings need to seal perfectly, and usually arnt replaced even though they are suppose to be.

 

maybe the idler pulley is starting to bind up....same thing happened to me until it completely seized up and snapped the belt....