Light gray smoke. There is a light-gray, odorless smoke coming from my ac unit. It still blows

Question

There is a light-gray, odorless smoke coming from my ac unit. It still blows cool air, but it starts blowing smoke within a minute of being turned on.I noticed that the smoke stops when the temperature control is low (almost to the point where there is no cooling).It has been used rather heavily in the last week, due to a recent heat wave.I don't notice any leaking (at least not on the side facing in), nor is it making any odd noises.Any suggestions..? ^^;Thanks in advance!Byron