850 Turbo with 130,000 miles: White condensation smoke appears out my tail pipe only when I have the a/c on and only when I'm idling (not seen while driving). It is a constant pillow of smoke about 3 minutes after the warm-up of car. It doesn't do it when the car is in park or when the a/c fan is off. I say it's condensation because I've held my hand about 6" from the exhaust pipe and I feel dampness. No dark gray smoke is seen, only white. I also hear a slight hissing/fluttering sound (like air leak)froming the engine while the car is on and the car feels a little rough while idling.

Any opinions from the experts?

Thanks. jp