AC hisses and blows cool air

Hi all,

It's about summer here, and I noticed my 1990 190E 2.6's AC does not blow cold air, just cool air from the vents. It also makes a slight hissing noise when the AC is activated. My car had been sitting for a few weeks before, and after redriving it that's when I noticed the AC not working the way it should. Do I need freon (sp.) or some kind of AC repair? Is having a non-operating AC a serious problem that may affect the function of the car? The car drives fine, but I just need to know if this problem will lead to more serious mechanical difficulties. Thanks in advance.

The hissing sound might be the vacuum escaping from somewhere giving you an inoperative vent. Have you had a look at the AC sight glass?

I have the same problem. What should I look for in the AC sight glass (I did find it). Another question, any suggested methods for tracking down a freon leak?

I would suggest going to a repair shop that can regas the system and get them to put a dye through to find the leak. Even if you find it you aren't going to be able to recharge it yourself.

Matt.