I turned my a/c on this morning in the car and its been giving a loud hissing sound through the vents. This is the first time its ever done that and I had my a/c recharged the end of last summer. I havent used it much this year other than maybe a handful of times. This is the first time it started to hiss. Anyone know what could be causing it? I also noticed that the a/c isnt as cold.

 

if the a/c isn't working/cooling that hiss your hearing could be the leak. When your system was recharged did the shop repair a leak? Or just recharge the system? Sometimes gaskets or o-rings in the system can leak, especially when there is a large swing in temperature outside, the gasket will expand and contract causing a small leak to become a large leak. (I hope that makes sense!) Some auto parts stores are selling a leak seal and recharge kit for like $50. It might be worth a shot. I haven't used the product myself but maybe someone who has can post their comments/results.



This is the stuff here:



http://www.redtek.ca/products_refr.html

 

Could also be a leaking heater core? How is your coolant level?