98' Concorde LXi 3.2L hissing
 

Recently I had on over heat and found coolant low. I filled up the coolant with the 50-50 mix and replaced reservoir cap. Car temperature is normal now, but paying more attention to it now, I noticed a hissing sound coming from the engine and some what looked like steam. I opened the hood and the hissing seemed to be coming from the compressor or the immediate area. Little bits of steam could be periodically seen from that spot too.

I found a few posts on other sites concerning AC. On hot days when the AC is at it's coolest setting at full blast. I read that when the engine is turned off, the pressure begins to dissipate and the condensation may be the source of the steam.

Any confirmations, other possible causes or other information?