Swishing Sounds
 

With my AC running, once in a while I'll hear a SWISHING sound somewhere within the dash. It only happens with the AC and not the heat.
Am I low on Freon????? Can I DIY add Freon??

2001 S80 2.9L 114,000miles

sounds like the AC isn't draining properly, there's just a backage somewhere, and there's water sloshin' around your dash, is it coming from the passenger side? My mom's RX-8 with 30k has the same problem right now lol.

It doesn't sound like a fluid sound but rather an air sound. Keep in mind that the sound occurs both driving and sitting still eliminating outside wind causing this sound.

It will make a little noise. If it the freon slowing and going faster as the compressor cycles on and off.

Your mom drives an RX-8?
Sweet mom.
Sorry, off topic!

Mine makes the same noise sounds like air hissing coming out of the dash you can turn the air off and it will stop. Have been told it was in the in line check valve or stem some call it.

Expansion valve?

yes i think that is what they called it Been doing for 2 years now cools great gonna leave well enough along

It is pretty much the same expansion valve block that Chrysler used in the 80's.

Any solution?

Replacing the expansion block.