So this last week my car's been making weird sounds while the A/C was on. It would intermittently make these pressure release sounds. It seemed to come from the passenger side then the middle vents. Just drove the car to a lift so I could pull the o2 sensor and it's no blowing hot air.

Is this normal for when it needs recharge? Is there a strange leak all of a sudden?

It may have been making the "sounds" for more than a week, but normally my music drowns it out pretty easily. It's just this week I've been afraid I blew my motor so I was listening for knock and that's when I started to notice it.

Any insight?

 

I see...

 

Don't know about the sounds, usually when the charge gets low enough the pressure switch will just keep the compressor from running, and then blow hot air. I'd pick up a recharge kit with a gauge and 134a with dye in it if you suspect a leak. If you have a guage see what the static (car off) system presssure is.