In the comments of that video the guy actually states the sound was coming from his alternator.
A failing AC compressor will make the same noise.
Tester
Well here is how it sounds on and off. Doesn’t sound very different to me.
AC Compressor On
AC Compressor Off
Therefore, since it hardly sounds any different with the compressor on/off, then I’d be pretty safe to assume it’s probably the expansion valve?
Try using a length of old garden hose as a stethoscope to isolate where exactly the noise is coming from.
It seems that your compressor has failed. It would be easier to diagnose had you not release some of the refrigerant from the system to make the pressure so low.
1 Like
UPDATE: I got the car properly recharged (vacuumed out and put frion in). There was actually no frion in the system beforehand.
The A/C is blowing cold now and there is no more hissing sound …but it only blows cold when the engine is at about 2k rpm. The shop I took it to told me that they found a minor leak, the compressor is likely going bad, and quoted me $1400 on replacing the valves, compressor, and condenser. Thoughts? About $950 was just for parts which I know for a fact I could get around half that and may not need to replace the valve? Is there I way I could just seal the leak if I find it?
That is a scroll type compressor, known to fail. The reason you don’t get cold air until 2000 RPMs is because the compressor is leaking internally and can’t build pressure, next it will seize.