I have a 96 4runner 5vzfe. When Im in park, the a/c compressor kicks on every ten seconds for 3 seconds. When the compressor is on I hear a hissing sound from the air vents. The hissing sound also occurs the entire time when im accelerating and stops when I'm in cruise.

I've tried adding refrigerant to stop the hissing and using dye to check for leaks without any results.

This isn't a major problem for me because the A/C stays cold. I would just like for it to be fixed as it is annoying.

Thanks for any help or guidance.