AC sound

[Ray_viva]

Hello all

I have a 2010 Matrix S auto with 13000 miles on it, when you turn on the ac, the ac compressor goes on and off itself, but Did anyone notice that when the ac compressor turns off, there is a little sound comes out from the engine near the area of ac compressor? the sound is very short its like something that scrub together (that sound is more noticeable if I pop up the hood and stand in front of the car), when it turns on there is no sound at all, it only happens when the time that it just turns off... is this normal???

[fishexpo101]

You mean like a hissing sound - like taking two sheets of fine sandpaper and rubbing them together? If yes, then that is perfectly normal - all of my cars (Toyotas) does this when the compressor is not running. Maybe some remaining when the compressor kicks on, but there is so much other noise, it tends to drown it out.

[Ray_viva]

I think its not a hissing sound , it sounds like "woooo" and it only happen when the engine is hot and the time the compressor just turns off... can only hear it at night time in a very quiet parking lot...