Noise while air conditioner is running on 2008 Acura TSX

My 2008 TSX started making a sort of high pitched "whoop!" sound when the AC is running on number 1 or 2 setting. I thought the noise was only audible from inside the car but you can also hear it from the outside as well, quite embarrassing at a red light. however, i had it in to the Acura dealer and notified them of the problem, and just like all other mysterious car noises they could not get it to do it. Any ideas on what this could be??

Asked by for the 2008 Acura TSX
3 answers 4 comments
I have a 2008 TSX and is making the same sound.
Hopefully someone figures out what it is.
its the a/c expansion valve pain in the butt to change its a 3-4 hour job the evaporator must come out under the dash if you can put up with the noise leave it no harm i have done a ton of these . 30 year honda tech
I have the same woop sound. But only happens when it's raining or rain. I had a clog in the sun roof drainage but that is ok now. Don't know what's causing it.
did you ever find out what the problem was?
No it is still unknown.
I just bought a 2008 Acura TSX, and I sometimes hear a high pitched "whoop!" sound with or without radio on. Look forward to hearing about possible cause!