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??

by in Harrisburg, PA on June 07, 2010
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3 answers 4 comments
ANSWER by , August 02, 2010
I have a 2008 TSX and is making the same sound.
COMMENT by , August 02, 2010
Hopefully someone figures out what it is.
COMMENT by , August 17, 2010
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
COMMENT by , September 28, 2010
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.
ANSWER by , July 26, 2010
did you ever find out what the problem was?
COMMENT by , August 02, 2010
No it is still unknown.
ANSWER by , July 31, 2010
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!