First time poster. Have owned a 2005 Crossfire for little over a year. Very little mileage. Today, for the 1st time, I heard a whistling sound (very shrill sounding) coming from the air vents. It is not continuous but off and on. When it happens, shutting off the a/c makes it stop. But once the a/c is turned backed on, it happens again within a few seconds.

No warning lights have come on. Any ideas or suggestions are welcomed. rw

 

Maybe there is something stuck in the ducts somewhere, or the air filter/fan area.

 

That would be my first guess too. Have you listened with the hood up to see if the sound starts or stops with the A/C compressor operation? If you only hear the sound with the A/C on and compressor engaged, then that may be your source too.

 

I am hoping it is not thecompressor ($$) but it does make sense. I will try your troubleshooting suggestion.

 

Did you ever figure out what is/was wrong.

I get the same whistle when a/c is off, setting the fan to lowest setting will stop it, that is unless I use the a/c, then it whistles and any fan speed.

I am thinking it is some vacuum leak, as it comes and goes while driving, steady speed there is no whistle, back off the gas and it begins. Feather the gas and it eases then goes away. When it whistles while the top is up it can drive you nuts.

I know it isn't debris in the blower housing. Anyone have an idea?

Thanks,

 

I'd replace the cabin air filter first, a clogged filter can really whistle.

 

Also make sure all of your vents are open that will cause a whistling also at least it did on mine

 

Thanks to both of you. I'll give it a try after work today and let you know how it goes.

 

There are flaps that are actuated by vacuum, there is also a white valve behind the dash that has caused problems, a leak in one of the these might cause a whistle.