Upon acceleration, I hear a whistling sound from my 2002 S2K. My mechanic says it's the cold air intake, but I don't hear other cars do this. I purchased this car with an after market 3" aluminum tube air intake. So I purchased an original air filter housing with all the parts for it and it still makes this sound. Anyone else have a similar problem? Solutions?
Thanks,
Wazio7

 

All throughout the rev range? only at a certain rpm? More details. My RSX-S whistled after installing a CAI right around 3k rpm.

 

It's the air intake. I remember when I drove without a box and just the arm and filter and all I heard was a whistling noise

 

Hmmmm I will have to double check that. Never really thought about it, but typically upon acceleration at any speed. Whenever the engine needs more air, it whistles for a second or two then it disappears. This never happens when testing the car in the garage, only under a little load on the road. It would be great if it sounded a little more like a turbo whistle, but it's a high pitched whistle.
I do have one vacuum hose that is unconnected. I have plugged it with a screw, but that didn't stop the whistling.
I'll take some photo's this weekend when I have time and post them showing the vac line that's disconnected. Maybe someone can tell me where it's supposed to go.
thanks for your response.
Wazio7

 

As others have said, most likely your intake. Even the stock intake whistles for me right around 3/4k RPM with the right amount of throttle.

 

Thank you all for your responses. I did pay attention to the whistle sound and when it happened today on my ride into work and YES it was between about 3-4K, so it appears we all have similar issues. I'll stop worrying that I messed something up under the hood.
Drive safe.
Wazio7