Right at 4000 RPM my car makes this whistle sound, the pitch increases with rpm. Sounds like a drill sorta.

Normal? or maybe a belt or something?

Any idea's?

Thanks for input.

 

Mine makes that sound somewhat. I think what you are talking about is normal.

 

I have the same whistle sound once I installed a K&N filter as the new filter draws more air into the engine than the factory filter. If you have changed the filter system then this could be the reason for the whistle.

 

No it's still completely stock under the hood. Only changed exhaust and tires.

 

Could be a vacuum hose

 

Any of you guys have radar detectors??? Cause I noticed this problem and I discovered the "drill" high whisling noise It was my radar detector making tha whistling noise. Apparently, the radar detector was picking up the RPM range noise and somehow, I don't know electronics, everytime it goes up higher in the RPM range, you hear this tiny electrical whislte "drill" noise. That could be the problem, but I turned down the volume **** just a tad, problem solved!