Hello everybody! Porsche 911 4S 2007! At high rpms like starting from 5000 till the limit I begin to hear kind of a whistle. My friends are surprised that I don't have turbo
It's really sounds like turbo! If there is someone who has an idea about this noise or having the same experience please let me know what it is! Thanks!

 

Although barely perceptible even after I turned up the volume, it sounds like cam chains to me. I can hear it in my 2008S ( only 12K miles). I think this is normal.