I got a Chromebook Spin 713 3W I7 1165G 256 GB two months ago. I use it with the AC plugged. Each time I start an application, I hear a 'grinding' noise, exactly the same I heard on old PC with a HD mechanical drive. I saw on the net that different people have had the same problem.
And yesterday, I unplugged the AC and use it with battery : the noise disappears. I plugged the AC again, the noise comes back. The plug was made on the first USB-C (on the 3W, the two USB-C are on the left side). Then I tried to plug on the second USB-C, the noise disppears. And when I replugged on the first USB-C, the noise has totally disapperead.
Strange no !
//Edited the content to add model name.