I have installed a 2.2 kW water cooled spindle on my machine and initially I did run it for few hours at low speed (5000 RPM) with no load.
Then I gradually increased the speed up to 24000 RPM.

I have used the spindle for some test cut on wood, nothing serious, less than one hour work and I noted a funny sound that I have recorded in this video https://www.youtube.com/watch?v=FzVwleJvOBo. Looks like I have a bunch of frogs in the spindle!

In the video the initial speed is 5000 Rpm than I increase it to 10000 RPM and the noise starts. It makes the intermittent frog noise between 8000 Rpm and 24000 RPM with and without load.

I forgot to say that there are no vibrations and the spindle is turning freely by hand.

Do you think the spindle is faulty?