MacBook Pro Retina Late 2013 (1TB SSD) makes Click Nois

dear Apple Community,

since 3-4 weeks my MacBook Pro makes Click nois in the left side of the keyboard (not from speake, it comes from the keyboard).

Here I have a Video:

https://www.dropbox.com/s/7qb9qzfwlg6m1v7/video%2028.03.15%2011%2022%2041.mov?dl =0

Ideas what this could be?

Since 2-3 weeks the macbook is for a checkup by a Apple auth. Service Partner and they not able to reproduce the nois.

It comes an goes and I dont know why...

If I do cpu powerfull jobs so the fan goes on the nois dont apears.

Thank you for help :-)