Please bear in mind that the Intel® Processors don’t have movable parts that may cause any noise. Personally I don’t think that the little mark will cause this issue. This noise could be produced by the cooling fan. You can try uninstalling and reinstalling the fan. Also, check if any BIOS version needs to be updated and also test a different cooling fan on the system or this fan on a different system.
If the issue continues, do not hesitate to contact your local Support Center. Please find the contact information at following link.
I've sent the "problematic" motherboard to support.
They've run extensevely tests to stress it. No noise was noticed.
I feel clearly the noise comin' from the back of the motherboard next to the metallic part under the processor but it seems to come from the capacitors.
Can you explain me if the part of the processor that gets in contact with the cooler is just a cover of it contains something vital?