Question Rattling sound from CPU fan when restarting computer

[jaxx80]

Hello
It is a brand new computer, which I built the previous days.
MSI B560M PRO-VDH, I5-11400F and Arctic Freezer 34 Esports (with 1 fan).
Each time when I restart my Windows 10, something in the revolutions of the CPU fan changes and there is a very clear rattling noise coming from it - multiple very fast rattles for a total period of around 1 second.
The fan is well attached to the heatsink and the heatsink itself is well attached to the motherboard. There are no loose parts.

What do you think could be the problem?
Is the fan defective or this is some kind of setting?

Thanks in advance

 

[Eximo]

Many fans ride on their bearings edges until they spin up to speed. This can make the fan blades wiggle around a little and sometimes hit the frame. Attached to a CPU cooler, it might sound louder or be actually contacting the heatsink.

Make sure the fan is attached with the frame/hub facing the heatsink, mounted the other way is technically backwards, and would have more chance of hitting things.

If it gets serious, ask Arctic for a replacement fan or buy your own high end fan.

 

[punkncat]

I have had more than one occurrence of Intel stock CPU fans being BOB. Where I have rarely had the issue out of 'aftermarket' it could happen. The last time I had this happen the retailer wanted me to send back to the manufacturer, which would have had me waiting a while before having a replacement and out the money. I opted to purchase another and then sent the bad one back for replacement and set it to the side up until I needed it.

 

[Eximo]

I have one Phanteks fan doing it at the moment, ticks to stop after the system is shut down. I have a spare and two additional now PWM versions of the same fan in a box.

 

[jaxx80]

Make sure the fan is attached with the frame/hub facing the heatsink, mounted the other way is technically backwards, and would have more chance of hitting things.

I mounted it as shown on the pictures - Freezer-34-eSports
with the Arctic logo facing away from the heatsink
not sure if it is possible to mount it backwards

 

[jaxx80]

I have had more than one occurrence of Intel stock CPU fans being BOB.
...

This is not the stock cooler from the I5-11400f box. I did not mount the stock cooler at all

 

[punkncat]

This is not the stock cooler from the I5-11400f box. I did not mount the stock cooler at all

I am aware of that. Thought the next line might have made that clear. Referenced as a 'just sayin'