The fan in my P4P seems loud and I'm thinking there may be an  anomaly. I'm wondering if I should send in the quad for troubleshooting, although I don't want a replacement. Btw it is out of warranty.  I have searched the forums and nothing popped up.  Any suggestions? Thanks in advance.

Perhaps you could post a short video so we can hear the sound.

This has been reported a few times by othew owners, it seems you can alter the loudness by pressing on the plastc housing underneath where the fan is located. if you feel inclined to take the bottom shroud off, it is possible to push a small piece of foam in there to quieten it.

Agree with 2#. Please upload some video, we'd like to see whether we can help.