PC making odd noise

[Greysonj]

I noticed when my fans get to 80%-100%, it makes an odd bubbling/rattling noise. I can't tell if it's coming from the radiator and fan for my NZXT H40 or from the fan right above it. I'm not having any temperature issues. Could this just be the water flowing from the rad to the tube?

 

[Radion Barakov]

Try chang the RPM of the fans, might be that they are set on high.
If they are doing weird noises it must be the fan engine and it means it's broken.