The fan on my laptop is no longer pushing out as much air or heat as it used to. While it's definitely not dead (there are spurts where it operates properly), it's normally working at a low buzz with occasional crunching sounds that I can also feel through the chassis. The problem is, there are also one or two second spurts where not only does it operate correctly, but it also operates without the loud buzz that suggests the bearings are going out.
I've cleaned dust off of the blades twice now, and that didn't help at all. I don't want to replace it as replacing the fan requires dismounting the entire mainboard just to take the fan off.
Taking the keyboard off and stopping the fan momentarily causes me to be able to replicate this issue repeatably and reliably. Stop the fan, let it start. Two seconds of high air/heat output, fan revs, crunches, then settles at a low speed.
I have no settings in my current BIOS that affects fan speed, and the only software that might control it is SpeedFan, however, SpeedFan is a recent installation to check temperatures and I didn't touch the fan settings on that. The issue has been going on for several months now.