G4 Noise/Vibration concerns

My old dependable G4 tower developed a bad new habit this morning. It's doing this cycling vibration thing that sounds like it's winding up, vibrates enough to feel it through the floor from 12 feet away, then it will reach this sort of crescendo before it goes quiet, then repeats. Indefinitely. The whole cycle last about 7 seconds. Is this thing on death's door? Is it just a mechanical fan issue?

Got the original start up discs?

Run Apple Hardware Test and see what it says about the state of the drive. Next option is to do a Google on quietening a G4, particularly if a MDD model, and it is always best to include your machine details King.

Quicksilver G4 Fan Noise Reduction:

PowerMac G4 Mirror Drive Door Tower Noise reduction

It is probably a fan issue. Have you taken a can of compressed air and cleaned those out?

I'll tell you what, it's definitely the fan/power supply box. I blew it out with some compressed air and it did the trick, but then a day or so later it was it again. I guess i'll take a stab at ripping it apart and being a little more thorough.

and that's a dead fan.

That for sure sounds like dry bearings on a fan. I was going to suggest power supply but looks like you found it!

I usually oil the bearings for a temp solution then get a new Fan.

Interesting. Thanks for the head's up about oiling the bearings. It so happens I have another G4 tower kicking around, but I don't want to lose my backup!