Yeah, something's odd. At first I thought that it was a short with my clutch override switch and my fan was going into overdrive(like a bad fan clutch). It makes normal noises now, but for two blocks, it was something just not working right - like 20x louder than normal.(clutch and gears were working fine, too).
I'll keep an eye on it, of course. If it does it again, I'll get a recording of it if I can.
Is it possible for something to have broken off or chipped/etc and gotten things stuck together? When I stopped, I put in in neutral and let it idle. I'd press the clutch down and there would be this 80db or so sound of something almost fan-like revving up and then when I let the clutch up, it would spin back down. Like someone was flipping a switch on a box fan on and off.