Below is a link to a video I shot of my auxillary water pump, screaming like an effing banshee. And it's definitely the auxillary pump--when I pull the electrical connector, the sound stops instantly.
Note--this was happening with an old water pump, so I bought a new one, installed it, and am getting the EXACT same noise. That's what the video is of. Ugh.
I've heard a rumor that if there are any air pockets flowing through the pump, it could make this kind of noise, but if that's true, how the heck are you supposed to install it? I thought it was just pull-out-the-old-one-and-put-in-the-new-one?