Belt squeak after washing car?
 

So I washed my car and immediately after my belt started squeaking like crazy, it finally subsided at idle, but now squeaks when you rev anywhere past 800rpms. I'm sure washing the car and the belt squeak starting is pure coincidence (It rains in oregon quite a bit, not like the car isn't used to getting wet), but now I have this squeak. It also seems to squeak whenever the tensioner pulley starts rattling about it looks like. I have one video of the noise I will upload to YouTube and link here, and then will take another of inside the engine bay.

Thoughts? What is this?

You probably got some cleaner or slippery stuff on the belt. Clean the belt with brake clean and you should be good. The tensioner moving is normal.

Did you wash inside the engine bay?
Could have splashed some grit onto the belt system.
If not, and the tensioner is wobbly, that needs to be replaced.