Hey guy, 2004 FX4 here, 4.0L 4x4

been offroading a couple times since I got this a few months back, and I’ve noticed a weird noise coming from the engine bay after crossing water.

it’s a ticking noise, and it seems to be coming from the alternator or something around it. Here’s a video:
https://imgur.com/a/X9jk5Z4

as you can see in the video, it seems to stop when I rev it, but once the engine settles back at idle, it starts back up. Only happens for the next 30 mins or so after crossing water, nothing too high to be concerned about water in the intake. I’ve had the noise come and go about 4-5 times now, each time after driving through a considerable amount of water, but again, nothing to be scared of getting water in the intake. Then it’s gone about 30 mins later, and only comes back after another water crossing.

it kinda just sounds like it’s water on the belt assembly being slung into something else. Anybody else have this noise when getting their truck a little wet? It’s kinda annoying and concerning, I wanna stop it if I can

it also seems like that tensioner wiggles just a little, is that normal? It steadys out when I rev it, which is also when the noise stops. Is that related or just a coincidence?

thanks guys, anything helps to try and get this noise hunted down. I wanna make sure I’m not hurting anything

 

Really? nobody else has had this issue?