Help with timing rattle

[cbower]

Hello, just purchased an 02 sport trac with 86k miles. I did a lot of research before and learned about timing rattle. When I bought the truck a month ago there was no rattle, and I had plans to do the timing tensioners as preventative maintenance, as luck would have it today I just noticed a rattle. It’s quiet but it’s constantly there and increases with engine RPM. Should I even try replacing tensioners? Most people say once you have a rattle something is broken and tensioners will not solve the problem, but I’ve heard others disagree
Thanks I’m advance, was super frustrated that this happened right after I got it…

 

[cbower]

I would like to add that the rattle is quiet (not as loud as you hear on videos, in fact you can only hear it when the hood is open and you are right next to the engine. Additionally, there was no rattle on startup, it only happens after the engine idles down and runs for a bit and the noise gets louder...

 

[Todd Z]

This could actually be a belt tensioner..... I would remove the serpentine belt and start the engine for a min to see if the noise is still there. If not, its an accessory, if it is, then its internal.