Rattle on Cold Startup

Hello, another thread I’m usually not a spammer but I’m having a really bad rattle on cold start on my 2012 TRD and I can’t seem to figure out what’s going on. It usually happens when temperatures go under 30 degrees and when it warms up it doesn’t do it anymore. Any clues? Thanks.

https://youtube.com/shorts/IXCrdyNsqw0?si=2nyVcPv5lNGkvk8Q

 

Is it the repetitive machinery knock that you're referring to? If so that sounds to me like it might be related to the truck's serp belt system based on it's frequency. If that's the case I'd pull the serpentine belt and see if any of the pulley bearings are starting to go bad and inspect the belt.

 

I cannot hear kind of "rattle" in the video , just thumping .
I do know the new earth friendly hypokenateuric pistons are prone to make a high pitched tick when started stone cold .
The ultra lightweight piston skirts ring like a bell with lots of extra clearance for reduced friction in order to save the planet from climate change
.....they slap like crazy until they warm up , its the new normal

 

I agree it sounds like piston slap to me also...

 

Thanks for the comments everyone i've since changed the oil for the first time using quality stuff and seems like the questionable noise went away it may have been cheap oil even though it only had 3k miles on it. I definitely have noisy pulleys I ordered replacement Koyo bearings to re-use the idler pulleys but no tensioner bearing since I don't remember if it was silent or not...

 

Update: Noise is getting worse. Issue is this is my siblings truck and when I drive to “check” it but I can never catch it. My best educated guess is the serpentine belt tensioner but also thinking maybe timing chain tensioner. Truck has 176k miles. Any guesses?
https://youtube.com/shorts/C8khdD8TG6k?si=FrKyPe8wowoQXaVC

 

I’ve checked every single area on the engine bay including belt and chain tensioner and nothing. That was during cold start im told when idling after driving it the chatter is present the most.