Ok, This is not my truck .BUT Mines been making this exact same noise.
https://www.youtube.com/shorts/GAnGM_mlVwgBeen making this exact noise for almost 3500 miles , or so give or take
Started about halfway between AZ and KY headed east back in April. Noise would come and go to some degree
I thought was a flex plate , So had that replaced by a shop I trust in KY ,
Once back together they called and said noise was gone, even though they didnt see any cracks in the plate,
Jusrt a small amount of out of roundness in 2 plate to crank bolt holes. Yet all the bolts were tight.
To me it looks like a rust stain from crank bolt to outer edge like its been loose . SO I had them install an new genuine Mopar flexplate and blue locktight on the bolts , retorqued to oem specs ( see attached pic )
Noise was gone for a few weeks / couple hundred miles. so thought was fixed.
Took a few qweeks but it slowly came back Drove it to the Nats with trailer behind it, Noise was there going up. But not a sound on the drive back to northern Ky
So, I changed the oil / filter right after - no change . no signs of anything in the oil
Next day noise was there , so it would come and go , get above 2000 rpm and sounds like noise fades / goes away .
Well, after driving it back across country from Ky to AZ noise is back / still there .
Today I had some time to dive into this once and for all
So,
Today I pulled the torque conv loose and pushed it back so its not spinning- no change in noise.
sprayed some WD40 up around crank seal area - no change
took starter off and ckd for wear witness marks - none found
removed engine serp belt - no change
Ive googled it a few times and come up with numerous ideas fix its etc etc
Is this possible to be a cam roller ?
spinning cam bearing ? - spun bearing in the lower end ? deep down I have serious doubts its this as I feel it would have gotten A LOT worst by now . It does NOT knock or tick in any way except for an exhaust leak pass side only when cold . But this aint that noise