Rapid sounding rattle when accelerating through 2500 rpm

[tdottrucker]

I have a 2016 RT with the 3.6. If I step on the gas off of a light, i will hear a faint metallic rattle that is very fast in sound occur as the vehicle gets to around 2100 and stops by 2500 rpm as the vehicle shifts. 
 

if I lightly step on the gas and slowly accelerate to a gear change, no noise will happen, but only on more average to aggressive accelerations.

 

In Neutral or park, I will hear this sound if I aggressively step on the gas and the RPM passes through 2500-2700rpm, but will not happen if I slowly press the gas and accelerate beyond 3000rpm. 
 

I’m trying to find out what is making this sound. I know I have a loose heat shield that makes a dinging sound while moving forward (verified it, just need to retighten it). But this sounds a little different. ** I can try to get a video of the sound if this would help identify the problem.

Edited August 16 by tdottrucker

[John/Horace]

Milage on car. Any recent work completed? Could be anything spinning on the engine. Remove surpentine belt and only for a min or two (water pump won’t be running) run the engine and listen for the sound. Report back.

 

Engine stethoscope are about $10 at Princess Auto/Harbour Freight. Very good for trouble shooting noises.

[tdottrucker]

153,000 kilometres with no recent work other then RF Hub replacement for RKE issues that are unresolved still. 

[5rebel9]

Just a guess as there are a number of heat shields under our rides. But possibly a cat converter heat shied coming apart?