GW2010

Digging into this issue tomorrow night. I'm thinking it might be the starter rubbing against the flywheel. Listened to a video from someone else and sounds very similar. Thoughts?

https://drive.google.com/drive/folders/1FbxA4fiLxttm2HGcRmkEe6UDG4GfPIrL Videos of the noise

I have a 2013 Chevy Silverado 1500 with the 5.3 making a tapping and/or clicking noise from under the vehicle. On a cold start-up, it does not make the noise. Once the vehicle has idled down, it begins. Weirdly enough, it comes and goes but 90% of the time the noise is there. The truck only has 74,000 miles and shifts, drives, and rides perfectly. Oil pressure at idle is 20ish and around 40 when driving in town or on the interstate. Again, you can't hear it from the top of the motor. I purchased the truck from an older gentleman who put 5,000 miles on it a year. Thinking it may have something to do with not being driven regularly. Because of this, I did flush the engine with BG (I purchased the truck with the noise FYI), and thought a good flush might get rid of the junk from being driven lightly. It did nothing but probably was needed anyway. Trans fluids looks great. The noise happens in Drive, Reverse, and Park. In Drive, when stopped, it will sometimes stop. Sometimes in Park, it might stop but it ticks the majority of the time. regardless of the gear. When you rev the motor up, it climbs with the RPM's for maybe 150-300 then it's gone but when you let off the gas, it comes down, and can hear it at 1000 to 500-600 where it idles. Anything above 1000 it's gone. Any ideas? Thinking bad trans solenoid, flywheel, or maybe torque converter? Does not sounds like a lifter. Thanks for your help.