Truck is a 02 sierra 5.3 113k stock..

I'm getting a ticking noise under load. At idle and in park reving it it's not there. When I get into 2,000 rpms it starts and stays till I let off the gas. Sounds like its going to explode when I floor it but it hasn't yet and I'm just wondering if anyone has an idea of what it is?
http://youtu.be/9Mh35hTr81o tried to make a video of the sound.

 

Had an issue similar to this....in my case torque converter bolts backed out..new bolts thread lock and about 20 min. Good as new.
Good luck

 

Yeah that was the first thing I checked I pulled off the bottom cover and spun it and I didn't see any of them backing out.

 

Drop the pan and look for metal. Suspect would captive needle bearing failure in the front planet. No way to tell for sure without a complete teardown, but if that is on it's way out it will take the drum, output shaft and planet carrier with it eventually if not corrected.
I personally would not drive it like that until at least the pan is inspected.

 

Check that the converter bolts and or flex plate are not contacting the back of the engine due to either a cracked or damaged flex plate or excessive engine thrust bearing clearance

 

Good news I found it! It was the plastic cover that's goes under the starter. It was broke and kept hitting the torque converter bolts. ... But now it has a ticking noise coming from the motor sounds like a collapsed lifter!?! It's there in park which is completely new...