1st post here but long time lurker!

2016 3500 Aisin SRW bought new, haul RVs. Just turned 588K ...

This noise just started about a few weeks ago.

Well maybe unrelated but a louder intermittent tick near turbo area ( vid of that also) but what is getting to me more is a loud metallic " snap-ping?" noise which happens anytime the truck gets over 100 degrees, while Idling, driving, cooldown and even does it once or twice after shutdown!

Here's the kicker, the engine is running great, turbo is building boost normally and the exhaust brake still working fine.

The noise can happen anywhere from a minute to 5 mins apart.

I cannot find any apparent exhaust leaks or cracks.

I have been told maybe the vanes are getting stuck then snap back but wouldn't that effect boost-brake?

Wheel end play is still in spec.

Either way I am prepared to drop $ on a BD screamer replacement but something is telling me the turbo may still be fine?

It is the original turbo and at 588k it owes me nothing at this point.

I have driven it 3k so far with this intermittent sound.

What else could it be?

It just doesn't make sense to be mechanical especially if it does it after shutdown (with and without the VGT unplugged) when I hold socket extensions up to the actuator and my ear it " seems" to come from that area.