Noise letting off throttle

[Mwaller]

I have a 2018 ecodiesel. I’ve been noticing a noise when letting off the gas, especially under load (backing a trailer, or holding the brake and revving about 2000-3500rpm and letting off) noise sounds like a bearing noise to me. It is coming from the tube that connects the throttle body to the intercooler (I think it’s the intercooler) I attached a video of the noise. Any info would be awesome.
View attachment IMG_1004.mov

 

[autoX]

There is a throttle bypass valve that opens when you charge air (rev) then slam the throttle plate shut. The air has to go somewhere or the turbo pump will be hit. Creates a pipe hammer effect. So it's that system that is chuffing.

I blew my bypass doing that in a Volvo R - full throttle 5K rpm to shut closed, that led to the entire car combusting a few days later

 

[Mwaller]

One thing to add it only happens after driving the truck for a while. If I start it up cold the noise is not there.

 

[BTdriver]

In addition to autoX's comments:
It's a boost pressure blow off valve. Much like what is seen in movies such as Fast and Furious where the engine is revved and then the boost pressure is released to the outside for visual effect. On our ecodiesels it is the same function, but far less dramatic. What you're experiencing is normal operation.