weird turbo noise?

[BSilveira]

Is it normal for my turbo to make a fading spring-like shudder when I shut down the truck? I have it on Performance mode on my Power Pup. I remember it making a fading whistle before I got my transmission work done. When the transmission shop installed the egt sensor, they told me they got a bunch of shaving in the turbo. They said they cleaned it out, but who knows? I hope nothing got messed up.