Screeching noise on DD13

The Trucks a 2017 Cascadia with a DD13. At higher RPMs above 1500, it gets a loud screeching noise. It’s consistently the same, I think it’s a heat shield on the turbo. Sounds terrible. Don’t think it’s anything serious. Let off fuel, it stops. Turn on jakes it starts doing it again. Anyone ever had this or a similar problem? If so what was the cause?

 

It sounds like metal to metal. Like the turbo fins hitting. That’s what I’m worried about. I originally wrote it off as nothing serious. Thought it was a clutch or a flywheel noise. I think it’s definitely on the engine near turbo. I’ll check the boots. Makes sense because it goes away as soon as I let off the fuel.

 

Good advice. Whatever the noise, it only happens at a certain time. Something rubbing, or a bearing. The engineers call it vibration frequency. Recently had a conversation with a mechanical engineer. The testing they do to find the frequency of parts, redesigning them, so the frequency is higher than needed. It’s really cool stuff. Has to do with thickness, type, and design of parts. I think I’ll take the heat shield off the turbo for a day or two. See if it goes away. All these newer engines vibrate so much. Rough idles, especially. Like they’re out of balance. If my series 60 idled like that I’d be very worried.