I have a question for all of you that are smarter than me on the 6.7. Today when I got home I stopped to check the mail and I heard a whistle noise and it sounded like the turbo was slightly spooled up at an idle. I brought the engine speed up about 200 RPMs and the sound went away. I let it go back to an idle and about 15 seconds later the whistle came back and the tach dropped about 50 RPMs and sounded like the engine was under a slight load. I thought mabye it was the AC so I turned it off but it made no diff. Anybody have any ideas, like trying to regen? Also no CEL or message on the overhead

 

Could it be that your exhaust brake came on?

 

Well Im not sure,what would make it do that. Is this normal or do i need to take it in?

 

Sounds to me like the EGR was circulating. I know when I pulled my DPF off and had the Edge (which did not stop regens btw) you could really hear it when it would open up the EGR system. Sounded like a jet. Similar sound to the EB being on and it idling.

 

That could be because at idle, I'll bet it closes the charger down tighter to give the EGR system enough back pressure to function properly.

I've heard it on my 2010, with and without the exhaust brake turned on. Should be normal!
Chris

 

OK thanks for your help I wont worry about it.

 

wouldnt worry about it mine does it