Whirr -cunk/cunk noise during throttle spool down

[eric_kurzhals]

I have an 08 with 60K miles.

I've had an occasional noise since I bought the truck. Usually it is during the cleaning cycle, but sometimes it is not. (It actually has gotten better since I bought the truck at 45K miles.) It makes a whirr (sounds a little like brake pads just starting to go bad) followed by a loud and slowing cunk-cunk-cunk noise that sounds like the turbocharger spooling down when I come off the throttle.

Any ideas? Sounds a little worse than I would expect just for cleaning cycle.

Thanks

[First_Ford]

Do you have an ntake on the truck? and are you sure it is a cunk-cunk-cunk noise, and not a bark-bark-bark-pthhhh? It sounds like the turbo. my two trucks do the same thing, and I would imagine it would be more noticable with an aftermarket intake.

[gunman41mag]

My truck make a weird noise when it's in regen mode & I turn off the truck

[Big Angry Hillbilly]

EGRTP opening and closing during regeneration, would be my guess.

[gunman41mag]

Originally Posted by Big Angry Hillbilly

EGRTP opening and closing during regeneration, would be my guess.

Thank You, Since I've had my truck 2 years, I figured the noise was normal

[Greenshield]

Most newer emission strangled diesels make this noise on throttle down. The Detroit Diesels in our Seagrave Fire apparatus at work from 2006 on do the same thing except mush louder.