Signature 600 chuffing

[Creek]

This is my first post.
ISX ReCon 600 CM570 just under 500k mile. Getting a chuffing sound at all rpms. Can hear it at idle. Gets louder of course with increased boost. Truck runs great, no power loss, good mileage, no smoke of any kind. Had a Volvo shop check the overhead. Said it was fine. Don’t really trust that opinion however. Thinking of getting it checked out again. I am in NC 45 miles NW of Charlotte. Any good shops up here? Anyone have an idea of what would be a good of course of action?
Thanks a bunch.

[Rawze]

you sure it is turbo chuff?

chuffing is usually an over-spooling turbo or a restriction in the CAC. What boost is it getting up to in a hard pull?

what turbo does it have on it?- Is it factory turbo? or something else?

When did problem start? some history?

[Creek]

No I’m not sure it’s turbo chuff, just sounds like back pressure being force out of air intake. I can faintly hear it on downgrades without using the engine brakes. On hard pull it pegs the the gauge at 35.. CAC was new about a year ago. It started doing this on a 80k load of wheat out of Montana in January. As far as I can tell it is factory turbo that came with the recon engine that previous owner installed.
Thanks for the reply.

[Creek]

Did a little more analysis while driving today. 14k, moderate pulls, (Catskills). Chuff is louder at mid boost than max. Some unusual vibration when engine braking (therefore not using engine brake)
If it didn’t perform so well I’d swear it was a dead miss.

[Rawze]

is it a random chuff (huff) or is it a popping sound that changes with rpm in intake, like maybe a an intake valve not seating?

[Creek]

More like the popping sound. Steady rhythmic changes with rpm.

[stevesparts]

I'd pull the valve cover and look at the cams to see if something is going on it. my 870 made sounds like that just before it eat the cam..

[Rawze]

(04-18-2019 )Creek Wrote:  More like the popping sound. Steady rhythmic changes with rpm.

maybe time to pull the engine cover and check valve adjustment. Also maybe boroscope it and see if there is a cracked intake valve.

read through this post carefully and follow its links for more info on this...
http://rawze.com/forums/showthread.php?t...1#pid14811

[Creek]

Yes I had the overhead checked by a Volvo shop a couple of weeks ago. They said it was fine. I need to take it somewhere else. But where? Cummins?
Thanks for all the replies.