Humming noise when idling 3.0L Duramax

[HighTechPauper]

@HighTechPauper, I think I figured it out! It is an actuator valve that increases back pressure to help the EGR valve recycle the exhaust.... So stupid emissions crap. See this Reddit thread.

Reddit thread

I’m still going to try and ask my parts department at the my dealership, that Reddit post is a little light on any detail. I already figured with location and an electrical connection it was either a flap or a sensor, so the search continues for a good explanation on what it might do. To help the EGR may be right, but I still want to do some more research on it. Thanks @TimelordLink, I appreciate the info!

 

[TimelordLink]

I’m still going to try and ask my parts department at the my dealership, that Reddit post is a little light on any detail. I already figured with location and an electrical connection it was either a flap or a sensor, so the search continues for a good explanation on what it might do. To help the EGR may be right, but I still want to do some more research on it. Thanks @TimelordLink, I appreciate the info!

Let me know what you find.

 

[HighTechPauper]

Will do @TimelordLink!

 

[GH_Racing_172]

I fixed this issue on my 2024 LZ0. It's the spring on that exhaust valve resonating. Here is a link to a kit I put together if anyone's interested. I have 10k+ miles on my truck since the fix. No "buzzing" sounds anymore.

3.0 Duramax exhaust "buzz" DIY repair kit | eBay

The resonance of the engine, specifically at idle during and after regeneration cycles, causes the torsional spring (pictured) to resonate, creating a “buzzing” noise. This kit is only intended to fix this issue and no other miscellaneous noises.

www.ebay.com