Dash rattle coming from passenger side

Washburnvincent · February 12, 2022

Hey guys I have a 2017 duramax L5p that I picked up a few weeks ago with 103,000 miles. Once the truck has warmed up I get this dash rattle when accelerating on the passenger side. Will start to rattle around various speeds and RPM ranges. I have noticed that I will hear the rattle more from about 25mph to 40mph, it'll stop rattling at 40mph and start back up at around 55mph and stop at 75mph. Just seeing if anyone else has had this problem, and has any fixes or remedies to stop the rattle. It drives me insane, and it's one of those noises once you notice it you will always notice it no matter how loud the radio is turned up. I've attached a video, hopefully you guys can hear it, and it uploads properly. Thanks in advance!

B&J Aviation · November 9, 2022

Wow, I have the same dash noise at 1600 rpm. Did you ever find what it was? I planned to take the truck to a car audio place and they are going to remove the dash and find what it is. I bought the truck from a NASCAR team that had 9 of these trucks and they said two or three had the same buzzing. So, this is an issue that GM should know about. Local deal did not know anything.

GMCustomerService · November 14, 2022

On 11/9/2022 at 10:26 AM, B&J Aviation said:

Wow, I have the same dash noise at 1600 rpm. Did you ever find what it was? I planned to take the truck to a car audio place and they are going to remove the dash and find what it is. I bought the truck from a NASCAR team that had 9 of these trucks and they said two or three had the same buzzing. So, this is an issue that GM should know about. Local deal did not know anything.

This is certainly not what we like to hear, B&J Aviation. Please know, customer satisfaction is extremely important to us. Our team would be more than happy to take a closer look into the concerns with your truck. To do so, please send an email to [email protected] with ATTN: B&J Aviation/GM Trucks in the subject line.

Please include your contact information, VIN, a brief description of your concern, and the name of your preferred dealership. We look forward to hearing from you. To learn more about GM’s privacy policy, please visit https://www.gm.com/privacy-statement.html.

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Gerald Strebendt · April 11, 2023

My 2018 Denali is doing the same thing and I've tried turbo heatshield, egr heatshield, visor screws that needed to be tightened... I can't figure out what's vibrating on the passenger side dash behind the upper glove box...

B&J Aviation · April 11, 2023

Gerald, my 2017 3500HD truck is currently at the Chevy dealer now and should be finished today. They found the EGR pipe was cracked at the flex area of the pipe. Tech said it is common. He said this was the cause of the vibration noise and the diesel smell I was noticing when coming to a stop in the winter. They removed the EGR pipe and two out of four stainless bolts broke off in the right exhaust manifold. Dealer said GM had the manifold on back order w no ETA. I waited a week and finally asked the dealer for the manifold p/n and made two calls found one in Maryland. Had it drop shipped to me last Thursday. I’ll know by tomorrow if the vibration buzzing noise is gone or not. It sounded like it was right behind the glove box. Just the exact same noise as the original post video. I even had pulled the a pillars and plastic dash trim looking for it. Hope this EGR pipe has fixed it.

Gerald Strebendt · April 12, 2023

Oh my god!!!! I've got the entire dash tore apart and it's still there. I think I may have the same issue you are having with the egr being cracked.... could you see the Crack while it was still mounted on the truck?

B&J Aviation · April 12, 2023

5 hours ago, Gerald Strebendt said:

Oh my god!!!! I've got the entire dash tore apart and it's still there. I think I may have the same issue you are having with the egr being cracked.... could you see the Crack while it was still mounted on the truck?

Sorry not sure if the crack could be seen when installed. However, when I was heavy on the accelerator (especially under a load pulling a trailer) I could hear a loud air sound, like an air leak, but I thought it was normal for the L5P. My LML does not do that. I picked up the truck last night. No air noise at all. Sounded like my LML and no buzzing noise, but the engine was hot (the buzzing always went away when the engine was hot).

This morning, I departed to Charlotte and I heard the dang buzzing noise again until the water temp gets above 170 degrees and seems to go away. So the EGR pipe replacement did not fix the buzzing in the dash. $3800 parts and labor and still have the buzzing.

I have researched this a lot and there is a Chevy bulletin on the LML engines where the heater hoses route through the firewall and the metal tubes rub on the firewall. I am convinced that is what is causing the buzzing, but the bulletin does not reference the L5P engine. I am going to take the truck back to the dealer again and ask them to read the bulletin again. I had given this PIP4826 to them, but he felt the EGR pipe was the buzzing noise.

This is a link to the LML site.

https://www.duramaxforum.com/threads/have-a-buzzing-sound-in-dash-after-egr-delete-solved.935730/

I found Technical Service Bulletin for the LML Duramax.

~~~~~~~~~~~~~~~~~~~~~~~~

Bulletin number PIP4826.

PIP4826: Vibration Moan Or Buzz Type Noise Heard Or Felt Inside Passenger Compartment - (Aug 31, 2010)

Subject: Vibration, Moan, or Buzz Type Noise Heard or Felt Inside Passenger Compartment

Models: 2011 Chevrolet Silverado

2011 GMC Sierra

Equipped with the 6.6 Duramax Diesel Engine ( RPO codes LML and LGH )

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition/Concern:

A dealer may encounter a customer concern of a vibration, moan, or buzz type noise heard from either inside the passenger compartment, or from under the hood. Noise may be described as coming from passenger side front of engine compartment, or from cowl area. The noise is heard better when the engine RPM is raised to between 2300 to 2600 RPM.

Recommendation/Instructions:

If the customer concern fits the noise described in this PI, verify if the noise will change if slight pressure is put on the heater hoses. If the noise dissipates with light pressure applied on heater hose, rotating the heater hose may alleviate the noise.

To rotate the inlet heater hose follow the steps below.

Make sure engine has cooled down, and cooling system pressure has been released.

Squeeze the clamp tangs to loosen the clamp on the EGR cooler heater hose (removal of the hose is not necessary so there should be no coolant loss).

Rotate the hose (approximately 60 degrees counter clockwise) on the steel pipe fitting at the EGR cooler. The heater hose has a molded bend and a quick disconnect fitting at the heater core. After the hose is rotated be sure the molded bend is at the highest vertical point or approximately the 12 o'clock position. Rotate or wiggle the hose connection at the vehicle's body side to remove any pre-load in quick-connect fitting.

Release clamp tangs to engage or tighten the clamp at the EGR cooler.

Please see completed hose relocation below.

Re-evaluate the noise after the hose has been rotated on the EGR cooler fitting.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.