3.0 Duramax exhaust smell in cab

DemonWorks · May 17, 2022

On 5/11/2022 at 3:53 PM, PrairieRifle said:

Got a brand new 2022 Yukon XL with 3.0. Thought I smelled diesel fumes at the dealer but brushed it off, because hey I'm a farmer. Wife cried when I brought it home and said she couldn't handle the smell. Needless to say it became even more apparent there was an exhaust leak in the engine compartment which would end up also stinking up the cab. Read this entire forum and it was not the exhaust check valve or the clamp on the bottom that have been listed on this thread. I located the leak at a clamp directly in front of the turbo. It was literally puffing out exhaust and there was soot by the clamp. Took it to the dealer who put on the new clamp and new gasket and they said it didn't work and we don't know what to do to fix it and they would have to call GM. I then decided to look at my friend's 2020 Sierra with a 3.0 which revealed the problem. The clamp has a metal strap that holds the two halves together. When you tighten it up it cinches the clamp tight which pulled the two pipes together. My factory clamp was welded together with a very large gap(about half an inch) between the two pieces while my friend's clamp was welded with the two pieces almost touching. This made it almost impossible for my clamp to effectively create a good seal between the front of the turbo and the exhaust pipe it is clamped to. I got desperate when no one could or would help me so I took it home, removed heat shield, took the clamp off, drilled out the two spot welds on one side of the clamp and rewelded that same side with the two halves of the clamp almost touching. I then loosened the brackets on the part of the exhaust pipe that went farther down into the engine compartment so that the clamp would be able to effectively cinch up without being restricted by the brackets. I then reinstalled the clamp and leak tested it with soapy water. Voila! No leak. I then retightened the brackets and put it all together and leak tested with soapy water again. Still good! The shocking part was even the replacement clamp from GM was manufactured incorrectly with too big of a gap. Which is why the GM service dept couldn't get it fixed. I'm sure they didn't try too hard anyway. I will include pictures as it was with a large gap when it leaked exhaust and i will also include pic of my fix. It's not perfect and doesn't look beautiful but at least it doesn't stink anymore. Shouldn't have to do this with brand new vehicles but that's just America today..... Best of luck to all.

That's a pretty awesome fix you did there !

I had the issue and mine ended up being the backpressure valve - there was a bulletin on it and I swapped mine out. No more smell. (i'm a tech at a dealer, so I did it myself.)

23DmaxYukon · November 19, 2022

We just took delivery of a 23 Yukon SLT with duramax yesterday. Build date was 10/2022. I noticed the diesel smell and mentioned it to the salesman but he brushed it off as "probably spilled fluids from Service department PDI"...we were excited to get the new ride home. This morning I went out to the garage after poking around these forums and saw this thread. I stick my hand over the cat pipe coming out of the turbo and sure enough I can feel the exhaust leaking like a hot hair dryer blowing pretty good. Stinking up the cab and my garage, especially when sitting idle...makes sense as there's little airflow when sitting still. I called the dealer and they're looking at it today. Shop Foreman took me back and showed me with the clamp removed how the cat pipe is misaligned from the turbo by about 1/8"... they are trying to loosen the cat pipe brackets down through the engine bay to see if they can get it realigned. It's impossible to move on its own as it's secured pretty well, according to the tech. They haven't ruled out that there maybe something out of spec with the casted part. Hoping it's a quick fix...they think they'll need it until Monday for now but if parts are required it could take much longer. Attached pics of the clamp you can see the soot built up.

GMCustomerService · November 28, 2022

On 11/18/2022 at 10:03 PM, 23DmaxYukon said:

We just took delivery of a 23 Yukon SLT with duramax yesterday. Build date was 10/2022. I noticed the diesel smell and mentioned it to the salesman but he brushed it off as "probably spilled fluids from Service department PDI"...we were excited to get the new ride home. This morning I went out to the garage after poking around these forums and saw this thread. I stick my hand over the cat pipe coming out of the turbo and sure enough I can feel the exhaust leaking like a hot hair dryer blowing pretty good. Stinking up the cab and my garage, especially when sitting idle...makes sense as there's little airflow when sitting still. I called the dealer and they're looking at it today. Shop Foreman took me back and showed me with the clamp removed how the cat pipe is misaligned from the turbo by about 1/8"... they are trying to loosen the cat pipe brackets down through the engine bay to see if they can get it realigned. It's impossible to move on its own as it's secured pretty well, according to the tech. They haven't ruled out that there maybe something out of spec with the casted part. Hoping it's a quick fix...they think they'll need it until Monday for now but if parts are required it could take much longer. Attached pics of the clamp you can see the soot built up.

This is certainly not what we like to hear, 23DmaxYukon. 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 2023 GMC Yukon SLT. To do so, please send an email to [email protected] with ATTN: 23DmaxYukon/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.

Privacy Statement | General Motors
Your privacy is important to General Motors. This Privacy Statement addresses the personal information GM collects and how GM handles that personal information.
www.gm.com

23DmaxYukon · November 28, 2022

The dealer was able to loosen brackets down through the exhaust system and then realign the cat pipe (down pipe?) with the turbo. They put a new clamp on it. They performed an exhaust leak pressure test and it seems to be repaired now. Just wanted to provide an update. It took them a couple of days to accomplish the repair and they gave me a 2019 Ford Expedition Max as a loaner. The expedition had some get up and go with that ecoburst motor but the steering and ride and overall plastic interior was not my cup of tea. It was nice to get back into our new Yukon.

JT82 · January 3, 2023

I am experiencing the same issues with my 30 days since delivery 2022 Chevy C1500 Trail Boss. I blew it off at first to regen but now I even taste it when driving around town. I stumbled onto this thread tonight after search of “Exhaust fumes in Chevy 3.0”. Not very happy to be experiencing this.

Edited January 3, 2023 by JT82

GMCustomerService · January 9, 2023

On 1/2/2023 at 9:05 PM, JT82 said:

I am experiencing the same issues with my 30 days since delivery 2022 Chevy C1500 Trail Boss. I blew it off at first to regen but now I even taste it when driving around town. I stumbled onto this thread tonight after search of “Exhaust fumes in Chevy 3.0”. Not very happy to be experiencing this.

This is certainly not what we like to hear, JT82. 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 2022 Chevrolet Trail Boss 1500. To do so, please send an email to [email protected] with ATTN: JT82/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. The information you provide may be monitored and recorded and is subject to the GM Privacy Statement.

Privacy Statement | General Motors
Your privacy is important to General Motors. This Privacy Statement addresses the personal information GM collects and how GM handles that personal information.
www.gm.com

adazabath · January 22, 2023

Having diesel exhaust smell in cab at cold start up. Taking to dealer on 1/24/23, I tried to show service manager Bulletin about Exhaust smell he didn’t even look at it, he said no history of this problem ! Not a good start! Update coming.

’

poppy510 · January 23, 2023

The OP, along with several other posters stated that this is happening only when cold and using REMOTE START. This is my issue. I do not seem to have the smell when I am in the truck starting it with the start button.

Can others clarify if they are having the issue with Remote AND Manual start, or just using Remote start.

Kchampagne · January 23, 2023

1 hour ago, poppy510 said:

The OP, along with several other posters stated that this is happening only when cold and using REMOTE START. This is my issue. I do not seem to have the smell when I am in the truck starting it with the start button.

Can others clarify if they are having the issue with Remote AND Manual start, or just using Remote start.

I believe it is both. If you manually start it and wait a few minutes with the cab doors closed you will probably smell it. Most people get in, start it, and go, so no exhaust leak has time to get into the cab. Using the remote start and running for 10 minutes or so gives it time to vent into the cab. It must be a cold start too. So if you take it to the dealer, drop it off the night before, leave it outside, and have them remote or manual start it cold and idle for 10 minutes with the cab doors closed to replicate the smell.

23DmaxYukon · January 23, 2023

I'd also make sure you check your climate control vents are open to outside air rather than on recirculation mode. If it's on recirculate, you may not smell the leak as well inside the cab.

adazabath · January 26, 2023

Renductant Fluid Injector not sealing off at NOX Catalytic Converter seal causing exhaust fumes to enter cab.

Corrected by Emission Reduction Fluid Injector Replacement.

part # 55515114 Injector

part # 55506825 Clamp

Found by using smoke test. See image!

GMCustomerService · January 30, 2023

On 1/23/2023 at 1:22 PM, poppy510 said:

The OP, along with several other posters stated that this is happening only when cold and using REMOTE START. This is my issue. I do not seem to have the smell when I am in the truck starting it with the start button.

Can others clarify if they are having the issue with Remote AND Manual start, or just using Remote start.

This is certainly not what we like to hear, poppy510. 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: poppy510/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. The information you provide may be monitored and recorded and is subject to the GM Privacy Statement.

Privacy Statement | General Motors
Your privacy is important to General Motors. This Privacy Statement addresses the personal information GM collects and how GM handles that personal information.
www.gm.com

poppy510 · February 7, 2023

Can some of you weigh in on this: I notice the smell at cold start when it is COLD out...i.e. near or below freezing. Are you all getting the smell in cold weather conditions only, or every time you start for the first time in the morning no matter what the outside temp is?

Thanks...trying to get the dealer to replicate...

Edited February 7, 2023 by poppy510
clarification

23DmaxYukon · February 7, 2023

8 hours ago, poppy510 said:

Can some of you weigh in on this: I notice the smell at cold start when it is COLD out...i.e. snow on the ground cold. Are you all getting the smell in cold weather conditions only, or every time you start for the first time in the morning no matter what the outside temp is?

Thanks...trying to get the dealer to replicate...

They replaced the clamp that connects the turbo to the downpipe however when we were in colder weather 20s to 30sF° and snowing I noticed the smell of diesel fuel and diesel exhaust. On some days I swear I can still smell the exhaust in the cab even when it's in the 50s and 60s. I've checked the downpipe and can't tell that there's any leak there so maybe it's leaking somewhere else? Not sure why I'd be smelling diesel fuel. When they replaced the downpipe clamp they claimed on the notes that they performed an exhaust leak test and it checked out but now I'm not sure. Maybe something else worked it's way loose? Will be reporting at the next oil change in April/May.

PrairieRifle · February 10, 2023

If i were you I would wait until your engine is cold. Take off that little safety shield above the turbo vclamp they replaced and have then have spray bottle of soapy water there. Start the engine and spray the soapy water all around that clamp to make sure it is fully sealed. If there is a leak bubbles will start appearing. Even after I fixed, replaced, and realigned my clamp i checked it that way and had to retighten the clamp before i got a complete seal. Even if you dont attempt the fix yourself which most people will not, at least you'd know of there is still a leak there. There are also some clamps farther down in the exhaust system that have been shown to leak also. Wish you the

Best. Mine has smelled just great with no diesel fumes in the cab since my initial fix and post.

Edited February 10, 2023 by PrairieRifle
Forgot details