3.0 Duramax smelling anti freeze after parked

cc1999 · March 9, 2022

My AT4 now has 10k miles and ever since the first oil change around 7000 miles mine has had the same coolant smell everyone is talking about.
I have had other mechanical minded buddies comment on it as well. At first I thought I was imagining it, when I could not find any visible problems.
Same as everyone else no codes, no leaks found anywhere, coolant levels have remained the same since I first noticed it about 3000 miles ago.

Gary S · June 23, 2022

I have the same issue. Used about 1/2 the reservoir on a 3400 mile trip. Dealer has had it 4 time, put in dye, no signs of a leak. Just smells when you shut it down.

Shipley · March 4, 2023

Anyone find anything new about this issue. I'm having the same problem.

cc1999 · March 4, 2023

None, here. Dealer could smell it too, ran all sorts of test on the coolant system. Never set a code, never a sign of a leak anywhere, my coolant was never found to be low in 20,000 miles. Just had that coolant smell. I sold mine to a good friend of mine, when I bought my 23 AT4X which only come with 6.2L gas engines. But I would have bought the diesel again had it been offered in the X .

Shipley · March 4, 2023

That's where I'm at now. They have ran all kinds of tests nothing found only the smell. So to me that says there has to be some kind of leak or vent. I took it in a 4000 mile round trip elk hunting trip and never lost any coolant only could smell it when I was outside the truck. But as long as I never lose any coolest I'll keep running it. I love the truck just hate that smell.

silveradosid · March 7, 2023

had the same problem on my 2020, took the dealership 2 days to find where the smell came from and it was the radiator. never left a drop anywhere but could always smell it

Tijerina79 · February 2, 2024

I'm experiencing this same issue on my 2021 Silverado 3.0 Duramax. So it sounds like this is not an uncommon issue. Has anyone been able to pinpoint exactly what's causing it? I wonder if Chevy is aware of it and if there are any technical bulletins regarding it.

Trotorx2 · February 3, 2024

I've been noticing it some on my 2023 LTZ 3.0 it's very faint and doesn't last long, at least so far.

GMCustomerService · February 9, 2024

On 2/2/2024 at 6:29 PM, Tijerina79 said:

I'm experiencing this same issue on my 2021 Silverado 3.0 Duramax. So it sounds like this is not an uncommon issue. Has anyone been able to pinpoint exactly what's causing it? I wonder if Chevy is aware of it and if there are any technical bulletins regarding it.

This is certainly not what we like to hear, Tijerina79. 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 2021 Chevrolet Silverado. To do so, please send an email to [email protected] with ATTN: Tijerina79/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.

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GMCustomerService · February 9, 2024

On 2/2/2024 at 7:04 PM, Trotorx2 said:

I've been noticing it some on my 2023 LTZ 3.0 it's very faint and doesn't last long, at least so far.

This is certainly not what we like to hear, Trotorx2. 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 Chevrolet Silverado. To do so, please send an email to [email protected] with ATTN: Trotorx2/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.
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Jamel Robinson · February 23, 2024

I just did a round trip of about 110 miles today and had the coolant smell. I have a 2021 Silverado RST Z71 Duramax with about 54k on it. The truck has been from Virginia to Georgia to Alaska -25F to Texas 117F and back to Georgia over its life. Just now about to replace the first set of tires tomorrow. Thread still good just notice cracking on them.
Today I saw high 220s temps while driving the above miles once I came off the highway and on the return trip didn’t see more than 212-13ish. This was the second time in almost the same exact manner on a trip in January. I did have to add coolant 2-3 weeks ago and it took almost 3/4 of the bottle. Didn’t look like it needed it but it was well below the minimum cold temp mark. I think I will take it to the dealer but I’m afraid of getting the runaround because I went through the ringer with a dealer with my ZR2 Bison Colorado to the point GM made them buy the truck back. There’s no codes other than the occasional emissions one that happens on these trucks and I always just clear it with my scan tool. So there’s nothing other than the smell and the slightly high temps.

GMCustomerService · February 26, 2024

On 2/22/2024 at 8:02 PM, Jamel Robinson said:

I just did a round trip of about 110 miles today and had the coolant smell. I have a 2021 Silverado RST Z71 Duramax with about 54k on it. The truck has been from Virginia to Georgia to Alaska -25F to Texas 117F and back to Georgia over its life. Just now about to replace the first set of tires tomorrow. Thread still good just notice cracking on them.
Today I saw high 220s temps while driving the above miles once I came off the highway and on the return trip didn’t see more than 212-13ish. This was the second time in almost the same exact manner on a trip in January. I did have to add coolant 2-3 weeks ago and it took almost 3/4 of the bottle. Didn’t look like it needed it but it was well below the minimum cold temp mark. I think I will take it to the dealer but I’m afraid of getting the runaround because I went through the ringer with a dealer with my ZR2 Bison Colorado to the point GM made them buy the truck back. There’s no codes other than the occasional emissions one that happens on these trucks and I always just clear it with my scan tool. So there’s nothing other than the smell and the slightly high temps.

This is certainly not what we like to hear, Jamel Robinson. 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 2021 Chevrolet Silverado having anti-freeze smell. To do so, please send an email to [email protected] with ATTN: Jamel Robinson/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

Sutfin_91 · November 9, 2024

Having the same issue here as well. Just started smelling coolant around front of truck lose about half the reservoir in last 1000 miles no signs of leak anywhere. Took covers and skid plate off to see if it would drip too with no luck 22 sierra. Anyone find a solution yet?

Edited November 9, 2024 by Sutfin_91

Kwicks · November 16, 2024

I'm experiencing this on my 24 yukon 3.0l Duramax. I had a faulty injector at 2000mi and ever since the repair I smell coolant thru the grill Everytime I drive it. Taken it back to the dealer and they said they did a pressure test and can't find anything wrong. Since there's no problem found they can't help as of now. Frustrated !