3.0 Duramax smelling anti freeze after parked

[rascal71]

On 12/3/2024 at 5:16 AM, Sutfin_91 said:

Now that the weather has been a bit colder I have not been noticing and not appearing to have lost any coolant from reservoir.

Same here. 

[redwngr]

On 11/16/2024 at 5:11 PM, Kwicks said:

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 !

 

Do you know if they test both coolant systems? 

[bravo8222]

Own a 2021 3.0 Duramax. Antifreeze has had a smell since it was new. Now I’ve found a small leak in the radiator. $2000.00 to repair. 60K miles.

[SG2020]

2020 Sierra 1500 3.0 Duramax. Got GM to cover the broken radiator at 76k due to smelling it from day 1. It still cost me $900 oop for the labor. Now its still leaking in a different spot an they want more to fix what they didn't fix right the 1st time. The fact that so many radiators are failing and GM knows they suck. That's what a radiator isn't covered under the diesel warranty because cheap plastic parts don't last.  So if the radiator blew and blew my motor because it's constantly overheating, I would be on the hook for the motor because the cooling system isn't "part of the motor". My lemon law attorney is working on a buyback, since GM has no fix for the 416,000 transmissions and they refuse to replace mine despite it being recalled as defective...

Edited January 30, 2025 by SG2020
typos

[SG2020]

On 1/15/2025 at 7:31 AM, bravo8222 said:

Own a 2021 3.0 Duramax. Antifreeze has had a smell since it was new. Now I’ve found a small leak in the radiator. $2000.00 to repair. 60K miles.

Call GM... they covered my radiator, but not the labor. ($900)

[s10dragracer888]

I saw something in a secondhand repair channel about head gasket issues early on (coolant smell, no obvious leak) on the early baby Duramax engine. Might be worth checking out. The radiators seem to be a common issue, too. I’ve never personally owned one, but just thought I’d spread the word in case you guys were still looking for answers.

[EricT]

I have a 2023 and like all of you have the same faint smell. I took it to the dealership from where I bought it. they did the pressure test. no leak, the service advisor had two options, 1 leak on the radiator. He called GM and the engineer said it could be a head gasket leak around a glow plug. To check they would have to pull the glow plugs then rotate the motor manually and see if antifreeze was coming out one of the glow plug holes. I had them change both radiator caps, me thinking one could be bad since it held pressure under the test. But still the faint smell.

[EricT]

I figured out where my leak is, after the 3rd trip to the shop. I said Ill try baby powder and put it on the area I smelled the antifreeze. I didn't have any so I used flour. drove the truck and couldn't see anything like the flour clumping up. Until I bought a black light flash light. It had to be completely dark as soon as I shined the light in the engine toward the radiator it lit up. the antifreeze was very easy to see with the black light. I think the flour didn't allow the antifreeze to vaporize and it glowed with the light.

[doublemax]

Have a 2021 Sierra 1500 and a 2024 Yukon, both with the 3.0. Both have the antifreeze smell. The Sierra tows my boat, etc. and works a touch harder. The dealer has done a pressure test on the Sierra and " No Leaks" yet I have had to add coolant a few times. Its going somewhere. Even though I smelled it early on, my Sierra is now past Warrranty and no pun intended, but I'm going to blow a gasket when they tell me the repair is 2K.

 

A good friend used to race top fuel dragsters and then sold auto parts for his career. Was my Saturday mechanic, could use stethoscope and 6 seconds later tell you whats wrong. When stumped, while selling parts would get tips from the liscensed mechanics and 90% of the time, symptom A was 1 or 2 common problems. 

 

I have read about this antifreeze problem in multiple forums and its becoming way too common for GM not to recognize it. The antifreeze smell is starting to smell more like GM is avoiding it and does not want to hold themselves accountable.