2020 LM2...Where is the coolant going?

[CmlSierraLM2]

I just purchased a 2021 also and the first time I drove it smell like coolant check the reservoir and sure enough it was low, top it off and is getting low again, no signs of leakage or puddles under the truck but I sure smell it after a long drive, bringing it to the dealership next week hopefully they find something

[Erikkillen]

Has the problem been fixed? My 2020 LM2 keeps getting low and I’ve been continuing to fill it up. No leaks in the driveway and no smell, yet the tank keeps coming up short. 

[KARNUT]

I had a similar problem with my 02 avalanche. The low coolant light would come on about every 4 months. Never on the stick or ground. I’d add about 1qt. About 2 years in I was getting an oil change with my annual inspection. The service writer said my oil came out in clumps at first. I found out later some models had problems with small cracks in the head. In went some bars leak one year later no light.

[Claxy515]

Anybody figure it out for sure yet? Same issue, 2021 Silverado with the 3.0 Duramax. No visible leaks, I don't think I've ever smelled coolant but I also always park outside, and yet the main reservoir loses the same amount as in OP's picture. I've filled it once to the line indicated on the tank (as well as I the manual), but it has gone down again since. 15,000 miles and no other complaint.

[Bubba10417]

I am also wondering if anyone else has insight on this. I also

smell coolant 1 in 20 times or so around the front of the truck after driving. My reservoir is also down about   1/2 of an inch. Anyone have any updated info I have a 21’ AT4 LM2

[AaronJoel]

I purchased a used 2021 3.0L Silverado High Country in October. I've had to top the coolant reservoir once not overly worried about that. I've been topping up the turbo coolant reservoir once a week but can't find it leading anywhere. Anyone else have a solution? 

[repairman54]

UV dye kit will find the smallest leaks. They have kits for every fluid in a vehicle. 

[SteveCZ]

My 2014 had the infamous radiator leak at the upper hose connection.  Got it replaced under warranty, with the same defective part and 6 months later, leaking again.  GM released an updated part number, but I already traded the truck in on a 2020.  I get the 2020 home and check the fluids the day after, and the coolant is low!  

 

C'mon Man!  

I top it off, and come to find out, it was just an air pocket in the heater core.  It burped and was fine since.  I do wonder if some of the radiators still have the same issues in small batches......

[Silverado4x4]

34 minutes ago, SteveCZ said:

My 2014 had the infamous radiator leak at the upper hose connection.  Got it replaced under warranty, with the same defective part and 6 months later, leaking again.  GM released an updated part number, but I already traded the truck in on a 2020.  I get the 2020 home and check the fluids the day after, and the coolant is low!  

 

C'mon Man!  

I top it off, and come to find out, it was just an air pocket in the heater core.  It burped and was fine since.  I do wonder if some of the radiators still have the same issues in small batches......

I had to do the same thing as I use to get that bubbling sound inside the cab at the heater core on start up on my 2019, I burped all the air out by just squeezing the top radiator hose and I could see the air bubbles going into the coolant tank I then had to add more anti-freeze and have not had the bubbling sound at the inside heater core since and that's been about 3yrs ago.