Jump to content

2020 LM2...Where is the coolant going?

Whipped500
 Share

Recommended Posts

Whipped500 Enthusiast

Whipped500

Posted
Posted

Have a 2020 LM2 Duramax with 14,600 miles. Since day one I've smelled antifreeze but reading on here, everyone seems to say it is nothing to worry about.  Well I am sure it is losing it now. When cool, it is about 1/2" below where it should be on the coolant bottle...where is it going? It's dry underneath. Motor is dry and no drips/puddles.

 

I've seen a few threads talking about this but never a resolution.  I am concerned about this and want to get it fixed because if it is burning it, I'm sure it isn't good for the DPF! I also think that by the time it does something very harmful to the DPF, it would be out of warranty.

 

I am going to make an appointment at the dealer, it's just that I don't have a lot of confidence in dealer mechanics lately,  especially if the scanner doesn't have a code to tell them to replace something. 

 

Just wondering if anyone has had this and have gotten fixed so I can have something to push back with if they say they can't find anything and just fill it to send me on my and tell me to keep an eye on it.

20220227_145332.jpg

reeseb Enthusiast

reeseb

Posted
Posted (edited)

Coolant expands when hot. That may be what is causing the difference in level.

Edited by reeseb
  • Like 1
Whipped500 Enthusiast

Whipped500

Posted
  • Author
Posted

I've been keeping an eye on it since new. It was at the correct level when new, but now it is low.

redwngr Senior Enthusiast

redwngr

Posted
Posted
1 hour ago, Whipped500 said:

I've been keeping an eye on it since new. It was at the correct level when new, but now it is low.

How many miles on it?

Has it ever been topped up (cold of course)? 

 

How's the other tank doing?

 

 

Whipped500 Enthusiast

Whipped500

Posted
  • Author
Posted (edited)
2 hours ago, redwngr said:

How many miles on it?

Has it ever been topped up (cold of course)? 

 

How's the other tank doing?

 

 

14,600.

Charge tank is fine/maintaining.

Never been topped off

Edited by Whipped500
Rubyralph Enthusiast

Rubyralph

Posted
Posted

I’m having the same issue with my LM2 at 8K miles. Had the dealership check for leaks but the only way they will confirm a coolant leak is to document it over some miles. I made the mistake of topping off both tanks twice myself. I’ve noticed a coolant smell in the garage after diving, some said this is normal, I never had a vehicle smell of coolant unless there was a leak in 50 years of GM ownership.

Whipped500 Enthusiast

Whipped500

Posted
  • Author
Posted
2 hours ago, youcantkeepup! said:

You are smelling the DEF. It smells the same

If it smells the same, then I can't be sure what I'm smelling...but as my tank shows, it is losing it somewhere. 

  • 8 months later...
tim27577 New Member

tim27577

Posted
Posted

No it is not DEF it’s coolant. My’n has 39k and same issue some days driving long distances after I park it. And shut off. I can clearly smell it maybe 1 time out of 10. I’ve lost coolant in my tank also. The purge tank is fine. Hasn’t lost any. 

Bradyorlando New Member

Bradyorlando

Posted
Posted

I've got the same problem as well, 2021 model with 22k mi and have been smelling coolant when I park since new, no drips anywhere but my coolant reservior goes down over time, have had to top off several times. I wonder if it's a small enough leak that it evaporates first or something. 

Spurshot Senior Enthusiast

Spurshot

Posted
Posted

Seems like it's fairly common.  My 99 1/2 GMC 2500 6.0L was losing coolant extremely slowly, but never dripped a drop.  I figured it was a leaky head gasket, since I'd read it was a problem with LS engines of the time. 

 

After I had sold it to a friend, he discovered a pinhole leak that opened when under pressure and evaporated as it sprayed/dripped on part of the radiator itself.   I believe it was in the plastic end tanks.  

 

Take a good look around the tanks with a flashlight, looking for dried coolant residue.

silveradosid Senior Enthusiast

silveradosid

Posted
Posted

i never seen a drop on the ground either. they had to remove my fans to actually find the leak. it took them 3 weeks to get a rad and i just kept topping it up, but still never seen coolant on the ground

Bradyorlando New Member

Bradyorlando

Posted
Posted

That's very helpful thank you, I will try checking my radiator and it's end tanks more thoroughly, I do seem to smell coolant the most around the radiator, and only when it's hot. Hopefully I can find it so I don't have to keep topping it off.

seamus2154 Enthusiast

seamus2154

Posted
Posted

I have the exact same issue. I have a 2021. Since new I always smelled coolant. I am now at 17K and the tank is low and I am expecting the light to go on soon. I am over 18 months into ownership. Short trips, very hot trips, interstate trips, towing. I no longer smell coolant, but my tank is as yours. ??? Don't know where it went, and if it were a big issue I expected to find out already??? I do oil analysis and there is nothing in the oil. Truck run like top, not one issue

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing

  • Recently Browsing   0 members

    • No registered users viewing this page.

  • Forum Statistics

    250.4k
    Total Topics
    2.7m
    Total Posts

  • Member Statistics

    342,760
    Total Members
    8,960
    Most Online
    MASONV88888888
    Newest Member
    MASONV88888888
    Joined

  • Who's Online   2 Members, 0 Anonymous, 1,453 Guests (See full list)

  • Latest Articles

  • Posts

    • MASONV88888888
      Another 6.2L engine failure!

      By MASONV88888888 · Posted

      My 2025 Silverado 1500 had to receive a brand-new engine (long block) under warranty last month at only around 16,500 miles. Before the replacement, the truck repeatedly displayed "Engine Oil Level Low" warnings, even though the Oil Life Monitor still showed around 50% remaining after about 6,000 miles since my last oil change. After seeing the warning several times, I checked the dipstick with the engine cold, and the oil level was completely normal. The next day, the message escalated to "Add Engine Oil." At first, I assumed it was just a faulty oil level sensor, so I brought the truck to the dealership. After inspecting the engine, they found internal cylinder wall scoring and ultimately replaced the entire long block under warranty. Before this happened, I was planning to install a 4-inch lift and suspension upgrade on my truck. After needing a new engine at just 16,500 miles, I honestly don't see the point anymore. I also contacted GM to ask whether my vehicle qualified for a buyback, but I was informed that it does not at this time. Anyway, this experience has left me with serious concerns about the long-term reliability of this engine. I sincerely hope NHTSA expands the current investigation or recall to include 2025 model and performs a thorough inspection of affected vehicles. My biggest concern is that these engines may fail shortly after the powertrain warranty expires. If GM truly stands behind this engine, then at the very least, please consider extending the powertrain warranty to 10 years for affected owners. That would go a long way toward restoring customer confidence.
    • Grumpy Bear
      OCI, not when but why?

      By Grumpy Bear · Posted

      Without exception but then I'm the odd duck, right? I know what goes into that test, how it is calculated and thus how to beat it. But EPA values are often not beaten by the general public and the government has in past years adjusted the means and methods to come to those values to more closely approximate "Joe Average".    The only real trick to beating that EPA average is don't drive like "Joe Average".    It's the same method you used to profit from "Economic Migration" and in doing so beat the 'stats'. But you, like me, are not "Joe Average".     The thing you don't seem to grasp is this "Purchasing Power Index" isn't forward looking. It doesn't predict what it going to be but looks backward and states what it was. They are not telling us what the THINK, they are telling us what they MEASURED. Example:    Wife says "I'm going to lose 40 pounds by Christmas". May she does, maybe she doesn't but the doctors office who weighed her when she made that statement and again at Christmas only REPORTS what the RESULT was. You and I can banter about what was possible and what aunt Tilly did till the cows come home but the result is the result. Arguing otherwise is.....irrational. That's all I'm saying. This isn't about:      What you are calling a 'Statistic' is a RESULT not a CALCUATION and as a result the RULE. Like gravity as a rule, it can not be broken. 
    • MASONV88888888
      Rattle in the rear!

      By MASONV88888888 · Posted

      Just wanted to say thank you for posting this. Years later, your thread is still helping Silverado owners.   I bought my 2025 Silverado 1500 in January 2025, and I've had what feels like the exact same rattle since day one. After reading your findings, I believe my truck has the same issue with the cable carrier contacting the rear sliding window. To be honest, I had pretty much given up on pursuing the issue. It wasn't until I recently drove another brand's pickup that I realized just how quiet their cabin was—and how noisy mine has been all along. On my truck, the rattle happens on almost any paved road, gets even worse on rougher pavement, and I can even hear it during braking and acceleration.   I actually referenced your thread when submitting my case to GM, hoping they'll recognize this as a recurring issue instead of treating it as an isolated incident. The reason I reached out to GM first is because my dealership told me they would need to keep the truck for at least two days just to diagnose the problem. I was concerned that even after two days, they still might not be able to identify the source of the rattle before giving the truck back to me. I had also asked a few dealerships about this issue during previous service visits, but none of them seemed to know what was causing it or had a solution. That's why I decided to contact GM directly first, hoping they might already have an official repair procedure or guidance for this issue.   I also hope GM eventually comes up with an official fix for this problem. I have a feeling there are many Silverado owners experiencing the same rattle, but most either choose to live with it or simply don't know what the cause is.   Really appreciate you taking the time to document your diagnosis. Your post is still making a difference years later.
    • Buckwild27
      Gas Prices

      By Buckwild27 · Posted

      I have 2 choices. 
    • Grumpy Bear
      Gas Prices

      By Grumpy Bear · Posted

      Do you have access to BP fuels? Some stations have Silver 91 E-0 priced the same as their 93 E-10.  There is a local Marathon with 90 alky free for $6 a gallon but I go down the road to BP for $5-ish. They also have a 100 E-0 but that stuff is $10 a pop. 

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...