21 duramax 3500

[tex78]

how common
mileage probability or age prone

Both

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[Cableguy]

you think a guy could prevent issues by flushing the system earlier in its life?

 

[tex78]

you think a guy could prevent issues by flushing the system earlier in its life?

Could yes

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[Rhodesie]

my guess is the issue starts the second they fire these things up off the line. 26900 kms on mine. core is dinked!

 

[Luke The Drifter]

Good info to know on these trucks. I'm nearing 60K kms on my 2022 LTZ Dmax but no issues with the heater (yet). I did have the DEF heaters fail around 50k kms and cause the truck to throw the "X KMS till derate" warning, Sherwood Chev had it fixed up in a day, can't complain about that.

 

[Rhodesie]

picked up truck at 11am this morning. good heat. no damage. no squeaks or rattles so far. flat rate is 9 hrs.

 

[JMCX]

picked up truck at 11am this morning. good heat. no damage. no squeaks or rattles so far. flat rate is 9 hrs.

You should ask for the old heater core and cut it open.

 

[Rhodesie]

You should ask for the old heater core and cut it open.

damn it. i never thought of that. i would like to see how much crap is in there.

 

[tex78]

picked up truck at 11am this morning. good heat. no damage. no squeaks or rattles so far. flat rate is 9 hrs.

Warranty time is 9 hours , not flat rate

That would be 15 ish depending on if it has r1234yf or r134a for a.c

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[Cableguy]

and what is it that is plugging the core up

 

[sirkdev]

It would either be glycol degradation or sand/solids from block casting

 

[Rhodesie]

Warranty time is 9 hours , not flat rate

That would be 15 ish depending on if it has r1234yf or r134a for a.c

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Yes my mistake

 

[Woodsie1984]

I have a 2020 3500 gmc had same thing happen…was over on gm warranty have extended warranty but they wouldn’t warranty it cause it was “plugged” not man defect…I was pissed…they wanted 2500$ to replace it , told them to Pound sand..made my own device to unplug the core myself. Flushed back and forth with water and air mixed together and heater core is good again. It’s black paint flakes plugging up the core. I will never get extended warranty again it’s such a joke.

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[Woodsie1984]

I’m actually doing my dad’s 2020 high country next week cause his is the same issue heat only on passenger side.


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[Rhodesie]

thats a kool fix. they told me they tried a flush but no workie. i did ask if it was covered before they started because i had read on forums that some guys were denied coverage. they said it was. i suggested that they say it is "defective" and not plugged. i also did suggest that if it isn't covered that i would be parking it back in the show room where i found it 3 years ago. only thing is the show room doors won't be open when i do it lol.

 

[Rhodesie]

I have a 2020 3500 gmc had same thing happen…was over on gm warranty have extended warranty but they wouldn’t warranty it cause it was “plugged” not man defect…I was pissed…they wanted 2500$ to replace it , told them to Pound sand..made my own device to unplug the core myself. Flushed back and forth with water and air mixed together and heater core is good again. It’s black paint flakes plugging up the core. I will never get extended warranty again it’s such a joke.

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that is total bull that you were denied. good on you for fixing it and not paying them to do it.

 

[Woodsie1984]

Haha..ya I was not happy…I tried just hot water first but nothing so I added shots of air and boom out it came


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[Rhodesie]

Haha..ya I was not happy…I tried just hot water first but nothing so I added shots of air and boom out it came


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thats awesome good for you buddy.

 

[tex78]

Came across this video this am

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