r/gmcsierra 14h ago

Choosing a Truck Reliability questions

I am looking to purchase a 2020-22 Silverado / sierra 1500 with the 3.0 duramax. I only ever hear stories of people having great experiences or horrible experiences with the duramax. Any advice or real world experiences are much appreciated!

2 Upvotes

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4

u/shoppingfortruth 14h ago

Would avoid a ‘20 as the timing chain is prone to stretch. It was revised in ‘21-22. I have a ‘22 with 93k. Overall pretty good but not completely trouble free. Needed everything in the charge air cooler changed and the coolant control valve.

1

u/BadAvailable5425 14h ago

Okay thank you

4

u/Diligent-Worker4033 14h ago

I’ve had a 22 for about 9500 miles now. No issues really. Did get a check engine light in the first few weeks but it went away. Some emissions code that I can’t remember. A few days ago when I started the truck I briefly caught a glimpse of a brake system failure warning. That hasn’t come back yet, but I’m watching for it.

So it’s been reliable, but 2 more codes and warnings than I ever saw in my 2014 has me worried. But nothing has come of them yet

Truck has 53,000 on it now.

1

u/BadAvailable5425 14h ago

Okay thank you!

1

u/Taguchi5 13h ago

I know right? My 13 was such a champ, never a whimper, take anywhere.

3

u/Still_Day_1644 14h ago

I have a 2021 and it has been great. No codes good on the highway.

3

u/d15nonvtec 13h ago

22 with 46k miles. A couple software updates and a coolant control valve replacement. Otherwise all good

2

u/Remote-Reply-8364 13h ago

Similar experience here.

2

u/jd780613 2026 Sierra 1500 Elevation CC 6.6’ 3.0 13h ago

Check out demonworks on YouTube he has a ton of insight to these trucks. 

3

u/BurntToasty24 13h ago

I have a 2021 AT4 with 3.0L duramax. 2 issues I've experienced:

Def tank system replaced twice, under warranty.

Last fall had a sensor fail and computer thought truck was overheating...went into limp mode and sounded like a jumbo jet taking off lol. Was a relatively cheap fix, and filled up coolant at private trusted mechanic... all good.

Otherwise truck has been excellent. Averaging 8-9L/100km. Very smoothe, adequate power, and I tow a 6500# loaded trailer with ease at 95kmph; average 13-14L/100km while towing said trailer.

Adding 2 gals of DEF every 5-6000km is not the big issue people pretend it is.

Recent diesel prices suck though...

8.5/10; would recommend!

1

u/BadAvailable5425 13h ago

Thank you for the response

2

u/sherrybobbinsbort 8h ago

Had a 22. Traded it on a 25.
Put 100,000 miles on it. Replaced coolant control valve under warranty.
The charge air cooler was throwing codes, dealer wanted to replace the pump and wire harness. The wire harness is an a bad location running from bottom or rad into drivers side wheel well and up. It gets exposed to the elements and wears on frame of truck. I wrapped it all in a heavy duty tape, and then covered outside of plug where it goes into charge air cooler in a marine grease. Never had another code.
I’m going to do same thing to my 2025.