2020 GMC Sierra 5.3L - Clear leak + engine light

Jbrockltd · August 25, 2020

Hi everyone!

just hopped into my first GMC Sierra 2020. Traded in my 2017 Tacoma which went 80,000km without an issue. 2-days in now and I’ve got an engine light, and clear water leaking from underneath the truck. It’s leaking from the joint with the two tubes which I’ve attached a picture of. Any thoughts on what this is?? I’ll be calling the dealership but just want to see if this is common?

also... anyone else notice the poor undercoat? Used my thumb to rub the undercoat right off to steel...

Edited August 25, 2020 by Jbrockltd

Transient · August 25, 2020

First, the water is condensation from the AC. Even Toyotas do it. Everything is fine.

Second, that's not a poor undercoat. It's a wax undercoat. GM offers to use wax on the frame to resist rust because they believe it is better than what everybody uses, and it's self-healing. Give it a little bit of time and that spot where you rubbed your finger on it should smooth out and recover the frame.

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steve841 · August 25, 2020

And for the CEL, welcome to the world of GM and poor software programming and the total inability to deliver OTA fixes (Sadly - like most OEM's). GM lives by the motto - "If no one complains, it works just fine"

Chances are, you'll have several software updates needing to be applied to your vehicle. Visit the dealer.

Edited August 25, 2020 by steve841

Pinnacle · August 25, 2020

16 hours ago, Transient said:

First, the water is condensation from the AC. Even Toyotas do it. Everything is fine.

Second, that's not a poor undercoat. It's a wax undercoat. GM offers to use wax on the frame to resist rust because they believe it is better than what everybody uses, and it's self-healing. Give it a little bit of time and that spot where you rubbed your finger on it should smooth out and recover the frame.

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LOL love the self healing part. Umm no it doesnt thats where the rust starts. Nothings better then a fully primed sealed and painted frame like RAM and Ford and Toyota use.

Pinnacle · August 25, 2020

19 hours ago, Jbrockltd said:

Hi everyone!

just hopped into my first GMC Sierra 2020. Traded in my 2017 Tacoma which went 80,000km without an issue. 2-days in now and I’ve got an engine light, and clear water leaking from underneath the truck. It’s leaking from the joint with the two tubes which I’ve attached a picture of. Any thoughts on what this is?? I’ll be calling the dealership but just want to see if this is common?

also... anyone else notice the poor undercoat? Used my thumb to rub the undercoat right off to steel...

Bad gasket if thats where its coming from. Just good ol GM... more problems to come.

carkhz316 · August 25, 2020

10 hours ago, steve841 said:

GM lives by the motto - "~~If no one complains, it works just fine~~" "it's not a bug, it's a feature." lol

34 minutes ago, Pinnacle said:

LOL love the self healing part. Umm no it doesnt thats where the rust starts. Nothings better then a fully primed sealed and painted frame like RAM and Ford and Toyota use.

Can't help but agree to some extent. All of those with painted frames seem to stay cleaner, for longer than the GM twins; at least around here in MN.

Jbrockltd · August 25, 2020

8 minutes ago, carkhz316 said:

Can't help but agree to some extent. All of those with painted frames seem to stay cleaner, for longer than the GM twins; at least around here in MN.

So essentially the frame undercoat isn’t something the dealership will remedy... and I’m assuming best for me to undercoat it myself? Haha

Pinnacle · August 25, 2020

35 minutes ago, Jbrockltd said:

So essentially the frame undercoat isn’t something the dealership will remedy... and I’m assuming best for me to undercoat it myself? Haha

yes, It took me about 40 hours to clean my frame and then prime paint it myself.

Jbrockltd · August 25, 2020

3 minutes ago, Pinnacle said:

yes, It took me about 40 hours to clean my frame and then prime paint it myself.

Well that’s exciting! Too many pros & cons with full size trucks it’s ridiculous. At $60k plus you’d think they would make em a bit better... hopefully I don’t regret not getting a Ford They seemed to have there fair share of problems as well...

Pinnacle · August 25, 2020

14 minutes ago, Jbrockltd said:

Well that’s exciting! Too many pros & cons with full size trucks it’s ridiculous. At $60k plus you’d think they would make em a bit better... hopefully I don’t regret not getting a Ford They seemed to have there fair share of problems as well...

Or you coulda stayed with Toyota, i just picked up a new Tundra

Colossus · August 25, 2020

Well you are better off than in a Ford, that's for sure. But what kept you from going to a Tundra? Just curious.

Transient · August 26, 2020

LOL love the self healing part. Umm no it doesnt thats where the rust starts. Nothings better then a fully primed sealed and painted frame like RAM and Ford and Toyota use.

1) Yet, the fully primed, sealed, and painted frames are rusting.

2) I did point out that's what GM is saying. Those aren't my words. The product GM uses is called Nox-Rust. GM also has a TSB on treating rusty frames.

https://www.google.com/url?sa=t&source=web&rct=j&url=https://static.nhtsa.gov/odi/tsbs/2019/MC-10154649-9999.pdf&ved=2ahUKEwiPtpiN77frAhVIQq0KHUI0BcoQFjALegQIAhAB&usg=AOvVaw0r4K_YpNNsZLqu9ln1KW8L

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Pinnacle · August 26, 2020

6 minutes ago, Transient said:

1) Yet, the fully primed, sealed, and painted frames are rusting.

2) I did point out that's what GM is saying. Those aren't my words. The product GM uses is called Nox-Rust. GM also has a TSB on treating rusty frames.

https://www.google.com/url?sa=t&source=web&rct=j&url=https://static.nhtsa.gov/odi/tsbs/2019/MC-10154649-9999.pdf&ved=2ahUKEwiPtpiN77frAhVIQq0KHUI0BcoQFjALegQIAhAB&usg=AOvVaw0r4K_YpNNsZLqu9ln1KW8L

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On a much slower pace. And it doesn't matter what gm calls it it doesn't heal itself I worked for gm and never seen it

Transient · August 26, 2020

On a much slower pace. And it doesn't matter what gm calls it it doesn't heal itself I worked for gm and never seen it

Again, not my claim. It's GM's. However, I'm not seeing anybody provide supporting evidence, such as numbers. It's only anecdotal claims. Here's a counterclaim, but unfortunately no numbers are provided either.

https://chevroletforum.com/articles/is-wax-frame-coating-the-secret-to-success-for-chevy-trucks/

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Jbrockltd · August 26, 2020

3 hours ago, Colossus said:

Well you are better off than in a Ford, that's for sure. But what kept you from going to a Tundra? Just curious.

I wasn’t able to test drive a tundra this year but just felt like there should be more motor options. Fuel economy was better on the GMC, and overall just get like more of a truck. Looks a lot better in my opinion too. Which was hard to accept since I love Toyota... just felt like there wasn’t any great options leaving the Tacoma. See the Sierra everywhere, use gmc vans for plumbing and they typically last 300,000+.