# New desoxD oil certification



## Barry Allen (Apr 18, 2018)

When researching dexos 2 oils on the official website, I noticed new dexosD oil certification: https://www.gmdexos.com/brands/dexosd/index.html

It's currently only two oils and it appears to be a new 0w-20 oil for the inline-6 diesel engine in the Chevy Silverado pickup.

What are the odds that GM retroactively recommends dexosD oil for their prior diesel engines?


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## Eddy Cruze (Jan 10, 2014)

I'm not sure if that's an Official Site for GM?


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## Barry Allen (Apr 18, 2018)

Eddy Cruze said:


> I'm not sure if that's an Official Site for GM?


It is. It's a site that lists all the brands of oil licensed to be dexos approved for gasoline engines (dexos 1) or diesel engines (dexos 2), and now apparently dexosD for the new 2019 Silverado 1500 diesel engine.


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## Ma v e n (Oct 8, 2018)

Pretty unlikely though anything can happen.

The 3.0 was delayed a couple months(no 2019s)and I believe its been for fuel economy reasons. I had heard that they were trying to certify the **** thing with 0w16! Its going to be GMs first post DPF fed EGR system, and I think besides trying to acheived fuel economy numbers, that has been a challenge. This engine has so much crap packaged in and on it it's ridiculous.

GM hasn't even released the full service manual for it yet even though they are sending special tools. This engine is gonna end up being a clusterfcuk. It appears to be a nightmare to work on based on the info I have. 

Oh....BTW....It's got internal drive chains and belts....Soak that it in. LOL


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## TDCruze (Sep 26, 2014)

Ma v e n said:


> Pretty unlikely though anything can happen.
> 
> The 3.0 was delayed a couple months(no 2019s)and I believe its been for fuel economy reasons. I had heard that they were trying to certify the **** thing with 0w16! Its going to be GMs first post DPF fed EGR system, and I think besides trying to acheived fuel economy numbers, that has been a challenge. This engine has so much crap packaged in and on it it's ridiculous.
> 
> ...


The post DPF EGR intake is interesting and aside from more complex piping/packaging it seems like a good plan, in theory anyway. 

I would not run 0w20 let alone 0w16 in anything I wanted to keep. Especially with a turbo!

As for the complex valve train... With belts and chains!? 
We need more info on how its configured to say how stupid or smart this is?


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## Ma v e n (Oct 8, 2018)

Yep, post-DPF EGR is a good idea in theory. Less crap back through intake and into cylinder again, lower intake/cylinder temps. Implementation is harder though because of the pressure differentials between the intake and the exhaust post-filter, as well as the transport of the exhaust this farther distance. On the 3.0Duramax the distance is reduced by how tightly packaged the entire exhaust after treatment suite is. It's virtually all underhood, and attached to the engine. Great for reducing the distance you need to route hot exhaust gas, a nightmare for on engine and underhood packaging. This engine takes up a lot of space.

I'm right with you on 0w20/0w16, 12, 8, etc....But that's where we are headed. As long as they don't adjust the engines to the point where thicker oils are detrimental to their longevity or functionality, I'll continue to avoid these supe low viscocity oils in my personal vehicles.


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## Taxman (Aug 10, 2017)

Ma v e n said:


> Yep, post-DPF EGR is a good idea in theory.


How about post-catalyst EGR for gassers?
Especially DI engines that have no way of cleaning the EGR crap off the intake valves.


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## Ma v e n (Oct 8, 2018)

Taxman said:


> Ma v e n said:
> 
> 
> > Yep, post-DPF EGR is a good idea in theory.
> ...


Don't jump the start...It's coming.(though EGR isn't widely used as a stand alone system on modern DOHC engines...They use VVT to accomplish it)

So are gasoline particulate filters. Don't worry soon diesel will have an edge again because gas will have all the same bullshit Emission equipment.


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## Barry Allen (Apr 18, 2018)

Ma v e n said:


> Its going to be GMs first post DPF fed EGR system


I could never figure out why diesel engine manufacturers didn't do that from the beginning. Take clean (relatively speaking) exhaust from after the DPF, cool it with engine coolant, and dump it into the air intake right before the compressor. The mixture of EGR and intake air can then go through the charge air cooler and be much cleaner going into the cylinders rather than the current method that gives air full of soot.

That is, unless combusting some of the soot is what it takes to keep the DPF from loading up with soot to where regen is too frequent.


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## Barry Allen (Apr 18, 2018)

Ma v e n said:


> Oh....BTW....It's got internal drive chains and belts....Soak that it in. LOL


Ford did that with their 3-cylinder Ecoboost. They discovered they could bathe a timing belt in engine oil with no ill effect, and it's basically a lifetime belt.

GM also did this to us with the Cruze diesel engine. The timing chain is on the back of the engine to dampen noise inside the transmission bellhousing. I shudder to think of the cost to change a timing chain if it starts to rattle or otherwise be defective. That will be an engine/transmission removal, split them apart, etc. Might as well throw a clutch, water pump, alternator, etc. in there and other maintenance items if you're going to invest in that much labor to take them apart.


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## Ma v e n (Oct 8, 2018)

Barry Allen said:


> Ma v e n said:
> 
> 
> > Oh....BTW....It's got internal drive chains and belts....Soak that it in. LOL
> ...


Yeah, the LH7 is a jewel with the back side timing and oil pump chains...But this mix of chain and belt is unique beyond that I feel.

There's gonna end up being Cruze(Equinox and Terrain) diesels that end up going to the crusher because they need timing chains. Timing chain is a 17+hr job under warranty. I'd guess out of warranty you're looking at 21-25hrs of labor. Add in the timing kit, the special tools, and all the fasteners, sealant, and seals that will be needed, not to mention the clutches that would likely get upsold as you mentioned, and timing issues are gonna condemn these cars. I've only seen one with an issue so far. It's a shitty job.


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## rcruze (Mar 22, 2018)

Well, I hope that the timing chain will last up to 300K miles.... I am not looking forward to doing that work LOL


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