6.2L or Duramax reliability

[DuraYuk]

I think there's a bit of minimization going on here. I don't think you can characterize a turbo charged diesel powertrain as, "Oh, we just substituted (but did NOT add) some components around from this naturally aspirated gas powertrain for this turbocharged diesel powertrain." I don't think the majority of the people following this thread would agree with that either.

GM simply f'd up the design and execution of the 6.2L V8 gas engine. There's no way that should be less reliable than the current 3.5 EcoBoost but alas, it is. Heck, it's arguably less reliable than the current Ford's DOHC 5.0 Coyote engine. Don't get me wrong, Ford has had their fair share of problems on their 3.5EB and 5.0 Coyote through the years, but those are largely reliable powertrains at the moment. Because the 6.2L V8 is primarily a GM f up, that doesn't mean that turbocharged diesel powertrains are just as simple as naturally aspirated gas engines (or even turbocharged gas engines).

Tell me what magic makes the lm2 anymore complicated then a dohc gas engine ? Diesels have higher compression. Different ignition source. And as you guys like to state, a 'complicated' emmissions system. Not much more to it.

GM didn't mess up the 6.2 suppliers did. The design is reliable and tried and true but the supplied parts have issues. Namely bearings and lifters.

As for whether the majority of people agreeing or not does not constitute the facts as being different. This is engineering not opinions.

 

[Polo08816]

Tell me what magic makes the lm2 anymore complicated then a dohc gas engine ? Diesels have higher compression. Different ignition source. And as you guys like to state, a 'complicated' emmissions system. Not much more to it.

GM didn't mess up the 6.2 suppliers did. The design is reliable and tried and true but the supplied parts have issues. Namely bearings and lifters.

As for whether the majority of people agreeing or not does not constitute the facts as being different. This is engineering not opinions.

I guess the reason HD diesel powertrains are so much heavier than their NA gas powertrains is because each manufacturer decides to add a couple hundred pounds of ballast inside the engine bay just for ***** and giggles since there's really "not much more to [a turbocharged diesel powertrain]".

If the suppliers messed up the bearings and lifters on the 6.2L, then it should have been a quick and clean changeover. Why do we keep hearing about 6.2L V8s failing in recent 2023 production run vehicles? Or does it have more to do with the switch from AFM to DFM?

 

[DuraYuk]

I guess the reason HD diesel powertrains are so much heavier than their NA gas powertrains is because each manufacturer decides to add a couple hundred pounds of ballast inside the engine bay just for ***** and giggles since there's really "not much more to [a turbocharged diesel powertrain]".

If the suppliers messed up the bearings and lifters on the 6.2L, then it should have been a quick and clean changeover. Why do we keep hearing about 6.2L V8s failing in recent 2023 production run vehicles? Or does it have more to do with the switch from AFM to DFM?

Could it be the extra plumbing for the turbo? Or perhaps the thicker/denser material composition of the block ? Or the heavier denser components for the engine due to higher compression ratios? The 6.6 gas engine is 100lbs lighter than the 6.6 duramax. So what's the couple hundred pounds you speak of? What ballast material ? Wth are you even talking about lol..
https://chevytrucks.org/gm-6-6l-l8t-engine-guide/ 720lbs for gas
https://chevytrucks.org/duramax-6-6l-turbo-diesel/ 835lbs for diesel
Wonder why they are even the same displacement if it's such a different design ? Lol could it be that they are similar yet different? Not any more or less complicated?

Im not gonna beat the dead horse of afm vs dfm. GM has had lifter failures since the dawn of the pushrod. It is nothing knew. Every generation that comes out gets the hammer and people seem to forget that it's a problem that has always reared its head for the unfortunate ones. Most if not all fail under warranty and are fixed accordingly. Go look at this forum. Every generation has lifter failures with about the same failure rate.

It's supplier issues as are most gm problems. The reason it doesn't affect all of them is because there is a tolerance range and some slip fail and most don't. Story as old as time.

 

[Polo08816]

Could it be the extra plumbing for the turbo? Or perhaps the thicker/denser material composition of the block ? Or the heavier denser components for the engine due to higher compression ratios? The 6.6 gas engine is 100lbs lighter than the 6.6 duramax. So what's the couple hundred pounds you speak of? What ballast material ? Wth are you even talking about lol..
https://chevytrucks.org/gm-6-6l-l8t-engine-guide/ 720lbs for gas
https://chevytrucks.org/duramax-6-6l-turbo-diesel/ 835lbs for diesel
Wonder why they are even the same displacement if it's such a different design ? Lol could it be that they are similar yet different? Not any more or less complicated?

Im not gonna beat the dead horse of afm vs dfm. GM has had lifter failures since the dawn of the pushrod. It is nothing knew. Every generation that comes out gets the hammer and people seem to forget that it's a problem that has always reared its head for the unfortunate ones. Most if not all fail under warranty and are fixed accordingly. Go look at this forum. Every generation has lifter failures with about the same failure rate.

It's supplier issues as are most gm problems. The reason it doesn't affect all of them is because there is a tolerance range and some slip fail and most don't. Story as old as time.

So are you saying that if we have two same make, model, trim, drivetrain, cab configuration, and bed length trucks with the only difference being the 6.6 gas versus a 6.6 Duramax, the front axle weight difference on a certified scale will only be 100lbs? Let's not kid ourselves here. You claim to be an engineer or mechanic or whatever you want to call yourself, but have you ever peered into an engine bay of a 6.6 gas versus a 6.6 Duramax? And when you did, did you think to yourself, "Oh, I see no difference... this diesel truck probably only weights 100lbs more lol."

"It's supplier issues as are most GM problems." Well you know what, at the end of the day, it's still a GM problem. If the supplier sucks, get a new supplier... or don't I guess... They're ultimately going to bring the vehicle into a dealer under warranty and say, "Fix it, GM" not "Fix it, supplier." The only people that I've seen so persistent in making that distinction are basically fanbois.

 

[DuraYuk]

So are you saying that if we have two same make, model, trim, drivetrain, cab configuration, and bed length trucks with the only difference being the 6.6 gas versus a 6.6 Duramax, the front axle weight difference on a certified scale will only be 100lbs? Let's not kid ourselves here. You claim to be an engineer or mechanic or whatever you want to call yourself, but have you ever peered into an engine bay of a 6.6 gas versus a 6.6 Duramax? And when you did, did you think to yourself, "Oh, I see no difference... this diesel truck probably only weights 100lbs more lol."

"It's supplier issues as are most GM problems." Well you know what, at the end of the day, it's still a GM problem. If the supplier sucks, get a new supplier... or don't I guess... They're ultimately going to bring the vehicle into a dealer under warranty and say, "Fix it, GM" not "Fix it, supplier." The only people that I've seen so persistent in making that distinction are basically fanbois.

I posted the links. The engines are 100 pounds different. Im basing it on what we know not what something may look like. Engine vs engine, gas 720lbs vs diesel 835lbs.

Yeah no doubt gm is still responsible. It their warranty and name.

Just trying to be objective here.

 

[Vladimir2306]

It's a pretty simple system. And in the states defeating diesel emmissions can land you in hot water really quickly..

Are you saying this because you have the experience of owning a diesel engine with Def at high mileage, or did you just read it on the net ??))

 

[Vladimir2306]

I posted the links. The engines are 100 pounds different. Im basing it on what we know not what something may look like. Engine vs engine, gas 720lbs vs diesel 835lbs.

Yeah no doubt gm is still responsible. It their warranty and name.

Just trying to be objective here.

Add to this another exhaust system, a particulate filter, a Def system along with a tank. And the difference will be completely different

 

[DuraYuk]

Are you saying this because you have the experience of owning a diesel engine with Def at high mileage, or did you just read it on the net ??))

I say this as someone with hands on experience.

 

[DuraYuk]

Add to this another exhaust system, a particulate filter, a Def system along with a tank. And the difference will be completely different

You missed the point.

 

[Vladimir2306]

I say this as someone with hands on experience.

What is the longest miles you have driven in a single DEF vehicle?

 

[Baja_Bob]

So the 6.2L doesn't use the 10 speed transmission?

I hope the diesel is still available when I get my next Yukon, even though the 5.3L suits me just fine.

 

[WalleyeMikeIII]

So the 6.2L doesn't use the 10 speed transmission?

I hope the diesel is still available when I get my next Yukon, even though the 5.3L suits me just fine.

All 2021+ full size GM SUV’s use the 10L80 transmission…

 

[DuraYuk]

What is the longest miles you have driven in a single DEF vehicle?

300k sometimes more. Company would trade them in around that time. At that point tho we would always have a new transmission. So if your worries about something that would be something to worry about. It's not a conspiracy. Working for GM we didn't see that many failures either. But a whole industry has built itself on the notion that it's some overly complex system that needs to be torn out. Of course they charge you money for that and many have paid for the privilege in the way of huge fines from the EPA. Sure the system can have failures but it's simple and quick to get them back on the road.

I think the most inconvenient aspect is running out of def or system thinking it's out or low and reducing performance as a result. The rest is just over blown sensationalism.

 

[Vladimir2306]

300k sometimes more. Company would trade them in around that time. At that point tho we would always have a new transmission. So if your worries about something that would be something to worry about. It's not a conspiracy. Working for GM we didn't see that many failures either. But a whole industry has built itself on the notion that it's some overly complex system that needs to be torn out. Of course they charge you money for that and many have paid for the privilege in the way of huge fines from the EPA. Sure the system can have failures but it's simple and quick to get them back on the road.

I think the most inconvenient aspect is running out of def or system thinking it's out or low and reducing performance as a result. The rest is just over blown sensationalism.

What's the name of a car that has driven 300,000 miles in your possession with the Def system without breaking down

 

[TollKeeper]

I have about 80-90 units in my fleet that have that many miles, or more, with a DPF/DEF system. 1 has 1,056,573 miles on it now, and it still has the factory DPF system. Although the dozer has been replaced twice. These are semi trucks, so I dont know if that counts.

I made the comment in another thread, diesels are meant to be driven. Yes you can drive them short distances repeatedly, but it comes at a cost because the DPF cant get to temperature so that the SCR system can work properly. It will get clogged. It will need to be cleaned/replaced.

Theres a reason that in Europe, they done have these systems.. They dont work. They cause more damage. They are worse for the environment.

 

[Vladimir2306]

I have about 80-90 units in my fleet that have that many miles, or more, with a DPF/DEF system. 1 has 1,056,573 miles on it now, and it still has the factory DPF system. Although the dozer has been replaced twice. These are semi trucks, so I dont know if that counts.

I made the comment in another thread, diesels are meant to be driven. Yes you can drive them short distances repeatedly, but it comes at a cost because the DPF cant get to temperature so that the SCR system can work properly. It will get clogged. It will need to be cleaned/replaced.

Theres a reason that in Europe, they done have these systems.. They dont work. They cause more damage. They are worse for the environment.

Wait, I don't mean commercial equipment. I'm talking about cars .. The fact that the Def system works perfectly on trucks, I know, the problems began when this system reached passenger cars

 

[DuraYuk]

What's the name of a car that has driven 300,000 miles in your possession with the Def system without breaking down

LML and L5P some trucks some cab chassis configurations. Some had more then 300k

 

[DuraYuk]

Gotta move the goal posts lol

Wait, I don't mean commercial equipment. I'm talking about cars .. The fact that the Def system works perfectly on trucks, I know, the problems began when this system reached passenger cars

 

[TollKeeper]

Irregardless of the above... If you can drive more than 20 miles at almost each and everytime you turn the key, you will be fine.

If you cant.... Well, they do make other vehicles/engines.

This is the reason Ford and Mopar quit making their 1/2 ton diesel. People were not driving them to the point of SCR Efficiency.

 

[Vladimir2306]

Irregardless of the above... If you can drive more than 20 miles at almost each and everytime you turn the key, you will be fine.

If you cant.... Well, they do make other vehicles/engines.

This is the reason Ford and Mopar quit making their 1/2 ton diesel. People were not driving them to the point of SCR Efficiency.

Here is the answer. This system is great for commercial vehicles, but not for personal cars. Where the road is most often home-school-work-home. Or house-supermarket-house