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?