GM recalls 721K trucks with 6.2L engine

[part-time-Farmer-NC]

BIL just bought a 2024 a few months ago. I believe it has the same motor.

With diesels, its not only the upfront costs of the motor upgrade, but every time at the pump. Around here its about 50-60 cts a gallon more expensive and more frequent oil changes. Most people never realize the savings as they trade out the vehicles after 4-6 yrs.

I do love a diesel though, especially the looks of a dually. Just can't justify the extra costs.

 

[deezler]

It's a 'new' engine yes but an improved version?
If they currently have thousands of improved engines around as available warranty replacements, for how long have they known there's been a problem and had time to manufacture them? I'll go with the theory that it's the old engine design which will outlast the warranty which is GM's main concern.

No, there is not a new design, it is the exact same component design, just now with better surface finish on the crankshaft, and no debris left in the oiling passages. IE, basic quality control.

GM does not produce and keep an inventory of thousands of old spare engines just in case. You may have heard that in early failures of these '21-'24 6.2L engines, there were simply not any new spare engines available to swap in.

If you get an engine swap now, it is not some old leftover engine that will have the exact same issues (I mean, it always still could, but any replacements is now a NEW/'25 version).

 

[WM75Guy]

BIL just bought a 2024 a few months ago. I believe it has the same motor.

With diesels, its not only the upfront costs of the motor upgrade, but every time at the pump. Around here its about 50-60 cts a gallon more expensive and more frequent oil changes. Most people never realize the savings as they trade out the vehicles after 4-6 yrs.

I do love a diesel though, especially the looks of a dually. Just can't justify the extra costs.

Diesels are nice and actually cheaper up front in the GMC Yukon and Chevrolet Tahoe, plus the higher MPG makes up for the difference in fuel cost. The 3.0L Duramax diesel is $1500 less than the 6.2L gas motor in the Yukons and Tahoes. My Yukon Denali with the Duramax 3.0L is getting a combined 25mpg and consistently gets over 30mpg on the highway. My wife's new 2025 Tahoe High Country with the 6.2L is rated for 14mpg city and 18 highway, too early to see real numbers. In East Texas diesel is $0.28 higher than gas, $2.74 vs $2.46. My 3500HD Denali dually with the 6.6L Duramax does get around 12 mpg combined but it only hits the road pulling a trailer or hauling supplies in the bed too large to fit in the Yukon.

 

[zzvyb6]

If you knew the REAL reason for this problem, you would not be shocked, but angry. Think Boeing doors and early ghosted parts. I worked for the company and watched it all start falling apart. J.D. learned a lesson in this, too, a while back. Funny as it gets. Think fake engineering drawings designed to throw off the Asian copy-cat clones.
If your product requires critical parts, make them yourself under a skilled watchful eye, not a Venn diagram staff..

 

[Snobdds]

This engine design has to be 20 years old now. Why are engine flushes not part of the fix if it is debris?

The only thing a higher viscosity oil does is provide greater shear resistance between bearing surfaces. It seems to me there are structural issues that thicker oil is trying to fix.

This should never happen in an engine design as old as this one is...

 

[Renze]

So part of what GM is saying - engines that exhibit low oil pressure and are near end of factory warranty, We will dump the super thin 0W-20? and put in oil rated as 40 weight when the engine is hot, hopefully making it past the warranty date before the oil pressure on the scored main and rod bearings isn't enough to keep what's left of the bearings alive? ( Not against thicker oil in general) To many manufacturers are using oil so thin to beat EPA mileage ratings they are under protecting bearings with oil that pours like water.

I have a 2007 Volvo V70 with the D5 diesel. Its basic design dates back to the 1991 gas motors in the 850, it just took them a decade to create the diesel version...
After i bought it, i found out i bought the right model year: MY 2006 they started prescribing a 0w/30 low friction - fuel saving engine oil. In 2007 they started to use improved cam and tappet hardening.

Anyways, using a liter of oil every 1500km at 20 euro a liter, isnt exactly "saving" anything...
With 5w/40 low wear oil i could hear the valve train is quieter on a winter cold start, because it leaves a sticky film on all metal surfaces even when the oil itself leaks back to the oil pan..

Anyways, my cam is the later hardened one so i dont fear wear, at 472.000km (300.000 miles)

My previous S70 with the VW 2.5 TDI did 560.000km (350.000 miles) before i had to let go because a crankshaft sensor was no longer available...

 

[deezler]

This engine design has to be 20 years old now. Why are engine flushes not part of the fix if it is debris?

The only thing a higher viscosity oil does is provide greater shear resistance between bearing surfaces. It seems to me there are structural issues that thicker oil is trying to fix.

This should never happen in an engine design as old as this one is...

All the components are supposed to hit the engine assembly line nice and clean already. Adding an active flushing/cleaning station to the assembly line is probably too expensive and logistically difficult, when it shouldn't ever be necessary in the first place.

Flushing the engine later on, after it has ran for thousand of miles or the customer notices an issue, would do nothing. The damage to the main and rod bearings is already started. At that point, the thicker oil helps prevent further damage to the bearings. Once the rod or main bearings reach a critical level of damage, they can quickly seize up and stall/lock the motor.

Yes the basic engine design is old as dirt. There is nothing structurally incorrect about the crankshaft/connecting-rods/main and rod bearing design in this motor. But any engine that sends and substantial debris down into the main and rod bearings is going to struggle to live for long.

 

[Renze]

With diesels, its not only the upfront costs of the motor upgrade, but every time at the pump. Around here its about 50-60 cts a gallon more expensive and more frequent oil changes. Most people never realize the savings as they trade out the vehicles after 4-6 yrs.

Whats your cost per mile ? Upfront cost, or price per gallon, is irrelevant. I use about 2/3 the fuel of the same vehicle with a gas motor.

 

[Snobdds]

All the components are supposed to hit the engine assembly line nice and clean already. Adding an active flushing/cleaning station to the assembly line is probably too expensive and logistically difficult, when it shouldn't ever be necessary in the first place.

Flushing the engine later on, after it has ran for thousand of miles or the customer notices an issue, would do nothing. The damage to the main and rod bearings is already started. At that point, the thicker oil helps prevent further damage to the bearings. Once the rod or main bearings reach a critical level of damage, they can quickly seize up and stall/lock the motor.

Yes the basic engine design is old as dirt. There is nothing structurally incorrect about the crankshaft/connecting-rods/main and rod bearing design in this motor. But any engine that sends and substantial debris down into the main and rod bearings is going to struggle to live for long.

Hoping you would say that...it's just too much work and money for GM.

So we have Toyota with basically the same problem in their 3.5 TT motors. Their solution is to replace the entire motor, everything.

GM is just putting in thicker oil.

GM deserves to go out of business if their solution is this pathetic.

 

[Renze]

My SIL just purchased a 2025 GMC AT4 with the 6.2 V8(I told him about the problems) because his 2020 5.3 failed!
Supposed to be fixed with the 2025,I hope so.
I used to trade every two years,not any more.

I buy vehicles 10 years old when the well used ones of that build have proven reliable.

Buying new vehicles doesnt automatically mean you get less problems