6.2 L87 (not LT1) discussion

[olrocker]

I didn’t know where to put this thread since while it’s a motor similar to 6th gen Camaros it’s not the exact same. So if mods think it needs to be moved go right ahead.

I’m really trying to follow the situation with the L87 6.2. I want to buy a new Tahoe with it but I am NOT touching them until GM has certifiably fixed the failure issues for CERTAIN with a documented engineering repair/redesign.

NOT a simple change in recommended oil viscosity. They’re still failing.

So can those of you with much more knowledge about the situation please post everything you know and where things are in the lawsuit?

Thanks.

[SS71SS24]

I think I speak for a lot Gen 6 Camaro owners of 22-24 MY who are a bit nervous about their LT-1 because of the health and durability of it's very close relative, the L-87.
I'm interested in a Tahoe as well. There's a dealership in Pa. that has a very large inventory of police duty 2026 Tahoes. Public cannot purchase. They're all 5.3L. Not sure if the 6.2 L available for police duty but if that's no longer the case, limiting those vehicles to the 5.3L is very telling, IMO.

[olrocker]

Originally Posted by SS71SS24

I think I speak for a lot Gen 6 Camaro owners of 22-24 MY who are a bit nervous about their LT-1 because of the health and durability of it's very close relative, the L-87.
I'm interested in a Tahoe as well. There's a dealership in Pa. that has a very large inventory of police duty 2026 Tahoes. Public cannot purchase. They're all 5.3L. Not sure if the 6.2 L available for police duty but if that's no longer the case, limiting those vehicles to the 5.3L is very telling, IMO.

Well I have about 14,000 miles on my Camaro and more than a few times I’ve let it rip to redline in first and second (hitting redline in 3rd is a felony in this thing if you’re not on a track)

And not a hiccup.

As I understand it these L87s are grenading almost the day people drive them off the lot, many with under 10k miles, and I don’t think anyone driving a Tahoe is trying to “have fun” so these engines aren’t even seeing close to redline.

[Capricio]

I'm sure you already know.

All of the relevant parts that are failing in significant numbers (rotating assembly etc) on the L87 are the same on the LT1.

FWIW, AI seems to think the LT1 may have different application specific rod/crank bearings for higher revving applications.

Yes, while the LT1 and L87 share similar Gen V architecture, connecting rods, and crankshafts, they do not necessarily use the exact same rod/crank bearings in production, and they are generally treated as different applications regarding bearing specifications due to different intended uses (high-RPM performance vs. truck towing/start-stop).

Key details regarding bearing differences:

Interchangeability:
Aftermarket bearing manufacturers often list the same part numbers (e.g., King CR8057MC) as compatible across 6.2L Gen V engines, including LT1, L86, and L87. However, this indicates they can fit, not that the factory parts are identical.

Manufacturing Differences:
The L87 (truck) has faced widespread reported bearing issues and failures, often linked to manufacturing defects and sediment buildup, which are not common in the LT1.

Operating Differences:
The LT1 is designed for high-RPM use and typically uses 40w oil, while the L87 is designed for low-end torque and efficiency (start/stop) and often calls for 20w oil, implying different bearing clearances and potentially different bearing materials or coatings to suit those needs.

Technical Bulletin:
A GM Technical Service Bulletin notes that various 6.2L engines, including both L87 and LT1, are susceptible to crankshaft thrust bearing issues (knocking/hard rotation).

Back on your topic, I'd wait it out for GEN VI V8 models at this point. Prob a whole different problem set of unknowns, but still better than a known lemon.

[snizzle]

Originally Posted by Capricio

Back on your topic, I'd wait it out for GEN VI V8 models at this point. Prob a whole different problem set of unknowns, but still better than a known lemon.

Did GM learn anything? Probably not if they're still chasing decreasing emissions and improving fuel economy. GM has stated the new V8s will do both.

[gtstorey]

Don't know how honest GM has been about the problems, but they claim it was a manufacturing problem and not a design problem. If true, they should have it straightened out.

https://gmauthority.com/blog/2025/04...oogle_vignette

[olrocker]

Originally Posted by snizzle

Did GM learn anything? Probably not if they're still chasing decreasing emissions and improving fuel economy. GM has stated the new V8s will do both.

No one who wants a V8 engine gives a damn about fuel economy. Especially the minuscule increase you get from the complicated and added expense and decrease in reliability of the VCM system.

Now that the CAFE regulations are relaxed GM should be focusing on making durable V8s with proven reliability with less technology and more mechanical stoutness.

Especially in truck/SUV applications.

[snizzle]

Originally Posted by olrocker

No one who wants a V8 engine gives a damn about fuel economy. Especially the minuscule increase you get from the complicated and added expense and decrease in reliability of the VCM system.

Now that the CAFE regulations are relaxed GM should be focusing on making durable V8s with proven reliability with less technology and more mechanical stoutness.

Especially in truck/SUV applications.

I agree, however, they know the admin will shift again. Anything done via EO will be reversed, rinse/repeat.

[Capricio]

Originally Posted by snizzle

Did GM learn anything? Probably not if they're still chasing decreasing emissions and improving fuel economy. GM has stated the new V8s will do both.

From things I have learned in the news and watching youtube videos... I gather that some OEMs just prescribed a lower viscosity oil on older platforms to meet fleet efficiency reqs, while other OEM's engines were designed around lower viscosities and actually changed clearances and used improved metallurgy on vulnerable parts, with lower viscosity oil factored into the design.

One would HOPE that GM is doing the latter with GEN VI, if thin oil on GEN V really was an afterthought. You'll know the truth by checking what they prescribe for overseas use on the same engine, where emissions/mileage regulations are more relaxed or don't exist.

[Realist]

I have had many V8 autos and trucks over the years and I must say I actually do look at and care about gas mileage. Maybe because I drive more miles than most but it does add up over time price wise. My 2500HD with the 6.0 is 10mpg, my Avalanche was 15mpg, my Escalade was 13mpg, 11 after MODs. My Daily is now a Canyon AT4 with turbo 4 averaging 18mpg on 87. And I’m not even listing all my past Camaros. Bottomline is gas can get expense and if you are racking up miles it does cost quite a bit. The 10speed trans have helped increase MPG for sure.

[Capricio]

Originally Posted by Realist

My 2500HD with the 6.0 is 10mpg,

my 2017 with L98/6L90 tends to get around 14mpg. Is yours an older LQ4/4L80?

Further off topic: Reading about the currently available 3/4 gassers... I'd take the Ford 6.8 mini-zilla, easily, for reliability, capability, efficiency (kind of) and simplicity.

[olrocker]

Originally Posted by gtstorey

Don't know how honest GM has been about the problems, but they claim it was a manufacturing problem and not a design problem. If true, they should have it straightened out.

https://gmauthority.com/blog/2025/04...oogle_vignette

If it’s a manufacturing problem they should have the exact VIN numbers it affected, the repair or replacement with the upgraded crank, and verification all new production vehicles have the new crank from the factory.

[Capricio]

Originally Posted by olrocker

If it’s a manufacturing problem they should have the exact VIN numbers it affected, the repair or replacement with the upgraded crank, and verification all new production vehicles have the new crank from the factory.

You mean, like Toyota did on their trucks?

Nope, not the General, you get an extended warranty up to 150,000 miles and they call it a day. If you don't make it that far, they won't have a replacement for you, anyways.

Yes, General Motors has identified a specific manufacturing window and established diagnostic procedures for the 6.2L V8 L87 engine defects. However, regulatory bodies are currently investigating if the original identification and remedies were sufficient.

Affected VIN Identification
The manufacturing problem is linked to a specific production window rather than a single contiguous block of VINs, making it essential to verify individual vehicles.

Production Dates: The suspect components were manufactured between March 1, 2021, and May 31, 2024.

Affected Models: 2021–2024 Cadillac Escalade/ESV, Chevrolet Silverado 1500, Suburban, Tahoe, and GMC Sierra 1500, Yukon/XL.

Verification: Owners must use the GM Recall Center or NHTSA VIN Lookup to confirm if their specific VIN is included in Recall 25V-274.

Repair or Replacement Procedures
GM does not replace every crankshaft; instead, it uses a two-tiered remedy based on a dealer inspection.

Diagnostics: Technicians use specialized tools, such as the GM PicoScope (digital oscilloscope), to detect out-of-spec dimensions or vibration signatures.

Full Replacement: If the engine fails the inspection or shows signs of failure (e.g., ticking or metal debris), the entire engine is replaced with a unit manufactured after the June 2024 cut-off.

Partial Remedy: If the engine passes inspection, the "fix" involves a mandatory switch from 0W-20 to a higher-viscosity 0W-40 oil, a new oil filter, and a new oil cap.

Note: As of early 2026, the NHTSA has opened a query (RQ26001) because some engines that received only the oil change later suffered catastrophic failure.

Verification of New Production (2025–2026)
GM has officially stated that all engines produced after June 1, 2024, include the upgraded components.

Factory Improvements: GM implemented manufacturing improvements before the start of the 2025 model year to address "contamination and quality issues" in crankshafts and connecting rods.

2025 Model Year: Vehicles from the 2025 model year are not included in the original recall because they were built after these quality controls were implemented.

2026 Redesign: For the 2026 model year, GM has further updated the 6.2L L87 engine, including revisions to eliminate Dynamic Fuel Management (DFM) to address separate long-term reliability concerns.

[FarmerFran]

My 2020 2SS blew up. The thread is on here somewhere. Very low miles. Broke my heart