[tortilla-flats]

I'm seeing a rumor about a potential recall on the L87 6.2L used in the GM Truck/SUV class, due to bearing failure. Does *not* include the LT1.

What is different in the long block between the L87 & LT1, such that this wouldn't potentially impact the LT1?

Also, anyone heard of bearing failures in the LT1?

[KingLT1]

The LT1,L83,L86 all seem to have a better track record than the revised L84 and L87 from 2019+. I don't know why exactly but the revised engines are having a lot more problems. If you want my honest opinion, I think it's from running shit 87 octane fuel and the engine knocking all the time. Even though they say you can run 87 octane it's absolute piss water for these high DCR engines. I recently seen GPI post that they have had stock trucks come in for mods and the ground straps are missing from the plugs on some cylinders.

Pro tip- If you want to run a cheaper fuel, look for the blue handle E15 88 octane. You wouldn't believe how much more knock resistant that blend is over E10 87. Any NA engine I have tried it in (Specifically the LGX 3.6 and the 5.3 in my Yukon) will knock on 87 but run full commanded timing with no knock on E15.

[Kelly@PCMofNC]

Originally Posted by tortilla-flats

I'm seeing a rumor about a potential recall on the L87 6.2L used in the GM Truck/SUV class, due to bearing failure. Does *not* include the LT1.

What is different in the long block between the L87 & LT1, such that this wouldn't potentially impact the LT1?

Also, anyone heard of bearing failures in the LT1?

Well, for one thing GM isn't going to recall anything extra that it doesn't have to, haha. So if it's mostly the L87s having issues they aren't looking to make it worse for themselves.

I saw the article also but thought it seemed a bit like a nothingburger. NHTSA says 39 engines have been reported to have issues, out of 877,710 vehicles....That is 0.00004 percent? Seems crazy to me that they would be able to make GM do anything about that. Those are not bad odds especially considering how many people do not maintain their vehicles properly.

To answer your question though here is a good article on the differences in the LT motors.

https://inthegaragemedia.com/the-ult...-engine-guide/

"The L86 and L87 are also very similar to the LT1 engine in the Camaro and C7 Corvette—they even share the same camshaft part number—but with a specific intake manifold and other variances to enhance lower-rpm torque production. Another win for the L86/L87 is a super-tough forged steel crankshaft."

Have not personally seen any bearing failures with LT1, the weak point is usually the pistons.

[N Camarolina]

I had a rod bearing failure with my LT1 at 5000 miles, but I track it. Other reported failures with LT1s that were tracked, so difficult to conclude it's an engine problem per-se. Tracking puts quite a bit more strain than everyday use.

[cdb95z28]

IMHO, this may come down to poor fuel quality (low detergent, non Top Tier) and extended oil changes. Possibly non Dexos spec oil use.

DI engines are harder on the oil. Owners rely on the oil life monitor that pushes the oil too long, compounded by increased fuel dilution. That fuel dilution becomes a problem because the fuel injectors start to lose optimum atomization. The larger fuel droplets of the poor atomization have a greater tendency to wash the cylinder walls and find its way into the oil. At some point the oil loses the necessary qualities.

Best thing any of us can do is use Top Tier fuels https://www.toptiergas.com/ or if that is not available, use a good PEA fuel system detergent fuel additive. Chevron Techron, Driven Injector Defender, Gumout Complete or Redline SI1.

Yes, there have been LT1 bearing failures. Some have been catastrophic failures. I do not follow the drag racing scene, but as far as the road racing use, there has been LT1 failures with large holes in the side of the block. That points to possible bearing failures during heavy loading. Lifter failures can be caused by deteriorated oil too. There's alot more truck and SUV engines out there. Greater chance we will hear about issues with them before our niche LT1s or LT4s.

[m6-lt1]

The difference between the newer GM engines and the older ones is dynamic fuel management. They can now turn off any combination of cylinders versus just one bank.

There has been more LT1 failures lately as well but I can’t say why they are failing for sure or what failed in them. The LT1 in the automatics still only use the old active fuel management system, not the new dynamic fuel management system. Keep in mind when I say more LT1’s have been failing I’m referring to tracked cars. My theory is that the SS 1LE was not available in A10 format until 2021 so that is why the newer ones seem to be failing more often than the older ones. I found out recently that the oil temps are higher in tracked A10 SS 1LE’s versus Manual SS 1LE’s. Roughly 25 degrees hotter.

The poster saying there hasn’t been many reported failures needs to look further than just the NHTSA report. They are failing left and right. I think what the posters above posted about why could be on to something.

[KingLT1]

I just recently learned that engines with Dynamic Fuel Management (2019+ L84/87) have 16 AFM lifters instead of 8. This is another reason why the L84 and L87 are having higher failure rates vs the L83/86. DFM can deactivate any combination of cylinders it wants at any given time vs AFM just deactivates the same 2 cylinders on each bank.