Bearing issues for the 6.2

ScathaTheWorm · Friday at 01:50 PM

Good evening gentlemen.

I have noticed recently between MY22.5 and MY24..there have been some issues with 6.2 engines randomly seizing and locking up. This issue is fairly serious, so much so that there has been a CSP issued for the 6.2 ONLY. I am not sure how many trucks/SUVS in total are affected by this problem...because I saw it in Reddit, in other forums, Tik Tok (one MY24 Denali, and one recent case of a brand new MY24 Tahoe at ONLY 320 miles- date of build unknown ). Many thousands of unverified claims that dealer lots are FILLED with trucks being waiting to get fixed.. (the date ranges would be good to know, especially with regards to MY24s ). From what I understand, it occurs VERY early when the truck is under warranty. I have heard one case here in Qatar.

For starters, it would be great if:

1) The amount of 6.2s produced between MY22.5 and MY23 (and MY24 so far)

2) I have heard there has been a part change recently- not sure if the MY25 facelift Tahoe will be affected as it will start prod on Oct sometime

3) What is the percentage of 6.2s failing due to this?

So the bottom line, is whether this is likely to affect EVERY truck (granted, they sell a lot so a large number can be affected, but NOT SO large to cover the entire volume).

Would like to hear your thoughts on this.

PunchT37 · Monday at 01:05 PM

What causes the bearing issue? The 5.3`s don`t seem to have the problem. Forged vs cast crank? Crank finish too rough? Hmmm. The lifter bore sizing on some blocks causing even lower oil pressure with the 0w20 oil? Add 420 hp to the mix? A 5.3 block is just a small bore 6.2.

Gangly · Monday at 01:15 PM

From what I understand, improper cleaning of the machined block during the build process. Debris gets pumped through the engine and causes failure. I could be wrong, but I believe it's a situation very similar to the Toyota engine issues.

However, I am skeptical of that as well.

PunchT37 · Monday at 01:33 PM

17 minutes ago, Gangly said:

From what I understand, improper cleaning of the machined block during the build process. Debris gets pumped through the engine and causes failure. I could be wrong, but I believe it's a situation very similar to the Toyota engine issues.

However, I am skeptical of that as well.

Are 5.3`s and 6.2`s cast at the same foundry?

diyer2 · Monday at 01:58 PM

Lucky or not lucky of having bearing problems. IMO the best answer is better oil, more changes. I repeat.

newdude · Monday at 02:02 PM

2 hours ago, PunchT37 said:

What causes the bearing issue? The 5.3`s don`t seem to have the problem. Forged vs cast crank? Crank finish too rough? Hmmm. The lifter bore sizing on some blocks causing even lower oil pressure with the 0w20 oil? Add 420 hp to the mix? A 5.3 block is just a small bore 6.2.

They just hit 3000 or so 5.3s in 2024s just made for machining debris taking out engines. Pending engine replacements.

Edited Monday at 03:19 PM by newdude

PunchT37 · Monday at 02:18 PM

15 minutes ago, newdude said:

They just hit 3000 or so 5.3s in 2024s just made for machining debris taking out engines.

Gotcha.

ScathaTheWorm · Monday at 03:47 PM

1 hour ago, newdude said:

They just hit 3000 or so 5.3s in 2024s just made for machining debris taking out engines. Pending engine replacements.

Most of the seized engines involved 6.2s...not 5.3s. It is good they are taking preventative action on the 5.3s...as I have not heard a forum case yet (I could be wrong though..).

And also, I heard there is a new part no change for the 6.2. Not really sure what this means.

ScathaTheWorm · Monday at 03:51 PM

2 hours ago, Gangly said:

From what I understand, improper cleaning of the machined block during the build process. Debris gets pumped through the engine and causes failure. I could be wrong, but I believe it's a situation very similar to the Toyota engine issues.

However, I am skeptical of that as well.

Those people had glitter in the oil...and probably ignored it EVEN when it was excess...when they should have got rid of it in the first place. Cheaping out using regular fuel DOES NOT help either and would increase the possibility of this happening.

Another issue that can cause a similar shut down is the fuel pump module. Also seems to be common on both engines (though I did not hear of this in Qatar...only the bearing issue). That is not fatal...but I will NOT be surprised if this module is on backorder...

ScathaTheWorm · Monday at 03:51 PM

In any case, are recent MY24 builds suffering from this problem? As in, Builds made in July 2024 and after. I know early MY24s have these issues...

newdude · Monday at 04:10 PM

19 minutes ago, ScathaTheWorm said:

Most of the seized engines involved 6.2s...not 5.3s. It is good they are taking preventative action on the 5.3s...as I have not heard a forum case yet (I could be wrong though..).

And also, I heard there is a new part no change for the 6.2. Not really sure what this means.

Its not preventative action really, its they had some 5.3s fail and they were able to pinpoint the VIN range and are going to recall them to replace the engines.

IMO, its all a quality control issue on these engines failing amongst other problems on current GMs and with all automakers. Where that QC issue stems from, everyone will have their own opinions on, but its a QC concern. Post pandemic fallout still present somehow.

ScathaTheWorm · Monday at 04:14 PM

3 minutes ago, newdude said:

Its not preventative action really, its they had some 5.3s fail and they were able to pinpoint the VIN range and are going to recall them to replace the engines.

IMO, its all a quality control issue on these engines failing amongst other problems on current GMs and with all automakers. Where that QC issue stems from, everyone will have their own opinions on, but its a QC concern. Post pandemic fallout still present somehow.

Well. The general point is...how will the MY26 or MY27 LTDs fare? At that point a new generation will be introduced...

asilverblazer · 2024-09-17T16:01:45Z

The problem has already been identified and presumably corrected. So there should be no issues going forward.

The problem as I see it is that there have been several QC issues regarding the 5.3 and 6.2 engines in the last few years.

1. Bad lifters

2. Bad lifter bores

3. Bad crank bearings

4. Bad crank bore/machining debris

I don't recall the specifics, but it seems there has been one major QC issue after another.

I wonder if tooling is wearing out... these engines have been in production for a LONG time and prior to these recent issues have been exceptionally trouble free.