Engine Failure - only 76,000 miles

dieselfan1 · November 16, 2021

On 11/7/2021 at 8:42 AM, Grumpy Bear said:

You do know that there is nothing special about the AFM parts to the 5.3 right? 6.2 and 4.3 use the same system and parts save the 4.3's VLOM casting but the parts on that casting are the same as the others. All have the same oil pumps and related parts as well. As far as the rest of this rant....I have 150,000 on mine with two very minor repairs. A weepy pinion seal I could have let go forever and a warps plastic heat shield around the starter that made noise. CadillacLuke has 200K on his without lifter failure.

Somewhere between 'can't get out of the driveway' and "flawless" the truth is the same for them all. Hardly over a 50% failure rate. Hint: stating a statistic without a verifiable source does not make a statement a fact nor true.

Ya got a lemon.

Exactly Grumps.

You're only going hear about the failures on here.

What about the millions of these trucks that haven't had this problem? I'm sure it's like a less than 1% failure rate.

C'mon man.

diyer2 · November 16, 2021

I believe some of it is oil related. OCI's play a big part in it IMO. Yes parts fail. I still think 7500 miles with semi synthetic oil is to long. To long for full synthetic also. The oil just gets dirty and the oil passages suffer.

Edited November 16, 2021 by diyer2

Grumpy Bear · November 16, 2021

1 hour ago, dzsmith said:

The failure rate is high....man. my bosses truck didnt have a lifter stick until 160k.....Another guy i work had one stick at 120k, my uncle had one stick at 90k and another guy i work with had one also stick at less than 100k.....its pretty common. by the way my uncles was the 6.2...i will admit you dont hear about it as much on other afm engines besides the 5.3 but thats mostly because 99% of gm truck owners i know have the 5.3....and i dont know a single 1500 gm driver with a 4.3 not one.

Interesting stuff that is. Of all the guys I know there has not been a single failure yet. I know some guys north of 200K on their engines as well. Now the shop I use has done a few and his take on it is that the guys with failures also seem to be the guys who push oil changes and whip on them regularly.

We were tossing something around in an other thread on this topic of failure differences between the 8 and the 6 cylinder motors yesterday I believe. @newdude verified that the parts are the same between them save the VLOM casting itself and after reviewing the TSB that failures are the result of aeration of the oil as a primary cause. There have been a few batches of 'bad' lifters GM has identified and shop experience has uncovered many cases of plugged VLOM pre-screens. That one under the pressure switch that nobody changes. That is a mistake. It's serviceable for a reason.

Best guess....0W20 vs 5W30. and oil system maintenance issues. Still...interesting stuff.

dyier2 wrote: I believe some of it is oil related. OCI's play a big part in it IMO. Yes parts fail. I still think 7500 miles with semi synthetic oil is to long. To long for full synthetic also. The oil just gets dirty and the oil passages suffer.

Edited 6 minutes ago by diyer2

Yep!

Edited November 16, 2021 by Grumpy Bear

newdude · November 16, 2021

2 hours ago, dzsmith said:

The failure rate is high....man. my bosses truck didnt have a lifter stick until 160k.....Another guy i work had one stick at 120k, my uncle had one stick at 90k and another guy i work with had one also stick at less than 100k.....its pretty common. by the way my uncles was the 6.2...i will admit you dont hear about it as much on other afm engines besides the 5.3 but thats mostly because 99% of gm truck owners i know have the 5.3....and i dont know a single 1500 gm driver with a 4.3 not one.

3 people you know, its "common" to you.

Been at a GM dealer for 12 years. Its not as "common" as lead to believe, but yes, they do happen. Out of all the AFM/DFM trucks we've worked on regularly in 12 years (hundreds to thousands) 99% of them have never been apart for lifter replacement. Low and high miles.

The internet and social media make it sound like every single truck built has had a lifter go. Not the case.

Hell, I think in the last 5 years we've had more 6L80s come out of trucks than trucks have come for lifter failure.

Edited November 16, 2021 by newdude

Grumpy Bear · November 16, 2021

4 minutes ago, newdude said:

Hell, I think in the last 5 years we've had more 6L80s come out of trucks than trucks have come for lifter failure.

Edited 1 minute ago by newdude

Oh man....you just turned this into a 6L80E failure thread!

:rollin:

customboss · November 16, 2021

On 11/3/2021 at 11:41 AM, KARNUT said:

Not really. I had a Ram V-10 out of warranty fail. They determined it was a defect. It was close to that mileage. I only paid labor. I even used it for pulling a trailer.

Absolutely. I did rebuild and warranty oil analysis failure and causal analysis for Chrysler 5.7 hemi's failing and we used Detroit Diesel to reman the replacement engines.

Many were getting engines out of warranty if the oil analysis showed the owner did nothing wrong and the engines rod bearings failed from defect.

Grumpy Bear · November 17, 2021

9 hours ago, customboss said:

Absolutely. I did rebuild and warranty oil analysis failure and causal analysis for Chrysler 5.7 hemi's failing and we used Detroit Diesel to reman the replacement engines.

Many were getting engines out of warranty if the oil analysis showed the owner did nothing wrong and the engines rod bearings failed from defect.

I had HONDA replace a motor out of warranty on their dime when they determined that it was entirely a casting issue and nothing anyone had control over post sale. Allot has to do with approach.

jrabenaldt · November 22, 2021

It certainly happens to old as well as new. My '16 6.2 spit one with 57K on it and my neighbors '21 just did it in August with 8K on it. I'm starting to think there's more to the lighter oil weight at least contributing to the occurrences.

steelerdude15 · December 1, 2021

On 11/16/2021 at 9:17 AM, Grumpy Bear said:

Interesting stuff that is. Of all the guys I know there has not been a single failure yet. I know some guys north of 200K on their engines as well. Now the shop I use has done a few and his take on it is that the guys with failures also seem to be the guys who push oil changes and whip on them regularly.

We were tossing something around in an other thread on this topic of failure differences between the 8 and the 6 cylinder motors yesterday I believe. @newdude verified that the parts are the same between them save the VLOM casting itself and after reviewing the TSB that failures are the result of aeration of the oil as a primary cause. There have been a few batches of 'bad' lifters GM has identified and shop experience has uncovered many cases of plugged VLOM pre-screens. That one under the pressure switch that nobody changes. That is a mistake. It's serviceable for a reason.

Best guess....0W20 vs 5W30. and oil system maintenance issues. Still...interesting stuff.

dyier2 wrote: I believe some of it is oil related. OCI's play a big part in it IMO. Yes parts fail. I still think 7500 miles with semi synthetic oil is to long. To long for full synthetic also. The oil just gets dirty and the oil passages suffer.

Edited 6 minutes ago by diyer2

Yep!

How often should the screens be serviced and how are they serviced?

Grumpy Bear · December 1, 2021

1 hour ago, steelerdude15 said:

How often should the screens be serviced and how are they serviced?

You have a PM

Millercm · April 22

Did you ever get this resolved? Have the same issue and GM isn’t doing anything about it They quoted me $9800. Truck doesn’t even have 100k on it.

GMCustomerService · April 24

On 4/22/2025 at 2:59 PM, Millercm said:

Did you ever get this resolved? Have the same issue and GM isn’t doing anything about it They quoted me $9800. Truck doesn’t even have 100k on it.

We know expensive repairs can be extremely upsetting. Although cost assistance is not guaranteed, we are happy to look into your situation and open a case on your behalf. We can be reached via email at [email protected], and we ask that you share your VIN, mileage, and dealership information. By sending us a message, you consent to the information you provide being monitored and recorded by GM or those acting on GM’s behalf, subject to the GM Privacy Statement: https://www.gm.com/privacy-statement.

Srode1 · May 7

i hadn't heard about the screen being servicable and haven't seen the TSB . Can someone explain the screen and service and post a link to the TSB?

newdude · May 7

6 minutes ago, Srode1 said:

i hadn't heard about the screen being servicable and haven't seen the TSB . Can someone explain the screen and service and post a link to the TSB?

12623757. Its above the oil pressure sensor at the front of the VLOM. Accessed by a plug in the top of the VLOM.

Srode1 · May 12

On 5/7/2025 at 12:26 PM, newdude said:

12623757. Its above the oil pressure sensor at the front of the VLOM. Accessed by a plug in the top of the VLOM.

Thanks, I found some information based on that. I haven't seen anything on a service interval though, only comments to replace that and the pressure sender when the oil pressure drops which doesn't sound right. Looks like a metal screen, so is it just for aeration reduction or is acting like a filter / getting clogged too?