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Posted

First of all, I love my Sierra...except for the repeated lifter failures.  New in 2016, cross country trip and first failure on #6 lifter & pushrod damage; dealer in Iowa fixed in short order.  2020 another failure, but tech didn't indicate which lifter failed, I should have confirmed.  2021, #4 lifter fail and pushrod damaged.  This week, #4 again.  Dealer is doing a deep dive to investigate how deep the damage may be.  Warranty has covered all fixes and I have extended warranty, so $ not the issue at this point.  What concerns me is the frequency of failures and how that impacts the life of the engine.  Has anyone on this site experienced these repeat lifter fails?  I'm thinking to reach out to GM and request of review of the failures and what consideration can be given; i.e. replace the engine???  Dealer has been great, but I don't look forward to repeats every 1.5 to 2 years.  Thanks for any feedback.

Posted (edited)

Lifters are not a maintenance item.  For such a repeated set of failures, there is likely some underlying root cause of failure that isn't being addressed, lack of proper oil flow or fuel dilution being top of the list.

Edited by 16LT4
  • Like 1
Posted

Sorry to hear your issue, especially with such low miles. I recommend, if you so desire, to educate yourself as to the "main reason" (IMO) for these failures. As a tooling engineer for over 40 years, I have seen & understand how these lifters fail on these DOD AFM. Ther's one guy on youtube that shows how he sees these failures all the time & it really make sense to me. The "lock lugs" in those lifters end up causing a burr inside & cause the system to jam.  To me the only fix, short of deleting the AFM parts, is to add a Range DOD AFM delete unit to the OBD2 socket. This stops the engine from going to the 4-cylinder mode. I've done this & don't really see that much of a fuel mileage difference. 

Here's the video where he explains how it works & the cause for most failures. (Stuck lifter & bent push rod) Disabling the DOD will eliminate the collapsed DOD lifters from getting stuck on that burr/pennied edge shown in the video.

It's my understanding that GM changes the steel alloy material to make it harder, so the penning was less likely to occur. I hope that makes sense.

 

 

Posted
3 hours ago, martinto said:

First of all, I love my Sierra...except for the repeated lifter failures.  New in 2016, cross country trip and first failure on #6 lifter & pushrod damage; dealer in Iowa fixed in short order.  2020 another failure, but tech didn't indicate which lifter failed, I should have confirmed.  2021, #4 lifter fail and pushrod damaged.  This week, #4 again.  Dealer is doing a deep dive to investigate how deep the damage may be.  Warranty has covered all fixes and I have extended warranty, so $ not the issue at this point.  What concerns me is the frequency of failures and how that impacts the life of the engine.  Has anyone on this site experienced these repeat lifter fails?  I'm thinking to reach out to GM and request of review of the failures and what consideration can be given; i.e. replace the engine???  Dealer has been great, but I don't look forward to repeats every 1.5 to 2 years.  Thanks for any feedback.

 

 

Did they ever replace the VLOM?  GM wants that replaced if it hasn't been done yet.  

Posted

Thanks.  Don’t know what that is.  Not noted on the invoice summary.  Today they advised they need to replace the cam shaft.  I’m pushing back on what all these failures and repairs have on the engine reliability.  Only 48,000 miles

Posted
3 hours ago, Snowcamo said:

Best comment ever💯💯💯

OCI?  I’m taking the position the given the frequency of failures…GM needs to step up.  May need the extended 3rd party warranty for other issues.  Given they now need to replace the cam shaft as well, big bucks on the horizon to the 3rd party or GM.  

 

3 hours ago, Snowcamo said:

Best comment ever💯💯💯

 

Posted
18 minutes ago, Snowcamo said:

Oil Change Intervral

 

Used to be 3k back in the day when engines outlasted vehicle ownership.

 

 

Interesting....my chevy dealer recommended OCI every 4k even under the Certified warranty when they were paying for it. 

I personally don't feel even 6k miles oil change is an issue with the new full synthetic oils. My oil isn't that dirty at 6k.

I feel that it's more of the mechanical design issue than oil failure. 

Posted
54 minutes ago, Snowcamo said:

Oil Change Intervral

 

Used to be 3k back in the day when engines outlasted vehicle ownership.

 

 

Oil changes by the dealer at specified intervals…with synthetic.  All my maintenance is done by dealer service.  When my tranny had the famous shudder, they followed the TSB with the new Mobil Blue fluid.  No problems since then.  

Posted
31 minutes ago, rav3 said:

Interesting....my chevy dealer recommended OCI every 4k even under the Certified warranty when they were paying for it. 

I personally don't feel even 6k miles oil change is an issue with the new full synthetic oils. My oil isn't that dirty at 6k.

I feel that it's more of the mechanical design issue than oil failure. 

Agree

Posted

The failure is a 100% mechanical as is with all the 6.2 engines. Either lifter bore issues or just lifter failure issues.

 

 I'm not gonna get into another oil thread here. There's way too many oil threads out there and everybody has her own opinion. I'm just old school and I'll keep my 3K to the day I'll fade away lol.

 

 Only thing I will argue is there's no magical fluid that  Truly fixes a transmission problem. There's only cover ups and bandaids. What GM has for failures out there in transmission world is not something a fluid can truly resolve.  There is a reason why sonnax has a list of parts that are made just to resolve GM transmission issues.

Posted

These failures do happen, unfortunately, there's no denying that.

 

However, I'm with 16LT4 on this one - there is something else clearly going on here, whether the past repairs were not executed fully or there is something else internally that is very wrong. Maybe bad lifters were used?

 

I mean, we're talking about FOUR lifter failures in the span of six years, three of which are only one year apart. I won't speak for everyone, but most of the time when these failures do happen it's fixed and then you're back on the road for a while. It is not normal for this to become an annual repair.

Luckily, you're under warranty, but I definitely agree with investigating this a little more

Posted
11 hours ago, OffTheAir said:

These failures do happen, unfortunately, there's no denying that.

 

However, I'm with 16LT4 on this one - there is something else clearly going on here, whether the past repairs were not executed fully or there is something else internally that is very wrong. Maybe bad lifters were used?

 

I mean, we're talking about FOUR lifter failures in the span of six years, three of which are only one year apart. I won't speak for everyone, but most of the time when these failures do happen it's fixed and then you're back on the road for a while. It is not normal for this to become an annual repair.

Luckily, you're under warranty, but I definitely agree with investigating this a little more

Thanks.  That is where I’m at.  Dealer says the cam shaft is damaged and needs to be replaced as well.  I question the durability of the engine given the history.  I requested what options to consider…extended warranty, which only covers cost of repair but at a cost of inconvenience, or should GM drop another engine in.  I’m sure there will be push back on either.  My service guy understands my concerns and is working to find an acceptable solution.  If he runs into a wall, I will need to escalate.  

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