2011 Yukon Denali 6.2

[Jhaley213]

I just purchased a 2011 GMC Denali with the 6.2 and I’m wondering about the known lifter issue? How common is it in this year? Seems to run fine I just have concerns from all the horror stories. Has anyone had one of these trucks go over 200k with no problems? Is there any specific maintenance that limits the chances? I’m just basically wondering how likely this is to happen to me and what I can do to make it less likely

 

[Noggles]

Its kind of a game of chance to some degree along with good preventative maintenance. I have seen some people have a lifter fail under 100k and others go 2-300 without issues. The easiest first step is to buy an AFM deleter dongle thing on amazon and run that (or always run in manual 5th gear) which will keep it from activating the cylinder deactivation. Then do proper oil changes and use quality oil and filters. The real key is to do a true AFM delete though which requires a cam and other parts. Once that's done IMO the gen 4 engines (what you have) become the best LS based engines.

My truck is a 5.3 but it has the same lifters your 6.2 does and it has 230k on it. AFAIK they are the original lifters but the previous owners took VERY good care of it and it runs great. Still have all the parts to do an AFM delete but mine will come with a 6.0 swap at the same time.

 

[Marky Dissod]

... just purchased a 2011 GMC Denali with the 6.2L, and I’m wondering about the known lifter issue?

So, you're SURE that your 6.2L is an L94, NOT an L9H? Check your glovebox for either of those engine codes.
If it's an L9H, stop wondering, just change the 5W30 a bit more often than you think you should (not over 5,000 miles).
If it's an L94, disable V4 mode ASAP, & change the 5W30 more often than you think you should (not over 4,500 miles).

'Disable': turn the feature off, but the problem hardware is still there.
'Delete': turn the feature off, then replace the V4 mode lifters with real V8 lifters.

 

[Jhaley213]

So, you're SURE that your 6.2L is an L94, NOT an L9H? Check your glovebox for either of those engine codes.
If it's an L9H, stop wondering, just change the 5W30 a bit more often than you think you should (not over 5,000 miles).
If it's an L94, disable V4 mode ASAP, & change the 5W30 more often than you think you should (not over 4,500 miles).

'Disable': turn the feature off, but the problem hardware is still there.
'Delete': turn the feature off, then replace the V4 mode lifters with real V8 lifters.

I just checked and it is indeed an L94. I bought the plug in device to disable AFM and it should be here tomorrow

So, you're SURE that your 6.2L is an L94, NOT an L9H? Check your glovebox for either of those engine codes.
If it's an L9H, stop wondering, just change the 5W30 a bit more often than you think you should (not over 5,000 miles).
If it's an L94, disable V4 mode ASAP, & change the 5W30 more often than you think you should (not over 4,500 miles).

'Disable': turn the feature off, but the problem hardware is still there.
'Delete': turn the feature off, then replace the V4 mode lifters with With 130k assuming I shut AFM off now and stay on top of oil say every 3,000 is it still possible to get over 200k without major repairs? Also thinking of changing tranny fluid and diffs just to be safe

 

[Jhaley213]

Its kind of a game of chance to some degree along with good preventative maintenance. I have seen some people have a lifter fail under 100k and others go 2-300 without issues. The easiest first step is to buy an AFM deleter dongle thing on amazon and run that (or always run in manual 5th gear) which will keep it from activating the cylinder deactivation. Then do proper oil changes and use quality oil and filters. The real key is to do a true AFM delete though which requires a cam and other parts. Once that's done IMO the gen 4 engines (what you have) become the best LS based engines.

My truck is a 5.3 but it has the same lifters your 6.2 does and it has 230k on it. AFAIK they are the original lifters but the previous owners took VERY good care of it and it runs great. Still have all the parts to do an AFM delete but mine will come with a 6.0 swap at the same time.

I plan on doing Mobil 1 oil change every 3-3.5k miles, I would think that would be pretty good right? Any other maintenance that can help me? And also how much money do you estimate it being to do the true AFM delete? I’m hoping to get 250k out of this truck or even more and I’d rather do my best to bulletproof it before total failure

 

[Joseph Garcia]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

You are already receiving sage advice from the knowledgeable folks on this Forum.

As stated above, it's basically a roll of the dice whether or not you will have an AFM issue in the future. My recommendation is to (1) buy the OBDII dongle to disable the tune electronically, or (2) purchase a proper tune (~$650), which will both electronically disable the AFM, and pep up your 6.2 motor and make dramatic improvements in the transmission's shift patterns. I went with option (2) for the motor and transmission improvements with BlackBear Performance (a valued vendor on this Forum), and IMO, it is the absolute best bang for your buck to improve your truck's performance and longevity (note that my 07 did not have AFM built into it).

Also, do NOT let your motor oil go over 5000 miles without an oil and filter change.

 

[swathdiver]

So, you're SURE that your 6.2L is an L94, NOT an L9H? Check your glovebox for either of those engine codes.

L9H was 2009 only in the GMT900 SUVs.

@Jhaley213 Your engine if it was made after April of 2011 has all the updates for that generation. If there was a dealer level repair made since it was built, it would surely have them all by now too.

This is not the same engine and parts that are currently failing in the L87s.

Plain Mobile One is not a good oil to run in these trucks. ACDelco 10-9330 or 19432322 and Quaker State Full Synthetic are far superior.

Compare the two oil samples on the right with the others, those were with Mobile One and the others ACDelco. I have another truck on Quaker State with nearly the same results.



Get your truck tuned and have them turn off AFM. This will extend the life of the drivetrain and deliver better performance. Use GM OE parts only and follow the severe service schedule for maintenance.

 

[Marky Dissod]

I'll recommend Valvoline Restore & Protect 5W30, since a chief concern is clean motor oil.
Can't reliably predict dice rolls, but if you use Valvoline Restore & Protect 5W30,
that'd likely be your best bet to get past 200,000 miles.

 

[Jhaley213]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

You are already receiving sage advice from the knowledgeable folks on this Forum.

As stated above, it's basically a roll of the dice whether or not you will have an AFM issue in the future. My recommendation is to (1) buy the OBDII dongle to disable the tune electronically, or (2) purchase a proper tune (~$650), which will both electronically disable the AFM, and pep up your 6.2 motor and make dramatic improvements in the transmission's shift patterns. I went with option (2) for the motor and transmission improvements with BlackBear Performance (a valued vendor on this Forum), and IMO, it is the absolute best bang for your buck to improve your truck's performance and longevity (note that my 07 did not have AFM built into it).

Also, do NOT let your motor oil go over 5000 miles without an oil and filter change.

Derry, NH and I will look into black bear

 

[Joseph Garcia]

View attachment 460515
Derry, NH and I will look into black bear

Very nice! And, there are at least 4 of us here in NH. You in Derry, @Fubar0715 in Merrimack, and me in Hollis. I don't remember where the 4th person is located.