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.

 

[Charlie207]

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.

I'm over in Claremont, but we've been trying to buy a house to move back up to Lebanon for far too long. Home prices here are crazy-high, luckily we have an amazing deal on our current spot. We went to look at a 15-acre lot the other day, and are juggling some imaginary numbers to see about buying it, paying it off, and using it as collateral on a new-contruction loan... but with current new-builds being at least $400/sq.ft. it's depressing.

 

[Jhaley213]

I'm over in Claremont, but we've been trying to buy a house to move back up to Lebanon for far too long. Home prices here are crazy-high, luckily we have an amazing deal on our current spot. We went to look at a 15-acre lot the other day, and are juggling some imaginary numbers to see about buying it, paying it off, and using it as collateral on a new-contruction loan... but with current new-builds being at least $400/sq.ft. it's depressing.

@Charlie207 it’s insane, can’t touch anything decent near me for less that 500k, I’m glad I bought in 2019 but my house is getting small for my growing family

 

[Fubar0715]

@Jhaley213 - I agree! Never could I afford what I have now and its WAY more than we needed. During the summer of Covid, everyone was buying up moderate sized homes and we kept being pushed out by other buyers or (true story) sellers concerned we were from Florida and not sure we would want to complete a purchase! Like what the hell people

 

[_GMAN_]

My take on AFM and possible lifter issues is if you go looking for problems, you will find them. We are clearly not the first owners of our vehicles, and they've served the previous owners without issue. That is if you've purchased one with no issues. The key is proper oil changes. More so that you dont rely on the computer to tell you when to change your oil, but be proactive. I change my oil ever 5000 miles. I know the previous owner (my son) so I know maintenance was kept up. The exterior not so much.

 

[Marky Dissod]

My take on AFM and possible lifter issues is if you go looking for problems, you will find them.
We are clearly not the first owners of our vehicles, and they've served the previous owners without issue. That is if you've purchased one with no issues.

GM's take is FAR more important than yours, and I guarantee that GM has noticed the uptick in vehicles leased,
the downward trend in vehicles bought both instead of and after lease, and how much GM profits from buyer financing vs maintaining / repairing older vehicles.
Those trends largely explain why the GMT-K2xx & GMT-T1xx are generally less reliable after the first 150,000 miles compared to GMT800 & GMT900.
Specifically regarding Engine Half@$$, it is far from famous for being trouble-free
(although I'll grant that far too many look for excuses to change oil every 6000-7500 miles - they largely correlate with the uptick in vehicles leased)

A less obvious issue is that Engine Half@$$ (and DFM / Cylinder Confusion, especially in conjunction with direct injection)
don't work nearly as well after 50,000 miles as they did when new.
Since most people don't meticulously track their MpGs THEMSELVES, they're unlikely to notice that V4 mode's MpG benefit wanes over time.
There's a significantly large group of people who notice that their MpGs improve after having their ecm & tcm tuned.
It's not as simple as 'allowable TCC clutch slip'.

The key is proper oil changes. Moreso that you don't rely on the computer to tell you when to change your oil, but be proactive. I change my oil every 5000 miles.

If you drove enough stop'n'go urban metro traffic, an oil change every 5000 miles would be adamantly asking for trouble.
On the other hand, if you drive all highway miles except to stop for fuel, you can get away with 6000 mile oil changes -
though it should be stressed that it never hurts to change oil more often than 'necessary' / 'indicated' in the long run.

Besides, you can make the Oil Life Monitor far more useful by skewing it 'pessimistically'.
Most NYC cabdrivers / livery drivers / chauffeurs apply the following 'skew' to the Oil Life Monitor:
Mostly all highway miles (NOT NYC), change oil & filter @ 20%, NEVER over 5000 miles.
More highway than local miles, change oil & filter @ 25%, NEVER over 4000 miles.
More local than highway miles, change oil & filter @ 33%, NEVER over 3500 miles.
Mostly all local miles (stop'n'go, LOTS of idling, no overdriven gear use, also lots of restarts), change oil & filter @ 40% - NEVER over 3000 miles.
If they intend to keep that car after the lease is up, oil changes may occur as often as every 2500 miles / every 5-6 weeks,
depending on the nature and number of miles accrued.

 

[_GMAN_]

GM's take is FAR more important than yours, and I guarantee that GM has noticed the uptick in vehicles leased,
the downward trend in vehicles bought both instead of and after lease, and how much GM profits from buyer financing vs maintaining / repairing older vehicles.
Those trends largely explain why the GMT-K2xx & GMT-T1xx are generally less reliable after the first 150,000 miles compared to GMT800 & GMT900.
Specifically regarding Engine Half@$$, it is far from famous for being trouble-free
(although I'll grant that far too many look for excuses to change oil every 6000-7500 miles - they largely correlate with the uptick in vehicles leased)

A less obvious issue is that Engine Half@$$ (and DFM / Cylinder Confusion, especially in conjunction with direct injection)
don't work nearly as well after 50,000 miles as they did when new.
Since most people don't meticulously track their MpGs THEMSELVES, they're unlikely to notice that V4 mode's MpG benefit wanes over time.
There's a significantly large group of people who notice that their MpGs improve after having their ecm & tcm tuned.
It's not as simple as 'allowable TCC clutch slip'.

If you drove enough stop'n'go urban metro traffic, an oil change every 5000 miles would be adamantly asking for trouble.
On the other hand, if you drive all highway miles except to stop for fuel, you can get away with 6000 mile oil changes -
though it should be stressed that it never hurts to change oil more often than 'necessary' / 'indicated' in the long run.

Besides, you can make the Oil Life Monitor far more useful by skewing it 'pessimistically'.
Most NYC cabdrivers / livery drivers / chauffeurs apply the following 'skew' to the Oil Life Monitor:
Mostly all highway miles (NOT NYC), change oil & filter @ 20%, NEVER over 5000 miles.
More highway than local miles, change oil & filter @ 25%, NEVER over 4000 miles.
More local than highway miles, change oil & filter @ 33%, NEVER over 3500 miles.
Mostly all local miles (stop'n'go, LOTS of idling, no overdriven gear use, also lots of restarts), change oil & filter @ 40% - NEVER over 3000 miles.
If they intend to keep that car after the lease is up, oil changes may occur as often as every 2500 miles / every 5-6 weeks,
depending on the nature and number of miles accrued.

Although I appreciate your long explanation, I am only referring to my GMT900 series vehicle. I have 225K miles and it still rides just fine. I know they got less reliable in the 2020's. I dont have one of those. I can only attest to what I have. I'll continue with my maintenance schedule as I do it. Every potential new owner has to do their due diligence on their on their own vehicle.

 

[Marky Dissod]

Was not specifically suggesting changing YOUR maintenance intervals, much less explaining to any ONE, specifically.
The OP & others might benefit from how you concluded that 5000 miles worked for your vehicle's use case.

 

[j91z28d1]

Although I appreciate your long explanation, I am only referring to my GMT900 series vehicle. I have 225K miles and it still rides just fine. I know they got less reliable in the 2020's. I dont have one of those. I can only attest to what I have. I'll continue with my maintenance schedule as I do it. Every potential new owner has to do their due diligence on their on their own vehicle.

you have 225k one with afm still active and working, not repaired or turned off at some point?


that's very impressive. I would enjoy any details you can give, like have you been around it since new? oil brand, weight and change mileage. use type, like city or highway? driving style, aggressive or just daily driven old man speed.


these things just don't last that long around here. generally 130-170 the engine afm has failed, the torque converter has taken out the first tranny meaning the truck has basically needed rebuild by the 2nd owner without any knowledge of the first 100k miles by the time. they end up here.

 

[_GMAN_]

you have 225k one with afm still active and working, not repaired or turned off at some point?


that's very impressive. I would enjoy any details you can give, like have you been around it since new? oil brand, weight and change mileage. use type, like city or highway? driving style, aggressive or just daily driven old man speed.


these things just don't last that long around here. generally 130-170 the engine afm has failed, the torque converter has taken out the first tranny meaning the truck has basically needed rebuild by the 2nd owner without any knowledge of the first 100k miles by the time. they end up here.

I helped my son buy this Suburban for his growing family back in 2012. At the time it was 5 years old. The only problem with the vehicle was a crack in the dash. Which got worse. (Check my previous posts for those projects). My son was 24 at the time when got this for his family. He is in his 19 year in The Navy now. At the time of purchase here in Houston, he immediately drove it to Lemoore, CA where he was stationed. Since it’s not a hot rod, it was not driven “Aggressively” like everyone else we like to pass the slow driver in front of us from time to time. This truck experienced Three trips from Lemoore to Houston. Then he got stationed in Pensacola, FL. Then the truck went from Lemoore to Pensacola, with the occasional trips back to Houston. Many highway miles. Lastly he went to Norfolk, VA where he is currently. Fast forward to the present. Their family has grown a bit, and he and his wife no longer want a big vehicle like the Suburban. Plus it didnt have the modern tech we are all used to like Bluetooth, navigation, Apple Car Play. Which is where I came in and got it back from them.
The Suburban had about 60K miles on in when we got it, and they drove it up to about 200K. I put the last 20K miles on it. In that time it has always had synthetic 5W30 oil. We are meticulous oil changers. I can’t speak for miles 0 thru 60k, but I would thing noting major happened during the first 5 years of its life. The last transmission service was at about 180K. I wont do another.

Here in Houston, Suburbans/Tahoes/Yukons/Avalanches are plentiful. I have seen many with older couples still driving their vehicles and they look immaculate.

I’m the 3rd owner, but technically the 2nd owner.