Driving in L9 and DFM

[SSGUNNER]

Great info. I havent tried it but may do so.

 

[Jgrimberg1979]

No, I wish they did notify when it’s engaged.

You can’t feel it turn on it? I swear I have not only that you know if it’s in dfu, it’s when you are idiling and not giving it much throttle. That will tell you it’s shutting down half the engine technically

 

[jimgeb]

It would be interesting to find out if the lifters fail as much even if AFM/DFM is deleted.

 

[SCiesie154]

Does anyone know what the maximum speed would be in L9? Here in the free state of South Dakota we have 80mph speed limits.

 

[olyelr]

Does anyone know what the maximum speed would be in L9? Here in the free state of South Dakota we have 80mph speed limits.

Im sure you could hit the speed limiter…why wouldnt it?

 

[SCiesie154]

Thanks olyeir, I didn't know we had a speed limiter. That is kinda like Close Up toothpaste, "It takes the worry out of being close." (-:

 

[CMoore711]

It would be interesting to find out if the lifters fail as much even if AFM/DFM is deleted.

I realize my rig is the previous gen ‘15 Yukon Denali XL; I have the 6.2 L86 and 8l90e 8 speed.

But in regards to your comment here.

I purchased my vehicle CPO with 22K miles. Installed a Range AFM disable device at about 30K miles. At 78K miles I still had a lifter failure. Covered under the power train warranty at the time.

There is also a difference between disabling the AFM/DFM and deleting it.

Disabling AFM/DFM is something done simply with a tune or Range type device. Still maintaining the stock mechanicals just not allowing the AFM/DFM to function or engage.

Deleting AFM/DFM is more of a mechanical delete of the entire system and parts; Changing the lifters, cam, VLOM, and some other engine parts (still researching the parts list) to a standard or more “traditional” push-rod V8. Think GM LS# motors. Some owners who have gone down this path have also reported a slight 1-3 increase in mpg. Perplexed.

 

[Geotrash]

I realize my rig is the previous gen ‘15 Yukon Denali XL; I have the 6.2 L86 and 8l90e 8 speed.

But in regards to your comment here.

I purchased my vehicle CPO with 22K miles. Installed a Range AFM disable device at about 30K miles. At 78K miles I still had a lifter failure. Covered under the power train warranty at the time.

There is also a difference between disabling the AFM/DFM and deleting it.

Disabling AFM/DFM is something done simply with a tune or Range type device. Still maintaining the stock mechanicals just not allowing the AFM/DFM to function or engage.

Deleting AFM/DFM is more of a mechanical delete of the entire system and parts; Changing the lifters, cam, VLOM, and some other engine parts (still researching the parts list) to a standard or more “traditional” push-rod V8. Think GM LS# motors. Some owners who have gone down this path have also reported a slight 1-3 increase in mpg. Perplexed.

Agree on all points. I did a full mechanical delete on my 2012 and it’s been wonderful. Yet, I also know that a lifter failure is still possible. It’s statistically less likely now, but non-AFM lifters still fail from debris, worn lifter trays, poor maintenance, and just poor metallurgy or QC during manufacture.

At some point, I will invest in a newer XL Denali I’m sure… one that’s 6 years old or so with around 100K, and it will be cheap relative to a new one. When I do, I will delete the DFM mechanically myself because I have the process down pat, and take the opportunity to refresh everything under the hood while I’m there. For $2-3K in parts and a couple of weekends, I’ll have a rig ready to roll for another 10 years. These are STILL the best, most versatile SUV you can buy, hands down. I’ll always have one.

 

[jimgeb]

I realize my rig is the previous gen ‘15 Yukon Denali XL; I have the 6.2 L86 and 8l90e 8 speed.

But in regards to your comment here.

I purchased my vehicle CPO with 22K miles. Installed a Range AFM disable device at about 30K miles. At 78K miles I still had a lifter failure. Covered under the power train warranty at the time.

There is also a difference between disabling the AFM/DFM and deleting it.

Disabling AFM/DFM is something done simply with a tune or Range type device. Still maintaining the stock mechanicals just not allowing the AFM/DFM to function or engage.

Deleting AFM/DFM is more of a mechanical delete of the entire system and parts; Changing the lifters, cam, VLOM, and some other engine parts (still researching the parts list) to a standard or more “traditional” push-rod V8. Think GM LS# motors. Some owners who have gone down this path have also reported a slight 1-3 increase in mpg. Perplexed.

 

[Fast_AT4]

This L9 topic is all new to me. I get in and hit D and drive away....am I missing some "performance mode" here by using "D"? Is this like a hidden "M Mode" that I have been accustom to in my previous BMW M5's? Any known downfalls to driving in L9...lifter issue specifically?

 

[Garth Knight]

Yeah, in regards to the 6.2L, does driving in L9/disabling DFM increase or decrease the likelihood of lifter failure? Anyone know?

 

[JasonHTX]

Looks like they'll never be a Range or Pulsar LT device for our rigs. Bummer.

 

[jimgeb]

Looks like they'll never be a Range or Pulsar LT device for our rigs. Bummer.

Is there is any evidence to indicate that disabling DFM electronically will prevent lifter failure, since the collapsible lifters still remain?

 

[Micahsd]

Is there is any evidence to indicate that disabling DFM electronically will prevent lifter failure, since the collapsible lifters still remain?

I have my doubts driving in L9 would be the perfect solution as when in Park the DFM will probably kick in while idling...if that's the case, then the issue is still going to crop up. That's just my take on it.

I've had one side replaced at 9,100...currently at 11,500 and a little leery as to when the other side will decide to go.

 

[dwlow09]

I'm glad I'm not the only one lol

Instead of putting in D select L for low and use paddle shifter to 9 for 9th gear and it dont do to 10th gear and go into dfm

 

[julio62]

I know I’m going to regret asking, but what is L9?

L9 or M9 is when you shift out of "auto" and put it in a gear manually. L9 would cover all the gears below that for shifting, that is it will shift automatically through gears 1-9. If you put it in L6 or M6 for instance, it will shift through gears 1-6.
2025 Yukons like mine have steering wheel mounted paddle shifters making going up and down quite easy.

 

[olyelr]

L9 or M9 is when you shift out of "auto" and put it in a gear manually. L9 would cover all the gears below that for shifting, that is it will shift automatically through gears 1-9. If you put it in L6 or M6 for instance, it will shift through gears 1-6.
2025 Yukons like mine have steering wheel mounted paddle shifters making going up and down quite easy.

AND, when u put it in that it disables the dfm from kicking in…

 

[murdrmunkee]

Well I am glad to hear that, I will be driving in L9 almost always from now on.
My Denali was built on May 18th outside of the dates specified for the lifter failure but unfortunately I don’t have to much confidence in that timeline.

I love this rig but the reason I purchased this as my retirement vehicle was to travel the country and being left stranded a few thousand miles from home is not very appealing.

Hi, which dates have been identified for lifter failure? how do i check if my car falls on that date?
Thank you!

 

[RG23RST]

Hi, which dates have been identified for lifter failure? how do i check if my car falls on that date?
Thank you!

September 1, 2020 to March 31, 2021. Contact any dealer and provide your VIN and they can tell you if any were replaced. Initially we were only replacing one side (which IMO was dumb) then after some time all 16 were instructed to be replaced. If yours got out before the stop-sale it's worth checking on.

 

[olyelr]

Pretty sure ive read about much newer model years than that blowing up. But i dont keep up on it.