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L9

buckshot85

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Has it actually been confirmed if using L9 deactivates DOD?

Supposed techs on some forums say they can still see the activation with their scan tool while in L9.

I use that mode every day. Just have no idea what the truth is.
 
Has it actually been confirmed if using L9 deactivates DOD?

Supposed techs on some forums say they can still see the activation with their scan tool while in L9.

I use that mode every day. Just have no idea what the truth is.
99.9% sure that it deactivates DFM (dont know if same with older AFM). You can tell by carefully listening to the exhaust sound at idle with L9 vs D. The rumble is quite telling. Also in my testing with the 2 drive modes I found that in L9 my gas milage is about 2 MPG less driving on the same exact country roads, with no different traffic or stops. So it seems that is the case that all 8 cylinders are active but L9 still messes with the lifters... I too would like to know EXACT answer to this though...
 
99.9% sure that it deactivates DFM (dont know if same with older AFM). You can tell by carefully listening to the exhaust sound at idle with L9 vs D. The rumble is quite telling. Also in my testing with the 2 drive modes I found that in L9 my gas milage is about 2 MPG less driving on the same exact country roads, with no different traffic or stops. So it seems that is the case that all 8 cylinders are active but L9 still messes with the lifters... I too would like to know EXACT answer to this though...
What do you mean by “L9 still messes with the lifters”?
 
Before I purchased my Range DFM disabler I would throw my truck into L5. I have a custom cat back and could definitely hear and feel a huge difference when driving in L5 compared to D. Also when in drive I would get really sloppy shifts due to the DFM engagement.

But of course I have the 6 speed so your experience may vary.
 
What do you mean by “L9 still messes with the lifters”?
With L9 all 8 cylinders should be active without any DOD activation, but the DOD hardware is still there and vulnerable to failure, arguably less than with the selection of fewer cylinders active.
 
With L9 all 8 cylinders should be active without any DOD activation, but the DOD hardware is still there and vulnerable to failure, arguably less than with the selection of fewer cylinders active.
That is not L9 messing with the lifters. That’s simply a function of the engine components and design.
 
That is not L9 messing with the lifters. That’s simply a function of the engine components and design.
Sorry that I was not clear, that is exactly what I meant. The L9 doesnt solve any possible lifter issue.
 
Sorry that I was not clear, that is exactly what I meant. The L9 doesnt solve any possible lifter issue.
Well, it alleviates one issue. That’s the pressurizing and depressurizing of the lifter and allowing it to float.
I’d like to see how fast the lifter has to expand/ pressurize in the time required to function. Just seems like you’re asking a lot of that component.
 
MY DOD, is disabled with each ride, generally at about 84 mph, the truck feels enough load to keep the rpms at about 2K...it does not drop down into DOD mode at all.
 
It's really going to be difficult to determine whether running in L9 (or using a defeat device like the Pulsar) is worth it or not. All we know is that it does not remove the possibility of a lifter breaking...they break regardless of if they are regularly used. The question of whether or not it lessens the percentage chance of that happening is something that would require probably a decade of objective data to answer...which we obviously cannot have yet on trucks that are barely 5 years old.

My recommendation is to either do a complete mechanical DFM delete, or just keep a powertrain warranty at all times. As of right now, my plan is to do the latter...but I make no promise that I won't change my mind.
 
It's really going to be difficult to determine whether running in L9 (or using a defeat device like the Pulsar) is worth it or not. All we know is that it does not remove the possibility of a lifter breaking...they break regardless of if they are regularly used. The question of whether or not it lessens the percentage chance of that happening is something that would require probably a decade of objective data to answer...which we obviously cannot have yet on trucks that are barely 5 years old.

My recommendation is to either do a complete mechanical DFM delete, or just keep a powertrain warranty at all times. As of right now, my plan is to do the latter...but I make no promise that I won't change my mind.
These lifters have been failing since the early 2000s, I believe. This isn’t a new problem.
 
These lifters have been failing since the early 2000s, I believe. This isn’t a new problem.

Correct - because they're still the same lifters. However, they seem to fail earlier now, likely because there's more of them and they are used more frequently...which is where the idea of prolonging their lives by not using them comes from. But then the question is - what percentage of failures is from the lifters being collapsed frequently and what percentage is just from the fact that they're collapsible lifters?
 

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