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DFM disable?

Jmccracken1214
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Hueless Enthusiast

Hueless

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Posted

It's out there. Beta testers have units, I am one of these and have had a great experience with the device so far. I believe they intended on going to the production phase but covid has slowed things down.

 

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Orlick82 New Member

Orlick82

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1 hour ago, Hueless said:

It's out there. Beta testers have units, I am one of these and have had a great experience with the device so far. I believe they intended on going to the production phase but covid has slowed things down.

 

I’ve read that DFM is more elaborate than AFM. Is it true you have to change the internals of the motor if you’re going to delete DFM? Right now range only offers AFM which is a completely different system. Just wondering.

 

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chadman Enthusiast

chadman

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I've only got 2,000 miles on my 2020, and to this point, it has been seamless with no issues or detectable hesitations. I work in the business, and I know GM put in a lot of effort to correct the shortcomings of AFM.  Time will tell I suppose. 

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175vTrailbossLT Enthusiast

175vTrailbossLT

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What is the beef with DFM/AFM? I drive my truck and don’t notice anything. It doesn’t even tell you how many cylinders are working at any given time.

The ONLY reason I have heard that makes sense to me is it could be trouble long term.

There’s a plate with solenoids that are pressurized off of oil pressure. If the solenoids fail or there’s an issue with oil pressure, well there you go- a good way to burn off a cylinder or head..block..whatever. It’s just one more part in the system that can go wrong in a mechanical system. When this was explained to me, I can see why you’d want to disable it.

Now with regard to the aftermarket solutions to disable- is this controlled by software or is a physical mod required that voids warranty?

 

 

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Thomcat Senior Enthusiast

Thomcat

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15 hours ago, 175vTrailbossLT said:

What is the beef with DFM/AFM? I drive my truck and don’t notice anything. It doesn’t even tell you how many cylinders are working at any given time.

The ONLY reason I have heard that makes sense to me is it could be trouble long term.

There’s a plate with solenoids that are pressurized off of oil pressure. If the solenoids fail or there’s an issue with oil pressure, well there you go- a good way to burn off a cylinder or head..block..whatever. It’s just one more part in the system that can go wrong in a mechanical system. When this was explained to me, I can see why you’d want to disable it.

Now with regard to the aftermarket solutions to disable- is this controlled by software or is a physical mod required that voids warranty?

 

 

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Early AFM systems developed oil burning problems caused by the discharge oil spray in the sump on nearby cylinders clogging the oil rings.In addition there were problems with the collapsible lifters of time oil problems at 60K+ and lifters at around 100K miles. Solenoids were never the problem, in fact the LOMA manifold with its own screen clogging problems, exclusive to AFM engines also uses them for the 4 AFM cylinders. Post 1/11 AFM production has addressed these problems with modified valve cover, modified PCV system, baffle over the AFM oil discharge valve, and a new gen of collapsible lifters less prone to damage caused dirty oil. Later volume increase of 5.3l sump capacity from 6 to 8 qts has also helped to extend oil life.

 

Here's my .02 opinion, take it for what it is worth. Had AFMs on my 3 Avalanches and '16 Silverado and by comparison the DFM system is totally seamless. I used the Range device in my '07 Avalanche because it had the early system with valve cover, lifter, PCV and AFM discharge problems. Never used it on the later ones nor will I use one on the '19 DFM because as far as I'm concerned there is no long term data on the new DFM system, talking years not accelerated studies, on use of a defeat device vs. use without one. Got to figure it has to be pulled periodically whenever car is taken for service, State inspections, grabbing codes for the EL, etc. Dealer spots it and no more electrical warranty.

 

The AFM and DFM engines are designed for operation on a varying number of cylinders and the solenoids along with the collapsible lifters are designed to flex thousand of times during each drive cycle. So I'd like to know what the effects would be of keeping the oil control solenoids idle or maybe worse open under constant voltage for an extended period....heat buildup?, varnish deposits inside tappets?....and what happens to collapsible lifters that remain in the one position for very long periods when the device is removed for inspection or service and they expand/collapse and jamb with accumulated varnish buildup in a static area? And what of variability of vehicle builds and that any particular gizmo will play friendly with each and every module programming in your particular vehicle as equipped ?.

 

I don't know and I don't think GM knows either since a DFM engine is barely 2 years old plus was not designed for usage in that manner......but I don't have to because system works just fine as is, plenty of pep and seamless operation.......and it makes no sense to fix something that isn't broken.

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Sierra50BMG Enthusiast

Sierra50BMG

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Posted

Just installed a catback on my 2020 and don’t really notice at cruising speeds as far as the jake brake sound. I notice it around town more but interstate it’s miles ahead of the AFM system. 

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175vTrailbossLT Enthusiast

175vTrailbossLT

Posted
Posted
Early AFM systems developed oil burning problems caused by the discharge oil spray in the sump on nearby cylinders clogging the oil rings.In addition there were problems with the collapsible lifters of time oil problems at 60K+ and lifters at around 100K miles. Solenoids were never the problem, in fact the LOMA manifold with its own screen clogging problems, exclusive to AFM engines also uses them for the 4 AFM cylinders. Post 1/11 AFM production has addressed these problems with modified valve cover, modified PCV system, baffle over the AFM oil discharge valve, and a new gen of collapsible lifters less prone to damage caused dirty oil. Later volume increase of 5.3l sump capacity from 6 to 8 qts has also helped to extend oil life.
 
Here's my .02 opinion, take it for what it is worth. Had AFMs on my 3 Avalanches and '16 Silverado and by comparison the DFM system is totally seamless. I used the Range device in my '07 Avalanche because it had the early system with valve cover, lifter, PCV and AFM discharge problems. Never used it on the later ones nor will I use one on the '19 DFM because as far as I'm concerned there is no long term data on the new DFM system, talking years not accelerated studies, on use of a defeat device vs. use without one. Got to figure it has to be pulled periodically whenever car is taken for service, State inspections, grabbing codes for the EL, etc. Dealer spots it and no more electrical warranty.
 
The AFM and DFM engines are designed for operation on a varying number of cylinders and the solenoids along with the collapsible lifters are designed to flex thousand of times during each drive cycle. So I'd like to know what the effects would be of keeping the oil control solenoids idle or maybe worse open under constant voltage for an extended period....heat buildup?, varnish deposits inside tappets?....and what happens to collapsible lifters that remain in the one position for very long periods when the device is removed for inspection or service and they expand/collapse and jamb with accumulated varnish buildup in a static area? And what of variability of vehicle builds and that any particular gizmo will play friendly with each and every module programming in your particular vehicle as equipped ?.
 
I don't know and I don't think GM knows either since a DFM engine is barely 2 years old plus was not designed for usage in that manner......but I don't have to because system works just fine as is, plenty of pep and seamless operation.......and it makes no sense to fix something that isn't broken.

Great response thanks!


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  • 1 year later...
G.Cramer New Member

G.Cramer

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Posted

Chevrolet did void our warranty because a previous owner had used the Range AFM/DFM disabler even though it is no longer on the truck they could tell. The void not only covers the drivetrain but ANYTHING on the vehicle including new parts and new work meaning if we pay them to fix a windshield wiper motor and it breaks again before we get off the lot they will NOT honor its warranty. However this is totally NOT legal and we will do our best to get this reversed but so far our warranty is VOID!! Just so you know!!

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lapoolboy Senior Enthusiast

lapoolboy

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10 minutes ago, G.Cramer said:

Chevrolet did void our warranty because a previous owner had used the Range AFM/DFM disabler even though it is no longer on the truck they could tell. The void not only covers the drivetrain but ANYTHING on the vehicle including new parts and new work meaning if we pay them to fix a windshield wiper motor and it breaks again before we get off the lot they will NOT honor its warranty. However this is totally NOT legal and we will do our best to get this reversed but so far our warranty is VOID!! Just so you know!!

BS.  They are inviting a lawsuit.

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  • 5 months later...
ManicFury New Member

ManicFury

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Posted (edited)
On 5/16/2021 at 1:14 PM, G.Cramer said:

Chevrolet did void our warranty because a previous owner had used the Range AFM/DFM disabler even though it is no longer on the truck they could tell. The void not only covers the drivetrain but ANYTHING on the vehicle including new parts and new work meaning if we pay them to fix a windshield wiper motor and it breaks again before we get off the lot they will NOT honor its warranty. However this is totally NOT legal and we will do our best to get this reversed but so far our warranty is VOID!! Just so you know!!

 

According to the Magnuson-Moss Warranty Act of 1975, a manufacturer can only deny warranty coverage if it can demonstrate that a non-original equipment part or related service caused a defect to occur to the original product.

 

Read the following link provided. A manufacturer can NOT "void" a warranty for any reason. The can only attempt to deny a warranty claim, but they bear the burden of proof.

 

As lapoolboy stated: they are inviting a lawsuit.

 

https://www.autoanything.com/resources/magnuson-moss-warranty-act-explained/

Edited by ManicFury
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