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Sierra Dan

Interesting Article Segment I Found Regarding Disabling of AFM

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4 minutes ago, TXGREEK said:

 

 


Thanks SS502 for posting the video


Sent from above

 

No problem, I just used the video @DenaliX14 posted in another thread, I learned something from it about the VLOM filters :thumbs:

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18 hours ago, GMC #1 said:

New here, I have a 2016 Sierra and installed the Range when I picked up the truck with only 5 miles on it.... has been on it since... at 19800 miles started making a racket.. it's at the dealer to repair the AFM lifters and whatever else is broken inside there. :(

Had a catch can too but removed it before taking it in.

Be interested to know if the filters in the DOD oil tray and sending unit were plugged  pbly not at only 20k 

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Is there a difference in the AFM/DOD system from my 2012 and newer?

 

:)

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12 hours ago, TXGREEK said:

 


You’ve actually noticed a difference in performance disabling the AFM?


Sent from above

 

Performance no...driveability yes.

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2 hours ago, diyer2 said:

Is there a difference in the AFM/DOD system from my 2012 and newer?

 

:)

You have a Gen IV (LS) engine (which this info pertains to), the K2 trucks (2014-18) have Gen V (LT) engines which this info is not referring to. Your AFM system differs slightly from the system used in the Gen V engines, but the working principal is exactly the same, you just cant cross over parts from the Gen IV to Gen V. Now they have even more crap on the T1 trucks (2019+)

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15 minutes ago, L86 All Terrain said:

You have a Gen IV (LS) engine (which this info pertains to), the K2 trucks (2014-18) have Gen V (LT) engines which this info is not referring to. Your AFM system differs slightly from the system used in the Gen V engines, but the working principal is exactly the same, you just cant cross over parts from the Gen IV to Gen V. Now they have even more crap on the T1 trucks (2019+)

Exactly the point of the video, shows how they work :thumbs:

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For those who have AFM turned off via Range, etc. yet do not have catch cans, how do you know that your vehicle burns no oil? It could be burning a miniscule amount that is too small to be picked up by the dipstick no?

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3 hours ago, L86 All Terrain said:

You have a Gen IV (LS) engine (which this info pertains to), the K2 trucks (2014-18) have Gen V (LT) engines which this info is not referring to. Your AFM system differs slightly from the system used in the Gen V engines, but the working principal is exactly the same, you just cant cross over parts from the Gen IV to Gen V. Now they have even more crap on the T1 trucks (2019+)

Thanks

 

:)

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8 hours ago, diyer2 said:

Curious

Oil change intervals?

:)

First change was when I brought it home.. it was a left over 16... next change at 500 miles.. others were before computer said to

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Picked it up today... Cam, lifters and I think lifter bores.. can't read the scribbled notes.. waiting for the hard copy .... $4000 worth of repairs.

I will say it sounds quiter than I remember.

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Performance no...driveability yes.


Completely agree


Sent from above
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On ‎2‎/‎11‎/‎2019 at 2:42 PM, tbarn said:

An automotive blog powered by Summit. Da ya think maybe Summit wants to sell the AFM elimination kits? Just sayin'.

 

On ‎2‎/‎11‎/‎2019 at 2:44 PM, tbarn said:

Ha!! Should have clicked on the link. Takes you straight to Summit. Scammers!!

Ummmm did you even read the article or just decide it had to be a scam because it was posted by Summit, a well respected company? No where in there do they even mention a particular brand, they do provide links to their site for those who want to explore costs and whatnot. Just an FYI- The Range offered (and they are an authorized retailer for Range) on their site is the EXACTLY the same $199 cost that Range charges. In fact the very first part of the article speaks of the benefits of AFM and then lists a couple reasons why people turn it off but I guess you would rather they give useful information and not even offer solutions?

 

Active Fuel Management (AFM) is a trademarked General Motors technology that improves gas mileage by shutting down half of the cylinders under light-load conditions to reduce fuel consumption. It is also known as Displacement on Demand (DoD) or cylinder deactivation.

How Does AFM Affect Performance?

AFM is good for gas mileage and can be 5-7 percent more fuel-efficient under certain conditions.

So Why Turn it Off?

There are a few reasons:

  1. Many people find the four-cylinder sound annoying if their vehicle is equipped with a louder aftermarket exhaust.
  2. Some drivers want V8 power under their foot at all times.
  3. AFM lifters have a history of failing and oil consumption can be a problem.
Edited by SS502
Typo
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It is a good article for folks like myself to better understand AFM. What I found interesting is the 3 "reasons" for disabling the system. The first two are IMHO, a personal preference and have nothing at all to do with longevity of the system. The third however is and relates to the need of increased engineering input for same. Speaking only for myself, I find that the system shifts better (smoother) in D rather than L5 (I have switch back and forth numerous times on my daily commute). I'm guessing this certainly isn't the case for all members here but is for at least some of us.  My questions are geared toward how GM is strengthening the lifter system itself and trying (on my end) to keep my oil supply as clean as possible from a practical standpoint.

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On 2/11/2019 at 5:25 PM, HondaHawkGT said:

There are well over 4 million Gen V (2014+) engines with AFM - GMC Sierra, Chevy Silverado, GMC Yukon, Chevy Suburban, Chevy Tahoe, Chevy Camaro, Chevy Corvette, etc. It doesn't take many AFM lifter issues to create the perception that they are plagued with AFM problems. Combine that with the fact that when someone has an AFM lifter issue, they often register here and vent about it. That has the effect of concentrating the number reports of lifter failures here, and distorts the reality of how reliable the Gen V system is. 

 

Guess that's why the Service Manager at 2 GM dealers that I know of say there are 2 kinds of vehicles with AFM problems:  1) those that already have problems because of AFM, and 2) those that will have problems because of AFM.  

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On 2/11/2019 at 8:09 PM, AE1M said:

I have found this topic of disabling AFM quite odd.  I am a fairly new (8 months) owner of a 2016 High Country. Sweet f’ing ride, none of the vibrations issues discussed.   On a recent long distance drive (over 1000 miles total) I achieved a tad over 23 MPG (actual measured) and saw the display switch to 4 cyl often while cruising,  Engineers at GM (I assume) worked hard to create this feature, why disable it?  In late summer in 2018 after buying this used truck, I had no issue towing 6500lb boat, launching etc....  

 

Why would I spend 100s and risk screwing up what was designed into the truck to improve fuel effiency etc?  My truck may be different as it was sold in Canada which has a few differences like no E85 etc...

 

Bob

 

1)  No risk whatsoever in turning AFM off.  2)  Many people on this website report no discernible difference in fuel economy with AFM turned off.  

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