Is AFM a concern?

Seems to me there are a lot of GMC/Chevy fans both on this forum and amongst outdoorsman in general. Ive always had the impression that AFM is a bad thing and problematic. I have a 2006 Dodge Durango that uses a valve shutoff (MDS) and i never liked it. I drive it in tow haul mode at all times to avoid it. GMC uses this technology (or the same principal at least) in their trucks. Ive read a little bit about it but i dont know very much. Does this feature make an engine less reliable? I think i would be willing to consider buying a GMC/Chevy when the time came to upgrade if i could be assured that this technology is reliable.

You dont want your Durango to go in to over drive?

My brothers 2008 Chev 1500 is down right now. Hopefully getting it looked at in the next few weeks but he believes the issue is a result of the AFM. He has a code for something related to a bad cylinder.

Hoping it’s just a coil or something easy, not thinking that is the case.

He bought a delete kit or whatever it is to bypass it a few months ago but never installed it. Truck is at around 260k.

not trying to open a can of worms or anything i just wanted some feedback on AFM technology and whether it makes for a reliable, relatively worry free engine.

What is AMF? I could goggle

Never mind. It’s AFM. I goggled it.

riverruns wrote:

Never mind. It’s AFM. I goggled it.

Active fuel management. Basically shuts down half the cylinders to save fuel.

2007 no problems 108000 miles, uses about a quart of oil 1500 miles.

crappie55369 wrote:

not trying to open a can of worms or anything i just wanted some feedback on AFM technology and whether it makes for a reliable, relatively worry free engine.

Me either sorry I didn’t realize that it was called active fuel management. I hate the idea and that was the number 1 reason I put a tuner in my ram. Sorry I posted before I thought about it. If you look into a tuner you can buy a tuner that shuts that off and it’s not hyping your truck up or doing anything crazy leaves in a normal mode just shuts down the things you don’t want and a very relatively inexpensive

I put a edge pulsar tuner in my 17 ram. It runs as a stealth unit. So I take it out prior to service work and it can not be detected. I eliminate shutting down to 4 cylinders. I would highly suggest finding one for your truck if you buy it and do the same. I never play with power booster or nothing like that. I also set it to fully turn off traction control.

I have a BIL that had an ’06 or ’07 Trailblazer with an AFM 5.3 that had a catastrophic engine failure at a bit over 100K. I thought it was a fluke. I bought a ’12 Tahoe with an AFM 5.3. Last summer, the week after it hit 100K, I toasted the engine. I spent almost $4500 on a used engine and traded that puppy in a few weeks later.

There are plenty of good ones on the road, but there are enough horror stories out there, too, that I won’t buy another.

It seems after 2012 they upgraded the system to make it more reliable, my wifes 2010 Yukon with the 5.3 has it and I will be tuning it out. It has 150k on it with no issues but I need this vehicle to go to 220k which shouldn’t be a problem with the 5.3 but the AFM might hinder that. My dads 2014 sierra with a 5.3 has 180k on it with absolutely no issues either.

Bearcat, when you tuned yours, are the dodge like the gms where it has a special cam shaft to allow cylinder deactivation? I know you can just tune it to prevent cylinder deactivation but some people suggest installing a non AFM cam as well. I won’t be going this route but was curious if you knew how the dodges did it.

I have a buddy that is big into cars. Was telling me when chevy first released this i know the engines lifters would start going out on the ones that would be shut down. He made a pretty good amount of money replacing lifters in those generations and reselling…

Bearcat, when you tuned yours, are the dodge like the gms where it has a special cam shaft to allow cylinder deactivation? I know you can just tune it to prevent cylinder deactivation but some people suggest installing a non AFM cam as well. I won’t be going this route but was curious if you knew how the dodges did it.
[/quote]

I dont know anything about the cam mods. All I know was dodge guy told me the shut down cylinders are always changing. So it has even wear through out the motor. But I dont like that idea no matter what. And it makes the exhaust drone and sound terrible in 4 cylinder mode. So I did that tune to eliminate it. I also have a buddy who did the same in his 2012 Chevy for that reason but I’m not positive on the cam answer

My next vehicle will have AFM. Chevy truck. I plan to purchase a device that will disable it along with start/stop.

Attachments:

1. 

   download-1.jpeg
   

suzuki wrote:

My next vehicle will have AFM. Chevy truck. I plan to purchase a device that will disable it along with start/stop.

Make sure it runs stealth if you have any kind of warranty. Other wise it will void when something goes haywire. That’s why I went in to lots of searching for mine. It runs completely stealth. Not detected. But now the 2019s have no tune that will run stealth yet

Bearcat89 wrote:

<div class=”d4p-bbt-quote-title”>suzuki wrote:</div>
My next vehicle will have AFM. Chevy truck. I plan to purchase a device that will disable it along with start/stop.

Make sure it runs stealth if you have any kind of warranty. Other wise it will void when something goes haywire. That’s why I went in to lots of searching for mine. It runs completely stealth. Not detected. But now the 2019s have no tune that will run stealth yet

Good point. They say this one does. It plugs into the diagnostic port and must remain attached to work. I’ll dig deeper when it comes time to purchase. Thanks for the heads up.

suzuki wrote:

My next vehicle will have AFM. Chevy truck. I plan to purchase a device that will disable it along with start/stop.

That is what I run in my chevy.

/blockquote>
Good point. They say this one does. It plugs into the diagnostic port and must remain attached to work. I’ll dig deeper when it comes time to purchase. Thanks for the heads up.
[/quote]

I have a buddy who did that to his 15 not knowing of warranty void and when he unplugged it, the computer tattled and showed he deleted it. Ended up voiding a issue not related to the delete kit. So when you purchase I suggest researching and or going to a shop that deals with them and they will explain everything.

Its seems a little strange to me that someone would pay for a truck with a technology on it, and then turn around and pay more money to add something to it to turn off / Bypass the technology that they originally paid for in the 1st place.

fishthumper wrote:

Its seems a little strange to me that someone would pay for a truck with a technology on it, and then turn around and pay more money to add something to it to turn off / Bypass the technology that they originally paid for in the 1st place.

Well I wanted a new truck with warranty, but it’s not a option in the truck i bought to not have all this dumb crap that I prefer not to use. I’ve stated before I’d rather buy a new 98 silverado. But that’s not possible.

fishthumper wrote:

Its seems a little strange to me that someone would pay for a truck with a technology on it, and then turn around and pay more money to add something to it to turn off / Bypass the technology that they originally paid for in the 1st place.

Who buys a v8 and then wants it to run on 4 cylinders. And who wants the truck to shut off at every stop light and sign. Is the fuel your saving( which isn’t much) worth the wear on the electronics and cylonoids that’s making that work.

To be blunt, YES. Pre-2012 had issues with the lifters not properly functioning and more or less destroying the motor. It can still happen with new engines, but it’s incredibly rare.

The disabling devices don’t solve oil consumption issues, they can actually make them worse by the high pressure oil pump bypassing the lifters and squirting the lower cylinder walls. If it’s a post 12′ vehicle, I would leave it. The lifters aren’t known to cause much of an issue.

The more crap you add to anything the higher the probability is of failure.
It is simple logic. More $hit, more problems.

I ran a Range delete device on my 2014 2ss/rs camaro and it did work for keeping it firing on all 8. But, I was looking for better throttle response though and it didn’t achieve that at all! I also installed an oil catch can to prevent oil from getting back into the intake manifold so I didn’t need to have that cleaned as recommended with AFM. The best bolt on mod was when I installed a Vitesse throttle controller, think fire by wire as in race cars and it was exactly what I was looking for.

riverruns wrote:

What is AMF? I could goggle

I know what that means,can’t say it here

If I got another GM truck,I would go with a Black Bear tuned PCM.

It will be interesting to see how the new DFM(Dynamic fuel management)works.I am sure the tuners are already preparing to modify that?But manufacturers are making it harder to jailbreak electronics.GM was always the easiest,and Toyota the hardest.

fishthumper wrote:

Its seems a little strange to me that someone would pay for a truck with a technology on it, and then turn around and pay more money to add something to it to turn off / Bypass the technology that they originally paid for in the 1st place.

I think its strange I cant buy what I want from a company that sold what I want for so long. So I will modify to accommodate.

I think its strange I cant buy what I want from a company that sold what I want for so long. So I will modify to accommodate.
[/quote]

This is exactly right. I absolutely hate the afm in my 2015 Chev. So much I thought about going back to my old faithful 06. I’ve been researching delete stuff just haven’t pulled the trigger.

I could probably live with AFM but not start/stop. Luckily you can turn off s/s but must do it every time you start the truck. Seems like AFM should turn off when you activate tow/haul mode?

suzuki wrote:

I could probably live with AFM but not start/stop. Luckily you can turn off s/s but must do it every time you start the truck. Seems like AFM should turn off when you activate tow/haul mode?

Mine would turn off if I turn on two haul. But of I remember correctly it eliminated 6 7 and 8th gear. Kept me in higher rpms.