AFM/DFM De-Activators

[Drew98]

Good Afternoon all. Long time viewer / lurker first post. Have learned and laughed a lot.
Anyway, anyone with any experience with aftermarket AFM deactivators that plug into the OMBd port?
I cant seem to find anything listing any potential "side affects" of said device. But, nothing sounds good about longevity of these engines (2013 Silverado 5.3L) and their valve trains.
Have heard some bad stories of guys aftermarket tuning their diesels, with substantial costs.

Thanks again.

 

[JimH]

If it's a 13 year old engine and still running good, what are trying to fix?

Usually any failures these have are mechanical, the plug in tools don't change the hardware.

 

[Theronswanson]

You can't just plug a tune into the ECM and be done with it. You need to replace the lifters, valley plate, camshaft, VVT solenoid (if equipped) etc.

 

[mreisner]

Have one on my 2018 Silverado. Works perfect,230k on truck now, 1/2 qt. Oil burn in 6000 miles, no torque converter issues. I have the Range one, highly recommend it.

 

[mreisner]

You can't just plug a tune into the ECM and be done with it. You need to replace the lifters, valley plate, camshaft, VVT solenoid (if equipped) etc.

If they don't engage they don't wear out.

 

[BillK]

What most people dont realize is the actual camshaft for the AFM engines is different. The lobes on the AFM cylinders are different. Yes they do make things to bypass the electronics but it really does not do it correctly.

If you want to spend money on something spend it on more frequent oil changes with the correct oil and you probably wont have an issue.

 

[66Caprice]

They work. All they are doing is telling the ECU not to go into the deactivation mode. I have one and so does my brother. They work fine.

 

[Wrench97]

The OBD2 port devices stop them from engaging but the lifters will still fail, the screens in the oil galley will still get plugged up.

 

[ericm]

Have heard some bad stories of guys aftermarket tuning their diesels, with substantial costs.

I don't know of any diesels with AFM. Aftermarket tunes to raise power, whether diesel or gas, are a completely different problem. Especially with turbo engines where you can get a lot more power from a tune. Many of the diesel truck transmissions can't handle the power the engines can be tuned to make. Or tuners in pursuit of numbers to get sales will push things too far. Even worse is when the tuner has software that lets the user monkey with things. I loved the way that the Cobb Accesstuner let me fine tune my Mazdaspeed3's throttle mapping but it also let you lean out the mixture and raise the boost way more than was safe. I used those options, but carefully. A lot of guys with less restraint blew up their engines.

Three of our four cars have tunes. Even my wife's car. I love that we can do them. The one that's still stock is the diesel pickup. It already makes enough power for its intended use and the transmission can't handle significantly more power.

 

[Rccrawlerguy]

My dad and I have used a couple of different brands on trucks in that era. The Range brand, is what one of us bought first, then we found some no name brands on Amazon. We were skeptical first about the cheapo ones, but he has had one on his truck for several years. I would suggest in buying an OBD2 port Y harness adapter. That way you can still access the OBD if you need without disconnecting the AFM- disable device.

A close friend had a truck with AFM, it had a miss (from the "stuck" lifter) He bought one of these devices. Some time later, he had a CEL come on. unplugged the AFM- disabler, plugged in a scanner, did whatever he had to. Started the truck ( device unplugged) and the miss/lifter noise came back. He plugged the thing back in, but too late. The lifter didn't quiet down.

But like ronswanson said... The "right way" to do it, is buy the parts and rebuild engine without the AFM, then reprogram computer to disable. If you use one of these, it keeps all cylinders active, all the time.

If your engine already has a miss or lifter noise, it is a **** shoot whether it will work or not. Might be too late.

 

[Gangly]

Range seems to be the go to as far as OBD II DLC port disablers are concerned. Though cylinder deactivation electronic control is bypassed, the hardware is still present (lifters and AFM/DFM cam). Lifter failures still occur even with the DOD disablers present, albeit it at a significantly lower rate, so don't assume you have eliminated the problem just because you installed a disabler.

The best thing you can do is pull the lifters, install a DOD delete kit, tune out the AFM/DFM all together and run with it. Yes, the modern LS and LT cams are designed with DFM and AFM applications in mind, but the lobe profile changes are so minimal that they will have zero affect on lifter longevity or engine performance when you switch to a non-collapsible lifter. 90% of DOD delete kits are being run with the stock cams, so don't worry about that.

The DOD kit can be installed in your garage over a weekend if you are mechanically inclined at all.

 

[472scout]

Regarding VVT. It's not the same system as AFM and is generally considered reasonably reliable and effective. Be careful of the advice here.

 

[zimman]

Regarding VVT. It's not the same system as AFM and is generally considered reasonably reliable and effective. Be careful of the advice here.

And VVT is affected by low oil, too much oil, wrong viscosity, oil additives (like Dad used) and stupidity. LMAO
Zim

 

[CraigStu]

The Range device is very popular w/ C7 Corvettes w/ auto trans. The auto trans car activate the 4 cyl mode automatically where the standard trans cars have a switch to lock out the 4 cyl mode.

 

[ER70S-2]

The hardware in these engines needs to be replaced (cam, lifters, valley plate, etc.). A deactivator might tell it not to go into AFM mode, but to avoid failure, you HAVE to replace the suspect parts. Deactivators are useless for these engines if preventing catastrophic damage is your goal.

 

[575cat]

Diablo

 

[ER70S-2]

If they don't engage they don't wear out.

This is, unfortunately, incorrect.

 

[mreisner]

While the lifter itself is a poor design if it's disabled right from the start and oil changes are kept up the chance of having a random lifter failure are greatly reduced with it. We've done a few of them and never had the problem unfortunately we didn't do it on our 2013 and did have the problem and had to change a few lifters.

 

[ER70S-2]

The engines that grenade seem totally random. The only way to 100% prevent failure is to swap the hardware. It's really not that hard and you can put a custom grind cam in at the same time to relieve some of the sting.

 

[Firebrick43]

The hardware in these engines needs to be replaced (cam, lifters, valley plate, etc.). A deactivator might tell it not to go into AFM mode, but to avoid failure, you HAVE to replace the suspect parts. Deactivators are useless for these engines if preventing catastrophic damage is your goal.

They are not useless. Maybe it’s not a 100% but it’s far from useless on the early DOD engines.

Failures post deactivation are significantly reduced on the early DOD engines that shut off the odd bank, which the OPs engine is. And lifter failures are

The later engines that can shut off any cylinder has an even worse design and should be deleted by lifter/cam replacement as catastrophic damage is typical.

 

[ER70S-2]

They are not useless. Maybe it’s not a 100% but it’s far from useless on the early DOD engines.

Failures post deactivation are significantly reduced on the early DOD engines that shut off the odd bank, which the OPs engine is. And lifter failures are

The later engines that can shut off any cylinder has an even worse design and should be deleted by lifter/cam replacement as catastrophic damage is typical.

I hear what you're saying, but to be clear, when I said that they're useless, I meant they are useless in 100% preventing catastrophic failure, which I think you agree with. It's not a fix. It's more of a band aid.

 

[ripperd]

Put one in our 2017 when at 100k miles the torque converter went out to lunch and killed the ******. rebuilt ******+torque converter and a AFM disabler and its working great these days.

The trans shop does the AFM disabler partially for the AFM part, but partially for torque converter longevity. It sounds like the computer lets the TC clutches be partially engaged and slip a little bit each time the motor enters or exits v4 mode, causing extra wear on the TC clutch material. The OEM torque converters had not enough clutch material to begin with and would wear it all aout and begin metal on metal, sending metal bits throughout the transmission.

 

[dr.k]

As I understand the issue, on newer LS engines the cylinder heads must be removed to get the lifter units out of the block valley.
There is a work around, but who would reuse old lifters on a new camshaft?
Not me or any other mechanic I know!

 

[ER70S-2]

As I understand the issue, on newer LS engines the cylinder heads must be removed to get the lifter units out of the block valley.
There is a work around, but who would reuse old lifters on a new camshaft?
Not me or any other mechanic I know!

What issue?

All LS engines are like that. The workaround you're probably thinking of is to hold the lifters up with dowels so the cam can be removed without needing to remove the heads or lifters.

 

[Burl]

My 2010 Silverado with a 5.3 and 135K has recently developed a small miss at idle, but runs good otherwise. A friend who is was a GM tech in his earlier years recommended a Seafoam treatment directly into the intake, cleaning a possible buildup around the intake valves. Also sounds like it could be a lifter problem.

 

[ER70S-2]

My 01 4.8 without AFM has 19x,*** on it and runs perfect

 

[Drew98]

Thanks for all the information.
I got over 350K on my 2011 which I still have, with a slight lifter tic, but no oil burn. Just body went to hell in N. IL.
Was just curious because i have been hearing A LOT of horror stories lately. Not sure if its just a GM burn or what.
Started watching the V4 activation sequence and was kind of shocked how many times and how long it engages.

 

[ER70S-2]

Thanks for all the information.
I got over 350K on my 2011 which I still have, with a slight lifter tic, but no oil burn. Just body went to hell in N. IL.
Was just curious because i have been hearing A LOT of horror stories lately. Not sure if its just a GM burn or what.
Started watching the V4 activation sequence and was kind of shocked how many times and how long it engages.

I'm a big proponent of getting the AFM hardware out of the engine, but if you have 350K on it, I wouldn't touch a thing.

 

[minytrker]

I disable AFM/DOD on a regular basis using calibration software to turn it off directly in the ECM. The cost is typically $100–$200, depending on the model year and platform.

I also offer the Range AFM/DOD OBD-II plug-in device; however, at $239.95, most customers opt to have the ECM flashed instead.

 

[dr.k]

Like I said.
Do you want to depend on used lifters on a new cam?
Not me!

 

[minytrker]

Thats just turning off the system. If we do a full delete we pull the engine, remove the heads, get the heads re-done at the machine, change all lifters, non dod cam, oil pump and all nessary seals and gaskets.

 

[Dan in Pasadena]

I've read online that Chevy discontinued cylinder deactivation on 2025 and 2026 5.3's but it's not been formally announced, it's reports from user forums like this and others. The failure are spring loaded lifters collapsing and then damage to camshafts. I've read that the lifters used on the engines are VERY sensitive to ANY reduction in oil flow so disregard the built-in oil changes sensors and go to short durations between changes like 3,000 miles, sometimes even sooner.

I'm driving a '21 Silverado High Country 3.0 Duramax and I really love this truck. Looks damn good, plenty of power, great mpg. Amazing for such a small displacement straight six. I bought it used w/62k miles BUT I finally had the trans pump go at 82,000 miles - covered under warranty then the Coolant Control Valve and those puke because of the damn Autostop function. Covered too BUT not the radiator replacement that they said caused it - $2700. All this has me afraid to own a new truck - any make - without warranty. That trans would have been $7400 if not covered.

Not sure what I'm going to do but I'm at 90,000+ miles running out at 100,000 or in December this year. Thinking MAYBE getting a 2025 5.3 but only if no cylinder deactivation, then be religious about short oil changes. I need reliability.

 

[ddurrett896]

I've read online that Chevy discontinued cylinder deactivation on 2025 and 2026 5.3's but it's not been formally announced, it's reports from user forums like this and others. The failure are spring loaded lifters collapsing and then damage to camshafts. I've read that the lifters used on the engines are VERY sensitive to ANY reduction in oil flow so disregard the built-in oil changes sensors and go to short durations between changes like 3,000 miles, sometimes even sooner.

I'm driving a '21 Silverado High Country 3.0 Duramax and I really love this truck. Looks damn good, plenty of power, great mpg. Amazing for such a small displacement straight six. I bought it used w/62k miles BUT I finally had the trans pump go at 82,000 miles - covered under warranty then the Coolant Control Valve and those puke because of the damn Autostop function. Covered too BUT not the radiator replacement that they said caused it - $2700. All this has me afraid to own a new truck - any make - without warranty. That trans would have been $7400 if not covered.

Not sure what I'm going to do but I'm at 90,000+ miles running out at 100,000 or in December this year. Thinking MAYBE getting a 2025 5.3 but only if no cylinder deactivation, then be religious about short oil changes. I need reliability.

I’ve got a 25’ Yukon with the 5.3. Where do you read they removed the cylinder deactivation?

 

[JimH]

I've read online that Chevy discontinued cylinder deactivation on 2025 and 2026 5.3's but it's not been formally announced, it's reports from user forums like this and others. The failure are spring loaded lifters collapsing and then damage to camshafts. I've read that the lifters used on the engines are VERY sensitive to ANY reduction in oil flow so disregard the built-in oil changes sensors and go to short durations between changes like 3,000 miles, sometimes even sooner.

Don't believe everything that you read on the internet. I don't care what Abraham Lincoln said about it.

 

[Theronswanson]

Don't believe everything that you read on the internet. I don't care what Abraham Lincoln said about it.

Abraham Lincoln never told a lie though......

 

[JimH]

Abraham Lincoln never told a lie though......

That was George Washington, and I haven't seen any quotes from him about the internet...

 

[Wrench97]

What cherry tree?

 

[Dan in Pasadena]

Don't believe everything that you read on the internet. I don't care what Abraham Lincoln said about it.

I just WANT there to be used 2025 5.3's without the cylinder deactivation and the unreliable lifters it brings. May or may not be true.......with my luck of course it's not true.

 

[Theronswanson]

That was George Washington, and I haven't seen any quotes from him about the internet...

Honest Abe???.... Anyways I read it online so it has to be true. It's in the Geneva Convention

 

[JimH]

I just WANT there to be used 2025 5.3's without the cylinder deactivation and the unreliable lifters it brings. May or may not be true.......with my luck of course it's not true.

If you believe the internet, every V8 GM has built in the last 20 years has blown up from AFM/DFM. I have put well over 100,000 miles on 2 of them and have 70,000 on my third, all without any issues. Don't let the horror stories scare you, they are actually pretty good engines.