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L9 works on the 2023 Silverado 1500 5.3 V8! I tested it today to and from work. Managed to get close to 22mpg with speeds up to 62mph. No vibration, no weird sounds, and no transmission weirdness!
Does it still work? I'm from Germany and I recently bought a 2022 Chevy Trailboss with the 5.3 l / 10 speed engine and I heard from the problems with the lifters. So I think about to buy the Pulsar LT to avoid this. I'm a bit concerned...
I did this also, as for mileage with my Silverado I've seen more variation depending if I had a headwind or not. My transmission temps down the hiway did increase to just over 200*, not really a good idea but not a deal breaker either. As for extending the life of the lifters it will. The lifter collapses when it unlatches and gets stuck in that position, if it never shifts it doesn't get stuck. Because of that I installed a AFM/DOD eliminator to check operation. It was 50 bucks, plugged into the ALDL port on my truck and works great. No more shifting cylinders, the trans runs over 15* cooler running down the hiway and it shifts much better with no lag waiting for a proper engine state to complete a shift. You can run around in manual mode but for the minimal cost the plug in mod it works very well for me and I don't have to think about anything except much better performance.
Great video. I bought a 22 Silverado, and it told to me that unlike the previous models, the newer engine didn’t just go from 8-4. The dealer told me that, with my 8 speed transmission, the deactivation could do any of 18 different modes, including dropping to only 2 cylinders. Now, I kept that truck about 18 moths, and found it to be very good at handling whatever was needed. After helping one friend with moving his belongings (including towing a car) from VA beach to Jax, we could tell when it was dropping down to 4 cylinders, due to my after market exhaust. What really truly impressed me though was driving from Tri Cities Tennessee out to Palm Springs to tow home a 1978 Thunderbird Diamond Jubilee edition. On straight runs, and running
How are you telling that the truck dropped down to 2 cylinders? I don't know of any indicator that says whether DFM is active, let alone how many cylinders it has dropped down to.
I used the system for over a year. Used a full tank of fuel over my normal driving week on average. Then started using L9 mode to prevent it activating. Started using only a half a tank of fuel during my normal driving week. Tested this by again using the system again a full tank a week. Went back to L9 moded again only a half a tank of fuel a week. I now only use L9 mode in my silverado. This is every day normal weekly driving. I haven't tested it for long distance freeway mileage. This is just my normal every day driving.
Thanks for the follow up on this after a year of changing your driving pattern and sharing your experience of using L9 around town for an extended period of time.
Just watched this video. I have a pulsar LT, and I've been using it for over a year now with no negative effects . As far as shifting back in and out of manual mode to L9. That's just something I personally don't want to mess with. I like most of your mods and I'm in the process of doing several on them to my 2020 GMC 1500 Texas Addition. I'm not interested in doing a full exhaust I'm just doing a muffler, and looking for a good pair of quad tips that doesn't take the bank to buy. Keep up the good work. I really enjoy all your videos.
I have a 2020 with the 5.3 8-speed. Shifting to L7 does NOT disable the DFM on mine. It still dropped cylinders. Finally broke down and purchased the Pulsar LT. Well worth the money to no longer hear the choppy sound of the DFM. As an added bonus my exhaust has a spectacular sounding gurgle thru my flowmaster while slowing down with it disabled.
From what I've heard, once the lifter has "deactivated" and has been commanded to go back into use, is where the problem exists. They drop out and won't come back without some damage being done to the lifter, getting stuck and damaging the cam. my thought is that if you prevent the lifters from going relaxed in the first place, it lessens the chances of effing up.
Doesn't the problem exist when they are constantly having to work in different driving conditions?? Is it a "damned if you do and damned if you don't" scenario?
@@edscorsese It could be, but I think that if you're going to have something activating and deactivating hundreds or thousands of times a day that eventually it's going to fail. If you don't work the device, it's less likely to screw up.
I’m a mechanic by trade but been in the collision industry last few years. I can’t picture how they have lifters set to deactivate. Seems like it would be on a compression stroke maybe the exaust would stay open? I don’t get it. I’ll have to see some videos of it mechanically working I guess
I had 2014 with afm. Bought Range AFM disabler. It kept my SILVERAYDO in V8. I read up on it before purchasing, and some said that they lost a couple of miles some said that they stayed the same and very few said they gained couple as I did. But in all everyone one was happy with the purchase. At the time it was $200. I’m sure it’s gone up a little but it’s something to look into. They do have one for DFM.
For the newer V8s with 10spd transmissions, the PulsarLT is the only plug-in option. It is $500+ depending on where you are and ordering it from. The install is a little more involved but still DIY
@@Donslife right on a buddy of mine bought a 2022 Sierra I was telling him about it so looked it up to verify if it worked for DFM ( it’s says it does on the range website ). Also looked for it on here and nothing for range DFM but pulsar LT. Thanks for the clarification, bud.
I have 08 Silverado. Installed a A F M disabled. It has a 6 speed. 350k did pretty good. Changed oil religiously. Did pretty good...But it has worn out not only collapsed inner spring loaded but camshaft to. Very expensive repair. Love the truck. Other wise. Very dependable. 👍🏻 5.3 by the way
Great video very informative. I use this also in my 2012 Silverado. But I am taking it to a shop that will do a AFM disable through an HP tuner then I’ll be able to use six gear again, I believe my gas mileage will be almost as good as if it used AFM.
I have had 2 - 6.2's and my 2015 lifters failed, after replacement I immediately disabled AFM and never had another problem. My current truck is a 2020 AT4 and I disabled the AFM as soon as I got the truck, 45k no problems. I highly recommend deleting or disabling the AFM immediately, I would rather be safe than sorry. Engines were not made to run this way. I personally also have a catch can as well that I empty regularly between oil changes with lots of nasty goo inside that I would not want going back into the top of my engine. Cheers!
I have a 2013 Silverado Lt 5.3. I bought it used with 160k on it. At about 170k I had my first misfire on cylinder 7. I changed the plugs( #7 was burnt to a crisp). I didn't have any problems till about 190k and in one week I had 2 more misfires on cylinder #7 . At this point I did some research and found your video and applied your method to my every day driving and I'm at 200k and haven't had a misfire since. I get in put the trunk in Manuel and shift to 5th gear and pullout. no issues whatsoever. I also have done a muffler delete and still no issues to date.
I've tried the L9 selection method for disabling the DFM in my 2023 Yukon XL and it appears to work as advertised. However, because my daily driving includes both town & country (highway) roads, I'm not sure how fast I should be driving before it becomes detrimental to the engine and should be switched back to the Drive mode. I'd like to purchase a Range Technology Plug & Play AFM/DFM Active Fuel Management Disabler; however, they don't yet make one for the 2023 GMC Yukon XL. 😕
I do a lot of travel in the mountains here in Oregon and oftentimes have to use the L gears when coming off the mountains behind slower traffic and not relying quite so much on the brakes. I didn’t realize I could switch to manual L7 (I have the 8 speed) while at a standstill. Thanks for that tip!
The number next to the L is the top gear you want the trans to go to. Like if you are towing something. You don’t want it to go into 10th because it’s an extra overdrive. Basically means that every time you touch the pedal, it will shift. Lowering the top gear while towing will lower your amount of gear hunting at higher speeds and keep you in a better power band.
"A bad lifter is a bad lifter. Even with DFM deactivated the lifter will eventually fail". I wanted a GMC Sierra Elevation but I can't buy one with the multiple quality issues of which the lifter issue is at the top. Only real option is a used Tundra prior to the change to the twin turbo mess.
Thanks Don for this very informative video. I was wondering about everything that you were telling us about. Specially the info on driving in L9 to avoid lifter failure. I just experienced this problem in the last month. I had to have all of the left bank lifters replaced on my 2020 GMC Sierra Elevation 5.3 liter because of lifter failure. I only have 12,500 miles on the truck so it was still under warranty and GM covered the cost. So when I found your first video on driving in L9 and how it might avoid lifter failure I was very happy. Now, after hearing what you said that it would not prevent lifter failure I not very happy😢. Thanks again for the information I do appreciate it. 👍
@@Donslife So, then, I'm going to assume you no longer suggest switching to L9? If it's accurate to say that it is only a matter of time before the lifters fail, then I'd rather run it in D and let the failure begin while my truck remains under warranty rather than delaying the inevitable and getting stuck with a repair bill after the expiration of warranty.
The products, such as the Range Disabler, help with lifter failure. In fact, my GM tech told me the lifters fail because they're not in use. Of course, that was an off-the-record comment, but I trust his opinion since he sees so many of these issues at the dealer.
I just bought a brand new Tahoe 2024 with a 6.2 L engine and I saw your video and I was worried about it. I just got rid of a 2024 Duramax pick up truck diesel engine 2400 HD and believe me when I took it for inspection they said oh you need a software update at that point I said to myself all right I’m treating this piece of junk in and getting a Tahoe and now I found out about all this engine stuff so I did what you actually said I went to work one morning and there’s hardly anybody on the road so I did put it in L9 and you’re absolutely right it makes a world of difference, also when you’re sitting at a stoplight or a stop sign, the oil pressure doesn’t move as much so I know now that the solenoids aren’t firing. The oil is rocksolid now in L9. Thank you very much for the video very informative and you’re a professional when you make these videos really happy the truck runs really good and L9 now thank you again.
I have a 2024 Silverado 3500HD SRW with Duramax and had to get the emmisions software update with no difference is operation. The factory only downloaded part of the program and there was a recall on the emmisions. As a matter of fact, my check engine light did come on and I did the OnStar diagnostics check and they told me it was the emmisions. But as far as the 2024 Duramax being a piece of crap, it's one of the finest trucks I have owned. I had a 2021 Duramax before it and this one if significantly better.
I have a 2016 5.3 with AFM. I have the range afm disabler and it works. The engine stays 100% on 8 cylinders. I don’t know if it’s going to prevent lifter failure but the truck drives much better.
Hi Don I have exact same truck as yours year, Color, options. I hate the auto shut off/start, and DFM. Your videos have been most helpful. Cheers from Ontario
The way cylinder deactivation works on a DOHC engine is totally different compared to a pushrod OHV engine. That isn't to say it will be reliable. Even Honda has had issues due to their use of cylinder deactivation.
@@JeffBarnaby-p8e See the problem with what you're saying is that in 99 the 5.3 didn't have all the extra AFM/DFM/DoD crap in it. So yes they were mechanically much more simple, reliable engines that are still on the road in vast numbers today having never been rebuilt. Once GM introduced the cylinder deactivation their reliability went through the floor because of variable state hydraulic lifters that can collapse and take the cam out causing you to need a serious rebuild that could get you to the $10k mark in repairs. Do you really want to buy a $40k truck that will likely need a $10k engine rebuild within 100k miles? I certainly don't. I recently sold my 2004 Silverado 1500 with the 4.8l V8 to a family member who was in bad need of a truck to work in. So when I buy another truck for myself (currently I can get around using either my primary or backup work van) I'm definitely not going to be buying a GM product specifically because of these engine issues. At this point I'd feel safer with a Ford with a 2.7l ecoboost than I would a GM engine with all the cylinder deactivation crap. I'll probably try to find a nice F150 with the 5.0 in it because at least it didn't have that crap (until either the 23 or 24 MY)
I am not comfortable with this new generation of truck's to buy one. I guess you figured it out, I'm old. Give me something problem free and I'll deal with fuel economy.tks for the video. 70 from pa.
At also works in a 6 speed tranny. I use the 5th gear when driving on back roads and around town. I actually gained fuel mileage on back roads doing that. The DFM never engaged.
Hey Don! Thank you so much for representing the true north so well. I have a 2021 Sierra 1500 Elevation with the 5.3. I wish I was still blissfully ignorant to this issue but recent issues and codes are seeing my truck head to the dealer for service. I’ll find out tomorrow or early next week if this is my issue. I’m wondering though, since you did this about 9 months ago, are you still running around town in L9 and what has your longer term experience been? I’ve also been considering the Pulsar. If my problem isn’t actually lifters it may be beneficial for me to consider either of these options in the hopes of saving trouble later!
I have a 2015 Chevy silverado.the number 4 cylinder went on it and the cost to replace it was 4 thousand dollars.i love it delete in my truck it runs way better then it did
I just bought a 07 Silverado i didn't know anything about afm so when u found out i got sick to my stomach but come to find out the previous owner had did a complete afm delete he did the lifters push rods cam shaft also he got rid of vvt so i dont never got to worry about liter failing because it doesn't have arm lifters no more that god
Lifter failures at higher mileage is caused by waiting too long to change engine oil. 7k is waaaaaaay too long. 5k is pushing it, too much if there is a lot of short tripping in cold weather. Changing it by 4k is probably a good balance. Learn about the abrasive soot that direct injection makes and how that soot ends up in the oil. Learn about how full synthetic reacts when the engine is short tripped in cold weather.
I have a 2018 Silverado 5.3 and an 8 speed transmission with a little over 58K miles. I drive in L7 almost all the time. I have notice at freeway speeds the rpm's are higher in L7 than in L8 or Drive. I would assume that means the fuel economy might be lower in L7. I don't check my mileage and the benefit of constant V8 power matters to me.
At 3:20 in this video I’m on the same page as you. Before my muffler delete mileage was up. Now with some good V8 noise mileage is down lol. Letting my 6.2L sing 🔊🔊
I could try to explain it to you but if youre not a mechanic you wouldnt understand why deactivating dfm will absolutely prolong if not completely prevent lifter failure dfm lifters have 2 seperate oil passages its hard to explain but basically the part of the lifter that allows it intentionally to collapse to deactivate it by deactivating it you arent working that part of the lifter which means again you greatly reduce if not eliminate possible failure people really dont understand how they actually work and the best thing you can do if youre not going to do it the right way and do a full mechanical delete then you atleast need to get a tune that completely deactivates it
Either trade it in just before warranty ends or totally delete/remove the AFM system or you’ll still have those faulty lifters in place. Mine bent the push rods and damaged the cam shaft which resulted in more work.
PLEASE READ ME!!!! Hey Don great video! I also wanted to take the time to add the following. Chester makes a lot of sense how the DFM works, but one thing I personally think that where all overlooking is the Auto stop/ start. You may ask why? Here's why I think when I bought brand new my GMG 1500 Sierra Denali crew cab 4×4 5.3 liter short bed. I'm a heavy hitter speed demon that is and all my vehicles I have put them through a good amount of speed and I have the tickets to show for em🤣. One thing I right away noticed when I took the truck for my 1st time cruise the truck went into AS/S mode at the light and I gunned it hesitated by a sec. Or 2 so I did research how to deactivate it and it showed me in the Manuel ever since then I never had issues other then getting frustrated with pressing buttons so eventually I canceled it with a pulsar. My truck has 21,000 miles and running strong of course I use synthetic oil, premium fuel, and has mods which yes I know that doesn't help but I maintain my truck to my driving ability! We all have that one triggeeing foot to gun it at the light but I think that feature by the time it responds to the take off, the lifters and valves don't respond to people's reaction time at light and makes that 1sec or 2 enough to cause a bent valve! That's my opinion on the As/S system. Sorry to make this long...... awesome channel!🤘😎🤘
One of the first things I did! Auto Start Stop Eliminator / Bypass GMC Sierra AT4. Full Review and Installation! th-cam.com/video/FGq25E2fRWU/w-d-xo.html
Hey Don, I've been binging your videos today because it's cold outside today 25F. Yeah,yeah,I know that's a heat wave for y'all in Canada. Anyway, I was wondering if the street sign at the 3 minute mark is a "Watch for Squatch" sign?
I have been using this "manual mode" or L5 mode (6 speed transmissions) for several years now, on a 2016 Chevy 5.3L and on my 2018 Chevy 5.3L Silverado. It definitely stops the afm & stays running on all 8 cylinders. Several years ago, I asked my local GMC dealer service manager if A) does this really work and B) does it cause any problems or harm? He said yes it does work, and it causes no problems. I think I might be getting slightly less mpg but the difference is so little I don't notice it. As I am an old school guy, I think running it always in the 8 cylinder mode is easier on the engine.
my yukon has a corsa driving in L9 the sound is more consistent the only issue is when I drive over 80 i have to shift either back to D or L10 otherwise the rpm will keep increasing
my 2017 50th Anniversary 2SS Camaro doesn't work this way. I have an 8 speed, and in manual mode, if I am in "M7" if my RPM's drop to a certain point when cruising it will actually still drop to V4 mode. I ordered a RANGE disabler... Now, I will say that if I leave it in an even lower gear it will mostly stay in V8 mode, but not just 1 gear down. at 55 - 60 MPH I have been running in about 5th gear or so, which is a higher rev (around 2800 RPM etc) and it will stay in V8 mode.
I put 0 miles engine from gm on my 2020 denali and from day 1 has de range technology chip , so we'll see if using 8 cyl all the time improves engine life
My truck is a 2008 GMC Sierra 1500 5.3. My display is manual lettering no digital. I recently got the Engine code of P3400 Cylinder 1 deactivaton solenoid. I don't see a way to disable AFM.
We are about to receive our 2023 1500 Sierra 6.2/10 speed. Though we are not happy about the DFM. Thank you for the follow-up video. Your truck sounds so good. I'm sure you did a video on your after-market exhaust, I'll look for it in your playlist. Was curious what you had installed. Thanks again ✌️out.
Nice 👍🏼 Here is the video : BORLA S-Type Cat Back Dual Exhaust Install Review 2019 - 2021 GMC Sierra Chevy Silverado 6.2L th-cam.com/video/lzjipXNF1UM/w-d-xo.html
Thanks for the tip Don! I just put a new Flowmaster muffler on mine with the 5.3 liter and 8 speed tranny. The new exhaust sounds great til it’s in 8th gear, and just cruising around town, then sounds horrible, as it kicks into V4. I tried L7 , and it was magic. In highway driving I just use D
Those lifters that are installed in the cylinders compress, to make that cylinder dead, the lifter itself doesnt fail, they just get stuck open or closed, Thats the design flaw of the lifter, so if you have the system never go into afm/dod mode then the lifter will not get stuck open or closed. As well as i leave mine in M5 (2011, 6l80 transmission) and at 80 mph its only at about 2500 rmps ish, not even screaming, on highways i leave it in M5, currently at 230k miles
I'm a lifelong Chevy owner and Master Certified Chevrolet mechanic. I now driving F-150 Ford I will never get in another Chevrolet pickup. I love the older trucks and cars as I am now a classic car Builder. Stay away from the Chevrolets
@donslife I was told that driving in L9 could have some negative affects on the transmission because of the change in RPMs versus being in drive… I’ve been driving in L9 99% of the time even in highways and haven’t had any issues. Have you heard of any issues.
From what I have learned about the potential problem, it is when the lifters are idle, then suddenly brought back to use, it causes a 'shock' to the lifter and cam. I purchased the Pulsar unit to permanently disable it. It may save me 50 bucks a year in gas if i used it, but could cost me $3500 repair in the future. I don't see the reward worth the risk.
I used a Pulsar LT on my ‘20 Trailboss 6.2 and loved it for about 20k until a lifter failed with DFM cancelled the entire time. I wouldn’t recommend buying a Pulsar if you think it will save the lifters. It’s still cool for the other features though.
@@Connor4x4 Going too long is the biggest one. I knew an older timer that had a 2011 Silverado 5.3 and changed his oil every 3000 miles or earlier. Never had an AFM issue in the ~190k miles he put on it. He retired and gave his youngest son the truck. That dunce started going 10k miles between oil change because that's what a lot of guys think you can do if you run a full synthetic and fancy filter. Less than 2 years later, lifter stuck.
@@travass100 Odds are the Pulsar didn't do the job it claimed to do and allowed the system to activate. A locked lifter should never be able to collapse without oil pressure there to unlock it.
I can attest to the fact that lifters can still collapse with AFM/DFM disabled with a Pulsar LT, Manual Mode or disabled in the tune itself. It happened to me... My Sierra is in the shop right now getting LS7 lifters, BTR cam, torque converter and a few other goodies all stemming from a collapsed lifter on bank 2 at 70k miles with AFM disabled in the tune since 38k miles. Maintenance was religiously followed. The design of the AFM/DFM lifters are prone to failure whether or not they're used for fuel management. Totally sucks. At least I'm getting cammed, baby! Chop chop chop chop 🤙🇺🇸
I just bought a 2024 Sierra 1500 elevation w/ dfm. Very helpful stuff. I love the truck but this is definitely something I’ll keep an eye on. I’ll prob drive on L9 to be safe, but also turn off the auto start/stop. Seems like this is the only worry with these trucks. Better than other defects with other trucks in my opinion. Anything else I could do to help prevent any dfm issues?
@@Donslife good to know. Thank you. I was driving in D today and i have an on/off button on my stop/start. Any time i drive in D I just turn that off too. Pretty smooth to be honest. I don’t feel any jump when i drive or lack of power. I’m gonna read the manual more when i get some time. Might start making videos about the truck also. Not many people on TH-cam that I see have these trucks.
Yeah I'm do for my first free oil change so I'm going to let the dealer look at it. My first thought was bad gas also. I put Lucas fuel treatment in it and new fuel no change. Just wondering if you had the issue before.
As a long time mechanic I disagree that disabling the DFM system won't help with reliability. The collapsible lifters have a release pin that when activated, allows the lifter to go into collapse mode. Just like anything mechanical, the more times those parts are activated, the more wear you will have on those parts to eventually cause a failure point. If the system is disabled full time you are far less likely that those lock pins will wear. Also, each time those parts are activated and then deactivated is a chance that they will not function correctly. Take away those chances are your failure percentage is much improved. As far as fuel economy, I don't have experience with GM but some experience with a Ram Hemi, MDS system (same concept as GM). The Ram I had actually seemed to get better fuel economy on the highway with the system disabled. I noticed that on sharper hills, the delay time of the MDS system deactivating actually caused the engine to need to 'recover' speed. Not so when deactivated manually. In city driving, the MDS seemed to help economy a bit.
I agree with you. I have to be mindful of how I phrase things on TH-cam. Someone might claim ‘you promised this would or wouldn’t happen’ and cause some unnecessary drama.
I put a Range deleter in my Denali and it stopped the 8cyl/4cyl transition but a very knowledgeable mechanic told me that I'll still have problems. He said poor engineering and they won't fix it. Why didn't you give some helpful results on the video. Are you saying this eliminates the collapsed lifter, busted cam, $10,000 problem or do you just like making videos. The buttons are right on the gear shift and for anyone that owns one already knows this.
DFM replaced AFM in the newest generation of these engines. Also the Range disabler isn’t fully compatible with all models yet from 2019+. Our best option is the PulsarLT which costs a lot more and has a more involved installation
My 2014 never drops down into AFM because i deleted it with a hog ass cam. And all of you should to. They make stock cams that are non dod/afm if you don't really want performance.
Well, like you I can only guess about lifter life, but I've got to think that disabling DFM would help to prolong their life because they don't have to perform the function required to shut down cylinders. They can just be normal lifters, no?
Do you notice when in L9 when coming to a stop it has a harsh downshift right before you come to a stop ? In D, it gives an engine/exhaust surge, but it’s only noise. The feel and shifting is smooth. In L9 the decel exhaust noise is great, but the last downshift before full stop is noticeable to me. Wondered your experience. Lastly is your column shifter loose feeling when in D. Mine has “slop” up and down. Thanks Great videos !!
I have a 2022 suburban with DFM that just had lifter failure at 43k . My 2015 with afm had lifter failure at 106k . The high hopes of dfm being more reliable than afm are dead wrong . I'm not the only one , I've had many conversations over the years with guys in the limo business who have been victims of this issue. The failure rate is exponentially higher than you think. I believe that the only true solution is a lifter retrofit kit to delete the Afm/dfm . Or .......... buy another brand . I'll be in the market for a Toyota sequoia next time around.
I had the same truck as yours. 2021 gmc AT4 6.2. The 4 lifters on the left side collapsed @ 40k mile. Had it repaired and traded it for the Chevy 6.2 ZR2. Hope I have better luck. Thanks for your good comments.
Hey Don, thank you for all of your videos! I have a 2024 5.3L 10 speed elevation with an aftermarket exhaust and typically drive it in L9 unless going above about 50-60 MPH. It seems to work great. I have read into if driving in L9 most of the time has any downsides apart from *maybe* fuel economy and came across it potentially being harder on the transmission. Is this something you've heard of and are you concerned about it?
Thanks for watching! In my opinion, the transmission is fine. I think towing is way harder on the transmission than using L9. I have not witnessed any real increases in transmission temps either. If anything, not using L9 I would experience some harder low gear shifts both up and down. Not often, but enough to notice.
Man your aftermarket exhaust tone sound awesome. I feel it doesn't sound loud at low-mid RPM, am I correct? Please let me know the exact exhaust setup. Thanks
Thanks! Here is the video: BORLA S-Type Cat Back Dual Exhaust Install Review 2019 - 2023 GMC Sierra Chevy Silverado 6.2L th-cam.com/video/lzjipXNF1UM/w-d-xo.html
I’d love be to know if my rumble on decel at 25-30mph is DFM, VVT, or torque converter. Does it M7 and M8. 2020 5.3 8-speed. So many systems cause similar problems.
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Does your truck have the 6.2 L engine
@@SKANK_HUNT49 yes it does
@Donslife ty so just lock out 10th gear and it will fire on all 8 cylinders?
Will the gears still shift all the way through on L9?
L9 works on the 2023 Silverado 1500 5.3 V8! I tested it today to and from work. Managed to get close to 22mpg with speeds up to 62mph. No vibration, no weird sounds, and no transmission weirdness!
Thank you for the update! The viewers will appreciate it!
My 2021 Silverado was built during the chip shortage. It was built without DFM. I get 22 mpg. 5.3. True V8. No problems at all
How would one know if their 21 has the dfm chip or not?
@@Nectaris73 it was on my build sheet. I forget the exact code but it would be on it.
@@Nectaris73RPO YK9
😂
I purchased a Pulsar LT a year ago, totally happy with the purchase. I wish GM would cancel the Autostop and DFM in their motors.
I did the same and I love it!
The auto stop in my 2020 trail boss has an on/off button.
Our government makes manufacturers reach high mileage requirements.
Does it still work? I'm from Germany and I recently bought a 2022 Chevy Trailboss with the 5.3 l / 10 speed engine and I heard from the problems with the lifters. So I think about to buy the Pulsar LT to avoid this. I'm a bit concerned...
@@insideoutsideupsidedown2218 my 2019 does too, but you have to push it every time you get in the truck. Pulsar disables it permanently
I did this also, as for mileage with my Silverado I've seen more variation depending if I had a headwind or not. My transmission temps down the hiway did increase to just over 200*, not really a good idea but not a deal breaker either. As for extending the life of the lifters it will. The lifter collapses when it unlatches and gets stuck in that position, if it never shifts it doesn't get stuck. Because of that I installed a AFM/DOD eliminator to check operation. It was 50 bucks, plugged into the ALDL port on my truck and works great. No more shifting cylinders, the trans runs over 15* cooler running down the hiway and it shifts much better with no lag waiting for a proper engine state to complete a shift. You can run around in manual mode but for the minimal cost the plug in mod it works very well for me and I don't have to think about anything except much better performance.
Great video. I bought a 22 Silverado, and it told to me that unlike the previous models, the newer engine didn’t just go from 8-4. The dealer told me that, with my 8 speed transmission, the deactivation could do any of 18 different modes, including dropping to only 2 cylinders.
Now, I kept that truck about 18 moths, and found it to be very good at handling whatever was needed. After helping one friend with moving his belongings (including towing a car) from VA beach to Jax, we could tell when it was dropping down to 4 cylinders, due to my after market exhaust.
What really truly impressed me though was driving from Tri Cities Tennessee out to Palm Springs to tow home a 1978 Thunderbird Diamond Jubilee edition.
On straight runs, and running
How are you telling that the truck dropped down to 2 cylinders? I don't know of any indicator that says whether DFM is active, let alone how many cylinders it has dropped down to.
@@greghale717 I just did some research bc I could hear the different tones from the engine.
Plus the dealer had told me to be aware
Two cylinders? 😮 wow, learn something new everyday. That was a good read. Thanks for the info. Enjoy!
I used the system for over a year. Used a full tank of fuel over my normal driving week on average. Then started using L9 mode to prevent it activating. Started using only a half a tank of fuel during my normal driving week. Tested this by again using the system again a full tank a week. Went back to L9 moded again only a half a tank of fuel a week. I now only use L9 mode in my silverado. This is every day normal weekly driving. I haven't tested it for long distance freeway mileage. This is just my normal every day driving.
Thanks for the follow up on this after a year of changing your driving pattern and sharing your experience of using L9 around town for an extended period of time.
For sure!
Just watched this video. I have a pulsar LT, and I've been using it for over a year now with no negative effects . As far as shifting back in and out of manual mode to L9. That's just something I personally don't want to mess with.
I like most of your mods and I'm in the process of doing several on them to my 2020 GMC 1500 Texas Addition. I'm not interested in doing a full exhaust I'm just doing a muffler, and looking for a good pair of quad tips that doesn't take the bank to buy. Keep up the good work. I really enjoy all your videos.
I have a 2020 with the 5.3 8-speed. Shifting to L7 does NOT disable the DFM on mine. It still dropped cylinders. Finally broke down and purchased the Pulsar LT. Well worth the money to no longer hear the choppy sound of the DFM. As an added bonus my exhaust has a spectacular sounding gurgle thru my flowmaster while slowing down with it disabled.
From what I've heard, once the lifter has "deactivated" and has been commanded to go back into use, is where the problem exists. They drop out and won't come back without some damage being done to the lifter, getting stuck and damaging the cam. my thought is that if you prevent the lifters from going relaxed in the first place, it lessens the chances of effing up.
Doesn't the problem exist when they are constantly having to work in different driving conditions?? Is it a "damned if you do and damned if you don't" scenario?
@@edscorsese It could be, but I think that if you're going to have something activating and deactivating hundreds or thousands of times a day that eventually it's going to fail. If you don't work the device, it's less likely to screw up.
I’m a mechanic by trade but been in the collision industry last few years. I can’t picture how they have lifters set to deactivate. Seems like it would be on a compression stroke maybe the exaust would stay open? I don’t get it. I’ll have to see some videos of it mechanically working I guess
@@sferg9582seems once it's deactivated it's permanent unless you remove the disabler.
Lifters are the failure.
I had 2014 with afm. Bought Range AFM disabler. It kept my SILVERAYDO in V8. I read up on it before purchasing, and some said that they lost a couple of miles some said that they stayed the same and very few said they gained couple as I did. But in all everyone one was happy with the purchase. At the time it was $200. I’m sure it’s gone up a little but it’s something to look into. They do have one for DFM.
For the newer V8s with 10spd transmissions, the PulsarLT is the only plug-in option. It is $500+ depending on where you are and ordering it from. The install is a little more involved but still DIY
@@Donslife right on a buddy of mine bought a 2022 Sierra I was telling him about it so looked it up to verify if it worked for DFM ( it’s says it does on the range website ). Also looked for it on here and nothing for range DFM but pulsar LT. Thanks for the clarification, bud.
Got the range in my 17’ 5.3 Silverado. Seeing 1 mile less mpg . Very minimal -
Bought one the other day on Amazon for $220
I have 08 Silverado. Installed a A F M disabled. It has a 6 speed. 350k did pretty good. Changed oil religiously. Did pretty good...But it has worn out not only collapsed inner spring loaded but camshaft to. Very expensive repair. Love the truck. Other wise. Very dependable. 👍🏻 5.3 by the way
Can’t complain too much with 350k
Great video very informative. I use this also in my 2012 Silverado. But I am taking it to a shop that will do a AFM disable through an HP tuner then I’ll be able to use six gear again, I believe my gas mileage will be almost as good as if it used AFM.
I have had 2 - 6.2's and my 2015 lifters failed, after replacement I immediately disabled AFM and never had another problem. My current truck is a 2020 AT4 and I disabled the AFM as soon as I got the truck, 45k no problems. I highly recommend deleting or disabling the AFM immediately, I would rather be safe than sorry. Engines were not made to run this way. I personally also have a catch can as well that I empty regularly between oil changes with lots of nasty goo inside that I would not want going back into the top of my engine. Cheers!
I have the Pulsar, but I don't think it works for the refresh just yet.@rxw5520
Good to know. I just got a 5.3L V8 Elevation. Had no idea about these issues. Will buy a Range to put in to disable and keep it in V8 mode.
How big of an expense is lifter replacement on a 6.2L? Thanks.
I have a 2013 Silverado Lt 5.3. I bought it used with 160k on it. At about 170k I had my first misfire on cylinder 7. I changed the plugs( #7 was burnt to a crisp). I didn't have any problems till about 190k and in one week I had 2 more misfires on cylinder #7 . At this point I did some research and found your video and applied your method to my every day driving and I'm at 200k and haven't had a misfire since. I get in put the trunk in Manuel and shift to 5th gear and pullout. no issues whatsoever. I also have done a muffler delete and still no issues to date.
Thanks for sharing
I've tried the L9 selection method for disabling the DFM in my 2023 Yukon XL and it appears to work as advertised. However, because my daily driving includes both town & country (highway) roads, I'm not sure how fast I should be driving before it becomes detrimental to the engine and should be switched back to the Drive mode. I'd like to purchase a Range Technology Plug & Play AFM/DFM Active Fuel Management Disabler; however, they don't yet make one for the 2023 GMC Yukon XL. 😕
I do a lot of travel in the mountains here in Oregon and oftentimes have to use the L gears when coming off the mountains behind slower traffic and not relying quite so much on the brakes. I didn’t realize I could switch to manual L7 (I have the 8 speed) while at a standstill. Thanks for that tip!
Don, I really enjoy your videos. They are very real life improvement and very informative. Keep them coming.
Thanks, will do!
I don't have DFM and my lifters have gone twice in 1st 6000km. So I doubt disabling it matters at all.
They do sell a full delect kit for this it replaces the cam, lifter pushrods.
Cool, who is offering it. I’d like to know more
Appreciate your videos Don! Always great clear info!
I’ve been running my 2019 5.3 in L5 for a year with no issues other than that annoying clicking stops. I always thought it was my transmission
so it stopped the clicking?
The number next to the L is the top gear you want the trans to go to. Like if you are towing something. You don’t want it to go into 10th because it’s an extra overdrive. Basically means that every time you touch the pedal, it will shift. Lowering the top gear while towing will lower your amount of gear hunting at higher speeds and keep you in a better power band.
I have a 2018 1500 5.3 had the DFM turned off by a tuner I know locally and it now gets 23 mpg while running all 8 cylinders.
How much charge?$$???
"A bad lifter is a bad lifter. Even with DFM deactivated the lifter will eventually fail". I wanted a GMC Sierra Elevation but I can't buy one with the multiple quality issues of which the lifter issue is at the top. Only real option is a used Tundra prior to the change to the twin turbo mess.
Thanks Don for this very informative video. I was wondering about everything that you were telling us about. Specially the info on driving in L9 to avoid lifter failure. I just experienced this problem in the last month. I had to have all of the left bank lifters replaced on my 2020 GMC Sierra Elevation 5.3 liter because of lifter failure. I only have 12,500 miles on the truck so it was still under warranty and GM covered the cost. So when I found your first video on driving in L9 and how it might avoid lifter failure I was very happy. Now, after hearing what you said that it would not prevent lifter failure I not very happy😢. Thanks again for the information I do appreciate it. 👍
Ya it has been a learning experience for me too. Subpar components can fail anytime. Thank you for watching!
@@Donslife So, then, I'm going to assume you no longer suggest switching to L9?
If it's accurate to say that it is only a matter of time before the lifters fail, then I'd rather run it in D and let the failure begin while my truck remains under warranty rather than delaying the inevitable and getting stuck with a repair bill after the expiration of warranty.
The products, such as the Range Disabler, help with lifter failure. In fact, my GM tech told me the lifters fail because they're not in use. Of course, that was an off-the-record comment, but I trust his opinion since he sees so many of these issues at the dealer.
I just purchased a 2023 Silverado RST 5.3
I will see if this works in it and update you tomorrow!
Well?
@@trounbyfire it did work...
I just bought a brand new Tahoe 2024 with a 6.2 L engine and I saw your video and I was worried about it. I just got rid of a 2024 Duramax pick up truck diesel engine 2400 HD and believe me when I took it for inspection they said oh you need a software update at that point I said to myself all right I’m treating this piece of junk in and getting a Tahoe and now I found out about all this engine stuff so I did what you actually said I went to work one morning and there’s hardly anybody on the road so I did put it in L9 and you’re absolutely right it makes a world of difference, also when you’re sitting at a stoplight or a stop sign, the oil pressure doesn’t move as much so I know now that the solenoids aren’t firing. The oil is rocksolid now in L9. Thank you very much for the video very informative and you’re a professional when you make these videos really happy the truck runs really good and L9 now thank you again.
You traded your Duramax HD truck that was a "piece of shit" because there was a software update?
I have a 2024 Silverado 3500HD SRW with Duramax and had to get the emmisions software update with no difference is operation. The factory only downloaded part of the program and there was a recall on the emmisions. As a matter of fact, my check engine light did come on and I did the OnStar diagnostics check and they told me it was the emmisions. But as far as the 2024 Duramax being a piece of crap, it's one of the finest trucks I have owned. I had a 2021 Duramax before it and this one if significantly better.
I have a 2016 5.3 with AFM. I have the range afm disabler and it works. The engine stays 100% on 8 cylinders. I don’t know if it’s going to prevent lifter failure but the truck drives much better.
I hear ya
Hi Don I have exact same truck as yours year, Color, options. I hate the auto shut off/start, and DFM. Your videos have been most helpful. Cheers from Ontario
Happy to be of service
Excellent video! Thanks! I’ll be looking for all your future videos!
I've read the '23 Chevrolet Colorado and GMC Canyon have this feature on their 2.7 litre engines, so I'll keep this in mind.
The way cylinder deactivation works on a DOHC engine is totally different compared to a pushrod OHV engine. That isn't to say it will be reliable. Even Honda has had issues due to their use of cylinder deactivation.
Waiting to get my truck back from GM now with bad lifters…. Can’t wait to get out of the 5.3 platform. Selling it as soon as it’s fixed
5.3is and has been one of best since like 1999’😮
@@JeffBarnaby-p8e See the problem with what you're saying is that in 99 the 5.3 didn't have all the extra AFM/DFM/DoD crap in it. So yes they were mechanically much more simple, reliable engines that are still on the road in vast numbers today having never been rebuilt. Once GM introduced the cylinder deactivation their reliability went through the floor because of variable state hydraulic lifters that can collapse and take the cam out causing you to need a serious rebuild that could get you to the $10k mark in repairs. Do you really want to buy a $40k truck that will likely need a $10k engine rebuild within 100k miles? I certainly don't. I recently sold my 2004 Silverado 1500 with the 4.8l V8 to a family member who was in bad need of a truck to work in. So when I buy another truck for myself (currently I can get around using either my primary or backup work van) I'm definitely not going to be buying a GM product specifically because of these engine issues. At this point I'd feel safer with a Ford with a 2.7l ecoboost than I would a GM engine with all the cylinder deactivation crap. I'll probably try to find a nice F150 with the 5.0 in it because at least it didn't have that crap (until either the 23 or 24 MY)
Very helpful!!!! Coming from a tacoma to a new silverado I was not aware of this issue
Right on
I am not comfortable with this new generation of truck's to buy one. I guess you figured it out, I'm old. Give me something problem free and I'll deal with fuel economy.tks for the video. 70 from pa.
Bought a Diablo tuner just to disable AFM/DOD. My truck still gets 17-19 mpg all city running as a true V8.
They make tuners now for the 2020 and abover trucks? The ecm is locked now from GM.
At also works in a 6 speed tranny. I use the 5th gear when driving on back roads and around town. I actually gained fuel mileage on back roads doing that. The DFM never engaged.
Hey Don! Thank you so much for representing the true north so well. I have a 2021 Sierra 1500 Elevation with the 5.3. I wish I was still blissfully ignorant to this issue but recent issues and codes are seeing my truck head to the dealer for service. I’ll find out tomorrow or early next week if this is my issue. I’m wondering though, since you did this about 9 months ago, are you still running around town in L9 and what has your longer term experience been? I’ve also been considering the Pulsar. If my problem isn’t actually lifters it may be beneficial for me to consider either of these options in the hopes of saving trouble later!
There's a delete kit you can buy and install, also a performance tuner (diablo) for dropping the ecm programming. Never have to worry after that.!
The ecm is now locked on the newer GMC/Chevy motors.
@@hockeystop5 HP tuners will get you in, did my '18 when it had 12 miles on it. My boss just had his '23 1500 done loves it.
@@keithschnick5831 how do I go about having HP tuners unlocking my ECM?
I have a 2015 Chevy silverado.the number 4 cylinder went on it and the cost to replace it was 4 thousand dollars.i love it delete in my truck it runs way better then it did
The only problem with running in Manual mode is the lock up torque converter will not lockup because that is the way its programmed.
I used the Range Tech to disable my fuel management system on my 2015 until I did the dod delete.
I just bought a 07 Silverado i didn't know anything about afm so when u found out i got sick to my stomach but come to find out the previous owner had did a complete afm delete he did the lifters push rods cam shaft also he got rid of vvt so i dont never got to worry about liter failing because it doesn't have arm lifters no more that god
Lifter failures at higher mileage is caused by waiting too long to change engine oil. 7k is waaaaaaay too long. 5k is pushing it, too much if there is a lot of short tripping in cold weather. Changing it by 4k is probably a good balance. Learn about the abrasive soot that direct injection makes and how that soot ends up in the oil. Learn about how full synthetic reacts when the engine is short tripped in cold weather.
I change every 3000 miles
Very helpful. I wish they would just add a dfm on/off button
I have a 2018 Silverado 5.3 and an 8 speed transmission with a little over 58K miles. I drive in L7 almost all the time. I have notice at freeway speeds the rpm's are higher in L7 than in L8 or Drive. I would assume that means the fuel economy might be lower in L7. I don't check my mileage and the benefit of constant V8 power matters to me.
I shift to Drive when doing highway speeds. L9 for me all around town which is most of my driving
Is the engine switching between 4 and 8 cylinder on the freeway? That is the only reason I drive in L7. Maybe I am wrong.
At 3:20 in this video I’m on the same page as you. Before my muffler delete mileage was up. Now with some good V8 noise mileage is down lol. Letting my 6.2L sing 🔊🔊
I could try to explain it to you but if youre not a mechanic you wouldnt understand why deactivating dfm will absolutely prolong if not completely prevent lifter failure dfm lifters have 2 seperate oil passages its hard to explain but basically the part of the lifter that allows it intentionally to collapse to deactivate it by deactivating it you arent working that part of the lifter which means again you greatly reduce if not eliminate possible failure people really dont understand how they actually work and the best thing you can do if youre not going to do it the right way and do a full mechanical delete then you atleast need to get a tune that completely deactivates it
Either trade it in just before warranty ends or totally delete/remove the AFM system or you’ll still have those faulty lifters in place. Mine bent the push rods and damaged the cam shaft which resulted in more work.
I appreciate your videos.
If only I had known that L9 trick before I bought a pulsar LT
If your using the PulsarLT for other features it has, then it might be worth it
It's been common knowledge. Guys have been using manual move to disable it since at least 2014.
PLEASE READ ME!!!!
Hey Don great video! I also wanted to take the time to add the following. Chester makes a lot of sense how the DFM works, but one thing I personally think that where all overlooking is the Auto stop/ start. You may ask why? Here's why I think when I bought brand new my GMG 1500 Sierra Denali crew cab 4×4 5.3 liter short bed. I'm a heavy hitter speed demon that is and all my vehicles I have put them through a good amount of speed and I have the tickets to show for em🤣. One thing I right away noticed when I took the truck for my 1st time cruise the truck went into AS/S mode at the light and I gunned it hesitated by a sec. Or 2 so I did research how to deactivate it and it showed me in the Manuel ever since then I never had issues other then getting frustrated with pressing buttons so eventually I canceled it with a pulsar. My truck has 21,000 miles and running strong of course I use synthetic oil, premium fuel, and has mods which yes I know that doesn't help but I maintain my truck to my driving ability! We all have that one triggeeing foot to gun it at the light but I think that feature by the time it responds to the take off, the lifters and valves don't respond to people's reaction time at light and makes that 1sec or 2 enough to cause a bent valve! That's my opinion on the As/S system. Sorry to make this long...... awesome channel!🤘😎🤘
One of the first things I did!
Auto Start Stop Eliminator / Bypass GMC Sierra AT4. Full Review and Installation!
th-cam.com/video/FGq25E2fRWU/w-d-xo.html
@@Donslife see and your truck has been running on point! Just something I think really is the problem.
Hey Don, I've been binging your videos today because it's cold outside today 25F. Yeah,yeah,I know that's a heat wave for y'all in Canada. Anyway, I was wondering if the street sign at the 3 minute mark is a "Watch for Squatch" sign?
Hit those like buttons! 😂 The crosswalk sign does look like that. I can’t unsee it
I have been using this "manual mode" or L5 mode (6 speed transmissions) for several years now, on a 2016 Chevy 5.3L and on my 2018 Chevy 5.3L Silverado. It definitely stops the afm & stays running on all 8 cylinders. Several years ago, I asked my local GMC dealer service manager if A) does this really work and B) does it cause any problems or harm? He said yes it does work, and it causes no problems. I think I might be getting slightly less mpg but the difference is so little I don't notice it. As I am an old school guy, I think running it always in the 8 cylinder mode is easier on the engine.
my yukon has a corsa driving in L9 the sound is more consistent the only issue is when I drive over 80 i have to shift either back to D or L10 otherwise the rpm will keep increasing
Totally, I do the same and recommend the same. I like it for my for the aftermarket exhaust sound
When I shift into L it shifts to the next lower gear that it was in D in. If I'm in 10 it will shift to L9
my 2017 50th Anniversary 2SS Camaro doesn't work this way. I have an 8 speed, and in manual mode, if I am in "M7" if my RPM's drop to a certain point when cruising it will actually still drop to V4 mode. I ordered a RANGE disabler... Now, I will say that if I leave it in an even lower gear it will mostly stay in V8 mode, but not just 1 gear down. at 55 - 60 MPH I have been running in about 5th gear or so, which is a higher rev (around 2800 RPM etc) and it will stay in V8 mode.
Always helpful!!!!!!!
Anytime!
I have a 2015 GMC Yukon XL and towing my 7k pound camper it will still go back and forth between 4 and 8 if in Drive.
Maybe on deceleration or going down a slight change in grade
I put 0 miles engine from gm on my 2020 denali and from day 1 has de range technology chip , so we'll see if using 8 cyl all the time improves engine life
How is it working so far?
I’ve been running in L8 and it seems to make a difference. Maybe in my head but L8 down is all I have.
Try L7. L8 (if that’s your top gear) will likely engage DFM when the engine is under a low load and not working hard
My truck is a 2008 GMC Sierra 1500 5.3. My display is manual lettering no digital. I recently got the Engine code of P3400 Cylinder 1 deactivaton solenoid. I don't see a way to disable AFM.
We are about to receive our 2023 1500 Sierra 6.2/10 speed. Though we are not happy about the DFM. Thank you for the follow-up video. Your truck sounds so good. I'm sure you did a video on your after-market exhaust, I'll look for it in your playlist. Was curious what you had installed. Thanks again ✌️out.
Nice 👍🏼 Here is the video : BORLA S-Type Cat Back Dual Exhaust Install Review 2019 - 2021 GMC Sierra Chevy Silverado 6.2L
th-cam.com/video/lzjipXNF1UM/w-d-xo.html
Thanks for the tip Don! I just put a new Flowmaster muffler on mine with the 5.3 liter and 8 speed tranny. The new exhaust sounds great til it’s in 8th gear, and just cruising around town, then sounds horrible, as it kicks into V4. I tried L7 , and it was magic. In highway driving I just use D
Love it!
If DFM is off in L9.... that would tax the lifters much less over time and in theory make them last longer no?
Those lifters that are installed in the cylinders compress, to make that cylinder dead, the lifter itself doesnt fail, they just get stuck open or closed,
Thats the design flaw of the lifter, so if you have the system never go into afm/dod mode then the lifter will not get stuck open or closed.
As well as i leave mine in M5 (2011, 6l80 transmission) and at 80 mph its only at about 2500 rmps ish, not even screaming, on highways i leave it in M5, currently at 230k miles
I disabled my 5.3 and it still collapsed a lifter at 97,000 miles along with lots of other issues. I'm done with Chevrolet.
Copy, understand, will do.
Thanks man.
I'm a lifelong Chevy owner and Master Certified Chevrolet mechanic. I now driving F-150 Ford I will never get in another Chevrolet pickup. I love the older trucks and cars as I am now a classic car Builder. Stay away from the Chevrolets
Ford is garbage too. Turns off and on. I’ll still drive a Chevy
Excellent info.
Thanks for Sharing.
My pleasure!
@donslife I was told that driving in L9 could have some negative affects on the transmission because of the change in RPMs versus being in drive… I’ve been driving in L9 99% of the time even in highways and haven’t had any issues. Have you heard of any issues.
I have heard some people claim that the downshifts are sometimes odd, but nothing alarming
awesome video thanks, maybe I'm hallucinating but it sounded as if you had an AWE exhaust, cheers!
Borla, but AWE is excellent too! Thanks for watching!
Still purchasing GM!
From what I have learned about the potential problem, it is when the lifters are idle, then suddenly brought back to use, it causes a 'shock' to the lifter and cam. I purchased the Pulsar unit to permanently disable it. It may save me 50 bucks a year in gas if i used it, but could cost me $3500 repair in the future. I don't see the reward worth the risk.
At idle afm isn't active. They usually fail when slowing down to a stop. And it switches back to 8. Or going too long between oil changes
I used a Pulsar LT on my ‘20 Trailboss 6.2 and loved it for about 20k until a lifter failed with DFM cancelled the entire time. I wouldn’t recommend buying a Pulsar if you think it will save the lifters. It’s still cool for the other features though.
@@Connor4x4 Going too long is the biggest one. I knew an older timer that had a 2011 Silverado 5.3 and changed his oil every 3000 miles or earlier. Never had an AFM issue in the ~190k miles he put on it. He retired and gave his youngest son the truck. That dunce started going 10k miles between oil change because that's what a lot of guys think you can do if you run a full synthetic and fancy filter. Less than 2 years later, lifter stuck.
@@travass100 Odds are the Pulsar didn't do the job it claimed to do and allowed the system to activate. A locked lifter should never be able to collapse without oil pressure there to unlock it.
Good video as always.
I got the Pulsar LT and love it!! You should get one. Thanks!!
When I buy larger diameter tires 🛞
@@Donslife What brand and size tires are you thinking about getting?
I can attest to the fact that lifters can still collapse with AFM/DFM disabled with a Pulsar LT, Manual Mode or disabled in the tune itself. It happened to me...
My Sierra is in the shop right now getting LS7 lifters, BTR cam, torque converter and a few other goodies all stemming from a collapsed lifter on bank 2 at 70k miles with AFM disabled in the tune since 38k miles. Maintenance was religiously followed. The design of the AFM/DFM lifters are prone to failure whether or not they're used for fuel management.
Totally sucks. At least I'm getting cammed, baby! Chop chop chop chop 🤙🇺🇸
How does the lifter still collapse if it isn't commanded to?
hola muy buen video gracia, tengo una 2022 Yukon 6.2 y me preocupaba ese tema del DFM, ya se que hacer gracias por compartir la información
Enjoyed your content very much and informative! What type of exhaust did you have installed if I may know?
Borla S-Type. Thanks for watching the videos!
Great review 👏 👌
Thanks 🙏🏻
I just bought a 2024 Sierra 1500 elevation w/ dfm. Very helpful stuff. I love the truck but this is definitely something I’ll keep an eye on. I’ll prob drive on L9 to be safe, but also turn off the auto start/stop. Seems like this is the only worry with these trucks. Better than other defects with other trucks in my opinion. Anything else I could do to help prevent any dfm issues?
When your transmission is in L9, auto stop/start is deactivated too. Some claim that more frequent oil changes can only help too.
@@Donslife good to know. Thank you. I was driving in D today and i have an on/off button on my stop/start. Any time i drive in D I just turn that off too. Pretty smooth to be honest. I don’t feel any jump when i drive or lack of power. I’m gonna read the manual more when i get some time. Might start making videos about the truck also. Not many people on TH-cam that I see have these trucks.
Why can't gm get it together and make non failing lifters? Does the 2022 have this same lifter issues?
Yeah I'm do for my first free oil change so I'm going to let the dealer look at it. My first thought was bad gas also. I put Lucas fuel treatment in it and new fuel no change. Just wondering if you had the issue before.
Let me know if they find something
@@Donslife will do
As a long time mechanic I disagree that disabling the DFM system won't help with reliability. The collapsible lifters have a release pin that when activated, allows the lifter to go into collapse mode. Just like anything mechanical, the more times those parts are activated, the more wear you will have on those parts to eventually cause a failure point. If the system is disabled full time you are far less likely that those lock pins will wear. Also, each time those parts are activated and then deactivated is a chance that they will not function correctly. Take away those chances are your failure percentage is much improved.
As far as fuel economy, I don't have experience with GM but some experience with a Ram Hemi, MDS system (same concept as GM). The Ram I had actually seemed to get better fuel economy on the highway with the system disabled. I noticed that on sharper hills, the delay time of the MDS system deactivating actually caused the engine to need to 'recover' speed. Not so when deactivated manually. In city driving, the MDS seemed to help economy a bit.
I agree with you. I have to be mindful of how I phrase things on TH-cam. Someone might claim ‘you promised this would or wouldn’t happen’ and cause some unnecessary drama.
I put a Range deleter in my Denali and it stopped the 8cyl/4cyl transition but a very knowledgeable mechanic told me that I'll still have problems. He said poor engineering and they won't fix it. Why didn't you give some helpful results on the video. Are you saying this eliminates the collapsed lifter, busted cam, $10,000 problem or do you just like making videos. The buttons are right on the gear shift and for anyone that owns one already knows this.
My 10-speed 2024 Sierra 1500 only manually shifts up to "L8"...not L9. And in L8 it seems that DFM is still functioning.
I thought it was AFM. I have the Range plugged into my obd 2 port to disable the AFM on my 2011 silverado.
DFM replaced AFM in the newest generation of these engines. Also the Range disabler isn’t fully compatible with all models yet from 2019+. Our best option is the PulsarLT which costs a lot more and has a more involved installation
My 2014 never drops down into AFM because i deleted it with a hog ass cam. And all of you should to. They make stock cams that are non dod/afm if you don't really want performance.
Outstanding!
Thank you! Cheers!
Well, like you I can only guess about lifter life, but I've got to think that disabling DFM would help to prolong their life because they don't have to perform the function required to shut down cylinders. They can just be normal lifters, no?
Thanks for clarifying that@@whales302
What a shame because they're nice trucks to drive. But I guess the 5.3 with AFM/DFM is a ticking time bomb.
Is there a list of the factors that disable or enable DFM any where? Why is it s big secret?
If you guys experience hard downshifting, it might be because you're using 87 instead of 91 octane gas
Good tip. I use 91 religiously
Do you notice when in L9 when coming to a stop it has a harsh downshift right before you come to a stop ?
In D, it gives an engine/exhaust surge, but it’s only noise. The feel and shifting is smooth.
In L9 the decel exhaust noise is great, but the last downshift before full stop is noticeable to me. Wondered your experience. Lastly is your column shifter loose feeling when in D. Mine has “slop” up and down.
Thanks Great videos !!
I can confirm my 2020 TB has slop in D, it bounces when I hit a bump! My 2016 never did that
I have a 2022 suburban with DFM that just had lifter failure at 43k . My 2015 with afm had lifter failure at 106k . The high hopes of dfm being more reliable than afm are dead wrong . I'm not the only one , I've had many conversations over the years with guys in the limo business who have been victims of this issue. The failure rate is exponentially higher than you think. I believe that the only true solution is a lifter retrofit kit to delete the Afm/dfm . Or .......... buy another brand . I'll be in the market for a Toyota sequoia next time around.
I had the same truck as yours. 2021 gmc AT4 6.2. The 4 lifters on the left side collapsed @ 40k mile. Had it repaired and traded it for the Chevy 6.2 ZR2. Hope I have better luck. Thanks for your good comments.
Sorry to hear that! I hope it works out for you too
Hey Don, thank you for all of your videos! I have a 2024 5.3L 10 speed elevation with an aftermarket exhaust and typically drive it in L9 unless going above about 50-60 MPH. It seems to work great. I have read into if driving in L9 most of the time has any downsides apart from *maybe* fuel economy and came across it potentially being harder on the transmission. Is this something you've heard of and are you concerned about it?
Thanks for watching! In my opinion, the transmission is fine. I think towing is way harder on the transmission than using L9. I have not witnessed any real increases in transmission temps either. If anything, not using L9 I would experience some harder low gear shifts both up and down. Not often, but enough to notice.
@@Donslife Thank you for taking the time to provide a thoughtful response, the insights are very much so appreciated!
Sounds awesome. What specific aftermarket exhaust are you running?
Borla S-type cat back with black quad tips
@@Donslife thanks
Thanks, but i prefer just goong tlwith the afm disabler. Your lifters will lastmuch longer including your engine as well
Man your aftermarket exhaust tone sound awesome. I feel it doesn't sound loud at low-mid RPM, am I correct?
Please let me know the exact exhaust setup.
Thanks
Thanks! Here is the video: BORLA S-Type Cat Back Dual Exhaust Install Review 2019 - 2023 GMC Sierra Chevy Silverado 6.2L
th-cam.com/video/lzjipXNF1UM/w-d-xo.html
Here is a link to the exhaust:
amzn.to/42M6Jmm
You get in an mess with the factory programming, the dealer will void that warranty.
Ya, I haven’t changed anything as far as programming. The ECU is locked on these too
I’d love be to know if my rumble on decel at 25-30mph is DFM, VVT, or torque converter. Does it M7 and M8. 2020 5.3 8-speed. So many systems cause similar problems.