Home Forums Hunting & Shooting Hunter's Campfire GM 5.3 and 6.2 liter AFM engines. Yea, Nay, Run away?

I've had 6 1/2 ton trucks with the 5.3 since 2000 and a 2008 impala ss with a 5.3. I don't recall ever having a problem with any of them.

My current truck is a new style ram with the 5.7 hemi which I never thought I'd own but I like it and the 8 speed transmission is great for a ram too.

My 5.3 chevys got a bit better milage than the ram. My dad has a suburban with the 6.2 and he gets 20 mpg quite often but it recommends premium fuel. I've heard the new suburban with the 5.3 and 10 speed do really well. I never ran premium in any of my 5.3s.

Bb

My 2011 Silverado has the 5.3 with AFM and 265K miles. I go 5000 miles between oil changes and add a quart a 3000 and another one a 4000. Started liking oil about 170K miles or so. Something with the AFM I guess but never had it deleted or fixed. It is starting to require minor BS stuff. I also have a 2018 with the 6.2 and about 25K miles with nothing other than oil changes. The 6.2 is a lot more fun to drive than the 5.3, lots more get up and go. Never noticed the AFM working in either truck.

I am coming off owning a 2016 Ram 2500 with the 6.4 Hemi engine 6 speed tranny 4X4 my city/highway MPG,s were 13.5 great truck no issues.We traded it in for a 2020 GMC Yukon Denali with the 6.2 engine with 10 speed tranny driving 55-60 mph we get 21 mpg, city/highway 17.5 mpg, s.This is my first GM product since 2005 time will tell on dependability ..

Not in the year range you're asking about, but my 2007 5.3 hauls or pulls whatever I want. Only has 112k & if I floor it to pass someone on interstate it's a done deal. I also like the overhead valve configuration with cast heads vs the modular ford engines. Driven several 5.4 that spit out multiple plugs & that crap is unacceptable.

I have a similar powertrain with the AFM and roller lifter setup. The manufacture specifies 0w-40 full synthetic oil in it. They claim that it can run to 8000.0 miles. I keep a close eye on it and do not feel comfortable with letting go past 5000.0 miles. These big gas V8's do work the oil hard when used. I pull a 30' travel trailer with it and it does it part as long as I do my part. I do not want to go down the rabbit hole of oil analysis.

I’ve had the 6.2 in 2 different trucks since 2014. The first one was a 2014 with AFM. The 2nd is a 2019 with DFM. Despite what you read about those cylinder management systems having big problems, I have never had a problem. I traded with 14 for the 19 at about 90k miles and will do the same with the 19 gets to that point so I’m not high mileage.

The 6.2 is also a beast when you put your foot into it

2014 GMC 6.2 with 141,000 trouble free miles. Great motor

Same here, 04 Tahoe with 5.3 179K miles and all the power needed for towing and passing on the highway.
The basis for the 5.3 [327]has been around a long, long time and is a proven workhorse.

AFM is so good they replaced it with DFM.

TO "Really" disable AFM you have to replace lifters, pushrods and a cam as well .

The varying options on pick ups is interesting. So much is in the eye of the beholder. I have a large sales territory, averaging over 50,000 miles per year, on company pick ups. I have had three Fords, one Chevy, two Toyota’s, and am now on a Dodge. The Dodge drives great, rides great, and is plenty powerful. Is is also of the least overall quality of any of my company vehicles. No doubt about it. My pick of the litter would be my 2008 F-150 that I bought from the company when it cycled out. My 05 Chevy would be a close second. I bought that truck too. I doubt that I will buy this Dodge if given the option.

I had a 2010 GMC with the 5.3 with AFM, no issues with it. Sold it at 153K miles, really only routine maintenance. Guy in town bought it 2 years ago, must still be OK cause I saw it about 2 weeks ago going down the road. Never once did I feel it surge, the deactivation or whatever of cylinders happens seamlessly.

Do any of you 6.2 users ever burn regular gas or always premium ??

Great engine with loads of power..

I'm on my 2nd used Suburban with the 5.3L V8 and it's the only Chevy I'd care to own. I wanted to find a cheap daily driver and regularly see these for sale with 250-300k miles so I picked my 2004 up with over 150k and sold it a few years later with under 200k. It wasn't much to look at by then as the rust had started to take off all along the bottom but it served its purpose. I picked up my current 2013 with just under 120k and am planning on also driving it until ~200k. In my experience, the weakest link with this vehicle is the fuel pump.......

2014 Silverado 1500 4x4, 5.3L. Eight speed/AFM. No issues so far with AFM, 82,000 miles.

Plenty of towing and passing power with 355 HP and 3:42 gears. Third full sized 4x4 GM truck w/5.3L since 2006.

Best ever mileage with the 2014, 24.7 on a trip when it was new and unladen. Just put over 400 miles on it, 19 MPG combined highway/local on this trip, About half that trip in mountainous northern PA, with lots of local driving. Even with all my "essentials" in the bed (500+ pounds), still knocks out a sustained 22 MPG at 75, on fairly level stretches of highway.

Gather my firewood locally now, but used to regularly cut it at camp and haul 2+ cords home (180 miles) on my 16' double axle flatbed. Zero issues towing. Last two years hauled 3 cords of red and white oak home at a time, in a friend's double axle dump trailer. No sweat for the 5.3L.

Owners manual SUGGESTS burning 93 OCT.I run 89 oct and 93 oct ever other tank.Tried 87 oct.once and had some spark knock when accelerating.

I appreciate all the responses. It looks like AFM's are not as bad as the internet would have you believe. Again, all responses appreciated, and I would much rather hear real life experiences than fanboy fawning or bashing.

I'm not a hardcore GM or Ford guy, but sure would have a tough time straying from either one of those. My Dad and brother are Ram converts. They give me crap about not switching over regularly. Makes for fun conversations most days.

My son in law just dumped over $6K into his 5.3 motored 1500 due to the AFM system ruining rockers internal parts. When he bought the truck he immediately reprogramed it to cancel this feature but apparently the 60k it was driven before he bought it let enough damage occur that it took a dump. No thanks on AFM for me.

Considering that a NEW Goodwrench 5.3L crate engine runs around $4K, I'd say his was money ill-spent? GM re-manufactured engines are even less than that.

Ever consider that whatever he did to modify it from original configurations, was the culprit? I personally know folks that have put well over 100,000 miles on 5.3L AFM Chevy engines with zero issues.

I've always heard it's not the motor on GM's you need to worry about, it's the transmission.

Nah. that was mid to late 90s Lamb 4x4s..

Neighbor's son had a '97 half ton 4x4 that literally ate two transmissions within less than a year and a half. Filed a Lemon Law case and got a replacement truck in '98. That one ate the tranny about a year later. After it was replaced under warranty, traded it on a new Ford.

My '84 Lamb 2WD half ton lunched the tranny at less than a hundred thousand. No more Lambs for me, although everyone I know with newer ones seem happy?.