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

Excuse my ignorance, but what exactly is a "Lamb" in referenceo a truck? Never heard of that before.

My dad bought the '84 RAM new. It quit on him multiple times over a period of two weeks, when he was at our cabin. It was less than a year old. Carb had black grit in it. Two different Chrysler dealers had it in, decided it must be grit from the black plastic gas tank? Cleaned carb, replaced fuel filter (duh). It quit again, took it to a garage, same deal.

My buddy and I went up, old boy told us about the issues with the truck. We cleaned carb, discovered the grit was coming from the fuel vapor recovery canister (charcoal filled). I disconnected the vacuum line from the canister, plugged the line to the carb, problem solved. Until he got it back home to the dealer he'd bought it from.They replaced the canister, eventually did it again. I installed a fuel filter in the vacuum line to the canister, end of that issue. Bought it from him later.

My buddy, a long time mechanic, pronounced it to be The Lamb and we forever after dubbed all Dodge RAMS, Lambs..

The biggest issue with AFM's is when they lunch out. Lots of parts.

To keep them from lunching out I'd use Premium fuel (even though many are E rated) and change the oil when it hits 10% of the oil life; 15-20% if its used primarily as a duty truck.

The first version of the 5.3 with AFM was introduced in 2007. We had an 07 that burned oil like crazy, started having other issues as well so we sold it with full disclosure to new owner. GM had issues with the early versions of the AFM, and they had it pretty much sorted out by 2011 models. There was a difference in the way oil and fuel was (or wasn't) delivered in the non-firing cylinders, a tweak of the valve lifters, and a redesign to the valve covers to help keep the oil from entering the combustion chamber, and a change to the tune to control when/how it would cut in and out. The next rig was a 2012 and the AFM functions better/smoother from a driving standpoint, and the rig doesn't use any oil at all.

It's possible to turn off AFM with a dongle or with a simple tune like Diablosport, Hypertech, etc. I think up to the 2020 models. The new rigs have over the air live diagnostics and updates so not sure about them.

I’ve got a 2013 pickup with the regular 6.2. Great engine no problems. I had a 2015 Denali with the 6.2 AFM. Great engine, no problems. I’ve got a 2019 Escalade with the newer 6.2 and AFM. Great engine, no problems.

The 6.2 has power to burn and is dead solid reliable. Paired with the ten speed transmission, the power is smooth like a golf cart.

Thanks. I just couldn’t figure that one out.

Same here as Cumminscowboy on newer chev pickup. Bought my wife a new 2019 Silverado. Was a poorly built rig. 6 months and it was down the road. Rattletrap! Still liking my 2017 Silverado. Edk

The 4L60e is probably what you heard about. I know more people that had issues than those that didn’t. Yes, I had one too.
Hard pass on any early version 5.3L with AFM.

Again, this is the answer. If you go the programmer route, you have to return to stock every time you get emissions done, and drive the sob for how many miles to reset the sensors before you test. With Range Technologies you just shut off the engine, pull it out of the OBDII port, restart and go get the emissions test.

As far as valvetrain problems thats "usually"(it can still happen if maintenance is lacking) below '14. In '14 GM went to a dual stage oil system and 0-20 oil. '13 and below it is a single stage pump and 5-30. The problem is lifter collapse.

Lifter collapse happened to my '11 under warranty, it happened to my dads '07 twice, both times out of warranty. As someone said in another post(where they stated the only way to get rid of AFM is to put 6.0 valvetrain in) was to tear the engine down and get a AFM delete kit using non AFM valvetrain. Thats wrong, again link above, Range Technologies. BUT, yes you can go that route and replace the valvetrain with a kit like THIS which can be kinda pricey when you add up all the parts...usually around $800 for parts if you pick a single bolt cam. Plus your time or someone elses labor.

I tell everyone, whether is early AFM or newer to install Range Technologies. Might notice 2-3mpg less, but itll solve lifter collapse AS LONG AS YOU KEEP OIL CHANGE INTERVALS REASONABLE! If you run 15k intervals all bets are off. Me personally, I go 10k max.

These engines arent cheap. You CAN go to a yard and get a 5.3 for a decent price if yours is scrap, but mines an LC9, all aluminum heads and block. LS engines are everywhere, but guys are buying them left and right due to their ability to produce some major horsepower quite easily. The heads flow phenomenally and the bottom ends are 6 bolt mains. Tough engines! Throw a turbo on and cam and youre producing 600-1000hp easily.

I have a 2015 Silverado with the 5.3 and have no problems with the switching to 4 cylinders. It has 123000 miles with no issues. I would buy another.