GM 5.3L EcoTec3 engine questions

[ABNAK]

Okay motorheads, need some input. Bought a new 2022 Chevy Silverado with the 5.3L EcoTec3 engine. As is the story of my life I start reading about the engine after I bought it. Seems as though there are two main issues: lifters failing and carbon buildup from the Active Fuel Management system, which shuts off four of the cylinders when demand on the engine allows for it, thereby increasing gas mileage.

Granted, the websites I read these complaints on are no doubt the place where people go who've had these issues, i.e. all you read are about these issues. No one really says "I haven't had any problems". So it might seem like it is a HUGE problem when it is a small vocal minority of buyers.

I am mostly vehicle illiterate; never worked on them, only know the basics, etc. I have a couple of questions:

1) Are these problems widespread, like a majority of buyers over time?

2) What can be done to alleviate these issues? Both the lifter and carbon buildup issues seem to be related to the AFM feature, am I correct?

3) Would shutting off the AFM feature reduce the chances of these two problems occurring? Would doing so otherwise adversely affect engine performance? How do you do it?



***A little recent background information to explain my trepidation: My wife bought a new Jeep Wrangler with the 4-cylinder turbo engine in it last October. In mid-August she and I were out one Sunday with one of our dogs for a drive. "Check electronic throttle control soon" warning light comes on. We're like WTF? Turn around, let's head home. Before long it starts sputtering and then the dash lights up like a Christmas tree. Damn thing dies with smoke rolling out from under the hood. Stranded by the roadside. Turns out the engine completely burned up (like NOTHING re-usable underneath the hood). It had 11,000 miles on it and was 10 months old. Obviously a warranty-covered issue. New in-the-crate engine had to be installed. Not only were we stranded by the roadside with a dog (which royally pisses me off considering what we pay on that damn thing per month) but the dealer had it for 41 days before we got it back a week ago. They him-hawed around about "no loaner cars available, sorry" but I told them they better pull a ride out of their ass so they rented us a car for that time after much prodding. Obviously now I don't trust the damn thing and we will not take it more than an hour or so away, with just over 3 years left to pay on it no less!

I just want too make sure I haven't stumbled onto yet another albatross, but this time a $57K Chevy. Any answers to the questions I posed above would be greatly appreciated.

Sorry, bent push-rods was another issue.....tied into the other two problems somehow?

[SomeOtherGuy]

Short version: don't worry, be happy. This is easily one of the most reliable engines with those features.

Details:

I also own 2022 Chevy Silverado with the 5.3L EcoTec3, in my case with a crew cab and 8-speed auto. In addition I own a 2019 Suburban with the previous generation of the exact same engine. In the past, I owned a 2008 Suburban with the original AFM 5.3L V8 engine.

For extensive details on the current engine, read here:

https://www.motorreviewer.com/engine.php?engine_id=200

My 2022 has the L84 with DFM, and I'm betting yours does too. DFM allows any number of cylinders from 1 through 8 at a time to operate, while AFM is either V4 or V8 only, nothing else or in between. I see better gas mileage AND better smoothness in operation on our 2022 with DFM. With about 9 years of daily driving on this engine across three vehicles, I know it pretty well.

Lifters: does not seem to be a real world significant issue. Do regular oil changes. Synthetic is recommended anyway, use a good one. At the moment, Quaker State (!) is one of the best synthetic oils, believe it or not.

Lifter issues with AFM vs. some sort of defeat: no idea.

Intake valve carbon issues: this is an issue for ALL gasoline direct-injection engines, because the gasoline is no longer able to clean away such buildups. Some cars seem to have a real issue with this.

From what I've read, GM has engineered these engines (and others) to minimize or nearly prevent carbon buildup, by adjusting the timing between intake valve closing and fuel injection. It does not seem to be a significant issue for these GM V8 engines.

AFM defeat and carbon buildup: there is little or no relationship between intake valve carbon issues in GDI engines and AFM. I don't think a defeat would make any difference.

Reality check: virtually any engine design will have some kind of expensive problem at high mileage. Looking at the Ecotec3 family, its volume, GM engineering, installed base and whatever else, I think the odds of trouble-free operation for a long time are MUCH better than with almost any other engine you could choose, particularly including Ford Ecoboost options. You could get unlucky, and you could get the one ABC Corp. junk engine that accidentally runs to 3 million miles, but playing the odds I think the GM V8 is among the best bets.

[ABNAK]

Thanks. I know that in life in general "one oh-shit outdoes ten attaboys" so that comes into play.

[Coal Dragger]

Okay motorheads, need some input. Bought a new 2022 Chevy Silverado with the 5.3L EcoTec3 engine. As is the story of my life I start reading about the engine after I bought it. Seems as though there are two main issues: lifters failing and carbon buildup from the Active Fuel Management system, which shuts off four of the cylinders when demand on the engine allows for it, thereby increasing gas mileage.

Granted, the websites I read these complaints on are no doubt the place where people go who've had these issues, i.e. all you read are about these issues. No one really says "I haven't had any problems". So it might seem like it is a HUGE problem when it is a small vocal minority of buyers.

I am mostly vehicle illiterate; never worked on them, only know the basics, etc. I have a couple of questions:

1) Are these problems widespread, like a majority of buyers over time?

2) What can be done to alleviate these issues? Both the lifter and carbon buildup issues seem to be related to the AFM feature, am I correct?

3) Would shutting off the AFM feature reduce the chances of these two problems occurring? Would doing so otherwise adversely affect engine performance? How do you do it?



***A little recent background information to explain my trepidation: My wife bought a new Jeep Wrangler with the 4-cylinder turbo engine in it last October. In mid-August she and I were out one Sunday with one of our dogs for a drive. "Check electronic throttle control soon" warning light comes on. We're like WTF? Turn around, let's head home. Before long it starts sputtering and then the dash lights up like a Christmas tree. Damn thing dies with smoke rolling out from under the hood. Stranded by the roadside. Turns out the engine completely burned up (like NOTHING re-usable underneath the hood). It had 11,000 miles on it and was 10 months old. Obviously a warranty-covered issue. New in-the-crate engine had to be installed. Not only were we stranded by the roadside with a dog (which royally pisses me off considering what we pay on that damn thing per month) but the dealer had it for 41 days before we got it back a week ago. They him-hawed around about "no loaner cars available, sorry" but I told them they better pull a ride out of their ass so they rented us a car for that time after much prodding. Obviously now I don't trust the damn thing and we will not take it more than an hour or so away, with just over 3 years left to pay on it no less!

I just want too make sure I haven't stumbled onto yet another albatross, but this time a $57K Chevy. Any answers to the questions I posed above would be greatly appreciated.

Sorry, bent push-rods was another issue.....tied into the other two problems somehow?

Stay on top of oil changes. Every 5,000 miles or 6 months. Use a full synthetic oil.

No exceptions.

The oil passages used to control the lifters in variable displacement systems, cam phasing in variable valve timing engines, or lurbricating oil for turbochargers are usually small and last in line for oiling in the pressurized oiling circuit. I just described a features found on every new 1/2 ton pickup sold today, one or more will be on every offering you can find. If your oil is dirty and starting to varnish, coke, or sludge those small passages get blocked eventually. Not to mention your oil control rings on pistons. At which point you get lifters failing, turbos failing, valve timing phasers failing etc, along with excessive oil consumption.

Manufacturers are obsessed with trying to portray their vehicles as needing less maintenance. So they recommend idiotic oil change intervals. You should ignore these and follow the above advice.

Clean oil and frequent changes to keep it clean.

The intake valve carbon build up on direct injection engines is a problem. Toyota and now Ford add port injection to their direct injection engines to solve this issue.

If you want a simple naturally aspirated V8 truck without variable displacement and direct injection trade in your Chevy on a Ford F-250 with the 7.3L “Godzilla” V8. Avoid RAM because as you have discovered Stelantis quality is utter shit. The GM 3/4 ton gasser is also direct injection but no variable displacement.

[ABNAK]

Stay on top of oil changes. Every 5,000 miles or 6 months. Use a full synthetic oil.

No exceptions.

The oil passages used to control the lifters in variable displacement systems, cam phasing in variable valve timing engines, or lurbricating oil for turbochargers are usually small and last in line for oiling in the pressurized oiling circuit. I just described a features found on every new 1/2 ton pickup sold today, one or more will be on every offering you can find. If your oil is dirty and starting to varnish, coke, or sludge those small passages get blocked eventually. Not to mention your oil control rings on pistons. At which point you get lifters failing, turbos failing, valve timing phasers failing etc, along with excessive oil consumption.

Manufacturers are obsessed with trying to portray their vehicles as needing less maintenance. So they recommend idiotic oil change intervals. You should ignore these and follow the above advice.

Clean oil and frequent changes to keep it clean.

The intake valve carbon build up on direct injection engines is a problem. Toyota and now Ford add port injection to their direct injection engines to solve this issue.

If you want a simple naturally aspirated V8 truck without variable displacement and direct injection trade in your Chevy on a Ford F-250 with the 7.3L “Godzilla” V8. Avoid RAM because as you have discovered Stelantis quality is utter shit. The GM 3/4 ton gasser is also direct injection but no variable displacement.

So keep the oil full synthetic and don't go past 5K miles. I'm good with that, my usual MO anyway. Anything to add or spray occasionally for the carbon on the injectors?

[SomeOtherGuy]

If you want a simple naturally aspirated V8 truck without variable displacement and direct injection trade in your Chevy on a Ford F-250 with the 7.3L “Godzilla” V8. Avoid RAM because as you have discovered Stelantis quality is utter shit. The GM 3/4 ton gasser is also direct injection but no variable displacement.

No argument on the reliability of those features, but a reminder to consider all-up costs. Our '22 pickup with the 5.3L replaced a '15 Chevy 2500HD with the 6.0L gas. Both trucks get the same use, a mix of farm use (move pallets of feed and heavy stuff, tow a 5k trailer) and daily driver / car use. The '22 is a 1500 but has a high payload, decent tow rating option - I think bed payload is around 2400lbs vs. 2730 in the '15 HD. So not perfect apples-to-apples, but not like a Civic vs. a dually.

The 6.0 returned 10-11mpg average, never better than 15-16 highway, while the 5.3L with identical use returns 19-20 average and 22-24 highway for us. At current gas prices that's about $2000 a year in additional fuel cost on the 6.0 / savings going to the 5.3. Even if you assume that the 5.3L will fail young and the 6.0 would go forever, $10k or so in fuel savings will pay for a lot of engine repairs. And that's before you count the cost of heavier duty tires and brakes on the HD, more suspension joint wear and replacements, etc. Just saying that if the 1/2 ton meets your towing and hauling needs, any repair risks may be offset by the fuel savings.

[jwfuhrman]

The 6.0 returned 10-11mpg average, never better than 15-16 highway

Bought a brand new 2003 Silverado LT 2500HD when I graduated High School in 2003(already had full time good paying factory job). I had that truck until winter of 2019 when I sold it with only 96,000 miles on.

That 6.0lt motor was the biggst let down ever. I kept that truck so long because I relgated it to farm use and had a couple other half ton trucks in between there. I had more power and towing capability with the 5.3lt Vortec and then the 5.3lt Ecotec's in half tons than I ever did with that 6.0 2500.

I've got a 2016 Silverado LT with the 5.3 Ecotec now. One of the best trucks I've ever had.

[SomeOtherGuy]

The old 6.0L Vortec sure wasn’t much to write home about power wise. Not much more grunt than a 5.3L in a heavier truck.

Yup.

That 6.0lt motor was the biggst let down ever. I kept that truck so long because I relgated it to farm use and had a couple other half ton trucks in between there. I had more power and towing capability with the 5.3lt Vortec and then the 5.3lt Ecotec's in half tons than I ever did with that 6.0 2500.

Yup.

We bought the 2500HD to replace a '06 Dodge 3/4 ton for towing our (then) gooseneck horse trailer, 5k empty and up to 11k loaded. The Dodge had a lot of faults, but 325hp of pre-DPF 2006 turbodiesel worked magic for towing, freeway speeds, 7% grades, whatever it was no biggie. We went up and down Black Mountain, NC with the big trailer in tow and no drama, for those familiar with that grade. With the Chevy, the 6.0L gas was... adequate, but not impressive in any way. 9-11mpg highway towing, minor struggle with the same trailer going up gentle hills at 70. This was OK because by then we weren't towing the big trailer as much or fully loaded, and thought the $9k lower purchase price PLUS lower operating cost of gas made sense, in 2014.

The 2500HD with the 6.0 also accelerated like a dog. I'm not sure 0-60 was even 10 seconds, much less anything sporty. Just not impressive as an engine. A bummer too because every other aspect of the truck was good to great. We had no complaints other than gas mileage, but we sold that big gooseneck trailer c. 2019, and getting just 11mpg or so average became a big deal when we stopped needing the heavy towing capability. We still tow smaller trailers (heaviest is 3500 empty, c. 6500 full) and carry >2k in the bed, but the half ton with the 5.3L works fine for all that.

[Hank6046]

Stay on top of oil changes. Every 5,000 miles or 6 months. Use a full synthetic oil.

No exceptions.

This, my I change my oil around the 50% percent mark, and always use full synthetic, I've had other problems with my truck but the engine has been solid

[Gabriel556]

Like SOG said, the GM engine is actually solid. Change your oil on time (I use 7000 mile intervals with full synthetic), buy quality gas (not the no name gas stations), and drive it, like actually drive. Carbon build up is actually caused by minimal airflow from excessive idling (like police cars) and the lower thermal load on the valves. Oil can also condense in the cylinders on idling engines then cook into carbon when subjected to rapid heating from fast starts as well. Just drive it. I have WAY more confidence in a GM than a Jeep but that is also why you had a warranty. Most engine failures happen very early or long after the expected life cycle.