BrendanC
$100 site donor 2024
step up to a quality 5w-30. install a catch can ASAP. run only top tier fuel, i personally wouldn’t worry between regular/premium as much as not buying gas from the cheapest cash place.
2018 6.2 Chev gasoline engine failure
- Thread starter cdlamb
- Start date
OVERKILL
$100 Site Donor 2021
IIRC, the AFM lifters can fail internally, IE, they don't lock up so valves don't open. That may be what you are looking for.
What is the cause of this failure in general? Is it related to maintenance (ex: oil change interval), or how hard the vehicle is driven,
or is it bound to happen eventually to these engines no matter what you do to prevent it?
BrendanC
$100 site donor 2024
i can tell you that we have yet to have a failure in industrial service and have atleast 20 afm motors in service. they see extended idling, towing etc. they were maintained by OLM until i took over service and then they went to 6k intervals on 5w-30 now at 12k intervals on HPL PCEO 5w-30. i think quality oil and driving them like a pickup is key.
Quality of parts is my opinion and also what I have read. The worse part about this is that it happens at all miles - you can't just say at 100k look for lifter troubles because we have done them with low and high and everything in between. I would think that better maintenance habits such as good full syn oil every 5k miles "should" push off the issue longer then say a person doing bulk oil at the OLM intervals. Trouble is I don't know for a fact. It is like the GM 3.6 timing chains...they would go 30k or 100k and anywhere else and give issues but we don't ever hear about the condition of the motors or it's maintenance. The last one we did last week I could tell the maintenance was spotty as the oil level was low and dirty. The inside of the motor was not horrible though - just some varnish. Others we have seen were pristine inside - like new.
You might be on to something. I wonder if the data (it were available) would show short trip use as a common demoninator to the issue??
BrendanC
$100 site donor 2024
our trucks start very early in the morning and run until late in the evening. no short trips/heat cycles. driver put 13k miles on a 21’ 5.3L in a little more than 2 months.
This is all great info to hear - and sharing your experiences are appreciated!
I would bet dollers to doughnuts that the problem isnt the fuel quality, unless he is really pushing it. The knock sensor would retard the timing and limit power if needed in protection of the engine. I,m sure you know the possabilities, holed piston broken valve etc. I would antocipate a holed piston. The milage is low but I have had one with slightly more hang a EGR that was ignored blow a hole. have them do a in cylander test and see where its leaking and go from there. The oil will not whisper much information that would be useful now. Yes know the why before fixing the problem or it will more than likely be a repeat ofender. Those engine should run 150.000 - 200000 miles no sweat with proper maintenance. Question who is changing the oil and what type is being used. Yes I have a 4.6 24 valve ford I have had timing gear issues with, rockers, exhaust manifolds twice and very early major rust issues from a poor design, open holes that catch mud in the body. She has been near gone for years. Sure its a 2010 with 140,000 miles nin the rust belt of new england and that doesent go unfactored. Im a praticle person that has been around machinery for all my life. This vehicle in particuler is a design nightmere that says the left hand is doing things that the right hand has no idea has happened. The issues makes me scratch my head in dis belief.
So Ford no Chevy no. Toyota Sure (maybe).
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Cracked pistons usually make more than 0psi.
I'm amazed by the prices to replace lifters or even a full cam swap! I'm the son of a mechanic and always did the work myself so I'm a bit spoiled lol. I will tell you that if I ever by a LS/LT engine with AFM the first thing I'll be doing is deleting that and potentially installing a new set of Hydraulic Roller lifters and probably a new camshaft.
When the AFM lifters fail....do they wipe the cam lobe or send trash through the engine?
When the AFM lifters fail....do they wipe the cam lobe or send trash through the engine?
They had the truck out and back on the road within 5 days.
I tried to contact the service advisor after the job was complete and paid for to see if they have any input on the cause. They never even returned my calls.
They rebuilt/ replaced the top end lifters.
Didnt require a cam shaft.
His bill was about $8600cad.
Seems like a lot of money for a truck with low miles, around 90,000.
I have heard others suggesting short tripping being hard on this engine, and maybe contributing to fuel dilution.
He is only 23 and was taking a college course. I am sure it was seeing lots of short trips during the past couple years.
We checked oil shortly after it came rom dealers, & the oil level was about 1/2- 3/4 inch above the full line. This suggests fuel dilution to me or dealer just overfilled it.
I will take a sample soon and will post results on here.
I dont see much data on here for those engines with oil analysis reports.
AZjeff
$50 Site Donor 2023
Disabling doesn't fix it, the parts are still in there. The only way to "fix" this is to replace the parts with non-AFM parts. @ls1mike did this on one of his vehicles, had a write-up about it I recall. This has been a problem since the first DOD - displacement on demand - engines in 2007. It's random and luck of the draw if you get good parts or not. I spent a lot of time on Chevy forums when I bought a truck with this and the only thing that seems to help is using good oil on short OCIs and not using the OLM. Dealer bulk maybe not the best choice but who knows. It's apparently not a large enough failure rate to have a recall or whatever but it sure does stink if it happens to you. The failure can happen at 20k miles or never no matter what you do except change out the parts.
I worked with a guy who bought a new 2007 Silverado 5.3 , first year of DOD and notorious for failures. He neglected the maintanence the whole time he owned it, OCs at whatever quickie place was handy when he thought of it, no concern about going long on miles, and it ran perfectly for 13 years and 140k miles until he wrecked it. Point being it's just random luck.
It shouldn't be this way but we all have to do our due dilligence no matter what we drive and be familiar with any known problem areas our vehicles have and the best way to deal with it. A lifter failure in a variable displacement GM engine is not a surprise.
I worked with a guy who bought a new 2007 Silverado 5.3 , first year of DOD and notorious for failures. He neglected the maintanence the whole time he owned it, OCs at whatever quickie place was handy when he thought of it, no concern about going long on miles, and it ran perfectly for 13 years and 140k miles until he wrecked it. Point being it's just random luck.
It shouldn't be this way but we all have to do our due dilligence no matter what we drive and be familiar with any known problem areas our vehicles have and the best way to deal with it. A lifter failure in a variable displacement GM engine is not a surprise.
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Disabling makes sure the lifter is never put into the position they tend to stick at. The best option is removal, but plenty of guys are disabling them.
AZjeff
$50 Site Donor 2023
And there were guys reporting lifter failure after disabling. No way to know if it prevents failure or if the engine wasn’t going to fail anyway. It doesn’t hurt anything to do it.
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The bulk of guys experiencing the failure on manual transmission equipped LT1/LT4 had it happen during operation after toggling from ECO (v4) mode back into other drive modes (v8). The manual cars won't go into AFM unless placed into Eco. The theory has been that the infrequent usage causes the sticking for the manual owners. Disabling or avoiding ECO mode might not be the cause of the reduction in failures, as it's possible GM revised something.
The automatic transmission guys have much more random results, but those cars are dynamically toggling AFM during normal driving.
The automatic transmission guys have much more random results, but those cars are dynamically toggling AFM during normal driving.
4WD
$50 site donor 2025
Did our 2017 @ 60k. The Range not only cuts the endless cycles - it’s taking duty off of the TC in my 6L80e … Went to 5W30 also …
The noticeable improvement was smooth delivery of power…
It’s approaching 100k now - no issues …
On a related note, I saw this in WSJ today (the link will bypass the paywall).
