2010 LC9 have the bad AFM lifters?
11-06-2014, 12:40 PM
#1
2010 LC9 have the bad AFM lifters?
Just picked up a 2010 Silverado Z71 Ext Cab Short Box.
Has LC9 aluminum 5.3 with VVT and AFM. I know early engines had lifter failures on the AFM cylinders. Was the issue fixed prior to 2010? I am thinking of keeping both AFM and VVT and working with them.
Has LC9 aluminum 5.3 with VVT and AFM. I know early engines had lifter failures on the AFM cylinders. Was the issue fixed prior to 2010? I am thinking of keeping both AFM and VVT and working with them.
11-06-2014, 09:54 PM
#2
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They all have problems even have had 12's in shop with bad lifters and or destroyed cams and then later on down the road destroyed bottom ends because of all the metal debris pumped through the system.
Ditch DOD and VVT since you are wanting to cam it and you will have a 5.3 that will go 300K miles like the old ones before they screwed them up
Ditch DOD and VVT since you are wanting to cam it and you will have a 5.3 that will go 300K miles like the old ones before they screwed them up
11-07-2014, 09:54 AM
#3
They all have problems even have had 12's in shop with bad lifters and or destroyed cams and then later on down the road destroyed bottom ends because of all the metal debris pumped through the system.
Ditch DOD and VVT since you are wanting to cam it and you will have a 5.3 that will go 300K miles like the old ones before they screwed them up
Ditch DOD and VVT since you are wanting to cam it and you will have a 5.3 that will go 300K miles like the old ones before they screwed them up
11-09-2014, 01:16 AM
#5
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Who knows its probable that it could make them last forever. Its all speculation no way to really prove if it will be as reliable as a non dod engine in disabled mode. I'd say to avoid cracking open a motor to swap lifters and disable dod if you werent going to cam it then disabling it in the tune is the way to go and you will just have to see if it has a lifter failure down the road. But if I were a betting man I would say its highly probable it will live a long healthy life throw the dice and see if it rolls snake eyes.
If I were to buy a new 5.3 tomorrow I'd feel safer pulling heads swap lifters and valley plate and not have to worry about it no questions asked forever. But that's me and for me it's no big deal cracking one open to do the work but others probably don't feel that way nor want to do it on a new engine.
If I were to buy a new 5.3 tomorrow I'd feel safer pulling heads swap lifters and valley plate and not have to worry about it no questions asked forever. But that's me and for me it's no big deal cracking one open to do the work but others probably don't feel that way nor want to do it on a new engine.
Last edited by 01WS6/tamu; 11-09-2014 at 01:24 AM.
11-09-2014, 12:51 PM
#6
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The VVT is proving solid and worthwhile. Theres a thread below with the first complaint Ive ever seen of a phaser failure and my two VVT engines have been working flawlessly for years now, and one spins to 7200 and the occasional 800RPM blip ( no limiter )
But the AFM issue is the lifters themselves. Lifters are a badly abused component as it is it took many, MANY years to get a really good roller lifter that was reliable for extended service which is why so many manufacturers use basically the exact same roller lifter as GM does. The AFM unit has to collapse to prevent the valve from opening and still do its normal job as well. Its a lot to ask of an already heavily taxed part especially when dealing with a part that needs to maintain a lash spec which is what gets all out of whack with the "over active" lifter issue. Fancy wording for a lifter thats falling wayyyyyyyy out of tolerance and is showing its weakness.
I do have friends running AFM engines with good success though, even one in a Camaro but its still on the stock cam. ANY cam swap type thinking with an AFM engine and this is where you really want to do an AFM delete as well.
But VVT is sweet tech. Its on ALL the new hi-perf vehicles fyi. Viper, Vette, Porsche, Lambo etc etc so I recommend utilizing it, not losing it.
But the AFM issue is the lifters themselves. Lifters are a badly abused component as it is it took many, MANY years to get a really good roller lifter that was reliable for extended service which is why so many manufacturers use basically the exact same roller lifter as GM does. The AFM unit has to collapse to prevent the valve from opening and still do its normal job as well. Its a lot to ask of an already heavily taxed part especially when dealing with a part that needs to maintain a lash spec which is what gets all out of whack with the "over active" lifter issue. Fancy wording for a lifter thats falling wayyyyyyyy out of tolerance and is showing its weakness.
I do have friends running AFM engines with good success though, even one in a Camaro but its still on the stock cam. ANY cam swap type thinking with an AFM engine and this is where you really want to do an AFM delete as well.
But VVT is sweet tech. Its on ALL the new hi-perf vehicles fyi. Viper, Vette, Porsche, Lambo etc etc so I recommend utilizing it, not losing it.
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11-09-2014, 09:42 PM
#8
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I agree VVT is a awesome have your cake and eat it too bit that is stone reliable. One phaser failure since 08 out of lord knows how many trucks we have sold and serviced they have the VVT dead nuts reliable.
When my truck was tune the VVT tables were left functional but stock. I've really been curious if there is any sizeable gains in either power or MPG by tinkering with these tables on a stock engine. As bad as I want to cam mine I've promised myself not to crack open this truck until I have a reason to.
When my truck was tune the VVT tables were left functional but stock. I've really been curious if there is any sizeable gains in either power or MPG by tinkering with these tables on a stock engine. As bad as I want to cam mine I've promised myself not to crack open this truck until I have a reason to.
11-09-2014, 09:57 PM
#9
(hypothetical of course because why would someone in your situation buy a 5.3 instead of a 6.2)
11-09-2014, 10:24 PM
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I tend to follow the "if aint broke dont fix it" rule around here. But If i was wanting to hot rod it around, tune for power maybe headers etc id seriously consider ditching it now. If I was cam swapping it would be a no brainer delete which I would probably do as I was deleting AFM so id do both, cam swaps in LS when done right are cherrrrrrrrrry fun.
That said, If i wanted a stock daily? Id run it til she blows, why fix what isnt broke and who knows maybe it'll be a good one and it'll last the duration.
That said, If i wanted a stock daily? Id run it til she blows, why fix what isnt broke and who knows maybe it'll be a good one and it'll last the duration.