2014 Yukon XL - LC9 5.3L blew up @ 94,*** Miles due to AFM - New Motor!

[EnigmaMan]

Hey guys, I have not been on here in a while and need some advice.
A few weeks prior i was getting random check engine lights that would go on / off and would say #1 cylinder misfire. I did the standard troubleshooting steps prior to that such as fuel injector, all new plugs / wires etc

Just recently my 5.3L LC9 engine decided to grenade itself (I think) due to the AFM - Active Fuel Management tweaking out and causing #1 cylinder to grind down, and break the lifter and what not. I had 0 oil pressure and the thing was knocking like crazy!

Luckily the guys at GM decided it wasnt worth it to try and fix the motor so they gave me a brand new crate motor (I know there will be some doubters so I attached the service order). I should play the lotto as it blew up right before I ran out of warranty!!

Since I have reset the clock on this motor and basically have a brand new vehicle (minus the transmission / rear end). Ive been looking at doing some upgrades right out of the gate since my warranty is almost up and probably wont get another motor!

1. On3 Performance Turbo Upgrade - ~$2300
http://www.on3performance.com/shop/...do-sierra-15002500-truck-single-turbo-system/

Been researching these guys, and I called them up and spoke with them, they said its a direct bolt on and can use stock fuel injectors, pump and comes with the parts to do the upgrade your self over the weekend. If you want to use E85, you have to upgrade the pump / injectors to handle it but it does give 200 RWHP which would be nice with this beast.

2. Cam swap / N/A upgrade ~ $$$ Sky is the limit
After doing some research here, I can get a stock GM performance Camshaft and swap it out with out pulling the heads and seems pretty straight forward, but summit racing is suggesting a AFM DELETE kit thats $414 and you have to pull the heads, comes with the correct hydraulic roller lifter set, a valve lifter guide set, new head bolts, and an engine valley cover. (I would prob use studs instead) etc etc.

https://www.summitracing.com/parts/cmb-09-0026


TL;DL Version
1. Any experience with on3performance and their turbo package?
2. Is a AFM Disable programmer good enough to disable it and do a cam swap?


Thanks!

 

[randeez]

Same happened to me, gm replaced a few months before warranty ended. I pulled engine back out and deleted the afm mechanically.

 

[EnigmaMan]

Same happened to me, gm replaced a few months before warranty ended. I pulled engine back out and deleted the afm mechanically.

Did you do it with a kit or other means?

Sounds like a 100k mileage problem where the motor just self destructs! Have others had this experience as well?

 

[randeez]

Mine didn't make it that long, about 50k miles. I pulled engine back out withing 5k miles of being replaced. 6.2 L94
I did order a kit, but swapped out and reused a few things.
Lifters I reused the 8 reg lifters, replaced the 8 afm lifters.(low mileage)
Ls9 head gaskets instead of the provided
Head studs instead of the provided
Valve seals I didn't swap (low mileage)
You'll need a cam, cam will need to be tuned anyway so may as well get something worth it.
At that point mine started ***********, bigger cam meant more lift, new springs, hardened pushrods.

 

[EnigmaMan]

Haha thats the part im afraid of!
You start off with a simple fix, and then while you are in there you start to upgrade 1 thing which leads to another haha

Either way, it sounds like a programmer that turns off the AFM doesnt really resolve the issue and you really need to get into the motor and fix it to really get longevity out of the motor I am afraid another 50-100k miles and I'll have the same issue as I did with the last one!

 

[randeez]

Yea I wasnt really up for trusting the afm lifters for any kind of longevity.
Luck the draw it seems honestly tho, there's plenty of nearly stock trucks supercharged would have been a whole lot cheaper to go faster, but I've got no worries about lifters failing and have an engine ready for some for some boost.

Also, I the install seemed pretty halfassed (done as dealership) I never dealt with them before and prob went ever again. But any bolt they could impact in was, and everything else was a touch over hand tight.

 

[09Magic]

For any AFM delete: you will need non-AFM lifters and a non-AFM cam. AMS racing has a really good AFM delete kit with the cam, 8 lifters, gasket sets, etc.

 

[swathdiver]

For any AFM delete: you will need non-AFM lifters and a non-AFM cam. AMS racing has a really good AFM delete kit with the cam, 8 lifters, gasket sets, etc.

What are the specs of the camshaft they're using?

 

[09Magic]

What are the specs of the camshaft they're using?

I don't have all the specs such as DUR/Lift/LSA. I'd ask AMS or Texas Speed. They both offer complete kits.

AMS responded really well to me. I know others have had good luck with Texas Speed too.

 

[01FormulaTA]

contact Texas Speed....they will set you up with everything you need, if you change out the cam you need to change the lifters, im not sure why you would even entertain keeping the AFM lifters after one just caused your previous engine to fail? Pulling the heads is not that much more work, do it right the first time....also keep in mind turbos create ALOT of heat so maybe not the best choice for a DD, and your stock flex fuel injectors are only around ~32lb/hr iirc and will only support around ~400 RWHP