AFM

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TJBrown

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I own a 2012 Tahoe LT 5.3. I would like to know at about what mileage can I expect the AFM to start giving me problems. Or has GM worked this out?
 

Geotrash

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I own a 2012 Tahoe LT 5.3. I would like to know at about what mileage can I expect the AFM to start giving me problems. Or has GM worked this out?
Some people have problems with it in the first 50K miles. Others go 300K with no issues. The system works with oil pressure so when one of the AFM lifters fails and wipes the cam, low oil pressure (another common issue) is often the smoking gun.

You can disable the AFM system with either a device that pugs into the OBDII port, or with a custom tune with the help of a local tuner shop or via email with Black Bear Performance. I use the former - a device made by Range and it works great.

You can also permanently remove it by doing a cam and lifter swap, which is what I'm in the process of doing. My parts are on the way and I'll do the job over a couple of weekends in November. I don't trust the AFM hardware, even if it's disabled.

Best,
Dave
 

Chert_Detective

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Just trying to get their average MPG fleet wide high enough for the EPA.

Oh I know, it's just a classic case of good plan (mpg) poor execution (AFM) and really adds to my love hate relationship with GM V8s.
 

1BADI5

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Mine had 77K when I did the full blown delete, cam and heads.

I had a well maintained truck, but was getting a random lifter tick on #6, so I opted to get it deleted and gone before it got bad
 

intheburbs

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I don't buy the whole, "GM fixed this around 2010" spiel. In my opinion, it is a flawed design and I will never own an AFM truck. The two trucks in my sig do not have AFM. If I have to, I'll get a Ram or Super Duty before I get AFM.

That being said, what I've seen and read is that it will act up most likely from 75k-100k miles, with collapsed lifter(s). If the engine makes it to 100k-125k with no issues, you got a good one.

Once, when I was looking to buy, I saw a used 08 Avalanche for sale with 96k miles that had just had the engine replaced. That, I would have bought. And then immediately disabled the AFM.
 

91RS

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It can literally happen at any mileage. I bought a 12 with 176k miles thinking if it were going to break it would have already and 6 months later started getting wierdo misfires on cylinder 6.

Disabling the system with a Range device or with a tune will make it last longer because it isn’t cycling any more but it can still break.
 

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