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GM AFM lifters

by spongebob on Jun 12 2017, 11:04 PM

What is the story on the Active Fuel Management GM DOD lifters making noise and failing? I have seen several of these trucks experiencing engine Misfires as a result of bad lifters.

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12 Replies

By spark derk Oct 10 2018, 10:58 AM

What we have found is that the AFM board is the main culprit due to oil contamination. Always replace the AFM (DOD) board when you replace your lifters. On the Gen 5 units, GM uses the same afm lifters. The lifters are not the root cause.

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By north peachtree valero Oct 09 2018, 6:33 PM

The way the engine is angled causes the rear sets of lifters to not get sufficient oil flow and causes them to wear out a bit after 100k miles, we've had great luck with replacing the lifters where other shops have told them they need a new engine. The first gen 5.3 don't do this but the later 5.3, 6.0, and 6.2's all seem to have this problem.

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By barnards Jun 16 2018, 9:17 PM

Change all the lifters and inspect the camshaft.

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By saltyslug Dec 14 2017, 5:09 PM

i had that happen TWICE with a 2007 gmc sierra which was my personal vehicle

i replaced all 16 lifters and the camshaft. IT DID THIS BEFORE IT GOT TO 120XXX MILES!!!

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By tricityautorepair Sep 20 2017, 7:13 PM

I AGREE REPLACE THEM ALL AND THE SCREEN UNDER OIL PRESSURE SWITCH NEAR REAR OF ENGINE.

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By oldstech Sep 18 2017, 10:25 PM

Inspect the cam, replace all the failed lifters. Have a tuner turn off the AFM function, problem solved. I did this for my cousins well maintained 2010 Denali.... No more failed lifters and no noticeable difference in fuel mileage (AFM was designed to increase mileage)....

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By oldstech Sep 18 2017, 10:25 PM

Inspect the cam, replace all the failed lifters. Have a tuner turn off the AFM function, problem solved. I did this for my cousins well maintained 2010 Denali.... No more failed lifters and no noticeable difference in fuel mileage (AFM was designed to increase mileage)....

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By ketteler88 Sep 14 2017, 9:50 PM

Regular oil changes with high quality oil really helps. Most of the ones I see are under maintained. Also if they run low on oil major issue, normal to see lifter failure after that. Just an FYI always check the cam when replacing. I have also seen the cam lobes scored as well.

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By c21go1965 Sep 13 2017, 3:44 PM

always change the whole set of lifters, not just the suspect ones.

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By jeffreyd1 Sep 11 2017, 6:37 PM

We see them fail quite frequently. Some of these trucks are very well maintained using DEXOS oil, & they still fail. Nature of the beast. Hopefully someone can figure out an improved lifter & sell them. When one fails, I try to replace all AFM lifters when apart if not too cost prohibitive for the customer.

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