Lifter Failures GM/Chevy 5.3L V-8 with AFM/DFM

[Blair Warren]

Just dealt with this on my Silverado. Seems to be a fairly common problem. Passenger side lifters wear out because of AFM/DFM switching from V-8 to 4 cylinder mode. Causing $$$$ repairs.


You guys probably knew this already, but just in case.... (I wish I had known sooner.)

There are AFM disablers that keep the engine in V-8 mode fulltime. Affects your gas mileage a bit, but from what I have read, mitigates the lifter issue.

Something like this...

Range AFM Disabler


There are less costly AFM disablers, but this one seems to be the gold standard.

I have not installed anything as yet. Can't recommend one at this point.

 

[Mike Hughes]

Just curious, why does it do that? I am not famaliar with how the whole process works. I would think that they are just turning off the injectors on those holes to make them dead. How does that wear out the lifters?
Mike

 

[Blair Warren]

Hey Mike,

Here is a link to a pretty good article that explains it:

AFM Lifter Failure

 

[Mike Hughes]

OH MAN......yeah, he started expaining and my brain was thinking of all the ways that could fail. Seems like a poor design. Is this just GM design. Was thinking about buying a new GMC truck soon. Love my GMC work truck.

My favorite quote "The best way to avoid a problem with AFM lifters is to avoid buying a car with an affected engine. AFM only applies to specific V6 and V8 models."

Mike

 

[Don Ferrette]

Just curious, why does it do that? I am not famaliar with how the whole process works. I would think that they are just turning off the injectors on those holes to make them dead. How does that wear out the lifters?
Mike

GM tried this before back in 1981 on the Cadillac line except it used solenoids to disable rocker arm fulcrums to go to 6 then 4 cylinder modes to save fuel. Needless to say it was an unmitigated disaster and that option was gone for 1982. Just like back then it's all about meeting the EPA mandated fuel mileage averages....................

 

[Blair Warren]

OH MAN......yeah, he started expaining and my brain was thinking of all the ways that could fail. Seems like a poor design. Is this just GM design. Was thinking about buying a new GMC truck soon. Love my GMC work truck.

A lot of the new GM trucks do not have the DFM (an updated version of AFM). Just have to look for a credit for the DFM on the window sticker.

 

[Blair Warren]

GM tried this before back in 1981 on the Cadillac line except it used solenoids to disable rocker arm fulcrums to go to 6 then 4 cylinder modes to save fuel. Needless to say it was an unmitigated disaster and that option was gone for 1982. Just like back then it's all about meeting the EPA mandated fuel mileage averages....................

Wasn't it the high voltage transmission lines that were doing them in? the good old V-8-6-4.

 

[Samuel Hagan JR]

Do a delete and get with someone that has HP tuner software to disable it. That’ll solve a lot of problems.

 

[Blair Warren]

Do a delete and get with someone that has HP tuner software to disable it. That’ll solve a lot of problems.

That would work as well.

The AFM disabler plugs into the OBD port. It does not reprogram the ECU. From what I read you can install it in a vehicle while it's under warranty. It can be removed and the vehicle goes back to "normal mode" and shouldn't impact any warranty work. The dealer would not know that you had installed it.

 

[Wasted wages]

I deleted mine by never giving GM any more of my hard earned cash for these failures.
Got rid of my 2007 GMC Yukon, bought a Dodge CTD dually 4x4 and never looked back.
Wife's car is a Toyota Venza 3.5L motor, we've put 82k on the clock, with absolutely no problems...

 

[Hydro Junkie]

This may sound strange but I actually like the shutting off of cylinders in my engine. It makes a huge difference in fuel consumption when I'm pulling my camp trailer. Granted, my Tahoe is a 2011 so it falls out of the range of "problem engines" that started in 2014 but, that said, my Tahoe has been reliable almost to a fault and it's now got almost 110K miles on it.

 

[Blair Warren]

This may sound strange but I actually like the shutting off of cylinders in my engine. It makes a huge difference in fuel consumption when I'm pulling my camp trailer. Granted, my Tahoe is a 2011 so it falls out of the range of "problem engines" that started in 2014 but, that said, my Tahoe has been reliable almost to a fault and it's now got almost 110K miles on it.

That's awesome your Tahoe is been a good vehicle for you. Once in a while you get a really good one.

I had a 2002 Silverado 1500, No AFM/DFM great truck.

On my 2015, I was impressed with how the gas mileage was with the AFM. Seemed to work great. On a long highway trip, would get 22+mpg.

The 2015 had been great until the end of October. I have 125K miles on it. Did all the suggested/required maintenance to try to keep it in tip top shape. I tow a camper as well.

Since the end of October: the 2015 has had lifter problems with 2 bent push rods and $3K to fix. Then shortly thereafter, fuel injector issues with another $2.6K to fix. Getting a little old.

If I had known about the lifter issues with the AFM, I would have opted for an AFM disabler.

The fuel injectors would have went bad anyways regardless of an AFM disabler. Just bad timing. LOL

I put the info about the AFM Disabler device out there to possibly help somebody else avoid the lifter issues and a $$$ repair bill. I have not used one as yet, but from researching them, they seem to work well.

 

[Hydro Junkie]

Trust me, I like the heads up since it gives me some warning about what could be looming in the future. Regardless on whether we have issues with the engine or not, the wife has already said we would just replace the engine or transmission if needed and keep on driving it. Same thing applies to our 2003 S-10. If the 4.3 or transmission fail, it will be rebuild or replace and keep driving it

 

[Brad Christy]

Trust me, I like the heads up since it gives me some warning about what could be looming in the future. Regardless on whether we have issues with the engine or not, the wife has already said we would just replace the engine or transmission if needed and keep on driving it. Same thing applies to our 2003 S-10. If the 4.3 or transmission fail, it will be rebuild or replace and keep driving it

Mark,

FYI...

We have a 2010 Avalanche with that same engine that had the exact same failure as described in the above article, at something just over 70K miles. Your 2011 does NOT fall outside the window. Luckily, ours wiped the lobes on the cam less than two weeks after buying it, and the truck came with a 30-day dealer warrantee. They didn't like it, but they covered it. Inconsistent with the article, however, we were told the failure was due to some fault in the parts; metallurgy, heat treat or plating, they couldn't really tell me. It is very possible, if not highly likely, though, it was the direct fault of the design. 100K+ miles later, we are still pulling our 7000K boat/trailer with it, though.

Thanks. Brad.
Titan Racing Components
BlackJack Hydros
Model Machine and Precision LLC

 

[dave roach]

Blair
There is a law suit on this and if i was you i would be checking it out.

 

[Norm Doerr]

GM tried this before back in 1981 on the Cadillac line except it used solenoids to disable rocker arm fulcrums to go to 6 then 4 cylinder modes to save fuel. Needless to say it was an unmitigated disaster and that option was gone for 1982. Just like back then it's all about meeting the EPA mandated fuel mileage averages....................

Had one of those. Got it CHEAP with 20K miles on it. A tech who was much smarter than most figured the thing out, pulled the radio, snipped some wires back there put the radio back in and it ran on all 8 cylinders after that.

 

[Blair Warren]

Blair
There is a law suit on this and if i was you i would be checking it out.

Thanks Dave,

I had heard a little bit about a lawsuit. I will be investigating it for sure.

I forgot to mention that there are aftermarket "kits" to totally delete the AFM. Involves new cam, lifters etc. It would be like open heart surgery. But if you have the engine apart, and need to replace those parts anyways it might be something to consider.

 

[Blair Warren]

We have a 2010 Avalanche with that same engine that had the exact same failure as described in the above article, at something just over 70K miles. Your 2011 does NOT fall outside the window. Luckily, ours wiped the lobes on the cam less than two weeks after buying it, and the truck came with a 30-day dealer warrantee. They didn't like it, but they covered it. Inconsistent with the article, however, we were told the failure was due to some fault in the parts; metallurgy, heat treat or plating, they couldn't really tell me. It is very possible, if not highly likely, though, it was the direct fault of the design. 100K+ miles later, we are still pulling our 7000K boat/trailer with it, though.

That was good that you were able to get the dealer to cover the repairs. I was lucky that the cam in mine was still ok. If it had been wiped out I may have gone with the AFM delete kit. No sense rebuilding/repairing things and having it fail due to the same issues . I agree that it is most likely a faulty design.

 

[Brad Christy]

That was good that you were able to get the dealer to cover the repairs. I was lucky that the cam in mine was still ok. If it had been wiped out I may have gone with the AFM delete kit. No sense rebuilding/repairing things and having it fail due to the same issues . I agree that it is most likely a faulty design.

Blair,

Yup. It went from sounding fine to having a slight valve tick to full-on valve clatter in a matter of 24hrs. I drove it to the sister dealership (we bought it from a Toyota dealership that was co-owned with a Chevy dealership) at about 25 MPH on the highway, with my foot almost on the floor, getting about 3 MPG. The cam was trashed, as were the lifters. We got an entire new top end out of the deal, but we had to go with OEM parts.

Thanks. Brad.
Titan Racing Components
BlackJack Hydros
Model Machine and Precision LLC

 

[dave roach]

Blair
Don't put new lifters on a old cam when the lifter were trashed You will have problems down the road.I was a Gm tech for 28 years.