Unsure if I want Tahoe with AFM

[Diezel Raccoon]

So I have been looking into getting a Chevy Tahoe. I have always been found of the 2nd gen style and wanted to get one in year range 2004-2006. I am very familiar with the 5.3 engines in those and how bulletproof they are. On the flip side the mpg on them is not as good as the newer ones. I do like the look of the 3rd gen and especially like the better mpg they get but I have had a lot of people tell me to avoid them because of the active fuel management system and how it causes issues down the road such as failed lifters. I had one friend tell me the issues with the AFM was resolved in the 2010 models and up.

If someone can give me some feedback on this I would greatly appreciate it. Thanks

 

[wjburken]

So I have been looking into getting a Chevy Tahoe. I have always been found of the 2nd gen style and wanted to get one in year range 2004-2006. I am very familiar with the 5.3 engines in those and how bulletproof they are. On the flip side the mpg on them is not as good as the newer ones. I do like the look of the 3rd gen and especially like the better mpg they get but I have had a lot of people tell me to avoid them because of the active fuel management system and how it causes issues down the road such as failed lifters. I had one friend tell me the issues with the AFM was resolved in the 2010 models and up.

If someone can give me some feedback on this I would greatly appreciate it. Thanks

Welcome to the forum from Iowa.

If you can avoid AFM, that is preferable. If you need to get one, get a newer model (2013 or 2014). If you can find a ‘07 or ‘08 and possibly ‘09 Yukon Denali with the 6.2, they don’t have it.

Worst case if you get one with AFM is you can do a tune delete where it turns it off or a full delete where you remove the AFM parts altogether and get a tune.

Or, you can do what I’m doing. Change the oil regularly and hope it doesn’t act up.

 

[wsteele]

I own a 2007 Yukon 5.3L Flex, AFM. My pistons and rings were replaced at 95K due to the valve cover and PCV issue they did fix in later models of that gen. Thankfully, I haven’t had any lifter issues (yet?), just installed a Range Tech ODB plug in that forces V8 mode all the time. Hopefully I can avoid AFM induced lifter issues with this mod. Only time will tell. Simpler is usually better.

PS - I love this truck so much, in the end, whatever it takes to keep it on the road and looking like new, I do. I can’t tell you how many hours, days and weeks I have spent looking for what might strike my fancy to replace it, they always come up short on what I already own.

 

[OR VietVet]

Welcome to the forum from Oregon. I hear lots of negatives here about the AFM engines. Like @wjburken said, get the year you want with the 6.2 engine and worries are gone. I do love my 2005 Z71 though.

 

[Bill 1960]

If you read forums, cylinder deactivation is usually seen as the work of satan. That goes across every brand of vehicle. And it IS one more thing in a vehicle that can, and does, fail.

My view, is it brings certain benefits -fuel economy- at a certain cost -more potential failures. Just like many things: power windows and locks, automatic transmission, power steering, and on and on.

I neither see it as a reason to buy, or a reason NOT to buy a vehicle I otherwise want. It’s easy enough to tune it off or to delete it mechanically if that’ll bring you peace of mind.

 

[Joseph Garcia]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

You have already received some great comments and advice from the folks here.

 

[cfmistry]

Every professional mechanic I've ever spoken to tells me the same thing: change your oil regularly and AFM failure is not an issue (extremely rare).

 

[wsteele]

Every professional mechanic I've ever spoken to tells me the same thing: change your oil regularly and AFM failure is not an issue (extremely rare).

That sounds pretty accurate to me.

I am certainly no expert on the subject, but looking at my ownership experience with my 2007 5.3L Flex/AFM Yukon, I think maybe some percentage of the increased failure rate in the AFM lifter area might be attributable to the old valve cover PCV design. In my car, this defective venting design promoted excessive oil being burned in the combustion chamber causing stuck rings and a downward spiral of oil consumption.

Even in cars regularly serviced, it may have lead to oil starvation or contamination between regular changes that may have gone unnoticed by customers who never checked oil levels between changes. In my engine's case, it was using a LOT of oil between changes. Someone who didn't check their oil level between changes might have thought everything was working fine when they were adding additional stress to lifters which don't hold up particularly well to stress, hence lifter failures that would never had happened had the valve cover not promoted excessive oil consumption.

If the above theory is correct, cars that came new with the updated valve cover (I understand sometime in the 2010-2011 timeframe), that have been regularly serviced, might show zero difference in lifter failure in AFM equipped cars.

 

[wsteele]

I just found this, TSB that covers essentially what happened to my engine.

I think if I were shopping for a Tahoe, I would make sure it either didn’t have AFM or came new with the updated valve cover (ie after 2/11 mfg date).

https://static.nhtsa.gov/odi/tsbs/2012/SB-10062524-7690.pdf

 

[adventurenali92]

Welcome to the forum from Oregon. I hear lots of negatives here about the AFM engines. Like @wjburken said, get the year you want with the 6.2 engine and worries are gone. I do love my 2005 Z71 though.

Except that this isn’t correct. 2007 and 2008 6.2s had the AFM components in the engine but were not activated the ECM software programming.
The ONLY 6.2 engine that HAD NO AFM system was the L9H 6.2 for 2009.
Everything from 2010 forward in a 6.2 had the AFM system and it’s active in the ECM software programming. Along with all 5.3 V8s from 2007-current.