2019 GM 6.2 AFM

[XL1200RFan]

The December issue of MOTOR magazine discusses the technical changes of various engines in the 2019 models. The Active Fuel Management system in the GM 6.2 V8 now has one solenoid per cylinder to control oil flow to the lifters, so the operation of each cylinder can be controlled individually. The author adds what I thought was wise (but amusing) advice: "With additional solenoid valves and faster operation, it should be obvious that regular oil changes become even more important.".

As the years & miles go by, it will be interesting to see how "neglect tolerant" this latest AFM system is.

 

[Snagglefoot]

The pre-2014 AFM version had the potential to be very troublesome.

The 2014 re-design was a package deal:

- Variable pressure oil pump with a higher pressure at cruising speed.
- Redesigned oil filter with a higher by-pass setting
- larger oil capacity in the sump
- requirement for Dexos D1G2 motor oil
- redesigned lifters and solenoids

I heard they work quite well. I might buy a used one in a few years so hopefully they run well!

 

[XL1200RFan]

I appreciate technical sophistication & solid engineering. As we discuss here every day, all day: oil quality, filter performance & OCI matters. Reliable performance from complex systems demand it.

 

[WyrTwister]

Originally Posted by XL1200RFan
The December issue of MOTOR magazine discusses the technical changes of various engines in the 2019 models. The Active Fuel Management system in the GM 6.2 V8 now has one solenoid per cylinder to control oil flow to the lifters, so the operation of each cylinder can be controlled individually. The author adds what I thought was wise (but amusing) advice: "With additional solenoid valves and faster operation, it should be obvious that regular oil changes become even more important.".

As the years & miles go by, it will be interesting to see how "neglect tolerant" this latest AFM system is.


Very good point . Our little 2015 Chevy Sonic has VVT & as I understand , engine oil is used as a hydraulic fluid . Which is why I run 100% synthetic and chang the oil / filter at 55% & 5% on the Oil Life Indicator . Do not want any tiny oil passages slugging up .

Plus , I am sure the rest of the moving parts do not mind !

I look at it as cheap insurance & changing it myself , not that expensive . Especially using on sale oil & filters .

 

[Phishin]

This is why I bought a truck with a 6.0L

No AFM on these old work horses

 

[dave1251]

Like a lot of "problems" BITOG members blow it out of proportion.

 

[Brigadier]

Originally Posted by XL1200RFan
I appreciate technical sophistication & solid engineering. As we discuss here every day, all day: oil quality, filter performance & OCI matters. Reliable performance from complex systems demand it.



Nah, just dump in Amsoil and run 25k OCI. You will be fine. Just ask Amsoil....

 

[LeakySeals]

I belong to a few Tahoe/Yukon/Escalade FB enthusiast pages and AFM related engine failures are maybe the the biggest complaint. Especially the 07-09 5.3L. Lesser for the 6.2, but still exists. Over time during AFM operation a lifter gets stuck, collapses. When it does, the shell rubs on the cam lobe. Wears the lobe down. The result is engine teardown for new lifters, new cam. A tune to delete or a device that disables AFM is very popular. There is also a TSB for a valve cover upgrade that helps. The valve cover has an integrated PCV valve. The PCV baffle hole in the cover was too small resulting in too much pressure, excess buildup of blowby. Further inflaming the lifter issues.

The difference using AFM is maybe 2 MPG as reported by many owners. Will things be different in 2019? Who knows. i hope so. Until then I'm sticking with my 6.0 LQ9

 

[64bawagon]

I have an 18 with the 5.3. I only noticed the AFM slightly before but I have made a few expressway trips recently and I have to say it is annoying. Its almost like a truck that cant decide if it wants to stay in overdrive. Its far from seamless and if you watch the instant MPG as it switches back to V8 mode it does tick downward significantly for a second or 2. I doubt thats a huge hit on fuel consumption but I question the cost/benefit of it. If this truck werent a lease I would buy a programmer and shut it off.

 

[CKN]

Originally Posted by 64bawagon
I have an 18 with the 5.3. I only noticed the AFM slightly before but I have made a few expressway trips recently and I have to say it is annoying. Its almost like a truck that cant decide if it wants to stay in overdrive. Its far from seamless and if you watch the instant MPG as it switches back to V8 mode it does tick downward significantly for a second or 2. I doubt thats a huge hit on fuel consumption but I question the cost/benefit of it. If this truck werent a lease I would buy a programmer and shut it off.



I have a 2018 Silverado 5.3 and the AFM is seamless and not noticeable. I traded in a low millage 2012 GMC Sierra with the 5.3 and the AFM was indeed more pronounced when making the AFM transition..

 

[GMBoy]

The transition from 4/8 cyl mode on my Ram Hemi is seamless and I do notice a worthwhile MPG increase if I drive trying to stay in the ECO mode. All the GM versions I have driven (many!) are also smooth and not noticeable. My 6.0L LQ9 Sierra Denali doesn't have it and I appreciate it's chances of being trouble free longer down the road.

 

[TiredTrucker]

Originally Posted by Phishin
This is why I bought a truck with a 6.0L

No AFM on these old work horses


Ditto!! While I am not against technology, there can be times when it is used as a solution in search of a problem.

And I am just an old Cavalry Sergeant.... I expect everyone to pack the gear. If I pay for 8 cylinders that is because I wanted 8 cylinders and I expect them all to carry the load. None of them taking union or government inspired smoke breaks while the others do the work. The only way I will ever buy into cylinder shutdown scenarios is whenever the OPOC engine finally comes out in a production vehicle.

 

[4WD]

Originally Posted by GMBoy
The transition from 4/8 cyl mode on my Ram Hemi is seamless and I do notice a worthwhile MPG increase if I drive trying to stay in the ECO mode. All the GM versions I have driven (many!) are also smooth and not noticeable. My 6.0L LQ9 Sierra Denali doesn't have it and I appreciate it's chances of being trouble free longer down the road.


I'm still baffled at how often our Tahoe goes 4 cylinders and how almost never the lighter Silverado does …

 

[DoubleWasp]

Recently drove a rental 5.3 Silverado, and I couldn't tell at all when it did it. Seem to have figures out the drivability. Reliability? Who knows.

 

[dave1251]

Originally Posted by DoubleWasp
Recently drove a rental 5.3 Silverado, and I couldn't tell at all when it did it. Seem to have figures out the drivability. Reliability? Who knows.



On current vehicles it is nearly seamless and you have to hunt to notice the shift from 3 to 6 or from 4 to 8. The ones complaining are the ones upset they do not have total control over vehicle operation.

 

[tony1679]

Originally Posted by Snagglefoot
The pre-2014 AFM version had the potential to be very troublesome.
Absolutely correct.
Originally Posted by Phishin
This is why I bought a truck with a 6.0L

No AFM on these old work horses
Smart choice.
Originally Posted by dave1251
Like a lot of "problems" BITOG members blow it out of proportion.
Oh, do elaborate please!

Originally Posted by LeakySeals
I belong to a few Tahoe/Yukon/Escalade FB enthusiast pages and AFM related engine failures are maybe the the biggest complaint. Especially the 07-09 5.3L. Lesser for the 6.2, but still exists. Over time during AFM operation a lifter gets stuck, collapses. When it does, the shell rubs on the cam lobe. Wears the lobe down. The result is engine teardown for new lifters, new cam. A tune to delete or a device that disables AFM is very popular. There is also a TSB for a valve cover upgrade that helps. The valve cover has an integrated PCV valve. The PCV baffle hole in the cover was too small resulting in too much pressure, excess buildup of blowby. Further inflaming the lifter issues.

The difference using AFM is maybe 2 MPG as reported by many owners. Will things be different in 2019? Who knows. i hope so. Until then I'm sticking with my 6.0 LQ9
Preach!

My 5.3L is 99% the same engine. In my case, my mpgs went UP by 2 by disabling AFM. Smart decision on the LQ9.
Originally Posted by TiredTrucker
Ditto!! While I am not against technology, there can be times when it is used as a solution in search of a problem.

And I am just an old Cavalry Sergeant.... I expect everyone to pack the gear. If I pay for 8 cylinders that is because I wanted 8 cylinders and I expect them all to carry the load. None of them taking union or government inspired smoke breaks while the others do the work.
Bingo! And the main problem is the EPA mandates on fuel economy. GM just can't figure out how to easily meet it, and comes up with stupid designs like this while trying.

at the smoke breaks. In my experience, those cylinders literally smoked out the tail pipes before I disabled it.

 

[64bawagon]

"On current vehicles it is nearly seamless and you have to hunt to notice the shift from 3 to 6 or from 4 to 8. The ones complaining are the ones upset they do not have total control over vehicle operation."

Thank you for telling everyone what I really meant, Presumptuous much ?

 

[dave1251]

Originally Posted by tony1679
Originally Posted by Snagglefoot
The pre-2014 AFM version had the potential to be very troublesome.
Absolutely correct.
Originally Posted by Phishin
This is why I bought a truck with a 6.0L

No AFM on these old work horses
Smart choice.
Originally Posted by dave1251
Like a lot of "problems" BITOG members blow it out of proportion.
Oh, do elaborate please!

Originally Posted by LeakySeals
I belong to a few Tahoe/Yukon/Escalade FB enthusiast pages and AFM related engine failures are maybe the the biggest complaint. Especially the 07-09 5.3L. Lesser for the 6.2, but still exists. Over time during AFM operation a lifter gets stuck, collapses. When it does, the shell rubs on the cam lobe. Wears the lobe down. The result is engine teardown for new lifters, new cam. A tune to delete or a device that disables AFM is very popular. There is also a TSB for a valve cover upgrade that helps. The valve cover has an integrated PCV valve. The PCV baffle hole in the cover was too small resulting in too much pressure, excess buildup of blowby. Further inflaming the lifter issues.

The difference using AFM is maybe 2 MPG as reported by many owners. Will things be different in 2019? Who knows. i hope so. Until then I'm sticking with my 6.0 LQ9
Preach!

My 5.3L is 99% the same engine. In my case, my mpgs went UP by 2 by disabling AFM. Smart decision on the LQ9.
Originally Posted by TiredTrucker
Ditto!! While I am not against technology, there can be times when it is used as a solution in search of a problem.

And I am just an old Cavalry Sergeant.... I expect everyone to pack the gear. If I pay for 8 cylinders that is because I wanted 8 cylinders and I expect them all to carry the load. None of them taking union or government inspired smoke breaks while the others do the work.
Bingo! And the main problem is the EPA mandates on fuel economy. GM just can't figure out how to easily meet it, and comes up with stupid designs like this while trying.

at the smoke breaks. In my experience, those cylinders literally smoked out the tail pipes before I disabled it.



Really do not need to eliberate the failure rate of the AFM is less than 1%. Yet the GM 5.3 is another example of internet over amplification of a very minor issue. A Volkswagen is much more likely to suffer engine issues then any GM 5.3.

 

[CKN]

Originally Posted by dave1251
Originally Posted by tony1679
Originally Posted by Snagglefoot
The pre-2014 AFM version had the potential to be very troublesome.
Absolutely correct.
Originally Posted by Phishin
This is why I bought a truck with a 6.0L

No AFM on these old work horses
Smart choice.
Originally Posted by dave1251
Like a lot of "problems" BITOG members blow it out of proportion.
Oh, do elaborate please!

Originally Posted by LeakySeals
I belong to a few Tahoe/Yukon/Escalade FB enthusiast pages and AFM related engine failures are maybe the the biggest complaint. Especially the 07-09 5.3L. Lesser for the 6.2, but still exists. Over time during AFM operation a lifter gets stuck, collapses. When it does, the shell rubs on the cam lobe. Wears the lobe down. The result is engine teardown for new lifters, new cam. A tune to delete or a device that disables AFM is very popular. There is also a TSB for a valve cover upgrade that helps. The valve cover has an integrated PCV valve. The PCV baffle hole in the cover was too small resulting in too much pressure, excess buildup of blowby. Further inflaming the lifter issues.

The difference using AFM is maybe 2 MPG as reported by many owners. Will things be different in 2019? Who knows. i hope so. Until then I'm sticking with my 6.0 LQ9
Preach!

My 5.3L is 99% the same engine. In my case, my mpgs went UP by 2 by disabling AFM. Smart decision on the LQ9.
Originally Posted by TiredTrucker
Ditto!! While I am not against technology, there can be times when it is used as a solution in search of a problem.

And I am just an old Cavalry Sergeant.... I expect everyone to pack the gear. If I pay for 8 cylinders that is because I wanted 8 cylinders and I expect them all to carry the load. None of them taking union or government inspired smoke breaks while the others do the work.
Bingo! And the main problem is the EPA mandates on fuel economy. GM just can't figure out how to easily meet it, and comes up with stupid designs like this while trying.

at the smoke breaks. In my experience, those cylinders literally smoked out the tail pipes before I disabled it.



Really do not need to eliberate the failure rate of the AFM is less than 1%. Yet the GM 5.3 is another example of internet over amplification of a very minor issue. A Volkswagen is much more likely to suffer engine issues then any GM 5.3.


This. And GM sells over 40,000 units a month Silverado/Sierra combined. And they made engine changes at the 2014 model year to correct AFM issues. GM is selling plenty of trucks at $45,000.00 to $60,000.00 (plus) a pop.

 

[tony1679]

Originally Posted by dave1251
Really do not need to eliberate the failure rate of the AFM is less than 1%. Yet the GM 5.3 is another example of internet over amplification of a very minor issue. A Volkswagen is much more likely to suffer engine issues then any GM 5.3.
You're really going to tell the owner of one who had major issues that it's "a very minor issue."?

Let me spell out how "minor" it is...

1. Burning a full quart of [synthetic] oil every 750 miles.
2. Constant heavy smoke out of the tailpipes when it re-engages the 4 AFM cylinders (from the burning oil).
3. Disgustingly oil-fouled Iridium spark plugs after 80k miles (should have been swapped AT LEAST 20k sooner).
4. Catalytic converter was oil-fouled and had to be replaced at 75k. Afterward, when I bought it at 76k, you could smell the new cat already being poisoned, and when I went to the dealer (because the cat was still under warranty) they told me to kick rocks and use top-tier (which I always do).
5. Terrible fuel economy (I averaged 21 - 85% highway. Now it's 23-24 with 8 cylinders full-time).

Shall I keep going? I certainly can.

When I disabled AFM at 78k, literally ALL of these problems disappeared instantly. Yes, even the oil burning. Hasn't burned any since. It's at the full mark before every oil change.

By your definition, I did not have a "failure" that counts toward your claimed 1%. But I certainly call that one.

I suppose you'll tell me the 4T65E(-HD) is a great trans too?