6.2 Lifter/Engine Failure Poll

[ZR2NYC]

I looked more into it not long after i got my 1500. There is some good videos online detailing GMs DFM and showing some of the failure reasons. The lifter is held open with a couple of spring loaded tabs. When dfm kicks in. Oil pressure is increased to that lifter by a electric solenoid and those tabs are pushed in. That causes the lifter to collapse and not open those valves. The two little tabs that hold the lifter open sit on a small shelf in the lifter body. The tabs or shelf can get deformed causing the lifter to not open or collapse properly. Or the tabs can just fail since they are all that's holding the lifter open in normal operation. That's why they fail even with DFM disabled. The lifter will collapse when it's not supposed to.

The whole system does rely on varying oil pressure and electric solenoids. Along with a couple of small spring loaded tabs. All that in engines that are known for oil consumption issues, lol. A lot of the failures could be lack of oil issues, but even with proper oil those tabs/springs or the lifter body can just fail. Not to mention the solenoids.

great explanation!!!! im gonna add L9 to deactivate DFM may be a myth.

 

[securityguy]

great explanation!!!! im gonna add L9 to deactivate DFM may be a myth.

L9 or Two/Haul should do the same. Whether it truly helps no one knows. I have read that it doesn't, but I run in T/H mode every time regardless.

 

[ZR2NYC]

L9 or Two/Haul should do the same. Whether it truly helps no one knows. I have read that it doesn't, but I run in T/H mode every time regardless.

correct...i do it cause its a mental feel good thing.

 

[8ball_99]

Unfortunately I don't think just keeping DFM off really helps all that much. I guess the lifters not collapsing or having to relock open could in theory reduce the chances. Looking at photo's of bad lifters online. It seems those tabs and that little shelf gets deformed and the lifter starts collapsing when it shouldn't. That or it collapses half way and gets stuck in the middle. I sort of got the impression the only real fix is a solid lifter that isn't held open with some spring loaded tabs. I also wonder if keeping DFM off most of the time could actually increase the odds of that lifter getting stuck if\when DFM does kick in. I mean it's a steel rod that fits pretty snug in a steel tube. Keeping them moving freely might actually reduce the chances of them getting stuck when they try to collapse.

Who knows. Gm isn't going to admit that there is even a problem, lol. So it's not like they are going to put any information out on best way to avoid lifter problems. Mechanics online just say keep your oil clean and topped off to reduce the chance of a DFM failure. I'm just glad the HDs don't have it.

 

[TexOffroader]

On the topic of T/H mode, if you are a fan like I am, you don’t need an Auto SS disabler because T/H mode on my 1500 disables Auto SS. So you don’t need to spend money on the Auto SS device and you only have to press the T/H button. The nice thing about T/H mode is that it doesn’t reset every time you turn off the truck. T/H mode will be disabled after the truck sits overnight or for a longer period of time so the computer must be making this decision based on a timer because if you are running errands, then T/H mode will still be enabled when you restart the truck. This post only applies to those of us who desire to be in T/H mode 100% of the time because you like the sportier feel of the shift points especially coupled with the Ultimate 9.

 

[Dragon]

Put the trans in "L" and shift up to 9. It won't cure the chinese lifter issue but it may make the motor last a little longer before it implodes. That will keep the auto stop off and stop the DFM from dropping cylinders.

The lifters are not chinese. Ram also has chinese parts.

 

[Dragon]

Seems very random some go early, so go a while, some have 0 problems.

I would recommend changing the oil at 1500 miles. I did mine and my wife's Tahoe and they both had a distinct silver color in oil and in pan. Both filters I cut open and they had plenty of metal shavings. I think with that much stuff in the oil, it doesn't offer optimum protection. I made a thread on oil filter anatomy.

I doubt that any specific failure could be pinned on oil, especially at 2k miles, but may as well eliminate the potential.

Metal shavings is not a good sign.

 

[AXE]

Metal shavings is not a good sign.

Sure it is, it means your oil filter is catching the break in particles. Most od which are left over from manufacturing.

 

[Dragon]

Yep that's why I've said you need to buy two GM trucks if you want to stay on the road nowadays.

They don't have a motor for you cause they are too busy selling new trucks and they need motors to do that. There's hundreds of 6.2L in inventory right now.

They got your money, so they couldn't care less. I'd get a lawyer and have them contact GM and the dealer. You'll get a lot more attention once they know you have retained counsel. They'll bring a deal to the table then.

I guess that would have been the situation with Toyotas as well... I heard about valve spring issues with the 5.7s that are similarly catastrophic.

 

[Dragon]

I looked more into it not long after i got my 1500. There is some good videos online detailing GMs DFM and showing some of the failure reasons. The lifter is held open with a couple of spring loaded tabs. When dfm kicks in. Oil pressure is increased to that lifter by a electric solenoid and those tabs are pushed in. That causes the lifter to collapse and not open those valves. The two little tabs that hold the lifter open sit on a small shelf in the lifter body. The tabs or shelf can get deformed causing the lifter to not open or collapse properly. Or the tabs can just fail since they are all that's holding the lifter open in normal operation. That's why they fail even with DFM disabled. The lifter will collapse when it's not supposed to.

The whole system does rely on varying oil pressure and electric solenoids. Along with a couple of small spring loaded tabs. All that in engines that are known for oil consumption issues, lol. A lot of the failures could be lack of oil issues, but even with proper oil those tabs/springs or the lifter body can just fail. Not to mention the solenoids.

I guess the 3 to 4% failure rate is those with proper oil or just bad luck. Oil changes matter greatly in these engines. If it was 15% GM would be out of business.

 

[Dragon]

Sure it is, it means your oil filter is catching the break in particles. Most od which are left over from manufacturing.

How does it happen? I hope it can be eliminated before the next oil change.

 

[AXE]

I've changed it and the next change was clean. You can see my detailed post with photos. I've got two rigs with 6.2s and they both did the same thing. One uses a little oil, but within spec.

 

[AXE]

I guess the 3 to 4% failure rate is those with proper oil or just bad luck. Oil changes matter greatly in these engines. If it was 15% GM would be out of business.

Ummmm........GM has been bankrupt before and it's certainly possible again.

 

[Dragon]

Ummmm........GM has been bankrupt before and it's certainly possible again.

That was the global recession back then. GM had multiple brands, got bailed out by paying the money in 5 years, and Ford also got bankrupt as well as Chrysler/FCA/RAM. Even Toyota struggled as well (they had to ask money from Japan).

 

[Dragon]

I've changed it and the next change was clean. You can see my detailed post with photos. I've got two rigs with 6.2s and they both did the same thing. One uses a little oil, but within spec.

That is good to hear. Fingers crossed both of them will not develop issues.

 

[DFWZR2]

Given the recent articles re: some 2023 models getting replacement engines...

 

[DFWZR2]

As an aside, if you happen to be the current owner of the following VIN(s), please vote. Those were my first two.

3GCUDHEL0NG657746
3GCUDHEL4NG573817

If both are still fine, that's technically 2 more votes for no failure...yet!

 

[44sixpack]

I've heard the Range chip locking the engine in v8 mode will prevent lifter failure, and some say it doesn't. this article and several others say it will prevent it, so when the chip comes out this summer I'll get one regardless. obviously this makes no difference on the '23's with oversize lifter bores.

They also say a higher quality oil will make a difference, which is kind of a no brainer. I use either Redline or Amsoil Signature in all my good rigs. so that's two things you can do.

Not sure how good the information here is, but it sounds logical.

AFM Lifter Failure Symptoms, Causes [How To Prevent] - Auto Chimps

Do you suspect that your engine's AFM lifter (active fuel management) has symptoms of failure? How can you prevent AFM lifter failure? Here's a guide.

autochimps.com

 

[Ereed45]

I've heard the Range chip locking the engine in v8 mode will prevent lifter failure, and some say it doesn't. this article and several others say it will prevent it, so when the chip comes out this summer I'll get one regardless. obviously this makes no difference on the '23's with oversize lifter bores.

They also say a higher quality oil will make a difference, which is kind of a no brainer. I use either Redline or Amsoil Signature in all my good rigs. so that's two things you can do.

Not sure how good the information here is, but it sounds logical.

AFM Lifter Failure Symptoms, Causes [How To Prevent] - Auto Chimps

Do you suspect that your engine's AFM lifter (active fuel management) has symptoms of failure? How can you prevent AFM lifter failure? Here's a guide.

autochimps.com

thanks for sharing

 

[XkenX]

thanks for sharing

Had a lifter failure on a 2017 Z71 6.2
At 11000 miles chevy rebuilt 1/2 the motor and paid me for issues. 36000
Miles after issue never problem till I traded it in. Was getting about 22 mpg average at 75 to 80 mph highway 60 percent time. Pulled like 4000 lb loads
7000 miles in that time. 47k at trade in combined lifetime mpg was 17.9 mpg.
Active fuel milage has it advantages when working properly. I can see if out of warranty this bypass could be very preventive vs a little extra gas, but under warranty I wouldn't pay to have
a bypass because of potential failure
From their poor quality control on a feature that was included.