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How would vlom solenoid cause lifter failure if afm is turned off with tune

Payton34

By Payton34
in Engines & Drivetrain

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Payton34 Enthusiast

Payton34

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So initially had cyl 7 lifter fail at 55k miles and I had afm turned off since I had 8000 miles.   I returned tune to stock before shop replaced all lifters but not the vlom.  I picked it up truck and dove home a couple miles afm was coming on and off lie I expected it to.  I retuned it and turned off afm that night.  I drove the next day running errands then 3rd day it was feeling like it was hesitating again like when I had the intital lifter fail.  So I did a hard acceleration and sure enough check engine and engine bogged down exactly what happpened first time I had a lifter fail.

I returned ecm to stock again and he towed back to his shop and I printed the bulletin for him about replacing vlom with lifters.  So basicaly he replace the failed lifter again and he had misfire code again then he finally replaced the vlom but still misfire.  He contact GM engineer who likley told him the his replaced lifter would need to be replaced again.  WHich he did replace the lifters a 3rd time and this time with the new VLOM and he said GM engineer tweeted some of the computer setting.  I have had it back 4 days and put on 150 miles and no issues and this time I didn't turn the AFM off right away.

 

I am wondering how I had a failed lifter with new lifters and turning afm off right away.  Was the solenoid still activating even though afm was turned off or was damage done when shop test drove and I drove home on the old vlom and new lifters?

 

When AFM is turned off with a tuned the solenoids do nothing correct?  I want to turn afm off again because I hate it in 4cyl with my exhaust but nervous since the shop told me my turner could have caused the second failure but I think this is BS.

shakenfake Senior Enthusiast

shakenfake

Posted
Posted

I am assuming they just botched the install. That is BS that the tuner could have caused the second failure.

Why would you want to stick with the AFM lifters and cam is my question?

  • Like 1
Payton34 Enthusiast

Payton34

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Im only keeping the truck about another year so didn't want to pay the extra labor for cam swap.

newdude Senior Enthusiast

newdude

Posted
Posted (edited)
5 hours ago, Payton34 said:

So initially had cyl 7 lifter fail at 55k miles and I had afm turned off since I had 8000 miles.   I returned tune to stock before shop replaced all lifters but not the vlom.  I picked it up truck and dove home a couple miles afm was coming on and off lie I expected it to.  I retuned it and turned off afm that night.  I drove the next day running errands then 3rd day it was feeling like it was hesitating again like when I had the intital lifter fail.  So I did a hard acceleration and sure enough check engine and engine bogged down exactly what happpened first time I had a lifter fail.

I returned ecm to stock again and he towed back to his shop and I printed the bulletin for him about replacing vlom with lifters.  So basicaly he replace the failed lifter again and he had misfire code again then he finally replaced the vlom but still misfire.  He contact GM engineer who likley told him the his replaced lifter would need to be replaced again.  WHich he did replace the lifters a 3rd time and this time with the new VLOM and he said GM engineer tweeted some of the computer setting.  I have had it back 4 days and put on 150 miles and no issues and this time I didn't turn the AFM off right away.

 

I am wondering how I had a failed lifter with new lifters and turning afm off right away.  Was the solenoid still activating even though afm was turned off or was damage done when shop test drove and I drove home on the old vlom and new lifters?

 

When AFM is turned off with a tuned the solenoids do nothing correct?  I want to turn afm off again because I hate it in 4cyl with my exhaust but nervous since the shop told me my turner could have caused the second failure but I think this is BS.

 

 

So if I am reading this correct.  You had all the lifters replaced but still the stock VLOM.  You drove it home, then turned off AFM, the next day it dropped a lifter.  

 

To me, two possibilities.  One, the new lifter failed, which has happened the last year with the lifter issues GM has.  Second, it is possible even with AFM disabled, that a solenoid could have done its job when it wasn't supposed to, especially seeing you had the original VLOM.  

 

I would say that as long as they replaced the new bad lifter and installed a new VLOM, that turning it off again shouldn't give you an issue, unless for some reason another new lifter took a dive.  

 

I don't think you turning it off had anything to do with it.  

Edited by newdude
  • Like 2
16LT4 Enthusiast

16LT4

Posted
Posted

In a previous post, you’d mentioned the truck is driven only about 5 miles each way to work. That tells me it isn’t a VLOM issue but a cold oil sludge issue. Never getting the oil to operating temperature is horrible abuse of the engine for many reasons. Lifter issues are probable for any engine living that life, not just one with AFM. The truck needs to be driven 50+ miles at a clip once a week. 

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Grumpy Bear Senior Enthusiast

Grumpy Bear

Posted
Posted
11 hours ago, 16LT4 said:

In a previous post, you’d mentioned the truck is driven only about 5 miles each way to work. That tells me it isn’t a VLOM issue but a cold oil sludge issue. Never getting the oil to operating temperature is horrible abuse of the engine for many reasons. Lifter issues are probable for any engine living that life, not just one with AFM. The truck needs to be driven 50+ miles at a clip once a week. 

 

I believe on the reasons my truck has been so trouble free is exactly this. I don't turn the key for under 50 miles and change the oil every 5K. IF I had the situation where I was 5 miles away I'd not only take it for a weekly 100 miler but change oil every 2500 miles or more. Dad had a trip like this when I was a child that was but 8 miles to work. Changed oil every thousand miles and we took weekend trips to anywhere.... very trouble free motors. 

  • Like 2
diyer2 Senior Enthusiast

diyer2

Posted
Posted

How often did you change the oil and filter? 

  • Like 1
It's Tim Senior Enthusiast

It's Tim

Posted
Posted
On 7/12/2022 at 2:15 PM, Payton34 said:

Im only keeping the truck about another year so didn't want to pay the extra labor for cam swap.

When it fails again you're in the hole for yet another repair.

Payton34 Enthusiast

Payton34

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21 hours ago, It's Tim said:

When it fails again you're in the hole for yet another repair.

I have a 2 year warranty from the shop for the lifters so I am not worried.  I will likely have a new truck in the next few months.

Payton34 Enthusiast

Payton34

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23 hours ago, diyer2 said:

How often did you change the oil and filter? 

I changed when the oil life monitor got to around 30%.  Since I have such a short commute I will change it every 3 months now.

shakenfake Senior Enthusiast

shakenfake

Posted
Posted

If you are selling the truck it is better to have the AFM lifters in anyways since sometimes it can bring the value down

  • Like 1
Mathew Kirsch Enthusiast

Mathew Kirsch

Posted
Posted

Interesting. In all my tribulations and posts on here about stuck lifters nobody mentioned the VLOM. I listed what was being done, and nobody said, "Did he change the VLOM?"

 

I just got off the phone with the mechanic who is working on my truck, and he just learned about the VLOM himself. The GM repair procedure he was going by didn't mention the VLOM but when it failed in <500 miles, he did a little more digging and found out about the VLOM.

 

Unfortunately there are no VLOMs to be had right now.

 

That's also why there are no pictures. It's been tore apart in his shop since July 5th. Glad I have other vehicles to drive.

  • 2 months later...
RustyGunz Enthusiast

RustyGunz

Posted
Posted

Hey, Had the exact same problem. 2015 Denali 5.3L. Lifters in cylinder 7 failed, mechanic did not replace VLOM and lifters failed again very soon. Lifters and VLOM replaced and seems fine. Figured that the VLOM solenoid for cylinder 7 was leaking allowing oil pressure to the lifters. This causing the pins to be pushed in far enough to let the pushrod collapse when the camshaft is pushing on them in V8 mode. which makes sense as I noticed both times they failed was when the oil pump was on high pressure mode (+3500RPM). My mechanic is thinking the VLOM possibly failed as the pressure relief valve in the pump seems failed as my oil pressure climbs above 550KPA when under high engine RPMS. I can not seem to find any info on high oil pressure.

 

So even with the 4 cyclinder mode deactivated there is still the possibility oil can get to the lifters causing them to fail. 

pokismoki Senior Enthusiast

pokismoki

Posted
Posted

i would recommend NOT going WOT from off idle or cruise condition while the V4 mode is active or while in Drive grear.   high engine loading and switching from v4 to v8, pressure fluctuations in the oil circuit of the lifters may cause damage.

 

shift to 5th gear to disable v4 mode , then you can drive like a nut without damaging the lifters

  • 3 months later...

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