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Posted

To say I am livid is an understatement.  I went to a very reputable popular shop near me that has done dozens of afm lifter repairs.  They found cyl 7 lifter in 2 pieces and cyl 4 had bent pushrods but the lifter wasnt bad in Cyl 4.  It may have been locked and released IDK.  $3700 later all fixed and drove it this past weekend no issues and today on a faster acceleration cyl 7 misfire and lost power.  I cannot believe the exact same cyl 7 would go bad again in under 100 miles.  I had normal oil pressue so I didnt think it was a lack of oil.  They cleaned out the VLOM oil pressure screen and all the oil passages when they did the work.  

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Posted
1 hour ago, Payton34 said:

To say I am livid is an understatement.  I went to a very reputable popular shop near me that has done dozens of afm lifter repairs.  They found cyl 7 lifter in 2 pieces and cyl 4 had bent pushrods but the lifter wasnt bad in Cyl 4.  It may have been locked and released IDK.  $3700 later all fixed and drove it this past weekend no issues and today on a faster acceleration cyl 7 misfire and lost power.  I cannot believe the exact same cyl 7 would go bad again in under 100 miles.  I had normal oil pressue so I didnt think it was a lack of oil.  They cleaned out the VLOM oil pressure screen and all the oil passages when they did the work.  

 

If they did not replace the lifter trays and VLOM when making this repair they did not follow SOP.  When the solenoids get out of time, they cause the destruction of the lifters.  Well, now you can delete it permanently and get it tuned.

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Posted
2 hours ago, Payton34 said:

To say I am livid is an understatement.  I went to a very reputable popular shop near me that has done dozens of afm lifter repairs.  They found cyl 7 lifter in 2 pieces and cyl 4 had bent pushrods but the lifter wasnt bad in Cyl 4.  It may have been locked and released IDK.  $3700 later all fixed and drove it this past weekend no issues and today on a faster acceleration cyl 7 misfire and lost power.  I cannot believe the exact same cyl 7 would go bad again in under 100 miles.  I had normal oil pressue so I didnt think it was a lack of oil.  They cleaned out the VLOM oil pressure screen and all the oil passages when they did the work.  

 

 

Cleaned the VLOM but didn't replace it?  GM wants the VLOM and lifter trays replaced, not cleaned.  

 

That said, some dealers have been seeing repeat failures right after repair even done the dealer way.  Our sister store has a truck getting a new engine as a result of low mileage repeat failure of a DFM lifter (same lifters as AFM) so I think there is still the possibility of a parts assembly/quality issue going on.  

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Posted

So they had it all day and are saying it has random misfire code and drives fine unless it is floored which triggers misfire. I went there before they closed and retuned to stock so afm isn’t disabled to see if it helps them figure it out  also gave them a bulletin I printed from melling about replacing trays and checking or replacing vlom. They said they checked the vlom solenoids and the the trays didn’t need replacing?

Posted (edited)

With their findings I would look at the ignition coil connector and plug wires. The inner coil connector gets corroded and will not throw a misfire code. Unless the miss becomes prevalent. 

Edited by Snowcamo
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Posted
1 hour ago, Frankielozano214 said:

Damn 3700$ and it’s still jacked up smfh, you might as well do the afm delete with a cam 

That is my thought but how much more should I put into it.  The shop has a warranty on their work but I guess if they determine its another collapsed lifter I will ask how much more labor is to change the cam.  I was only planning to keep it for about another year.

Posted
7 hours ago, Payton34 said:

That is my thought but how much more should I put into it.  The shop has a warranty on their work but I guess if they determine its another collapsed lifter I will ask how much more labor is to change the cam.  I was only planning to keep it for about another year.

I did the afm/dod delete when lifter#7 collapsed haven’t have any issues since, I highly recommend doing it if your gonna keep the truck other wise have the shop fix it with their warranty, well had a misfire but that was due to my headers touching a wire but it was a cheap easy fix.

Posted

Which Delete kit did you use?  I am trying to figure out how much more labor will cost for the cam swap and find a place to reprogram ecu.  They determined one of the new lifters failed again after 50 miles of driving with afm turned off on my diablo tuner. 

Posted (edited)
On 6/15/2022 at 6:39 PM, Payton34 said:

They said they checked the vlom solenoids and the the trays didn’t need replacing?

 

 

They may be a "reputable" shop, but that isn't too promising that they didn't follow GM's procedures.   It's one thing to help customers out and save them a buck or two, but if the OEMs (no matter the brand) have known fixes or issues, independents have access to most all of that documentation, so no reason not to follow it.  

 

 

36 minutes ago, Payton34 said:

Which Delete kit did you use?  I am trying to figure out how much more labor will cost for the cam swap and find a place to reprogram ecu.  They determined one of the new lifters failed again after 50 miles of driving with afm turned off on my diablo tuner. 

 

 

IF they got new GM lifters, than that new lifter has a 2 year part warranty.  I don't know how the shop would handle the labor and other parts involved, but they can at least get the new lifter on GM's dime.  

Edited by newdude
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Posted
7 hours ago, newdude said:

 

 

They may be a "reputable" shop, but that isn't too promising that they didn't follow GM's procedures.   It's one thing to help customers out and save them a buck or two, but if the OEMs (no matter the brand) have known fixes or issues, independents have access to most all of that documentation, so no reason not to follow it.  

 

 

 

 

IF they got new GM lifters, than that new lifter has a 2 year part warranty.  I don't know how the shop would handle the labor and other parts involved, but they can at least get the new lifter on GM's dime.  

So it was a defective lifter at cylinder 1. They are replacing it under gm warranty and the shops labor warranty is 2 years so thankfully I don’t have to pay anymore. They said they see brand new lifters  that are defective all the time some go bad before they pull the truck out of the bay and the Chevy dealer they get their parts from always has a ton of lifters in stock with how many they replace and how many are defective.  What garbage. I really have a bad taste for GM after this. Possibly my last GM truck and I have always bought GM trucks 

Posted
On 6/15/2022 at 6:39 PM, Payton34 said:

They said they checked the vlom solenoids and the the trays didn’t need replacing?

 

It doesn't matter if they look good or not.  They are supposed to be replaced.  When a solenoid gets out of time, it destroys the lifter.  It's not the lifter's fault.  Though lifter failure happens on its own, it is much more common for a solenoid to cause it.

 

You have a world class engine.  Put some coin aside to delete the AFM system and if physically able, do it yourself. 

 

GM has established protocols for good reason, they don't want the vehicle to keep returning as it upsets the customer and costs everyone time and money.

Posted

Im going to tell them to replace the vlom it’s cheap so no big deal but I turned off the afm with my turner when I got home from it being fixed so the vlom wouldn’t have been doing anything when cylinder 1 lifter failed 4 days later right. I would think cyl 1 didn’t fail as a result of a bad vlom out of sync.  If my afm was active when it failed then possibly 

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Posted

So shop called and after the lifter was replaced and the vlom manifold truck is showing misfires on cyl 1 when reading with scan tool but no check engine code and isnt running right.  The shop isn’t sure but think the ecm is bad. It isn’t running right but the afm is activating as it should but no codes. The shop has a call into GM engineering and will hook their computer to truck to share with the engineer but I am totally frustrated at this point. Could the ecm had been the issue from the start?  Possibly ecm giving incorrect commands and caused the afm lifter to fail?

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