Jump to content

Unlocking lifter.....VLOM problem?

Ryan Bokros
 Share

Recommended Posts

rellgmc Enthusiast

rellgmc

Posted
Posted
On 12/29/2016 at 4:18 PM, Ryan Bokros said:

Ok, new guy here! So I know that there is and has been a ridiculous ongoing issue with the AFM lifters sticking or collapsing entirely and all that mess. I have a 2007 GMC Sierra 5.3 Flex Fuel 4X4 - 160k miles. Pretty regular maintenance, I am not OCD, but I try to do my best at around 3500-400 miles - full synthetic Mobile 1 oil, AC Delco Filter, every other change gets a half quart of MMO.

 

 

 

 

Here is my situation....

 

 

 

 

 

No ticking whatsoever (which I know is usually attributed to this), BUT recently a terribly bad misfire on Cyl 4 (one of the AFM cylinders) and throwing the typical 304 code with stabilitrak warning. Before pulling the valve covers, I checked EVERYTHING (well, except compression, should have done that) - I checked plugs (a little black, but not wet), coils, injectors, fuel and oil pressure, etc. That is what led me to go ahead and pull the valve covers to check for any slack in the rockers/valves due to a collapsed lifter (even though there is no noticeable tick). Initially pulling the covers, I was pleased with how clean everything was....and how tight everything was. No slack in the rockers whatsoever, from what I could tell the valve springs look good, etc!! Yay...but WTF is causing this?

 

 

 

 

 

Well, I fired up the truck and found that the intake valve in cyl 4 was not moving. BUT...when my wife got home, I had her turn the engine over for me so I could see it all without doing it myself. Here is what I am confused about - on start up, the valve moves...once maybe twice, it goes through the whole compression cycle then stops once the engine is running...when the engine it turned off, it does the same thing - one or two cycles. If it was collapsed or busted, it wouldn't push the valve at all, would it? Could this be the VLOM and not the lifter? My oil pressure reads well, so I am not experiencing low pressure like others I am reading, but I am aware of the filter leading to the VLOM...maybe that is the next step. Thoughts?

 

 

 

 

 

Thanks!!

 

 

 

 

i have a 2007 gmc yukon xl 1500 flex fuel and i am having the same exact problem as you down to the T.  my #4 cylinder is doing the same exact thing yours was doing and im am wondering if you ever found out what was the cause of the problem. i really hope you still visit this site because i really need an answer on this one. Thx.

  • Replies 37
  • Created
  • Last Reply

Top Posters In This Topic

Popular Days

Top Posters In This Topic

Popular Days

Popular Posts

newdude
newdude

GM dealers have the special tools to test the VLOM so I'd say next step would be the dealer either with the truck, or to see if they can test the VLOM for you. The GM test equipment has a solenoid co

TheBigOldDog
TheBigOldDog

For those interested in this common problem and how to fix it, sometimes very inexpensively, go to youtube and search for the name CrazedPerformanceRepair and watch his videos, especially, Lifter Rele

rellgmc
rellgmc

I am in marrero, Louisiana and no I have not done any of that. I'm going to take it to a shop that I believe will do that.....idk what the problem is......I have done all I know how to do lol .......

swathdiver Senior Enthusiast

swathdiver

Posted
Posted
30 minutes ago, rellgmc said:

i have a 2007 gmc yukon xl 1500 flex fuel and i am having the same exact problem as you down to the T.  my #4 cylinder is doing the same exact thing yours was doing and im am wondering if you ever found out what was the cause of the problem. i really hope you still visit this site because i really need an answer on this one. Thx.

When the solenoids in the VLOM begin to fail, they get out of time causing the lifters to collapse at inopportune times.  The AFM system likes clean oil and no additives, that fella was adding Marvel Mystery Oil which is a no no in AFM engines.

 

The VLOM was updated to a new design several years after yours was built as were the lifters and driver's side valve cover (oil consumption).  You can change the VLOM before replacing the lifters but have to weigh time versus money and effort for your situation.

rellgmc Enthusiast

rellgmc

Posted
Posted

i have a 2007 gmc yukon xl 1500 flex fuel and i am having the same exact problem as you down to the T.  my #4 cylinder is doing the same exact thing yours was doing and im am wondering if you ever found out what was the cause of the problem. i really hope you still visit this site because i really need an answer on this one. Thx.

rellgmc Enthusiast

rellgmc

Posted
Posted
43 minutes ago, swathdiver said:

When the solenoids in the VLOM begin to fail, they get out of time causing the lifters to collapse at inopportune times.  The AFM system likes clean oil and no additives, that fella was adding Marvel Mystery Oil which is a no no in AFM engines.

 

The VLOM was updated to a new design several years after yours was built as were the lifters and driver's side valve cover (oil consumption).  You can change the VLOM before replacing the lifters but have to weigh time versus money and effort for your situation.

Thx for responding so quickly. i have already replaced the lifters and have put the engine back together and everything. i also changed spark plugs, wires, coils, and fuel injectors, and still i have a misfire on #4 cylinder.  So i removed the valve cover and cranked the engine and thats the only cylinder that is not working.  So you think its the vlom........I sure hope so......thx for helping me out.  ill see about changing it today or tomorrow. my wife is so aggravated right now with this truck lol.

swathdiver Senior Enthusiast

swathdiver

Posted
Posted
19 hours ago, rellgmc said:

Thx for responding so quickly. i have already replaced the lifters and have put the engine back together and everything. i also changed spark plugs, wires, coils, and fuel injectors, and still i have a misfire on #4 cylinder.  So i removed the valve cover and cranked the engine and thats the only cylinder that is not working.  So you think its the vlom........I sure hope so......thx for helping me out.  ill see about changing it today or tomorrow. my wife is so aggravated right now with this truck lol.

You're welcome.  I'm not certain as I'm not there to test it but it is the usual culprit and is SOP to replace when doing the lifters.  Stick with a GM VLOM, the Dorman ones do not last.  Keep us posted.

  • 2 weeks later...
rellgmc Enthusiast

rellgmc

Posted
Posted

ok man i order a GM vlom and i have replaced it. i havent gotten a chance to put it on a diagnostic tool but it is still doing the same thing.  when i took it for a drive the check engine light is still flashing like is was doing before. i was wonder if this is one of those situations when i need to take the vehicle to the dealership shop so they can delete the code with their special tool. 

swathdiver Senior Enthusiast

swathdiver

Posted
Posted
On 2/29/2020 at 5:17 PM, rellgmc said:

ok man i order a GM vlom and i have replaced it. i havent gotten a chance to put it on a diagnostic tool but it is still doing the same thing.  when i took it for a drive the check engine light is still flashing like is was doing before. i was wonder if this is one of those situations when i need to take the vehicle to the dealership shop so they can delete the code with their special tool. 

Where in Louisiana are you?  Have you done a compression test on that cylinder or stuck a borescope camera down the spark plug?  Do you have a bi-directional scan tool?

rellgmc Enthusiast

rellgmc

Posted
Posted

I am in marrero, Louisiana and no I have not done any of that. I'm going to take it to a shop that I believe will do that.....idk what the problem is......I have done all I know how to do lol .......

  • Like 1
swathdiver Senior Enthusiast

swathdiver

Posted
Posted
2 hours ago, rellgmc said:

I am in marrero, Louisiana and no I have not done any of that. I'm going to take it to a shop that I believe will do that.....idk what the problem is......I have done all I know how to do lol .......

I know a guy up near Baton Rouge that's good with engines, private individual, not a shop.

  • 3 weeks later...
20Silverado13 New Member

20Silverado13

Posted
Posted (edited)

Sorry im late to the topic but i have an 08 Impala SS that does the same thing. Stabiltrac and Traction Control light came on along with the Cyl. 4 misfire code. I replaced the lifter twice along with the VLOM and deleted the AFM in HPTuners. I have found that if the #4 lifter has already started to fail before showing any problems it will cause the Camshaft lobe for that lifter to begin to flatten. This is because the valve lifter oil manifold is faulty and spin the lifter 180 degree(Lifter will be spun around). This causes the camshaft lobe to flatten. I also think that the lifter trays has something to do with this as well but I cant remember but I would replace those as well. If you can, pull the cam out and see if any lobes are flat and if not make sure you soak the AFM lifters in 5w30 oil before reinstalling. Hope my response helps

Edited by 20Silverado13
Updated Information
  • 1 month later...
AlecT23 New Member

AlecT23

Posted
Posted (edited)

Rellgmc,

were you ever able to figure out this problem? I have a 2008 GMC Sierra 1500 5.3 and I have a 6 cylinder valve sticking. When you start the truck it will start to move but after 3 or so times it’ll stop and stick. I replaced the VLOM and no change at all. 

Edited by AlecT23
  • 4 weeks later...
Ivan Chavarria New Member

Ivan Chavarria

Posted
Posted

good day, I have a problem with my gmc sierra denali 2015, in the last year the cylinder 7 liffter has been damaged three times, I am from Mexico and I no longer trust the repairs we are doing, what do you recommend? Should I change the VLOM? Would it avoid damage if I cancel the VLOM with the RANGE device?

swathdiver Senior Enthusiast

swathdiver

Posted
Posted
On 6/13/2020 at 5:14 PM, Ivan Chavarria said:

good day, I have a problem with my gmc sierra denali 2015, in the last year the cylinder 7 liffter has been damaged three times, I am from Mexico and I no longer trust the repairs we are doing, what do you recommend? Should I change the VLOM? Would it avoid damage if I cancel the VLOM with the RANGE device?

Changing the VLOM is standard operating procedure when replacing a lifter.  It is the failure of the VLOM, the mis-timing of the solenoids, that jams the lifters.  Run Dexos approved oil and keep clean oil in the engine, 7500 miles is too long.

  • 2 months later...
Kenr New Member

Kenr

Posted
Posted

Has anyone found solutions? Mine is 2013 silverado 5.3l. Random misfire on all 4 AFM, CEL on STabletrak anf Traction control.  Shop says #4 is the main problem. The truck was skippin and jumpin. I have tried workin on it over last 8 months, new plugs clean throttle body. It has sat in garage for 6 months and battery died. I jumped it off, put some seafoam directly in oil. Odd thing to me is, the truck was running perfect. No dash lights. So I drove it for about 30 miles with no problems at all. Come home parked it. Changed the dirty seafoam oil the next day. Started it up the CEL , traction and stabletrak is on again. I disconnected neg terminal to drain the battery. Started it up and ir ran perfect for 10 miles. Shut it off and started it and once again the dash lights are back on??

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing

  • Latest Articles

  • Posts

    • StingerZ16
      Looking at ordering a '26 WT because I want a std cab, std bed

      By StingerZ16 · Posted

      The amount of storage in the rear seat area is huge. You can keep all your cycle gear dry and clean back there
    • Sparky176
      Subtle vibration, can of worms opened.

      By Sparky176 · Posted

      Truck in fluid changes and investigate subtle shudder at cruising speeds.  Told them it felt like my ‘14’s shudder when AFM kicked in.   Dealer #1 :  You need a new torque converter.   6 weeks later, after causing other damages to my truck, I get the truck back.  Same shudder exists. New, more violent shifts and vibrations at low speed.  After choice words and a few more weeks of waiting for them to replace my running boards supports, I move on to another Dealer.   Dealer #2:  The cruising speed shudder is DFM.  (I didn’t realize truck had it.) The TCM/ECM needs updates.  Updates will solve all vibration issues.   They perform updates, truck seemed ok in lot.  Not a mile down the road, SERVICE BRAKE PAD MONITOR. Dealer #1 stated brakes were at 4mm.   took truck back to Dealer #2, rear brakes at 2mm and less than 1mm.     New pads/rotors on rear, new pads up front.   truck seems good. Toggle through menus, brake monitor system is disabled.  Huh?  Why? Turn that sucker on : SERVICE BRAKE SYSTEM!     will not reset manually, automatically, or even after pulling negative bat cable for 30min.     Could the TCM/ECM updates the culprit?    A torque converter diagnosis for a “normal” shudder and now I’m thousands in the hole and the truck still isn’t right!  Beyond pissed.  
    • riddler
      Oil Consumption

      By riddler · Posted

      Your right on. 👍🏻
    • c4racer2
      Trim level custom/pro

      By c4racer2 · Posted

      Seats matter a lot.  I would start there - good advise here.  I had a 2018 LT Colorado before my 2026 LT Silverado, and the seats are so much better in the new one it's not even a contest.  That was one thing I always hated about the Colorado and I owned two of them spanning 10 years - but I did it so I could park in the garage mainly.  Now I have a much larger property and a huge barn so I have plenty of parking options and a full size is more useful for maintaining the property and current hobbies as well.  I wasn't evenb thinking about the seats as part of the reason for the move to the Silverado, but after two back to back 700mile road trips I am sold on the LT seats w/ leather 100%.  The other LT features are also nice - one thing I really like is the power rear window on the back window by the bed.  And the lighting in the bed is also very nice to have - I doubt that comes on the lower models.  Power tailgate - also quite useful - it's a heavy slug!  What else - I could take or leave the screen - but heated seats and steering wheel and cruise control on the steering wheel is very useable - I would never want to live without that.  Even the colorados had that.
    • c4racer2
      Oil Consumption

      By c4racer2 · Posted

      I think the ship has sailed on the fuel injection type - everything is getting direct now.  Does it help with mpg?  Not really and nobody buying a HD truck really cares anyway.  But that is what it is at this point.  Piston rings is something they may well adjust over time to get them right.

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...