Unlocking lifter.....VLOM problem?

[Johnny Dash]

2015 Silverado 5.3 Engine.  60K miles.  Started chirping noise.  First little then louder.  Becoming more of a tick.  Removed all belts.  Still have the noise.  Sounds like coming from under valve cover toward front on passenger side.   So 2 and 4 cylinders.  Probably 4.  I took valve cover off.  All looks right.  I took rockers off and push rods out.  All looks good.  I sprayed carb cleaner in push rod ports.  I put back together and treated with MotorMedic products.  Then changed oil.  Still have the noise.  The noise is there until the engine heats up after about 7 minutes of running.  Then there is no more noise.  You can drive it from then on with no noise.  So....the question is WHY?  Why is the noise there until engine becomes hot OR oil pressure is increasing?  Is it that the heat expands metal and once it expands the lifter operates normal?  OR is it that oil pressure builds and it works normal after it gets to proper oil pressure?  I can't afford thousands of dollars.  Im thinking try to replace the VLOM.  Even a used one to see if I can see a change.  The next step would be replace the lifters.  Ultimately I would remove AFM which allows you to get rid of the AFM lifters.   Also there is an oil screen on the VLOM that I have not checked.

[diyer2]

Oil pressure is higher upon a cold start and lowers as engine warms up. Oil flow, gallons per minute changes also.

I think you're going to have to replace the lifters.

 

 

[shakenfake]

On 9/10/2021 at 5:10 PM, Johnny Dash said:

2015 Silverado 5.3 Engine.  60K miles.  Started chirping noise.  First little then louder.  Becoming more of a tick.  Removed all belts.  Still have the noise.  Sounds like coming from under valve cover toward front on passenger side.   So 2 and 4 cylinders.  Probably 4.  I took valve cover off.  All looks right.  I took rockers off and push rods out.  All looks good.  I sprayed carb cleaner in push rod ports.  I put back together and treated with MotorMedic products.  Then changed oil.  Still have the noise.  The noise is there until the engine heats up after about 7 minutes of running.  Then there is no more noise.  You can drive it from then on with no noise.  So....the question is WHY?  Why is the noise there until engine becomes hot OR oil pressure is increasing?  Is it that the heat expands metal and once it expands the lifter operates normal?  OR is it that oil pressure builds and it works normal after it gets to proper oil pressure?  I can't afford thousands of dollars.  Im thinking try to replace the VLOM.  Even a used one to see if I can see a change.  The next step would be replace the lifters.  Ultimately I would remove AFM which allows you to get rid of the AFM lifters.   Also there is an oil screen on the VLOM that I have not checked.

You'd need to swap the camshaft as well and do a full AFM delete. You cannot just swap lifters for non AFM lifters.

[BarryKH]

I've got a 2013 GMC and have a ticker in it, but so far no misfires. If I have the kind of problems you all are having, I'll probably try to find a Hemi and make it fit. You know as in Blasphemi, on Roadkill. These AFM engines appear to be nothing but continous headaches. I didn't realize they were in the GMC's until after my purchase. I got it used. I think someone before has already programmed the AFM out, as it stays in V8 all the time. Never seen it in V4. GM boondoggle in my book.

[Patty Leonard]

Hi I have a 2008 Chevy Avalanche 5.3L gas. Only 120,000 miles on it.

Flickering lights, check engine light, traction control off, service stabilitrak,Misfire cylinder #4, I replaced all plugs,wires,and swapped a couple of coil packs around, pulled injectors 2 and 4 out hook the injector up to a 9-volt battery, so I can open and close the injector while spraying the carburetor cleaner through a tube I made, I put injector 2 in the spot 4 injector, and I put injector 4 in the spot where injector 2 was ,new alternator,map sensor,  and throttle position sensor, also did a compression test that was good, still misfire cylinder 4. So I decided to remove the valve cover, all rockers are solid, no movement at all, so I did a crank test first,and all the lifter's moved, next I started the engine,and all lifters moved, within 5 seconds, lifter #4 exhaust side stopped moving. I have no ticking sound from the engine at all, could this be the VLOM solenoid? Or possibly the ECU, the ECU is what commands the solenoids to open and close from V4 to V8. I had a friend come over with his professional scanner, and the scanner showed misfire cylinder #4, brake control modular, and something with the  ECU.

Edited November 17, 2021 by Patty Leonard

[Patty Leonard]

On 9/14/2021 at 3:15 PM, BarryKH said:

I've got a 2013 GMC and have a ticker in it, but so far no misfires. If I have the kind of problems you all are having, I'll probably try to find a Hemi and make it fit. You know as in Blasphemi, on Roadkill. These AFM engines appear to be nothing but continous headaches. I didn't realize they were in the GMC's until after my purchase. I got it used. I think someone before has already programmed the AFM out, as it stays in V8 all the time. Never seen it in V4. GM boondoggle in my book.

I didn't know either, I just found out 3 weeks ago about the AFM issues,after researching my cylinder 4 misfire, if I knew about it,I would of had it deleted from the ECU

[Jws2012silverado]

I have a 2012 Chevy Silverado 1500 LT 4x4 with 5.3. I’m having problems with rough idle and traction control and stabiltrak. It’s throwing the code for the number 1 cylinder. Replaced the plug and wire and coil pack and injector. No change. Pulled valve cover off and both lifters in cylinder 1 aren’t moving. Just did a lifter change and put all back together except the valve cover. Started it up and lifters work for about ten seconds then they quit again. Still cylinder 1. Camshaft and everything inside motor looked to be in great shape when had it tore down. Should have replaced the vlom while I had the intake off but didn’t. Will installing the range afm disabler bypass the solenoids on the vlom and possibly keep from shutting off cylinder 1 lifters?

[Johnny Dash]

On 10/20/2019 at 10:39 PM, swathdiver said:

Yes, you need to replace the VLOM and Lifter Guides too.  This is SOP with AFM repair.  It is the failure of a VLOM solenoid that causes the lifters to collapse because of a missed timing event.  If yours was built before April 2011 or so, get the new valve cover for the driver's side too.  (Well, make sure someone didn't replace it already). 

Swathdiver, can you contact me.  Im in Vero.  [email protected].  Lifter issue.  Tks.