By Crazed Performance Repair | Sep 1, 2026 8:26 PM
May 31, 2023
"
You might want to pull a wiring diagram and follow that wire you grounded to see where it's supposed to ground to. I'm too busy now to look it up. Remind me later if you need me to pull one. I'm open to do it on here because it's a gm AFM related post. Normally that's reserved for the premium membership forum area.
One big thing to consider though is that it might not be a wiring issue at all. What other codes do you have? It's possible that the computer is seen something that makes it not want to ground the coils. It's perhaps disabling it has a safety thing to prevent damage.
By Jim Brouillard | Sep 1, 2026 8:26 PM
May 27, 2023
This AFM/DOD delete project got put on the back burner. Yesterday was ready to start. Found out there was no spark. Grounded 7 pin coil bank connector black wire to firewall and it started. Before beginning this project ran fine except #4 lifter. Oil pressure was good on start up, brief run and was running very rough. Did a quick scan and saw reduced engine power, cam position sensor. Did not not run for more than 20 seconds or so. The ground for the coil was temporary and as the wire jiggled the engine would stop. Did I miss a ground on reassembly that was overlooked. I will look more today. The obvious ones are the one on the passenger side front of head (two wires, battery and one from loom) and the strap attached at firewall above brake booster. I will clean up those connections well today and add dielectric grease. Any other locations I should look at that may have been disturbed during the delete? Project was done in vehicle 2011 Tahoe 5.3.
By Gene Donachie | Sep 1, 2026 8:26 PM
May 08, 2023
I would try to free the lifter using the CPR tool first. I just did it on #4 of a 2008 suburban with 208000 miles on it. All it cost me was the price of the tool and a few hours of work.
By Jim Brouillard | Sep 1, 2026 8:26 PM
Apr 21, 2023
I have new hardware in this project. Thanks for the advice. You answered my main concern.
By Crazed Performance Repair | Sep 1, 2026 8:26 PM
Apr 21, 2023
"
It doesn't matter if it's continuous or not just that you make the required total degree of rotation. Most important thing though is to make sure you're using new bolts. I hear far too many people that try to reuse the old bolts and do that same torque method then snap the bolts off in the block.
I personally sometimes won't even use a torque angle meter or my fancy degree torque wrench. Sometimes I will just figure the 60u00b0 per point of a 6-point head and use that with a sharpie to do the math to get the correct angles. For example I believe that the harmonic balancer bolt is 120u00b0 which would be two points on a six-point head.
By Jim Brouillard | Sep 1, 2026 8:26 PM
Apr 21, 2023
I haved torqued heads to spec, now comes the TTY "torque to yield" values. I'm old school and have never used TTY bolts. Idealy I would imagine if let's say 90 degrees is required first pass you could make one continuous 90 degree sweep. What if space would not allow (like cyclinders 7-8) a full sweep. Could you make two 45's to make the 90 since total movement is still 90 degrees? Does some scientific crap (bolt heats up while stretching and end value will be compromised if more than one effort is used to achieve the 90)come into play ? Or am I over thinking it? Using an angle guage of course. Goes without saying engine is still in vehicle.
By Jim Brouillard | Sep 1, 2026 8:26 PM
Apr 20, 2023
Update, bought afm/dod delete and had pcm reprogrammed. Removed oil pan and cleaned and replaced with new pick up tube "O" ring. Winding down the project. Looked at several sources about disabling fuel and ignition to build initial oil pressure prior to starting. My engine compartment fuse block is missing the recommended relay to be unplugged,any advice? Everything worked as it should before the #4 lifter failure.
Show more replies
By Crazed Performance Repair | Sep 1, 2026 8:26 PM
Jan 08, 2023
"
You are mostly correct in your observations/assumptions. Couple things to note though, torquing the VLOM down should be 16-17ft lbs. I've seen 18 strip out aluminum blocks. VLOM bolt tq won't effect oil pressure unless it was near the oil pressure sensor area. If oil pressure doesn't improve I have several videos, forum post, and even a copy paste thing I typed up on the matter. Just let me know if you need info on it.
Going non AFM components can be required for several reasons beyond just a collapsed lifter situation. One could have a AFM lifter spin from a bad plastic guide, the roller/cam could get wiped out from pitting or gauling, you could even maybe find you low oil pressure situation is because of a bad second camshaft bearing and decide, "well, I'm already this far, f-it let's delete this trash."
One more thing I'd like to note. The best way to check for a successful lifter release. After you are done tightening up the VLOM, use the starter relay to crank it over and watch the rocker. If the rocker works for at least 6-7 times in a row and not stopping till you stop cranking, you should be good to go. Just use this trick with caution or with ECM out. If you jump the wrong relay pins you could short out ECM.
By Jim Brouillard | Sep 1, 2026 8:26 PM
Jan 07, 2023
Like many I have been cramming all your info trying to make an informed decision. Please correct me if I am wrong, below is what I understand needs to take place.
Remove intake manifold, VLOM, and valve cover.
Try special tool to release stuck lifter.
Insure lifter is unstuck with 6-7 revolutions.
Cut round gasket seals that match to towers on VLOM to prevent higher oil pressure to lifter and prevent activation.
Clean VLOM filter/screen
Place VLOM plug at oil pressure sensor install location blocking passage to VLOM valley preventing oil to solenoids.
Insure VLOM bolts are torqued to 18-19 lbs and insure everything buttons up tight
Send ECM for afm/dod delete before driving
My VLOM bolts were barely finger tight (the front two I can reach so far) my oil pressure is a little low wondering if the bolts torqued correctly and VLOM filter clean will improve.
Considering one of the engine flush methods to release suspected sludge from the 260k engine (trans fluid, engine oil additive, seafoam etc - chime in your experience with this if you like)
I understand going to conventional lifters and cam is only necessary if the lifter remains stuck requiring head removal to diagnose/remove stuck or damaged lifter and or cam/ lobes.
I assume since afm lifters are pressure activated, once the pressure is removed they will function like normal lifters of course until the day they finally fail.
Thanks a million for your dedication to helping the average guy.
Jim
By Crazed Performance Repair | Sep 1, 2026 8:26 PM
Dec 31, 2022
"
I have seen the release trick last long over 50k miles, but I have also seen something else fail valvetrain related very soon after the release trick. As long as the release trick holds and done properly by disabling AFM though it is a long term fix. The release trick does require disabling the system though so any mileage gained from it will be gone. However the system doesn't get used over 55mph cruising speeds anyhow. So long term trips you really shouldn't loose any mileage. Also, just replacing a lifter isn't a option as it will likely fail again. This is of course if you don't saw the little oil pressure concern first. The reason these lifters fail is from lacking 26 PSI or higher oil pressure at the lifter during activation. If it doesn't have that much pressure while it activates the locks will bind and damage the AFM portion of the lifter. Considering the VLOM is loose and if the screen inside of it is plugged. In your position I certainly would not hesitate to do the lifter release trick.
I did this message via cell phone while doing other things. If I missed anything please don't hesitate to ask again.
Members
Ryan Tucker
Follow
jsomething
jsomething
Follow
johnwillsey
johnwillsey
Follow
Tom DeWitt
Follow
Taylor Byrd
Follow
See All Members (39)
4.9 u00b7 Reviews
