TRNW-2: MISCELLANEOUS, 2018 SILVERADO 5.3 WITH A MISFIRE

[Scott Kleinlein]

You can get the lifter to unstick and then just disable afm. If you’re
allowed to that is. Just take the valve cover off and it should be obvious
if the afm lifter is collapsed. If it is you’ll have to remove the intake,
vlom and use a long punch to smack on the lifter through the oil passage it
should unstick then you can just turn it off with hp.

On Mon, Jun 9, 2025 at 8:49 AM Brent Erwin via trnw2 <trnw2 at trnw.net> wrote:

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> Brent Erwin posted in the Technical Discussion Forum
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> <https://www.trnw.net//images/members/generic_add.jpg> Brent Erwin
> Fresno , California, USA
> Sat Jun 7 23:41:56 PDT 2025
> *Subject:*Re: TRNW-2: MISCELLANEOUS, 2018 SILVERADO 5.3 WITH A MISFIRE
>
> I would run compression check I would highly suspect lifter failure the
> AFM lifter on that truck are on cylinders 1,4,6,7 and if you are repairing
> look at kit from Texas speed to remove those to resolve issue for good
>
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> Original Post*Date:* Sat Jun 7 18:52:40 PDT 2025
> *Subject:* MISCELLANEOUS, 2018 Silverado 5.3 with a misfire
> This isn’t a transmission problem so please forgive me for that. I just
> bought a 2018 Silverado with 110K. It started making a light tapping noise
> on moderate to heavy acceleration. About 3 days later I had to punch it to
> beat some oncoming traffic and it started misfiring severely. The #1
> cylinder is counting misfires so I pulled the spark plug and they
> definitely haven’t been replaced yet. Hoping for the best I replaced the
> spark plug but it’s still counting up on #1. I swapped the coil with #3 but
> it didn’t change. I hear the lifters on these AFM engines have issues. Does
> anyone know what goes wrong with the lifters and how to diagnose it? Would
> it have no compression? Sorry for the dumb question but book time is over
> 20 hours and I don’t want to do the wrong thing. Any help or insight would
> be greatly appreciated.
>
> Tod Chretien
> Ralph's Transmission
> Modesto, California USA
> tod at trnw.net
>
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