TRNW-2: MISCELLANEOUS, 2018 Silverado 5.3 with a misfire

[Joe Shilling]

A compression test may not give you the best results.  Do a cylinder 
leakage test to check the valves.  Then pull the valve cover and check 
the rocker arm motion.

On 6/7/2025 9:56 PM, Ryan D via trnw2 wrote:
> Yes, compression test .
>
> On Saturday, June 7, 2025, Tod Chretien via trnw2 <trnw2 at trnw.net> wrote:
>
>
>     *Post ID:* 21395
>     <https://www.trnw.net/trnw/forum_thread.php?post_id=21395&forum=2>
>     *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
>
>
>
>     ------------------------------------------------------------------------
>
>
>     *To Read The Entire Thread, Click The Link Below*
>
>     Read Entire Thread
>     <https://www.trnw.net/trnw/forum_thread.php?post_id=21395&forum=2>
>
>
>
>
>
> -- 
> Ryan
>
> This message was sent from the TRNW Technical Discussion Forum (trnw2). You were sent this message because you have subscribed to our mailing list. If you don't want to receive these emails from TRNW in the future, please unsubscribe here:
> https://www.trnw.net/unsubscribe.php?forum=2
> TRNW Inc., 2825 Walnut Terrace, Modesto, CA 95355
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.trnw.net/pipermail/trnw2/attachments/20250607/3fb12206/attachment.html>