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

[Chris and Cathy Kershaw]

Tod, my understanding is that replacing a lifter only in one of those
engines would be like replacing a converter only in a 200k 6L. There’s a
local guy here that works alone and 90% of his work is top end rebuilds on
late model gm v8s. He says the best way is pull the heads, replace cam,
lifters etc. Something about leaving the heads on is possible but not worth
the aggravation? Just my observations, no direct experience on these.

On Sun, Jun 8, 2025 at 9:26 AM Tod Chretien via trnw2 <trnw2 at trnw.net>
wrote:

> Thank you for the replies. After I posted, I found this bulletin.
>
> #19-NA-219: Diagnostic Tip on Misfire, Chirp, Squeak, Squeal or Tick
> Noise, Malfunction Indicator Lamp (MIL) Illuminated - DTC P0300, P0301,
> P0302, P0303, P0304, P0305, P0306, P0307 and/or P0308.
>
> After reading this TSB I am thinking it may be a flat cam because the tick
> noise had a little chirp to it. The TSB says that it's very difficult to
> see if the cam lobe is worn through the lifter hole. Often times the worn
> cam is missed.
>
> If I remove the valve cover and watch the lift on the rocker arms, how do
> I distinguish between a worn cam lobe or a collapsed lifter?
>
> I am going to do the relative compression test possibly today or maybe
> tomorrow.
>
> --
> Best Regards,
> Tod Chretien
> TRNW Inc.http://www.trnw.net
>
> On 6/7/2025 9:28 PM, Steve Everett wrote:
>
>    I believe I'd pull the valvecover for that side and watch the rocker,
> if it is moving some but not full movement the spring on the lifter is
> likely collapsed,  That is one of the cylinders that the DOD affects,
>  since it happened after you punched it chances are its just the lifter as
> opposed to the camshaft lobe being damaged.
>
>    Steve
>
> On Sat, Jun 7, 2025 at 9:53 PM 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
>>
>>
>>
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> --
> Best Regards,
> Tod Chretien
> TRNW Inc.http://www.trnw.net
>
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