2017 5.3 Cyl 6 dead misfire

DeePa · November 8, 2022

Add another to the list.

2017 5.3 with 147k on the clock. Religious maintenance. Cyl 6 dead misfire. Swapped coils, still junk. Replaced injector, still junk.

another GM AFM lifter failure. Probably wiped the cam too. AFM was tuned out in March of 2019 with about 75k on the clock.

Truck needed a 6 speed trans replacement at 107k too.

I’ve maintained everything possible on this truck. No rust. No rot. Only two small dents and one scratch.

engineered to fail.

time for a rebuild of the motor with non AFM parts. What have you all been using? Truck is tuned for an extra 30 hp 30 TQ and I’m not really looking to put a bigger cam or anything like that. Maybe a 6.2 intake if that would make a noticeable difference and be worth the $$$.

I have a 383 C4 that I can flog on if I feel the need.

local mechanic / engine shop will be doing the work but offered for me to get all of the parts. Plans are AFM deleted cam / lifters, machine and blast the carbon out of the heads, oil pump / timing chain / any bearings and gaskets needed.

about 6 months ago, I noticed slightly lower oil pressure. I’m wondering if that was the start of the lifter failure.

I love this stupid truck. I drive a lot. It’s a pleasure to drive. But for two major components to **** off at under 150k? That rots. I don’t want this to be my last GM as I think all 3 of the big 3 suck overall, but it may be time to go back to a 20 year old truck like my 04 5.3 and keep it simple. It even got better gas mileage than this new tech bullshit.

thanks

mike

KevinRum · November 8, 2022

I'm with you Mike! Just sent my 2014 to the shop this morning for a transmission. Spent most of this summer in and out of shop with 4x lifter failures and an oil pump. I will have spent >$13K on repairing my truck this year, wondering why I ever sold my 2000 Sierra:(

Sounds like you have a good plan though.