2011 Silverado 5.3 Hydraulic valve lifters replaced

joshw1303 · January 21, 2013

So i just turned 40k on motor. Was cold out one day and heard lifters very loudly I took it to the dealer and told them about the valves being loud, Next thing i know they took the block a part and replaced valve lifers. Tech cause: Engine Hydraulic valve lifter has internal noise. Inspect engine for noise.re and re both cylinder heads to inspect and replace all hydraulic valve lifters with active fuel management. - Warranty.

Well before AFM did not go in and out so much. Now it is always coming on and off and i am getting tons of vibration at low rpm under 1500. Feels like its going to stall, not getting best fuel economy at hwy speeds anymore.

Another thing, Came home at 2 am -12c was sitting in truck without power on and truck shuts off, low battery, start engine.

Can anyone help me figure out whats going on?

joshw1303 · January 22, 2013

Bump

Jedi_Jr · January 22, 2013

If you have not put a battery in it yet at 40K then it is time. Mine has 16K and it gives me the Low Batt Start Engine warning all the time when sitting for a few minutes. Battery is weak (think lightweight and it saves the manufacturer money) from the factory, and the CAN buss really never powers off and at -12c.....

Also, they probablly reflashed the ECM to the new code that came out and seems that V4 stays on more when I flashed mine last week.

Are the lifters quiet now, atleast?

joshw1303 · January 22, 2013

If you have not put a battery in it yet at 40K then it is time. Mine has 16K and it gives me the Low Batt Start Engine warning all the time when sitting for a few minutes. Battery is weak (think lightweight and it saves the manufacturer money) from the factory, and the CAN buss really never powers off and at -12c.....

Also, they probablly reflashed the ECM to the new code that came out and seems that V4 stays on more when I flashed mine last week.

Are the lifters quiet now, atleast?

I think so, going to listen to the motor before work tonight. Ya Original battery truck has over 40,000km. New flash eh, well it comes on a lot, almost always on. But i thought when they changed the valves, they do an oil change but they did not, sitting at 74% OLM.

Jedi_Jr · January 23, 2013

I was talking miles, not km, regardless the Batts are weak. if i put a 6 amp smart charger on it, from just sitting overnight, it will take 4 hours to reach full charge; just too much load while asleep and it kills the battery. Put in dual batts and you will be fine. I also hear that there is a BCM or Dash update to address the early Low battery warning. They may have changed the oil and not reset the OLM.