Oil Consumption 2011 Silverado with AFM 5.3

[2011rado]

I have a 2011 Silverado with 125k miles, bought the truck with 90k and found out the problems with the active fuel management on these model trucks so I put a programmer in the truck to delete those hoping it would help make the engine last longer. It’s is now burning oil, has a puff of white smoke when it starts after sitting for more than 3-4 hours, and the fuel alcohol sensor acts up when it’s cold outside making the truck start rough and idle rough for about 30 seconds. Is anyone else having all these problems? 

[MaverickZ71]

All too common.  Be sure to run a Dexos1-rated (semi-synthetic or full synthetic) oil, free-flowing oil filter (to help mitigate the AFM lifter ticking), and run 2 bottles of Chevron Techron Fuel System (not Fuel Injector) cleaner every 2000 miles, if you are running gasoline and not E85 as fuel.  That will help free your stuck piston rings and clean your fouled spark plugs.  And make sure AFM is turned off--sounds like you've already done that.  You might also look at adding an oil catch-can into your PCV system.  

 

The only real permanent fix is to tear the engine down and rebuild it with new piston rings and an AFM-delete kit.  

 

Check out the "Is your GMT900 truck using oil" poll on this 2007-2013 1500 forum for many more details on those items listed above and what else has been tried over the years.   

[NHUSA]

I am also new to the forum and just got a 2013 Silverado, 5.3 LC-9, 4x4, 6-speed with 124 K miles.

It runs great and is getting 19 MPG on the highway.

I assume that it has AFM.

How can I tell for sure and if so how do I disable it?
 

 

[TillerLife88]

New to the forum and I just Deleted the DOD of my truck entirely and have low OP. New L99 pump, the filter bypass has been plugged, the valley towers are plugged and once it’s warm it drops to 20lb at idle and runs 38lb at 2500RPM. I’m goin bald over here and debating on an iron block non DOD 6.0 swap.

[CamGTP]

If you want to get technical, that's not low oil pressure. roughly 40psi cruising is great and 20psi at idle is more than enough to keep it happy. GM states that like 7-10psi per 1,000rpm is "okay" if I remember right, though it's surely on the low side if you see 10psi.

 

I'm sure your WOT oil pressure is well above 50-55psi now.

 

My 2012 was 25psi hot idle.

[mn camper guy]

Replacing the valve cover fixed my startup smoke and oil consumption issues.
2010 5.3l.

Google : Bulletin 10-06-01-008M

I relaced cover and plugs at 100k. Oil consumption less than a pint now down from 1+qts per 3000 mi. #7 plug was oil fouled. Now at 116k on the truck.

Note: i have had afm off since 20k miles via diablosport.

Sent from my Pixel 3 using Tapatalk

[swathdiver]

On 2/15/2019 at 4:30 PM, 2011rado said:

I have a 2011 Silverado ...and the fuel alcohol sensor acts up

Nope, doesn't have one.  It uses the O2 sensors to calculate the alcohol content.

On 2/25/2019 at 12:57 PM, NHUSA said:

How can I tell for sure and if so how do I disable it?

The LC9 is an AFM motor.  You can switch to instant MPG on the DIC and see V8 or V4 mode.  You can get a tune to turn it off or a Range device.

On 3/9/2019 at 2:53 PM, TillerLife88 said:

New to the forum and I just Deleted the DOD of my truck entirely and have low OP. New L99 pump, the filter bypass has been plugged, the valley towers are plugged and once it’s warm it drops to 20lb at idle and runs 38lb at 2500RPM. I’m goin bald over here and debating on an iron block non DOD 6.0 swap.

You downgraded your oil pump.  The LC9 runs an M365 which moves 1/3 more oil every revolution.  It also runs at a lower pressure, the bypass spring is 33 psi with the yellow spring.