Is Your Gmt-900 Truck Or Suv Using Oil

arz71 · November 3, 2014

One thing for certain, I have never heard or read where anyone regretted disabling AFM. Virtually 100% positive comments when they do it. Mine was only AFM enabled for about the 1st 240 miles on the odometer. Been disabled ever since. I noticed an improvement right away. Smoother cruising and acceleration. Many claim a person can't really tell the difference, but I sure can.

Does the new trucks have the ability like a 2014/2015 turn this mess off with AFM?

Sounds like this AFM is a dumb design.

The EPA is the worst thing to ever happen to the auto industry, just my 2 cents.

Cowpie · November 3, 2014

Yes, the new pickups, the AFM can be disabled or turned off. The concept to have this stuff on engines sounds good on paper, but has been less than stellar in application. On a nice, controlled test track or engine dyno testing, I suppose that there was some measurable fuel economy gains by having this stuff. But we all know, a nice test track or dyno lab is not where we run our pickups. Frankly, I wish the AFM thing was brilliant in design and application with no need to disable it. I would rather have spent my money on other things than ways to disable features that the OEM felt I needed.

2017SierraSLT · November 3, 2014

That's too bad that a 2013 should already be having issues. My 2013, with roughly the same number of miles, barely uses a drop. I have 5000 miles on this fill of engine oil and the level has barely moved off of full. Been pretty much like that since I bought it. But then, I attacked the problem issues within the first 1000 miles like disabling AFM and installing a PCV catch can. Thing is, I really hadn't kept up with this stuff until I bought this pickup. Right away I started reading various forums, saw what was going on, and immediately started preemptive measures before the engine had time to go goofy.

Same here. No issues with mine. I added a catch can, and tuned out AFM at 1000 miles.

arz71 · November 3, 2014

I got a 2009 Silverado with 40,000 miles on it, on disabling this AFM mess is there anything else you recommend?

On our 2000 Z71 5.3 it is almost 15 years old and just 'works' as designed.

I heard something about replacing the lifters on the AFM cylinders or it may cause problems if you disable AFM???

Any input or info on that or is that a old wifes tale?

MPFit · November 3, 2014

I change every 5000 miles with mobile1.

2012 Sierra 1500 SLE 5.3 AFM

I'm down 1.5QTs since first change. Bought truck at 20k miles; did first change within 100 miles.

Just did 2nd change at 25k miles and low 1.5QT.

Cowpie · November 5, 2014

1.5 qt in just under 5000 miles would raise my eyebrow, but sometimes there is a slight increase in oil consumption if the brand and type of oil used was different that before, until the engine gets used to the different oil. Unless you knew what the original owner was using and it was the same oil. I would just watch it and track how it does over the next couple of oil changes. The Mobil 1 might actually clean out some build up from a previous oil and that would cause a little early consumption.

Cowpie · November 5, 2014

Any input or info on that or is that a old wifes tale?

Too early to tell probably. I have not ever heard of anyone having issues with lifters and such when they disabled the AFM early on. I have for a few that had already run for some time with AFM functional and then disabled. But there doesn't seem to be a lot of talk about it happening.

Along with the AFM disable, a PCV oil catch can is almost a must have item to install. It will make you vomit after you see all the junk it catches, that had gone thru to the intake prior to installing one. I capture roughly a full ounce or more of oil, condensation, etc in every 1000 miles. Imagine how much would go thru in 50,000 miles on a engine that didn't have a catch can! That wold be like dumping a couple of quarts of oil into the intake! Is it any wonder why these engines are having issues?

Edited November 5, 2014 by Cowpie

arz71 · November 6, 2014

Too early to tell probably. I have not ever heard of anyone having issues with lifters and such when they disabled the AFM early on. I have for a few that had already run for some time with AFM functional and then disabled. But there doesn't seem to be a lot of talk about it happening.

Along with the AFM disable, a PCV oil catch can is almost a must have item to install. It will make you vomit after you see all the junk it catches, that had gone thru to the intake prior to installing one. I capture roughly a full ounce or more of oil, condensation, etc in every 1000 miles. Imagine how much would go thru in 50,000 miles on a engine that didn't have a catch can! That wold be like dumping a couple of quarts of oil into the intake! Is it any wonder why these engines are having issues?

Do you got any pics of the oil catch deal?

Got a 2009 with almost 39,000 miles on it want to have that AFM turned off.

The EPA mandates results in so many problems. Imagine how trouble free a vehicle would be without these forced regulations. Just me thinking the 'buyer' is the one who foots the bill.

Can't imagine the cost or maintenance on a v6 turbo in turbo is going to be after 7 years or so. Or if it would even be running...

Cowpie · November 6, 2014

I am on the road now, but will post some more pics on my oil catch can setup later.

Yeah, we all get hit for all the emission stuff and goofy design ideas that come about to appease the government. While what we are dealing with here is bad, you ought to take a good look at how it affects heavy commercial trucks. Tens of thousands of dollars PER TRUCK in both initial cost and increase maintenance issues and lost revenues due to downtime. It is staggering. That is why I ordered up a 2013 Freightliner WITHOUT an engine and transmission, and then dropped in a pre-emission, factory rebuilt engine and factory rebuilt transmission. Saved $40,000 on the total price of a new semi truck and had complete new truck warranties throughout on everything! And it was all legal! A loophole in the EPA and IRS regs made it legal to do all of this. The EPA ties the emissions to the year the engine is made, NOT the year the vehicle is made. In essence, if GM and the others were to offer a pickup, without engine or transmission, available thru the parts stream to consumers, we could buy a new pickup and drop in a earlier made engine. But they don't do that. At least, on the commercial heavy truck side of things, the OEM's have figured out how to do this and offer it to the consumer. Since pickups and autos are only made with new produced engines, they have to comply to the latest regs.

Edited November 6, 2014 by Cowpie

2017SierraSLT · November 12, 2014

Do you got any pics of the oil catch deal?

Got a 2009 with almost 39,000 miles on it want to have that AFM turned off.

The EPA mandates results in so many problems. Imagine how trouble free a vehicle would be without these forced regulations. Just me thinking the 'buyer' is the one who foots the bill.

Can't imagine the cost or maintenance on a v6 turbo in turbo is going to be after 7 years or so. Or if it would even be running...

My Elite Engineering can:

Cowpie · November 16, 2014

I use a dual Conceptual Polymer catch can setup. The first, a CP standard filter unit, followed by a CP High Efficiency unit to catch what might have slipped by the first. I capture about 1+ oz of oil, crud, condensation per 1000 miles on average. A little more in winter due to heavier condensation. The oil in the jars shown was from around 300 miles since last dump. I set the jars next to a filter for size perspective. The jars are about 4.5" tall.