What do you do about oil usage?

flyboyron · August 2, 2016

I have a 2009 with the 5.3L and it now has 68,000 miles on it.

I checked the oil one day and it was a quart low. The mileage since oil change was 4,000 miles.

After putting in a quart, I ran it 2,500 miles and now it is 1/2 quart low.

I have read several of the posts over the years about trucks using oil and was wondering what has been determined to be the problem.

Has anyone done anything to improve the oil consumption such as repairs, or even using one of those oil additives like Slick 50, Liquid Ring, Matrix?

I have used Slick 50 in vehicles in the past, they did not use oil before putting in the additive, but I did get better gas mileage and they ran great for a long time.

I have used Matrix in my airplane, and it restored the compression readings on two cylinders so I didn't have to have them pulled.

Just wondering what you guys have come up with?

.....also.....does it get worse as the the truck gets older or does the usage stay consistant.

KARNUT · August 2, 2016

I've owned two vehicles that used 1qt every 2500 miles. 99 ford p/u bought new put a s/c on it at 20oook mile traded at 100k ford said that was ok. Second one 94 z28 put 130k miles, cut the clogged converter off at 60k. Both did just fine. My worst is my 92 gmc s/c Chevy truck one qt. ever 500 miles I was pissed when I bought it, 5 years 7k miles still hauls ass. Doesn't smoke or leak don't know where it goes but still I see smoke no reason to rebuild.

flyboyron · August 2, 2016

I never really studied the posts on oil consumption in the 5.3 since I didn't think I had an issue.

How is this for a therory?

If the AFM is active and a cylinder does not have a combustion cycle, which would expand the rings to seal the cylinder and scrape the oil down off the cylinder, but instead has a vacuum or suction (since there is no combustion) which causes two things.....the rings don't expand, and the suction or vacuum sucks the oil past the rings and that is why it is using oil.

Any thoughts on that?

I also read a post or two about the Range disabling device.....might sound like a good idea.

dennismc · August 2, 2016

My 2008 5.3 had been using about a half quart every 3000 miles. Since it wasn't leaking or burning any oil I targeted the AFM by doing two things, I installed a updated drivers side valve cover and had the AFM turned off in my Black Bear Performance tune. It now uses zero oil.

I cant say if it was the valve cover or AFM or combination of the two that was causing the usage.

flyboyron · August 2, 2016

My 2008 5.3 had been using about a half quart every 3000 miles. Since it wasn't leaking or burning any oil I targeted the AFM by doing two things, I installed a updated drivers side valve cover and had the AFM turned off in my Black Bear Performance tune. It now uses zero oil.

I cant say if it was the valve cover or AFM or combination of the two that was causing the usage.

Did the valve cover have the PCV valve in it, or some type of crankcase ventilation on it? One post I read said that their PCV was sucking oil into the intake.

dennismc · August 2, 2016

Our year trucks do not use a PCV valve, not sure what year they began omitting them. The revised valve cover has a baffle in it to prevent it from sucking oil.

arcasey · August 2, 2016

My 2008 5.3 had been using about a half quart every 3000 miles. Since it wasn't leaking or burning any oil I targeted the AFM by doing two things, I installed a updated drivers side valve cover and had the AFM turned off in my Black Bear Performance tune. It now uses zero oil.

I cant say if it was the valve cover or AFM or combination of the two that was causing the usage.

Did the valve cover have the PCV valve in it, or some type of crankcase ventilation on it? One post I read said that their PCV was sucking oil into the intake.

GM trucks from 2007-2011 had known issues with AFM causing oil consumption issues. There was a TSB issued for a shield that was supposed to alleviate that issue. A lot of people are stating there oil consumption issues go away after deactivation of the AFM. You could get a tuner and try that or just ask nicely at the dealership if they can turn it off since it's using oil. They will probably tell you that your oil consumption is considered acceptable and won't do it anyway.

Bob D · August 2, 2016

No 5.3L or AFM here, rather a 4.3L.

Owned since new, lovingly maintained, no serious leaks.

Uses a 1/2qt every 1,200 - 1,600 mi.s.

What do I do about it....add a 1/2 qt every 1,200 - 1,600 mi.s.

arcasey · August 2, 2016

No 5.3L or AFM here, rather a 4.3L.

Owned since new, lovingly maintained, no serious leaks.

Uses a 1/2qt every 1,200 - 1,600 mi.s.

What do I do about it....add a 1/2 qt every 1,200 - 1,600 mi.s.

I've got a 96 K1500 that uses about a quart every 2500 miles and I do the same thing.

Honestly flyboyron, if the fact that it's using oil and you don't see any major leaks doesn't bother you all that much, then the cheapest option is probably to just add the extra oil that it's using. If you want it fixed, I would start with getting the AFM turned off and see if that resolves the issue.

MaverickZ71 · August 2, 2016

Ron, welcome to the wonderful oil-using world of GM AFM systems! You will want to read the 44 pages included with the oil usage survey pinned at the top of this forum. This topic has been beat to death and then some, but here are the Cliff notes:

Sometime in 2010/2011 the GMT900s rolling off the factory assembly line started getting a different driver's side valve cover (with revised PCV orifice) and an oil deflector in the oil pan. There is a TSB out covering the addition of these to 2007-2010 models that did not include them, in addition to a procedure to clean the piston rings. This works for some trucks and doesn't help much on others.

The main idea is to get the AFM turned off as soon as possible, either via a modified PCM tune or Range V8 module. Once your piston rings get really gunked up, nothing short of new rings is going to totally fix your problem. And most people don't notice any major change in their fuel mileage by having AFM turned off.

Excessive oil usage will foul your spark plugs, throwing misfire codes and making your truck idle really bad. And it messes up your oxygen sensors and catalytic converters over time, too.

So you'll probably want to turn off your AFM--the GM dealers will not do this for you, run Dexos1 or equivalent motor oil, run some Techron Fuel System cleaner in your gas tank to help unfoul your valves/spark plugs, and run some AutoRx or equivalent in your motor oil to try to free your piston rings. Some folks also install 'catch cans' in their PCV systems to catch the oil blowby, and that also seems to help.

flyboyron · August 3, 2016

GM trucks from 2007-2011 had known issues with AFM causing oil consumption issues. There was a TSB issued for a shield that was supposed to alleviate that issue. A lot of people are stating there oil consumption issues go away after deactivation of the AFM. You could get a tuner and try that or just ask nicely at the dealership if they can turn it off since it's using oil. They will probably tell you that your oil consumption is considered acceptable and won't do it anyway.

You know what really pisses me off, is that I go down to the Chevy dealer and tell the guy I want to find out about this TSB figuring that might be the first thing to check, and the guy goes off about how acceptable the oil consumption is and doesn't even bother trying to help me by looking up the TSB. If that is the way they treat their customers, I won't be back. I am going to look at ordering a Range and see how that helps. I did some quick calculating and found that at 10,000 miles a year, if I lost 2 mpg, it would cost me about $200.00 a year in gas. I think, I would rather pay the gas, than to have the engine rebuilt earlier than it should be because of oil related problems.

MaverickZ71 · August 3, 2016

Here is a PDF file of that TSB.

#100601008G-1.pdf

arcasey · August 3, 2016

You know what really pisses me off, is that I go down to the Chevy dealer and tell the guy I want to find out about this TSB figuring that might be the first thing to check, and the guy goes off about how acceptable the oil consumption is and doesn't even bother trying to help me by looking up the TSB. If that is the way they treat their customers, I won't be back. I am going to look at ordering a Range and see how that helps. I did some quick calculating and found that at 10,000 miles a year, if I lost 2 mpg, it would cost me about $200.00 a year in gas. I think, I would rather pay the gas, than to have the engine rebuilt earlier than it should be because of oil related problems.

Yea I figured that's what they'd tell you based on articles I've read about this topic stating that GM had already established their "acceptable oil consumption". Don't let one bad apple spoil them all though, all the dealers are not that unhelpful. And I really don't think you will loose all that much fuel mileage. If you watch the AFM in the DIC it is very rarely in V4 mode unless you are coasting or on very flat ground on the highway.

flyboyron · August 3, 2016

Here is a PDF file of that TSB.

Thanks that was helpful.

I ordered the Range, and the order was cancelled because I live in Ca.

So I am trying something else and I will see if this will allow me to get one.

flattop · August 4, 2016

My truck is a 2013 GMC sierra with the 5.3. I have run mobil 1 5W-30 since the first oil change (1000 miles). Now with 95,000 miles I do add about 3/4 of a quart during the approx. 7500 miles between changes.

I really do not have a problem with this amount over 7500 miles. It was less when the truck was newer, but it always burned some during that duration.

I guess it probably has something to do with the AFM function, but it may be partially due to my acceleration habits!