little oil consumtion

[tiger862]

All my cars used oil at one time or another. 1/2 qt at 2k is not a problem it is normal for most manufacturers. Had a 1980 chevy p/u that used 1 qt a 1000 for 300k miles. Try getting dealer to warranty it when new and they tore motor down and couldn't find anything wrong according to them. They even sent heads out to machine shop and reworked and checked leak down on cylinder etc. an everything was in spec. After a month in shop I gave up complaining and drove it until it broke. After 300k just got a Ford and it used a qt. between changes and fast forward to today and my Vue 4 cyl is losing a 1/2 qt in 5k. Don't worry just put recommended grade Dexos oil in her and enjoy. I would not go with OLM since many problems with this system are documented causing problems with AFM components on longer oil changes. Some are changing at 5k with synthetic oil and no problems.

 

[hounddog]

Synthetics have a a better flash point,hence less oil used. All oils have different flashpoints. So certain synthetics have different9 flash points then others. OCI of 3 to 4 thousand miles is way low. 6000 on my Hemi is low. I should run it a minimum of 7500.

 

[hounddog]

Here s a tread that is going on. This will give you a hint to when to change oils and show how different oils perform. http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2890705&page=1

 

[threeputtpar]

Oil comsumption is a well known fact on GM AFM engines. I service two 3.9 V6s with the AFM and one of them is driven on the highway >50% of the time. In the 4 quart sump, she burns through 2 quarts (when the low oil light comes on) every 3k miles.

There is no concrete evidence where the oil is really going, but it is disappearing. How much you go through is directly dependant on how much time the engine spends in cylinder shutdown mode.

GM won't admit their mistake, but the fact that they stopped offering AFM in the 3.9 after the 2008 model year is an admission of guilt in my book. And yes, I have heard of an aftermarket tune that will disable the AFM and solve the problem.

 

[uart]

Originally Posted By: threeputtpar
Oil comsumption is a well known fact on GM AFM engines. I service two 3.9 V6s with the AFM and one of them is driven on the highway >50% of the time. In the 4 quart sump, she burns through 2 quarts (when the low oil light comes on) every 3k miles


Is that a true low oil level light or is it actually a low oil pressure light (as most are). In my experience, people who routinely drive until the oil pressure warning light comes on before taking the car for a service are destined to see increasing oil consumption and a shortened engine life.

 

[sopususer]

In their latest TSB dated 1/4/13, GM is placing the oil usage in their AFM 5.3 motors on one of two things. Oil pulled through the PCV system or oil discharge from the AFM pressure relief valve in the oil pan.

For usage due to the PCV system: Trucks built after 2/2011 have a new left side valve cover. The updated valve cover has the PCV drain hole relocated so oil supposedly cannot as easily enter the intake. There are different replacement part numbers for the valve cover depending on the year of the vehicle.

For usage due to the AFM pressure relief valve: GM blames discharge from this valve for spraying on the pistons of the deactivated cylinders. Over time the spray on the pistons will cause the rings to gum up and stick. GM has designed a shield that fits over the valve to keep it from spraying on the pistons. If the rings have been stuck due to this GM tries a chemical soak to free the rings and if unsuccessful will replace with new pistons and rings. Trucks built after 10/1/10 are supposed to already have this shield in place to prevent the spray from reaching the pistons.

Here is a link to the tsb if anyone is interested. GM tsb 3242444

 

[wolfc70]

Originally Posted By: chevydude
I have an '07 Silverado that has a little bit of oil consumption caused by AFM. I am reluctant to have the issue corrected by GM so I was wondering if there is some oil that may help with the consumption. I have been using VWB 5w-30 since day one. Truck only has 40k. GM is aware of the oil consuption issues with '07-'09 models that is for sure and the fix may be worse than the problem looking at the long term.


Keep monitoring it, and go back to the dealer when it gets worse.

My co-workers 09 Avalanche with the 5.3 had his engine replaced at 63K miles. Oil consumption started at 30k and kept getting worse. It got really bad while towing 3 four wheelers on a hunting trip. He called me en route in panic because he had gone through over a quart of oil in 900 miles. He took it to the local dealer who did a leak down test and found bad rings. On tear down, they found really loose rings and worn ring lands on 3 pistons. Those bores were also scored due to (presumably) the rings moving around too much. He got a new engine, and so far, so good. But he only has 10k on the new one.

Seems like GM still has some parts supplier issues, along with quality control problems.

 

[hounddog]

They have design problems.

 

[hounddog]

They have design problems.