Oil for Silverado w/5.3 afm

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I've been reading about 07+ 5.3 L GM truck motors with the advanced fuel management feature (cylinder deactivation) developing an oil usage problem around 30-40K miles. Some people believe it is a problem due to the special lifters used in the deactivated cylinders, but some believe it is attributed to an oil problem where oil that is cooled in the deactivated cylinders gums up the rings and allows oil usage to begin after a few thousand miles. I believe GM even has a TSB where the piston is to be chemically cleaned in trucks with engines torn down for this problem.

Since there are so many BITOG experts here, would this oil problem even be possible, and if so what could be done to remedy it? I've even read of synthetic users M1, PP, etc who are having this problem. I can't see this as an oil problem especially when a great cleaning oil like either of these are used, but I'm far from an expert.

Long story short I have an 11 Silverado with the 5.3 AFM. I know GM has gone to the Dexos spec for 11+ and I plan on using PP or QSUD in this vehicle. I'm more than comfortable with that decision, but is there anything else oil related I could/should do to help me avoid this problem, if indeed it is an oil problem.
 
PP or PU would be great at keeping it clean. you could do 3k ocis, that would help too. also a pint of Kreen added on top of the oil once a year would also keep it clean and take care of any deposits in the ring packs
 
This isn't the same engine as in my 08' Impala SS???? It has the 5.3 liter engine alonw with cylinder deactivation too. My engine has been rock solid but admit I only have around 13K.

Durango
 
Originally Posted By: sopususer
Some people believe it is a problem due to the special lifters used in the deactivated cylinders, but some believe it is attributed to an oil problem where oil that is cooled in the deactivated cylinders gums up the rings and allows oil usage to begin after a few thousand miles. I believe GM even has a TSB where the piston is to be chemically cleaned in trucks with engines torn down for this problem.

While I am no expert with this problem, it would seem very strange the cylinders could cool enough to cause the oil to gum. The oil is continuously flowing and there should be enough heat from the remaining cylinders, not to mention there is still friction in the deactivated cylinders to maintain heat. Additionally, if synthetic oil was being used this condition would seem even less probable. Basic engine operation causes the rings to rotate so even if the cylinder is inactive, the reciprocating motion of the piston should still cause the rings to rotate even partially.

From my point of view, it seems unlikely the oil is the root cause of this issue especially with so many different "flavors" in use. If this was happening with only 1 or 2 types, then yes maybe, but not with the multitudes of oil that different people use.

Perhaps one of the other members has more insight into this...
 
If it is gumming up the rings, just do a few long hard pulls up to the rev limiter. Yes, this isn't a true solution to a possible design flaw but it may prevent the build up. Shoot I have done this on a weekly basis and had 413k miles on a 3.0 5spd ranger and 196k on my Zetec powered ZX2. I would agree that the "flavor" of oil has little to do with it.
Dusty
 
I had 42k on an 07 with a 5.3 L and never had an issue with oil consumption. I ran M1 5w-30. Engine ran strong and never used a drop between oil changes.
 
I have a Grand Prix GXP with the DOD engine and it burns a quart every 1200 to 1500 miles. It drinks Mobil 1 and I have switched to PP as other people that I know with this problem have said that PP does not burn off nearly as fast.
 
I had an 07 Silverado 1500 w/ 5.3L and AFM. I never developed any oil usage issues at all. 5K OC's with full synthetic 5W-30(RP). Never so much as a 1/2 qt down over the 5K. I have a 2008 Dodge Ram 1500 5.7L HEMI w/ MDS right now which is the same basic thing as the AFM and no oil usage there either. Same 5K OCI's with RP( 5W-20 this time ). There are no oil cooking on the pistons issue with MDS 5.7L's and as said AFM and MDS are very similar.

FWIW when I had the Silverado and was on the GM forums PP and Valvoline Synpower were very popular for the 5.3L AFM engine with people. PP was probably the most popular.

I would not attribute it to the AFM. You are out of more than in deactivation mode to start with and even when AFM/MDS kicks in it isn't on long enough to really cool anything down. Plus as another member said you have heat transfer from the active cylinders anyway.

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I have the 2010 Tahoe 5.3 with cylinder deactivation.
I have seen plenty of stories with oil consumption on the 07-08 models, but have not really found any complaints for the 2010-2011 models. Have you seen info specific to the newer model years?

I already have 33000 miles on it. I was down 1/2 quart after 6300 miles using M1 EP. That was the first time I noticed any loss. I am running PP now, and am watching to see if I end up low again at the 6k mark. I know 1/2 quart in theory is fine, but after driving a new Chrysler or Ford SUV every other year, for 50k miles a year, for the past decade, this is the first time one used any oil between changes.
 
07 suburban here, has the issue of going through oil, almost at 100,000 miles now. This thing has been in the dealership many a time! Its latest "repair", was all new rings. still hasn't fixed it.

this problem isn't uncommon... they obviously know what the problem was, you don't hear much about it on 08 models, and you certainly don't hear much about it on 09/10 models.

Edit - Ok after a little searching on google, apparently the "fix" is a splash guard in or near the oil pan.
 
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Guess I am lucky my 07 didn't do it although I had less than 20K when I sold it. I would have been highly upset. I must not have been around the Chevy forums long enough for these vehicles to wrack up the miles needed for this to show up which explains why I hadn't heard of it.
 
I have an 07 Silverado with 5.3l AFM with 55,000 miles. I do 7-9k OCI's per the OLM with Mobil 1 5w30 EP. To keep the oil level at the top of the 'safe range' on the dipstick, I add 2-3 oz every 2-3k miles. Has been this way since new. YMMV
 
I have a 2007 Yukon XL and yes I had this dreaded oil use issue. This truck is driven VERY short distances during most of the week(less then 20 miles total, driving it every day), so I would say it just about always ran on all 8 cyls. About one weekend a month it takes a trip of all highway miles of about 200 miles. So after 2.5 years, aprrox. 15,000 miles, I began getting the low oil message. The dealer did the TSB, which included an oil change to monitor usage, and sure enough every 800-1200 miles it would display the low message and it was a quart low. The dealer added the oil pan splash guard, didn't work, did some sort of engine tear down and clean, didn't work, and so finally changed the engine. Now I have a little over 1,000 miles on it and NO problems. Before the engine change I used Mobil One Syn. I don't know if this helps the OP but I just wanted you to know I don't believe it's the cylinder deactivation feature, IMO. If I missed anything please feel free to ask.
 
Driven VERY short distances and putted around.... NOT good.
I say get er' on the highway and open it up to get things clean. it is VERY hard on a car or gas truck to be putted around at less than 3k rpm for 60k miles...
 
Thanks for all the replies. I've had the non AFM 5.3 on three previous trucks. Two were Mobil 1 trucks and one was PYB. No engine problems on any of the trucks. Right now I'm thinking QSUD or PP for this truck since they both meet the DEXOS requirment. Since it "seems" PP might have some small cleaning advantage over QSUD I'll probably go with it. Like I've said I've used M1 before with two other trucks, but I'm sold on the SOPUS synthetics. I use PU in the wife's Subaru. If anyone else has GM 5.3 AFM and oil consumption issues could they post the OCI's and brand? Like posted before I'm having a hard time seeing this as an oil issue on the 07-08 trucks. As the 09-11's gain miles I wonder if we'll see the same issues. As many trucks as GM sells I'm hoping this is a rare problem and that I manage to avoid the problem.
 
Just found this topic through site searching with Google.

I have a 2007 Silverado with the 5.3 AFM. Mine has been eating oil for a while. The first time I noticed it was when I got the low oil level warning at around 40-50k miles (may have been using all along, idk). That also happened to be the first time I used Pennzoil Ultra (I don't think it's the oil).

I have got the low oil level warning since then once or twice. This OCI which is 72k miles start to currently 77k miles I have had to add 2 quarts. I'm debating on trading this thing in pretty soon.

GM dealer told me that GM pretty much won't do anything unless you are burning 1 qt+ per 1k miles. Any less is "normal".

FWIW my buddy had a 2009 GMC Sierra that used around 2 qts every 3k miles so he traded it (20k miles on it). My cousin has a 2007 Silverado with 140K+ miles on it, and it usess 1 qt every 3k miles the last time I asked him. I've also heard many other stories but not sure on specifics of those.

Really dissapointing to have a nice vehicle with this problem. I wonder if the 2012 models will be the same....?
 
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