Is Your Gmt-900 Truck Or Suv Using Oil

[MaverickZ71]

My 2009 Silverado Crew Cab Z71 4x4 (5.3L LC9 V8 flex fuel, 3.42 gears, 6-speed auto trans) was progressively getting thirstier over the last year and a half or so, up to the point of where it was drinking around 4 quarts of 5W-30 over 5K miles. Regular dino-oil or synthetic, and Fram's best or AC Delco PF48 oil filters seemed to make no difference whatsoever. Seemed to always use more oil during hot weather, on long trips where AFM was kicked in longer. I do not haul heavy loads or tow anything, nor do I race it--don't remember ever flooring the throttle on this truck. I do most of my own maintenance work and am picky about meeting or beating the factory service intervals and using quality oils, etc., and now use only PF48 oil filters.

 

I was getting fed up with this oil usage situation, and worried that using that much oil was going to mess up my catalytic convertor, etc. Local service manager says "yeah, a lot of them AFM motors do that!" which didn't help my situation any or make me feel any more comfortable about my purchase of any present or future GM products.

 

The last few months I started reading more on the internet about AFM engines using oil and what to do about it. So I started driving in Manual mode on the transmission around town (5th gear selected) so AFM would not kick in. Thought I could tell the oil usage was slowing down. Then I purchased and installed the Range V8 module to turn AFM completely off. After a couple of months and a few thousand miles, my oil usage has all but stopped! I'm hoping that the oil usage will stop completely, but at this point, I could live with a quart being used over a DIC OLM-indicated oil life interval if I have to, as it would certainly be a relief not to be pouring in a new quart in less than a thousand miles like I used to have to do. (Can't believe I just said that, as up to now I always viewed any oil usage in a non-abused motor as being unacceptable. But when life gives you lemons. . . )

 

So this was not a scientific study by any means and I anticipate being bashed by the AFM-couldn't-possibly-cause-any-problems crowd. But the fact is that NOTHING changed with my oil, filters, gasoline, driving habits, etc. over the last few months with the exception of TURNING OFF AFM and then my oil usage has ALL BUT STOPPED. I am not a paid spokesperson for Range or Blackbear or any vendor or anybody else, but am personally convinced that turning off AFM stopped my oil usage and would recommend others with oil usage problems to look into turning their AFM function off as soon as possible. My miles-per-gallon has not dropped noticably, either, since turning AFM off, so I'm not sure how much it really helps save gas, anyway.

 

Cheers, and I hope this helps somebody.

Edited June 11, 2013 by Maverick Z71

[ur2slow]

I just purchased a 2008 Suburban with the 5.3 alum. flex fuel motor. It had 33,000 miles on it three weeks ago when it was purchased. I had the dealership certify it when I purchased it due to a engine light being on during the test drive. They told me that they did an oil change and fixed some "air bag sensor" to fix the problem so all was good.....for a week. After the first 1000 miles I checked the oil and it didn't register on the dip stick! I thought that they made a mistake while filling it. Very soon after that the engine light started coming on again so I took it in to a different dealer who came up with a o2 sensor code??? I start doing some internet research and find this sight and feel like I've been swindled. I checked the oil today and it was dry again with only another 1000 miles on the odometer! it took 2 quarts to get the level up to the top hole on the stick. That's 3 quarts in 2000 miles!! I have a feeling that is the reason the o2 sensor went bad and the previous owner traded it in.

 

I went to the dealer to have a talk with them and will be starting the consumption test.....wish me luck. I love the truck and sick that I just spent $32,000 on a BIG problem.

[dead3ye]

A buddy of mine has a 08 Serria 1500 with the 5.3, 4 speed tranny. It was using about 2-3 qts every 3,000 miles. Went through the whole consumption test, they installed oil splash gaurds in the pan and other stuff which made absolutey no sense to me. Went through the whole comsumption test again. Still using oil.

 

GM finally came back with the solution of replacing the pistons, rings and knuckles (whatever knuckles are).

I'm thinking it would be easier to replace the whole motor. Oh, and the service manager said they have done two of these procedures already so they are pretty sure they'll have no problems. Yeah right. I'd be worried. This doesn't sound like something a dealership service dept should be doing. If I were him, I'd be trading it right back to them after they're done.

 

I thank God everyday my 2008 uses absolutely no oil. Amazing how the two trucks being virtually the same age can be so different. I drive pretty aggressively and he doesn't. Plus if I'm going below 35 I'll drop it down to 3rd almost always to disable AFM because it sounds terrible with Magnaflow duals. Maybe that's the difference.

[hillbilly4u]

Hey guys. Haven't logged on for a while but I have read the posts. Wow 300 + posts. Glad GM is stepping up and helping out our fellow consumers. While I still enjoy my Silvy, I'm going to sell before it hits 30k on the rebuild job. Just don't trust AFM to not start using oil again. I will not buy another GM product if it has AFM. If I find someone I trust not to lie, with a Silvy for sale, then maybe I'll buy a used one then. There's gonna be a lot more traffic to this site and a few others. All you gotta do is google 5.3 and all links lead here.

[aflesch]

Vehicle info in sig. Went through 1.75 qts in 9800 miles on Mobil 1 Extended Performance.

[HateCarpetGuy]

My 2008 5.3 used to consume 2-3 qts / 5,000 mi. until I changed valve cover and got the newer design of PCV valve. The original PCV design allowed for too much oil to pass out of valve cover and back into intake manifold. Oil would then pool in cavities of intake and spill over into cylinders when you stop at red light on incline, park on slope, etc.

 

Since I changed valve covers (and you only need to do 1 side, I think there's a TSB about this) I have not burned any significant amount between oil changes. If you have not done this and you burn oil, I'd highly recommend looking into upgrading valve covers.

 

I have almost 300K on my 2008 1500 CC 4x4 and it runs better now than it did at 100K when all these issues surfaced (oil consumption, plugs fouling, misfire error codes, AFM acting up, etc.) Turn as much OFF as you can, do not be buffaloed into thinking that your V-8 runs more efficient on 4 cylinders. AFM is a marketing ploy to sway EPA bureaucrats into giving Govt Motors a higher corporate fuel rating. Since turning off AFM, my truck runs smooth, gets same fuel mileage, and all 8 cylinders feel needed and not neglected!

 

[JaBradt85]

I have almost 300K on my 2008 1500 CC 4x4

 

Pictures or it didnt happen.

[HateCarpetGuy]

Pictures or it didnt happen.

Here ya go JaBradt85, I drive about 1,000 mi/wk; 40-50K/yr. Like I said, truck runs fine now with no oil consumption after: AFM turned off, New design of PCV valve cover installed, use castrol 5w-30, even get it changed at local GM dealer at 5K (despite oil % showing 40-50% life left--I just have a hard time trusting a GM idiot light/message that nobody at the stealorship can explain how it calculates %). I just hope my pics come through below, by choice, I'm a newbie on the forum-post thing.

[Cowpie]

Very Good! That is impressive! I got a jump on this thing right out of the gate. Unfortunately, I didn't read up on all of these issues before buying, but started coming across this kind of stuff within days of the purchase. So, I disabled the AFM when the pickup had less than 500 miles on it. Not going to play a wait and see game. Gambling only is valid at the casino. But for extra good measure, I also installed an oil catch can system inline on the PCV from the valve cover to the intake. Almost mind boggling the amount of oil that goes thru that PCV line and piles up in the intake just compounding the problem. Just hope these two things will put me in the extreme low risk class of problems with my 5.3L.

 

Man, if there ever was an application of the law of unintended consequences, this whole AFM thing has got to be the poster child.

Edited July 17, 2013 by Cowpie

[frankycjr]

I was at my dealer last week for another oil reading. They have agreed to add the umbrella to the oil pan valve and to replace the valve cover. The also have to replace my lifters. I explained to the manager that they needed to replace the piston and tings as well. Manager has opened a case with GM to attempt to get permission to replace the piston and rings under warranty. I just don't see how putting cleaner on the top end of the piston is going to clean the carbon and oil buildup on the oil control rings.

 

I'm betting I'm going to end up having to call GM corporate with the case number to push them into doing the right thing for me. Plus how do you test to make sure the catalytic converters, O2 sensors, and fuel injectors have not been clogged or damaged by the burning if the oil ? Lots of questions, but not a lot of answers at this point, but progress is being made.

[Service1956]

It is no longer required for the dealers to do an oil consumption test on new cases that come in!! And it should also be noted that "ALL DEALERS" now have this important T.S.B.

[frankycjr]

@service1956 which TSB do the dealers now have and what are they required to do ??I'm still waiting to hear back from the Service Manager whether GM has agreed to replace the piston and rings as I have demanded, in a nice way

 

Can you provide a copy of the TSB or the TSB number ?

 

Thanks

 

Frank

[Kblaze94]

My 09 w/47k is at the dealer now getting the oil changed, they said it was 1.5 quarts low, I change it every 5k. They said chevy claims 1 quart every 2k miles is normal... my 94 isn't even that bad... pretty pathetic imo

[Cowpie]

My 09 w/47k is at the dealer now getting the oil changed, they said it was 1.5 quarts low, I change it every 5k. They said chevy claims 1 quart every 2k miles is normal... my 94 isn't even that bad... pretty pathetic imo

 

Personally, I would call that claim to be a pile of meadow muffins. That would be 1.5 gallons in 15,000 miles and my 12.7L Detroit Series 60 in my semi doesn't even use more than a quart in that many miles. These GM V-8's should not use more than a quart in 5000 miles..... tops. My '98 454 V-8 would not use a quart between oil changes. So I would politely tell whoever is making that claim that they are breathing too much exhaust.

[Service1956]

@service1956 which TSB do the dealers now have and what are they required to do ??I'm still waiting to hear back from the Service Manager whether GM has agreed to replace the piston and rings as I have demanded, in a nice way

 

Can you provide a copy of the TSB or the TSB number ?

 

Thanks

 

Frank

This is what you want. Read the last sentence under Condition. Do a google search for T.S.B. #10-06-01-008G.