Oil consumption tests done

[sumo]

Just got her back from the Dealer. They replaced the valve cover. Not sure if they did one or both. What ever was involved with the recall. They did a engine decarbon. Dropped the oil pan and installed a shield/deflector for the AFM sensor. They also replaced the leaking fr axle seal. I asked for an alignment which i paid for. Good thing because they found the fr hub assembly to have play and they also replaced that under warranty. Finished the service with a fresh oil change. Total charges for today $89 bucks for cost of alignment. On the way home engine felt smoother and a bit stronger. That decarbonizing stuff they use is some good stuff.

 

[NautiKev]

any update if this has made your truck use less oil?

 

[willcla]

Is this common on the 09's as well or only on the 07's ?

 

[sumo]

any update if this has made your truck use less oil?

Wont know for a bit. ill report back when i get to around 50%. Thats when i started to notice when oil was getting low on the stick,

---------- Post added at 08:44 PM ---------- Previous post was at 08:43 PM ----------

Is this common on the 09's as well or only on the 07's ?

Seems to be all NNBS trucks. Maybe not all, but a lot

 

[LILC509]

Wont know for a bit. ill report back when i get to around 50%. Thats when i started to notice when oil was getting low on the stick,

---------- Post added at 08:44 PM ---------- Previous post was at 08:43 PM ----------



Seems to be all NNBS trucks. Maybe not all, but a lot

I went through this for a year and paid off last September. I got a new engine which includes everything in the block and heads. All engine accessories are the original ones. But for free and no more oil consumption I got a new engine at 85K mi.

I was burning 1 quart or oil every 200-300 mi. without any smoke throught the exhaust.

 

[willcla]

So to get this problem solved did ya'll have to get your oil changed at the dealer and have them note that the engine was consuming oil or has this become a well known problem and I can simply go to the dealer and get them to work on it.

 

[sumo]

So to get this problem solved did ya'll have to get your oil changed at the dealer and have them note that the engine was consuming oil or has this become a well known problem and I can simply go to the dealer and get them to work on it.

Yes You have to complain of a oil loss/consumption. Gm will require 3 visits to your dealer usually 1000 miles each interval to log oil consumption. After your 3rd visit they will have the ok to do what is needed depending on what they find.

 

[willcla]

Yes You have to complain of a oil loss/consumption. Gm will require 3 visits to your dealer usually 1000 miles each interval to log oil consumption. After your 3rd visit they will have the ok to do what is needed depending on what they find.

So will this be covered under the powertrain warranty?

 

[sumo]

100k or 5 year

 

[LILC509]

So to get this problem solved did ya'll have to get your oil changed at the dealer and have them note that the engine was consuming oil or has this become a well known problem and I can simply go to the dealer and get them to work on it.

They will do all the documentation but you are the one that needs to push for the next step, next step and the next step or at least that's how my GM dealer is. They are not resistant but slow on doing things. Like I said it took me like a year for all their documentation, splash guard, cleaning of the engine but nothing worked and no leak or exhaust smoke. Be patient and it will pay off. If your truck is getting close to the warranty period or mileage then it should be done ASAP. Just an FYI the warranty is 5 years from in-service date not from date of your purchase if you bought it new or used and obviously 100K mi which ever comes first.

Good luck!

 

[sumo]

also if you start your log or concern before the warranty is up but go over the warranty time, it should be fine. The concern is logged during the time time warranty was active. THats how my dealer is and i hope that standard for all dealers

 

[91RS]

I'm surprised they didn't replace the pistons or piston rings.

Just to note for those who asked, this problems affects the AFM engines. The valve cover can be a problem on the non-AFM engines, but it isn't nearly as common as the issues with the AFM engines. I believe the problems could be prevented by not folling the oil life monitor, but I'm not going to get into an argument about that. Just stating my opinion from what I've seen.

 

[sumo]

I'm surprised they didn't replace the pistons or piston rings.

Just to note for those who asked, this problems affects the AFM engines. The valve cover can be a problem on the non-AFM engines, but it isn't nearly as common as the issues with the AFM engines. I believe the problems could be prevented by not folling the oil life monitor, but I'm not going to get into an argument about that. Just stating my opinion from what I've seen.

yea i found that roughly the mileage of following the oil life is like 7k in miles. I was always taught by my dad 3k for oil changes but no more than 5k.

 

[domin8]

I was following the oil life monitor. Having worked with a Mechanical Engineer who was at one point a GM supplier (but stopped because he got sick of GM being cheap) and working with Valvoline at my last job, it is okay to go by the oil life monitor. Quality oils are made to last longer than OLM tells us to change the oil. GM knows this too.

Imo, the problem is the AFM. Even though the fuel injectors and spark plugs are being shut off, there is nothing combating the heat from compressed air. Because fuel not only provides combustion, but helps cool things down too (hence the stoichiometric value of Air:Fuel @ 14.7:1) things in the cylinder are not allowed to cool like they normally would. Things are just heating up more and more, thus allowing the oil molecules to bake on to the cylinder wall and corrode the piston rings. Yes, synthetic oil MAY help because of the uniform size and shape of the molecules, but also due to its higher boiling temp. This question is to what capacity, if any, would running synthetic oil help? Everybody who knows anything understand how important a correct AFR is. The thing with the AFR of AFM is that the numbers are way off with the AFR of N:0, N equaling however much air that is allowed into the cylinder. Imo, a real fix to the problem would either be removing AFM, or doing something mechanically with the cams to prevent the intake valves from opening when AFM is activated.

In case people haven't been paying attention, oil consumption is also an issue for Honda with their V6 in the Pilot that'll shut off 2 or 3 cylinders.

Additionally, GMs oil level indicator only works when you first key the engine on, and not while your engine had been running for awhile. If you drive long distances like I do on occasion you may end up with a situation where you drive several hours with low oil and no warning, thus damaging your engine. Not even my oil pressure gauge gave any indication of a problem. I had even installed a radiator with an oil cooler and used a deeper oil filter. None of it mattered even though my increased oil capacity was approximately 1 quart.

I hope GM is smart enough to not use AFM on the new DI engines coming out with the next generation truck.

 

[NautiKev]

I started using 15-40 weight oil and I've seen my oil consumption drop to almost zero. It's been 3500 miles, city hwy and towing and I'm not even down a 1/2 quart. I think I'll just keep using this oil and forget about it. I know many people that have run this weight oil since new in a bunch of their delivery vehicles and have over 300K with no problems.

 

[TinyTot2]

I got the "add engine oil" message today. Just under 3000 miles since last change and oil life at 48%.

Should I get the tests done? Not like the Tahoe is under warranty anymore, though (2007 model, 88k miles).


Edit to add that I did check, and yes, it was actually low.

 

[91RS]

If you have a good relationship with your dealer, you should talk to the service manager and they may be able/willing to take care of the repair for you or charge a deductable.

 

[TinyTot2]

I started using 15-40 weight oil and I've seen my oil consumption drop to almost zero. It's been 3500 miles, city hwy and towing and I'm not even down a 1/2 quart. I think I'll just keep using this oil and forget about it. I know many people that have run this weight oil since new in a bunch of their delivery vehicles and have over 300K with no problems.

Has anybody else here tried this with success? And are you using full synthetic? It sounds a bit much for this vehicle...

 

[NautiKev]

Has anybody else here tried this with success? And are you using full synthetic? It sounds a bit much for this vehicle...

I tried fully systhetic 10-30 with no luck. the 15-40 I use is not systhetic, just valvoline brand.

 

[Zed 71]

Just curious. Is everybody that is having this problem regularly using dyno or synthetic?