What oil are you using, Rotella, Delvac, 5W40, etc.... The Farm has a 2003 that uses a quart of Schaeffer 9000 5W40 every 4000 miles and has done so since it was new. It has 100K+ miles on it and runs great. GM says that one quart of oil usage for every 100 gallons of fuel is acceptable.... I got a 496 gas engine that uses a quart about every 5000 miles, can't complain.

http://www.bobistheoilguy.com/cms/

I think its a GM thing. LOL Sorry I could not resist.

docgj

I have a 2001.5 Dodge 2500 with 290,000 miles on it. I bought the truck new and I have changed the oil every 3500-5000 miles. The truck has never used any oil, I don't ever recall the oil level even going down on the dip stick. My only comment would be Made in the USA, wish I could say the same about the new Ford motor.

I pulled new RV trailers for awhile and I can tell you the drivers with the Fords and GMs carried extra fliuds of every description with them. I am a dyed-in-the-wool Ford man but I only recently purchased a used 2007 Ford F450 because I was not satisfied with the service or lack of service I received from the local Dodge dealer and I did not want a Made in Mexico engine.

The Ford 6.0L used 15qt. I changed the oils a lot on mine and remember. And I never noticed either of my engines consuming oil between changes.

The New 6.7L uses 11 or 12 qts. I've let the dealer do the first two oil changes and don't  remember what the manual said for volume.

Not only does the new engine use less oil per oil change, But they have built in a sensor that tells you when to change your oil based on how you worked the truck. Ford is pushing it as a "Greener" solution by not needing as much oil as previous motors and to not be wasting oil on 3000 or 5000 mile oil changes but rather when the oil needs to be changed. Now I'm not an engineer and can't even start to explain how they determine that its time to change the oil. But on my truck that sensor turned on the light at 7500 miles of use. So I'm going to try it on this truck and see how it last. I haven't seen a way that you reset or tell the truck you changed the oil, So it's not a clock or odometer tracking the time the oil in the engine. It is sensing something in the oil itself.

On the Ford  6.4L engines (2008-2010) they had a problem with the engines "making oil"  When the engines would inject diesel fuel on the exhaust stroke of the piston to increase the exhaust temps during regen, some of that fuel was getting past the rings and into the oil and increasing the oil level by dilluting the oil with fuel.

WHY are you using a blend???  Either use the full syn. or regular oil.

Your duramax should NOT be using oil at 70-k miles at all!

I was ol' school about oil until I did some research on Amsoil so I jumped into with both feet (now I can buy it wholesale here local) and changed my Dodge (6.7 Cummins with NO EPA stuff) to Amsoil full syn. and the Amsoil filter, what a difference it makes.  Better fuel mileage for sure!

Mine will burn most of quart in 10,000 miles, normal if the truck is being worked.

I understand about using what is recommended, just wanted to know why the blend syn. instead of full syn.?  Like I mentioned earlier I was old school about oil and always used Rotella until I researched the syn. oils, I only took me a year to make up my mind about changing to the syn., but I will always run it now.  Your next post about winter being the problem, I would say no I would think summer would cause more troubles with oil loss than winter. 

Are you 100% sure you do not have any leaks and it is getting full when you chnage it?  Just asking cause on my Dodge if I do not let the drain into the engine about 15min. before checking it, it will show full before it actually gets full.

Maybe I overlooked it, but does the truck have any check engine lights on? I would check around the valve covers, headgaskets, sensors that go into the block, turbo, oil filter, oil pan, and where the engine and transmission meet for any oil residue, but it really sounds to me like you've got an internal leak. Do you know the condition of the turbo? If it's in need of repair, that could be a good oil burner.

When I change the oil on our Fords, I'll do the same. Fill to "full," run it for about 15 min and check again. Fill as needed. Never "used" any of the 15 quarts of oil though. :) The only truck I had that used oil was an old dodge with a 318. It had almost 170,000 miles and bad valve seats -- it smoked like a freight train.  Still ran good though.

I am a diesel mechanic by trade, and have overhauled many many diesel engines.   I drag race  and have built 8-10 high performance drag engines.  So I have some basic knowledge of how engines work.

   The good news is,  Your Duramax probably will not hurt itself with the oil consumption you see.

   The bad news is,  This is NOT normal for a diesel engine with so few miles,  Your GM dealer and area rep WILL NOT DO ANYTHING TO HELP YOU.   The reason that they say that this oil use is "Normal" is so they don't have to overhaul your engine under warranty.    Sorry to have to say so, but this is a pattern for GM, Both with the larger gas engines, 6.0 and 8100's are notorious for oil use.   And the Duramax diesel.   As a mechanic this seems to be a parts and machining problem.    The problem is that when your truck is out of warranty and then starts burning LOTS of oil GM will  deny that there was ever a problem and you are stuck with a $10,000 bill for a new engine.  Even if they know of early issues you will be denied coverage.  I would consider trading up to one of the newer trucks and pass on the issues to someone else.  IMHO

Here is something you can check your self, then we will know more about your engine.  First with the truck running remove the oil cap and pull the dip stick out a few inches or so.  What you need to look for is any smoke coming from either location.  If there is then turn the truck off and open up the air box and look into the intake tube going to the turbo and see if there is any oil in it.

Let me know what you find and we will go from there...

Diesel motors use a little oil on a cold start up. With aluminum pistons and a steel block, there are differences in the expansion and contraction of the two metals when it is heated. With a cold motor you can hear some piston slap until they warm up and better fit the bores.

Many diesels also use pressurised oil sprayed onto the bottom of the pistions to cool them when under high loads. If the rings are worn, some oil will be by passed and burn off.

An engine start inflicts the most amount of wear on the life of a motor, other than an over heat condition. With the advent of better lower viscosity oils, this has been well addressed. Synthetic oils in particular, will protect the newer motors with their tighter tolerances, protect the metals under high heat conditions, and have a much higher shear strength than a petroleum based product.

Oils have three basic functions in an engine; lubrication, cleaning and very importantly, cooling. By having a high volume crankcase, the large oil bath dissipates a large amount of heat from the engine's wearing surfaces. Even with a remote cooler, the large oil bath is the first line in preventing an overheating condition.

Even though all the motors are built on the same assembly line and meet specifications, there will be differences in some. The HP and torque ratings can vary. The fuel and oil consumptions can differ. Some will run very well, and in some batches, there may be a lemon. I've had motors that use no oil between oil changes, and I've had one that uses a quart every 3K.

Oil consumption is perhaps the least expensive part of a vehicle ownership. If it is not maintained, it can very well result in the most expensive repairs.