Duramax Oil Consumption

[coyotekid]

My Duramax has never used ANY oil since the day I drove it home. I realize that all engines use some oil, but I'm refering to oil consumption based on visually checking the dipstick.

I'm running Mobil Delvac 1, and after a recent 2500 mile trip to California, I've confirmed that I've lost approximately 1 quart in 4400 miles of driving.

This was the first long trip I've taken, so I'm not quite sure what to think. For several consecutive days, the truck was run for 14 + hours without shutting down, and most of this was cruising at 75-80 mph. In one day alone I went 830 miles without shutting down!

I realize that this isn't considered to be excessive oil consumption, but it is "out of character" for this truck, and that's the part that bothers me.

I've recently added some power enhancements so that I'm now putting approximately 400 HP to the ground. My dad is thoroughly convinced that all this extra power is causing the engine to burn oil, but I'm not convinced that I'm ruining this engine--I am concerned though.

What should I do? Should I change the oil? Should I top it off and leave the same oil in? Should I get an analysis sent out? The truck has 14,500 miles right now, and I haven't sent any samples in for analysis yet.

Thanks for your help!

 

[Pick]

Hmmm, don't know what to think. My Duramax is a 2003 LB7, completely stock, and does not seem to use a drop, at 27K miles. I have run mine for 18 hours straight, pulling a 10K gooseneck horse trailer from Ohio to Florida. It may have used a little, but the dang dipsticks are so hard to read on these things.
I have been running Delvac 15W40 dino since day one. I have switched to Rotella T full syn, 5W40 on this OCI. Strangely, my oil pressure seems to have gone UP 5-10 lbs.

 

[coyotekid]

I'm glad I'm not the only one who thinks that the dipsticks are hard to read!

I remember reading about one guy who drilled holes between the tick marks in his D-Max dipstick to make reading more accurate.

Now that I'm checking the oil more closely, I'm having trouble getting consistent readings. I'm parking the truck on the same exact level concrete pad each time. Now I'm not quite sure I've used a quart, but it seems like I've definitely used SOME.

 

[k1xv]

I have no personal experience regarding the effect of performance enhancing boxes on Duramax oil consumption. I am running totally a stock 2003 Duramax/Allison Crew Cab, no trailering.

I do note that I normally do not need to add anything between my 6000 mile oil changes of Rotella Synthetic 5w-40. However, I believe that long hard runs could cause a loss of a quart in 4000-5000 miles, particularly with performance enhancement. The only time I have ever had to add oil between changes was after a 2500 mile four day interstate trip in summer.

I would keep an eye on it, but not worry about this unless there is a trend where it gets worse.

Do worry if your oil level goes UP, especially if it smells a bit of diesel fuel. This means stuck injector problems, and I believe that performance enhancements are hard on the injectors.

I would install, if you have not already, a diesel pre-filter, such as the one at www.nicktane.com

 

[1sttruck]

Dunno about the Duramax but Cummins specifically states not to use a synthetic for the first 20k miles. I started with a blend at 15k miles and continue to use one. With higher loads/speed I saw some oil loss for the 1st 20k miles or so, but haven't noticed much since then (I have a bit over 30k miles). With the large sumps (12 qts for mine) it's also tricky to read the dipstick, where it'll change by a qt or so depending on how you drive it. On my dipstick there is a 'no fill' zone, and as long as it stays in that range it's ok. After two or three time of seeing it drop a bit but stay in the no fill zone and topping off, and then seeing it overfilled, I've learned to use it as designed.

 

[coyotekid]

I'm well aware of the injector problems that BOSCH is having on both the newest Duramax and Cummins 600 engines. I've got a Racor 2 micron filter installed along with the "new and improved" primary GM filter.

I regularly check my balance rates, and all is OK there.

I've talked with Mr. Dyson as well as many other experienced Duramax techs, and they all stated that switching to synthetic would cause no harm in itself at about 6,000 miles when I did the switch.

The Duramax LLY has a crancase vent that goes into the intercooler tube, and I have found some oil there. This is probably where my "missing" oil has gone.

I think the best thing I could do is collect a sample and then have it sent off for analysis. It may end up that this particular engine just doesn't like Delvac? Is that possible?

P.S. How should I collect the sample without dumping the oil?

 

[Bill Plock]

quote:

---

Originally posted by coyotekid:
...How should I collect the sample without dumping the oil?

---

THIEF for capturing oil Samples without changing oil available from AVLube.com

 

[coyotekid]

Thanks Bill! I saw those a while back on the avlube website, but I didn't know how well they worked. They do a good job, though?

If memory serves me correctly, you drive a D-Max too, right? What do you think about this deal?

As I mentioned, I was having a hard time getting consistent readings on the dipstick, so I drilled holes in it today, and now it looks like maybe I'm making a big deal about nothing. I think I've lost a little, but probably not that much now that I'm getting better readings. Besides, the oil has 4400 miles on it, the engine was working some long hours at high speeds, and it certainly isn't fully broken in yet.

Analysis will tell me more, hopefully.

 

[kenneth neeley]

With my 03 LB7, the engine now has almost 30K on it. It has ran on a program that has made 400 hp on a dyno, for over 17k miles. The engine still has never used a drop of oil, Delo 400 dino. I ran Delvac 1 for about 8K miles, samples taken every 100 hrs. Copper readings along with other metals increased about 4 times normal. Changed back to Delo and ppm's went back. The power enhancement should not becausing the oil comsumption unless you are just running it to death. Do you use a pyrometer? How high are the egt's going. Also check the Blow by pipe and under the engine look for signs of oil vapor. My engine never broke or seated in until I put the programmer on. Pull a oil sample and check metal content and for fuel.

 

[Bill Plock]

coyotekid,

I haven't used the Thief but I remember Arlen Spicer posting that he used one with good results.

Regarding Duramax oil usage, I find my 03 is sometimes down a little after 4-5k miles - maybe a half a quart or less. I also find it's hard to get an accurate reading - adding the holes as some other Dmax owners have seems like a good idea. From what you have described your truck sounds normal ... Just enjoy all the Dmax power!

 

[JTH]

I have a 01 duramax with 97,000 miles on it and since switching to Royal Purple 15/40 it will use a little oil but not much.These motors are odd in the way the oil level seems to give false readings I always let it sit for about 5 minute when oil is hot and longer when cold. My last change was about 16,000 miles on the oil and the sample still showed lots of life left in it.

 

[TonyMazz]

I have an 04 LB7 and thought it was strange to see this motor with only 18K on her down 1/2-quart after 4-5k on Mobil 1 SUV Syn 5W-40 oil.

Guess I compare to my 99 Blzr running "dino" Castrol GTX 5W-30 and it never uses a drop after 161K on 4K OCI's.

The Duramax runs perfect, just have to keep tabs on oil....

Do you think that I should bring to the dealer and raise the issue or not worry about it ? Seems that it shouldn't burn a drop to me....

 

[reyjay1]

You must not be used to diesels, at 18k your engine is not likely to be even fully broken in yet, and 1/2 a qt down in 4-5k is nothing. If you take it in they wouldn't bother looking at it if it was over a qt every 1000 mi., this was what was standard for the 6.5L Diesel before the Duramax. If you break it in right you may get that down to 0 usage or you may not, if you are using M1 and not Delvac 1 that may make the difference right there. You can probably switch to a syn. in the diesel after 10k mi. but you will probably just be prolonging the breakin period. I didn't run the firt round of synth in the 7.3L until 20k.

 

[Ken2]

The high speed high power run will increase oil consumption slightly. If you have just changed to this oil from something else, it is not uncommon to have extra consumption until the remnants of the old oil are gone.

A good guy in Montana to talk to about oil is **** Williams, 406-459-5957.


Ken

 

[Cougar281]

Yours sounds like about what mine is using (2004 LLY). I just put in about 1.5 Qts at just shy of 6000.

 

[blakegeo]

I have a 2002 LB7 with 31000 miles and it uses 1 qt in 4000 miles--Delvac-1--mostly hwy 60-65 mph