Oil turning black as soon as you start the engine

[Grizzly]

When you change oil on a 3rd gen 5. 9, why does it turn black as soon as you start the engine? I know the question has been discussed several times in the past, but I can't remember because I'm old. A friend and neighbor, who has an 06 3500 DRW with a 5. 9 Cummins asked me the question and I couldn't remember the answer.



george

 

[Motorhead]

The internal EGR with the late last injection event causes this. Normal

 

[fox]

All diesels are like this.
They just have a dirty crankcase from the blowby and unburnt fuel.

 

[Motorhead]

All diesels are like this.
They just have a dirty crankcase from the blowby and unburnt fuel.

Well I partly agree with you but since the EGR in the later trucks, 2004. 5 up, the oil turns black almost right away. I owned a 2001. 5, 235 hp truck and even with 4-5,000 miles on it you could still see through the oil. It wasn't all sooty.

 

[rscurtis]

All diesels are like this.
They just have a dirty crankcase from the blowby and unburnt fuel.

The oil in my signature truck never turns black, it is still clear and coffee colored after 18K miles. The old Mercedes, that's another story.

 

[B.G. Smith]

The oil in my signature truck never turns black, it is still clear and coffee colored after 18K miles. The old Mercedes, that's another story.

I just changed the oil in mine a few minutes ago. It doesn't get black until I start the engine. What is your secret to keeping the oil looking like oil? I did notice something different though. I put three sealed gallons of Rotella in and ran it till the gage showed warm, killed the engine and let it set probably ten minutes and i am about 1/4" to 3/8" below the top of the crosshatch on the dip stick. bg

 

[seafish]

I just changed the oil in mine a few minutes ago. It doesn't get black until I start the engine. What is your secret to keeping the oil looking like oil? I did notice something different though. I put three sealed gallons of Rotella in and ran it till the gage showed warm, killed the engine and let it set probably ten minutes and i am about 1/4" to 3/8" below the top of the crosshatch on the dip stick. bg

Pretty sure that his "secret" is that his truck is a 2003, without the internal EGR or even a third injection event.

 

[Grizzly]

Well I partly agree with you but since the EGR in the later trucks, 2004. 5 up, the oil turns black almost right away. I owned a 2001. 5, 235 hp truck and even with 4-5,000 miles on it you could still see through the oil. It wasn't all sooty.

I tend to agree with fox and Motorhead.



Another question. My dip stick will be the full mark before I drain the oil and I won't get 12 quarts out. That means some of the oil is staying in the crankcase. And I let it drain for a very long time while I go do something else. How much oil stays in the crankcase or the engine?



george

 

[BLNRAY]

a lot of things contribute to oil black,first it is a diesel issue and has been long before egr came around. kind of oil,filters,maintenience frequency and driving habits all contribute to black oil.

 

[jelag]

Motorhead... I'm lost here... I own or owned a 04. 5 & 05 and don't have an EGR valve on either engine. . and I'm not sure Grizzly has one on his 06, when I installed his exhaust brake I don't remember seeing it or the related plumbing... didn't it arrive later...

 

[cerberusiam]

I owned a 2001. 5, 235 hp truck and even with 4-5,000 miles on it you could still see through the oil. It wasn't all sooty.

Push that engne up to 320 HP and its a different result. Major differences in injection and combustion cycles between a jerk pump and a CR also contribute.

Motorhead... I'm lost here... I own or owned a 04. 5 & 05 and don't have an EGR valve on either engine. . and I'm not sure Grizzly has one on his 06, when I installed his exhaust brake I don't remember seeing it or the related plumbing... didn't it arrive later...

Every CR built has a form of in-cylinder EGR. The 600 series engines took to a new level with injection events, event timing, and cam grind. That was the only way they could meet emissions.

 

[Shadrach]

The 03-04 stay cleaner longer because of the internal differences, as stated earlier, like piston bowl shape for example. This one of the thing referred to as " internal EGR". If you have ever had the valve cover off you will see lots of puddles of oil in the rocker box. You never really get all the dirty oil out regardless of year. When I do an oil change I pour in a half to a full litre ( quart ) of clean oil while the drain plug is still out. This helps flush out a bit more of the dirty oil. I don't use syn oil so the cost isn't much and I think the benefit out ways the cost. Shad

 

[JJPage]

The oil in my signature truck never turns black, it is still clear and coffee colored after 18K miles. The old Mercedes, that's another story.

Pretty sure that his "secret" is that his truck is a 2003, without the internal EGR or even a third injection event.

My 03 oil stays translucent until around 5k miles, after that it gets pretty black.

 

[Grizzly]

How much oil stays in the crankcase when the oil is drained, in addition to what Shadrach said on post #12?

 

[AH64ID]

About a quart will stay in the oil cooler, passages, and head when you drain the oil.

The in-cylinder EGR is comprised of 5 main parts. Timing, 3rd injection event, cam grind, pistons, and the turbo. They all add to the oil blackness, but I believe that the piston design is the leading cause of the black oil.

I have replaced my cam, turbo, and run tuning that does not have a 3rd injection event and does not run the extremely late timing that stock does and my oil is still BLACK.

This last winter I did an experiment on my motor. I always wondered how much of the black was from the previous oil, so I changed the oil 3 times over a period of 150 miles. I also did engine flushes on the first two changes, and while doing the second change I pulled the valve cover and used a syringe to pull all the old oil out of the freeze plugs, etc. I also poured about a gallon of clean oil into the motor and breifly started it to push the clean oil into the cooler and passages, and the last of the dirty oil out. So when I added my normal Amsoil I was amazed to see perfectly clean oil after running the motor for a few minutes. (as you can see in the photo below).

I checked the oil a few times before 500 miles and it was still pretty clean, but was BLACK by 1500 miles. It now has 4K miles on it and looks like normal BLACK oil. While the oil does leave a small stain on the motor, I am fairly certain my oil didn't turn black again due to the detergent factor and from the motor design.

So, based on my modifications to the motor I can safely claim that it's the piston and nozzle design that puts soot in the oil.

#ad

 

[cerberusiam]

In addition to everything AH64ID pointed, the engine operation programs are all slanted to running stoich rich. Emissions dictates complete combustion is bad so there is always excess particulates left to be transferred to the oil. Run a 12V the same way and it will turn black almost as fast.

 

[Grizzly]

In addition to everything AH64ID pointed, the engine operation programs are all slanted to running stoich rich. Emissions dictates complete combustion is bad so there is always excess particulates left to be transferred to the oil. Run a 12V the same way and it will turn black almost as fast.

The oil in my previous 95 Dodge/Cummins, with a 12 valve engine didn't turn black right away.

 

[Grizzly]

About a quart will stay in the oil cooler, passages, and head when you drain the oil.



The in-cylinder EGR is comprised of 5 main parts. Timing, 3rd injection event, cam grind, pistons, and the turbo. They all add to the oil blackness, but I believe that the piston design is the leading cause of the black oil.



I have replaced my cam, turbo, and run tuning that does not have a 3rd injection event and does not run the extremely late timing that stock does and my oil is still BLACK.



This last winter I did an experiment on my motor. I always wondered how much of the black was from the previous oil, so I changed the oil 3 times over a period of 150 miles. I also did engine flushes on the first two changes, and while doing the second change I pulled the valve cover and used a syringe to pull all the old oil out of the freeze plugs, etc. I also poured about a gallon of clean oil into the motor and breifly started it to push the clean oil into the cooler and passages, and the last of the dirty oil out. So when I added my normal Amsoil I was amazed to see perfectly clean oil after running the motor for a few minutes. (as you can see in the photo below).



I checked the oil a few times before 500 miles and it was still pretty clean, but was BLACK by 1500 miles. It now has 4K miles on it and looks like normal BLACK oil. While the oil does leave a small stain on the motor, I am fairly certain my oil didn't turn black again due to the detergent factor and from the motor design.



So, based on my modifications to the motor I can safely claim that it's the piston and nozzle design that puts soot in the oil.



#ad

Thanks AH64ID. That's the best explanation I've heard on the subject.

 

[AH64ID]

The oil in my previous 95 Dodge/Cummins, with a 12 valve engine didn't turn black right away.

I think he meant if you tune it like a CR it will turn black, but they way they were tuned didn't put the soot in the oil the same.

I did forget to mention that I run a 15um full flow and a 2um bypass, and it has no appreciable effect on the color of the oil. There are 2 reasons for that. Modern oil is designed for modern engines that put soot into the oil, so the oil has additives to keep the soot dispersed to reduce wear and increase oil life. That's good and all, but it also makes point #2. The soot is too fine to filter out, and on older oil the soot would agglomerate and get caught in the filter and the oil appeared cleaner. Now we just have to live with it, so thank you emissions.

 

[Bill Stockard]

The 03-04 stay cleaner longer because of the internal differences, as stated earlier, like piston bowl shape for example. This one of the thing referred to as " internal EGR". Shad

The internal EGR is done by a patented engine design exclusive with Cummins called "deep spray technology" which began with the 2004 EPA regulations requiring less NOX in the exhaust stream. Other on-highway diesel engine manufacturers, except Caterpillar, had to resort to EGR systems while Cummins by using "deep spray technology" in their mid-range engines, including the Dodge Ram product, did not. CAT used ACERT instead of EGR on their on-highway engines and we know how that turned out.



The history of "deep spray technology" and how it came about is detailed in the book, "Red, Black, and Global, The Transformation of Cummins 1995-2010"



Bill