oil is black immediately after oil change

[rv4jesus]

I have a 2010 Prostar with a Cummins ISX motor and the oil is black immediately after the last two oil changes. At first I thought the shop didn't change the oil correctly but a different place changed it last time and it looks black as soon as you can pull the dipstick after letting the motor run for a minute. As far as I know twelve gallons were added and all oil filters were changed. I change my oil between 12,000 and 15,000 miles. What is causing this? Any help is appreciated.

[preacherboy24]

I would like to know the same. I have had the government mandate taken out of my engine and still get black oil on the stick after the new oil is in. I do know that if the oil is changed cold that at least a half gallon stays in the engine after you pull the plug....that is fact. I change my oil at speedco right off the highway. Still black.

[stevesparts]

Just a few question. do you have a oil by pass system on your motor to help clean up the soot? and you need to get it "tuned" up by someone who knows what their doing.(like some on here :)) then you might see what your looking for. but there is no guarantee that will give you what you are looking for. it is a diesel after all. :)

[Running rough]

@m*m^2 will definitely cut down soot loading, however it seems to me the cm2250 the oil stays clean a lot longer then a cm870, not sure how a @m*m^2 871 would compare

[dbl overdrive]

Your oil should not be black after removal of mandate. It will turn brown like Jack Daniels after about 15,000 miles.

[Marajin]

first of all,.. a bypass oil filter WILL NOT keep your oil from changing to black in color.


SOOT is the number one cause of black oil in a diesel engine.


ALL older engines that have fixed-vane turbochargers on them produce enough soot to keep the oil black. This is normal.

ALL newer engines with Variable Geometry Turbo's are perfectly capable of being adjusted so that the engine does not produce soot any more (as long as the engine is in good shape) but there is a problem. That problem is that these same engines are required to have emissions control, EGR, etc. on them, and it is the EGR system and Emissions tuning that makes excess soot and keeps the oil black.


If you want clean oil, like in many of the trucks I have seen,.. The only way to achieve it is to have it custom tuned by someone who is very very good at it!.

The engine oil does not lie!. It is extremely difficult to get a diesel engine to have perfectly clean oil after 15,000 miles or so, but it is very do-able. It does not take special filters, bypass filters, or anything else to try to remove it. It takes an engine with a Variable Geometry Turbo, and some really good custom tuning to both the the engine AND the turbo. Removing the EGR or so-called "Mandate" itself is NOT ENOUGH to achieve this, though it is one of the steps typically necessary.


If you want clean oil (roughly same color as the bottle) after 15,000 miles in a class-8 diesel engine, here is what it typically takes...

* the engine running very well already with no significant intake or exhaust manifold leaks. This means the fuel mileage will usually be very high too.

* The "Mandate" likely removed.

* A Variable Geometry Turbo that has been very well mapped.

* Really good custom tuning in the ECM. -- So far, there are only 3 people known to be capable of tuning an ECM on this level (soon to be 4). They are all participants on this forum as well.

* Having the power level in the engine set to something reasonable, like 575 horsepower or less.

* The driver not idling the truck for extended periods of time.

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Preacherboy, in your case, if you are not idling your truck and it is still turning black,.. Then you still have something wrong with either your engine, or its programming. I have seen a lot of CM870 engines with clean oil.

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The benefits of having perfectly clean oil in the engine all the time are huge. It is well known by now that a CM870/CM871 will yield about 40% less wear in most of its components when set this way.

[Rawze]

My engine has perfectly clean oil in it, and has for more than 800,000 miles. It now has a total of 955,000 miles and I am making Video of it being in-framed for youtube. It will be a long series with lots of talk in it as well as taking things apart.

It is unbelievable how clean the inside of this engine is, and this the first time it has been opened up. Other mechanics form different shops that have visited us are in complete astonishment, and in total disbelief that an engine with roughly a million miles on it can not only be so clean, but have about the same wear as an engine with only about 470,000 miles on it.

BTW:
since we are on the subject of oil yet again ...

http://rawze.com/forums/showthread.php?t...64#pid2064

[preacherboy24]

(04-09-2016 )Marajin Wrote:  ...
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Preacherboy, in your case, if you are not idling your truck and it is still turning black,.. Then you still have something wrong with either your engine, or its programming. I have seen a lot of CM870 engines with clean oil.

==============

The benefits of having perfectly clean oil in the engine all the time are huge. It is well known by now that a CM870/CM871 will yield about 40% less wear in most of its components when set this way.

The bottom of the engine is fine so I will be doing the top end this year. Hopefully we will find an issue with the head. I did the bubble test and found two bad injectors. I am going to see if that works and then look at programing. A reputable guy (who works with Unilevers and is on this board) did the tune so I dont think that is it.

[rv4jesus]

Thanks for all the input but maybe I didn't clearly state my problem.

I understand the things that I could do to keep my oil clean between oil changes and I'm sure I should do an EGR tuneup as Rawze suggests. My problem is the oil is black on the stick as soon as it has been changed. What makes this happen? How would an EGR tuneup effect the color of the oil immediately after an oil change? As far as I know it is a Cummins 871 with the stock oil filters.