Oil change issue

FRP

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Oct 3, 2019
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changed oil and new oil was black within an hour or running.
changed oil again and second oil was balck after two hours
What could be the issue with my engine?
MX5100
 

Tornado

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Not an expert on this, but I have always read that oil is almost always black on a diesel engine. It is not like a gas engine where it stays nice and caramel looking.

Oil in my brand new L2501 is also black for what its worth. Haven't hit 50 hour maintenance yet. Ive been told this is normal.

EDIT: Just thought id further clarify why its black. It is actually soot from the combustion process in a diesel engine. Diesel engines produce a lot more soot, and it stays suspended in the oil and is not a problem until it hits a really high concentration. This is entirely normal though as Ive always read. This is true for all diesel engines I believe. Others with far more experience will respond in time here im sure. But in the short term dont panic, this is 100% normal, nothing is wrong!
 
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SidecarFlip

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I'll be making buttered popcorn for this thread.............:D
 

BruceP

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Engine oil in a Diesel engine ALWAYS turns black fairly quickly.

This is why it is important to use oil INTENDED for a diesel engine which is formulated to encapsulate, suspend, and deal with the soot.

Oil COLOR is not a measure of its lubricating ability. Simply change the oil at the designated intervals and be happy.
 

Magicman

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Yup everything is normal, but if you are too concerned I will give you 10 cents on the dollar to take it off of your hands. :rolleyes:
 

SidecarFlip

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Engine oil in a Diesel engine ALWAYS turns black fairly quickly.

This is why it is important to use oil INTENDED for a diesel engine which is formulated to encapsulate, suspend, and deal with the soot.

Oil COLOR is not a measure of its lubricating ability. Simply change the oil at the designated intervals and be happy.
If I'm not mistaken, the newer Tier 4 final, common rail engines blacken the oil more quickly. Kind of reminds me the 60 Series DDEC (Detroit Diesel engines). You can change the oil and filters, run the engine an hour and the oil is black as coal. I believe it has to do with how much blowby and carbon is introduced to the engine oil that causes it to darken quickly and like was state, color has nothing to do with it's lubrication quality.

Now, both my M9's don't do that and one has 4000 meter hours on it (other has 2000. Neither darken the oil very quickly but between changes the oil does get dark.. not black, just dark brown but then both are pre- tier 4 so maybe that is the key ingredient, not sure.

Neither of my cars get black either and when I drove big truck. they had Cats in them and they didn't get black, only the Detroit's.

Got my popcorn all ready....:D
 

freewheel3

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Engine oil in a Diesel engine ALWAYS turns black fairly quickly.

This is why it is important to use oil INTENDED for a diesel engine which is formulated to encapsulate, suspend, and deal with the soot.

Oil COLOR is not a measure of its lubricating ability. Simply change the oil at the designated intervals and be happy.
Not ALWAYS. Usually yes, but I have seen rare exceptions, including my 08 cummins that I deleted the EGR and DPF at 100K. Deleted it, drove it home, dropped the black oil, drove it 100 miles and did another oil change that came out just slightly discolored.
I now have 600,000 on it, do oil changes every 8000 and the oil comes out looking like dark brown honey. This engine has over 16000 hours on it and frequently runs 24/7 through our -30 cold snaps sometimes for a week or longer.
I just had the head gasket replaced and the mechanic said it was one of the cleanest engines inside that he had ever worked on.
I don't know why it is this way, it just is.
 

Bulldog

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Turning black in a hour sounds a little excessive to me.

Did you drain both sides of the pan when you changed it?

Some oil changes color quicker than others. Rotella will turn dark much faster than what I use.
 

North Idaho Wolfman

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changed oil and new oil was black within an hour or running.
changed oil again and second oil was black after two hours
What could be the issue with my engine?
MX5100
I'm with Bulldog on this, did you drain both drain plugs on the oil pan?

Also fairly normal for diesels to turn the oil black in a very short amount of time! ;)
 

GeoHorn

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The Wolf is right on the money.

Also, if your oil doesn’t change color or begin to turn dark fairly soon after changing (like 5 hours or so)... then you are using poor quality oil that has no detergent capability (regardless of what you paid for it or what brand label is on that bottle.)
 

D2Cat

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Geo if what you say about oil color is true, how is it you can put a particular brand of oil in two diesel engines and the darkness of the oil is different in equal time used?
 

GeoHorn

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Geo if what you say about oil color is true, how is it you can put a particular brand of oil in two diesel engines and the darkness of the oil is different in equal time used?
The difference between two different engines is the difference between apples and oranges. A better test of the veracity of my statement is if you use different oils in the SAME engine and see which oils turn darker more quickly. Those are the ones with better cleaning capability. ;)

Ill add another anecdote: In the aviation world, Mobil attempted to transfer the technological advantages of their Mobil-1 automotive oils to aircraft. It resulted in aircraft engine failures and expen$ive lawsuits.
The reason? Aircraft use leaded fuel in spark-ignition engines. Synthetic oil is a poor scavenger of some contaminants such as lead. Lead build up in those engines resulted in mechanical failures. (The solution was found to be Synthetic Blends.)

If you find you are using synthetic oils as a replacement for your previous mineral-based oils, dont be surprised to find different scavenging results. (Synthetic oils often appear cleaner because they cant dissolve contaminants and keep them in suspension for the filter to remove. Those contaminants are often found as sludge in the bottom of sumps and passages in many engines.). My point is to be certain that, if you are comparing oils, its important to make ALL the comparisons.... comparable.)
 
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SidecarFlip

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Turning black in a hour sounds a little excessive to me.

Did you drain both sides of the pan when you changed it?

Some oil changes color quicker than others. Rotella will turn dark much faster than what I use.
I sincerely hope that wasn't directed towards me.....:eek: I do know there are 2 drain plugs under there. Had the m off many, many times and I renew the copper sealing washers every time as well (available at Auto Zone btw).:)
 

SidecarFlip

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George... Airplanes don't mow lawns or plow snow or dig holes...lol

I guess they could though (and have in the past)....:D
 

SidecarFlip

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From George...

"If you find you are using synthetic oils as a replacement for your previous mineral-based oils, dont be surprised to find different scavenging results. (Synthetic oils often appear cleaner because they cant dissolve contaminants and keep them in suspension for the filter to remove. Those contaminants are often found as sludge in the bottom of sumps and passages in many engines.). My point is to be certain that, if you are comparing oils, its important to make ALL the comparisons.... comparable.)"

I have to say Hmmmmmm

Was at my dealer today and my open station M9 is there getting some R&R and the overhead run. Dennis took the valve cover off while I was standing there and at 4000 meter hours and a steady diet of synthetic (Rotella) diesel oil, the overhead is as clean as when it was new. So no I was pleasantly surprised at the absence of sludge or blowby for that matter. Me thinks she will go 10K hours with no issue.

I was really expecting some but there wasn't any. Like I said, my oil never gets dark between changes, dark brown but never black. In fact none of my diesels turn the oil black. All get fed Rotella T5.
 

JeffL

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Most diesel engines turn the oil dark/black immediately after an oil change due to the high residual amount of oil left in the system. Some engines have more residual designed in than others. Want to see clear oil do a second change 5 hours after the first. Will stay clear for awhile. No real advantage to this just happens.
 

Bulldog

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I sincerely hope that wasn't directed towards me.....:eek: I do know there are 2 drain plugs under there. Had the m off many, many times and I renew the copper sealing washers every time as well (available at Auto Zone btw).:)
Why would you think that?

I was just thinking that if the OP didn't drain both sides of the pan that might explain why the oil turned black so fast.