(overly?) dark oil

rickinAZ

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So....I changed my oil 1,600 miles ago and, when I recently checked the dipstick, I noticed that the oil is so dark brown that it's going on black. I make mostly short trips. The oil life "gauge" reads 73%. Is that number scientifically generated, or is it just a simple algorithm driven by mileage? Is everyone seeing darker oil, or just me?
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NBB

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Pitch black oil is a part of diesel ownership. Diesel's higher compression creates more blow-by through the piston rings - of dirtier combustion byproducts. Black soot in the oil is normal and generally considered harmless. Surprised after 1600 miles you see any brown - still new.
 

Compression-Ignition

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I just peeked at mine the other day and it is about halfway in between the golden clean oil color and brown oil. I changed the oil at around 3000 miles, and it currently has maybe 5200 on it. Tons of idling. I was actually expecting it to be black. Seems all of these newer diesels soot the heck out of the oil. And usually the oil will be black within 1000 miles. Perhaps the soot just isn't built up quite enough to dilute the color as quickly?

Also of note, just because the oil is dark, or even black, means next to nothing. An oil analysis would tell us how far we could potentially safely go between OCI's, but realistically, I'm sure 99% of us would be just fine trusting the oil life monitor.
 

Whiskey 13

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All diesel engines I have owned the oil's color within a few hundred miles after change is like coke. As long as there is no milk like colors or metal flake all is well.
 
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rickinAZ

rickinAZ

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Thanks for the quick replies. I'm an every 3,000 mile changer, so, based on the input, I should be fine.
 

Jeff

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Mines black at 4200 miles since changing and getting it analyised at 5000 miles. (9200 miles total) It's all good. Switching to AMSOIL at 10k.
 

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Mines black at 4200 miles since changing and getting it analyised at 5000 miles. (9200 miles total) It's all good. Switching to AMSOIL at 10k.

Who did your UOA?
 

calemasters

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So....I changed my oil 1,600 miles ago and, when I recently checked the dipstick, I noticed that the oil is so dark brown that it's going on black. I make mostly short trips. The oil life "gauge" reads 73%. Is that number scientifically generated, or is it just a simple algorithm driven by mileage? Is everyone seeing darker oil, or just me?
You can not judge the condition of the engine oil by color. The oil life index is driven by an algorithm based on engine speed, engine load, ambient temperature, engine run time, oil temperature, miles, etc. There is no engine oil chemical analyzer.
 

toolaide4fit

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I saw somewhere in the forums where someone sent their oil in for analysis when they changed it at 10,000. Their oil was still within specs. Todays synthetic oils are NOT like the oil when I was a kid. Changing it early doesn't buy you anything except spending money on more oil and oil filters.

IMHO I follow the oil life based on what the jeep is telling me. I will NOT go longer than 10,000 between oil changes.

I don't think badly about anyone that does it sooner than recommend. I personally think it a waste of money. I did this with my Duramax Diesel and went over 200K with zero problems. Do what makes you feel good.
 
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