Black oil

[frankiee]

People talk about black oil.
They think that because the oil is black that it is no good anymore.
Is there any truth to that.
I heard that oil turns black after 2 hours due to a chemical reaction regardless of dirt.
I am talking about internal combustion engines of course.
And if dirt and black oil have anything in common, please let me know.
Thanks

 

[unclesyd]

Every diesel engine that I've dealt with would turn the oil black shortly after an oil and filter change. We never worried about the color, just went by the hours for a changing.
It's been my experience over the years that the GM 53 and 71 series were the worst offenders. They would turn the oil black before you could get filler cap on. It normally took the 4 cycle engines a little longer unless they were worn completely out.

 

[rmw]

The 92's weren't any better, either.

rmw