Diesel Engine Oil Color

[Twins]

Does the color of my engine oil have any bearing on its ability to lubricate?

Thank You,

Twins

[The Newell]

None whatsoever. Detergent oil will turn a dark blue-black after it is heated. Non-detergent oil will turn a reddish-brown. Most diesel engines will turn oil black in the first few minutes of running time. The only accurate way to determine an oil's lubricating value or contamination level is through oil analysis or a portable oil quality analysis. Keeping a good schedule of maintenance goes a long way in keeping your oil uncontaminated.

[77newell]

If the oil has been used awhile, the last color you want to see is colorless since that would indicate failure of the detergent in the oil to suspend contaminants which would all that stuff is left in the engine. I've only seen this once when someone didn't change oil until way past time, I doubt that is anything any of us here would ever let happen - so, no oil color is largely irrelevant.

Jon
77 coach