How often have you been doing an oil change on your vehicle and noticed that the oil was black or even brown looking in color when changing it? And yet when you put the new oil in the engine it is more like a light golden color. That is something that is probably asked by many do it yourself mechanics and others in the trade. We had one company that posed a question recently on this vary topic. 

"During our routine equipment inspections, we have noticed that our lube oil appears darker. Is this cause for concern? If so, what should our next steps be?"

A lubricant color change can be cause for concern, as it often indicates the oil's composition or chemistry has been modified. You must first consider the lubricant's original color.New lubricants typically have a color that is related to their viscosity and formula. In general, lower viscosity lubricants like common motor oils and hydraulic fluids have a lighter color than higher viscosity lubricants such as gear lubricants.

In addition, certain additives and dyes can affect the original base stock color. The color of new oil may also change if the formula has been modified or if any of the raw materials have been replaced. This type of color change usually does not affect the lubricant's performance or specification, but be sure to confirm this with the lubricant manufacturer.

Keep in mind that an oil naturally becomes darker as it oxidizes. Lubricants oxidize during service due to the combination of the operating temperature and exposure to oxygen in the air. The higher the temperature, the faster the oxidation process and the shorter the lubricant's life. Darkening is a signal of lubricant oxidation. If your oil has become darker faster than expected, check for abnormally high operating temperatures. Excessive temperatures can have a variety of root causes, so it is important to investigate the origin.   

Contamination is another common reason why a lubricant changes color. An oil can become darker if there is lubricant cross-contamination or the presence of solid particles from the environment. When an abnormal color change takes place, the presence of contaminants should be explored. If this is the case, the most probable solution would be to change the oil. Depending on the severity, an oil flush may also be required or suggested. There is many products on the market designed for this process, make sure to use the selected product based on directions.

If the same lubricant is used in several machines or engines and all of them show a progressive change in oil color, this likely would be an indication of natural lubricant aging. On the other hand, if only a few machines have lubricant discoloration, it would be necessary to identify the origin of the color change.

Finally, whenever an abnormal condition is suspected, it is always best to perform oil analysis to determine the lubricant's health as well as to check for the presence of contaminants. An oil change-out or additional filtration may be needed if contamination has occurred.

We are happy to assist you with sampling any engine or equipment that you may have concerns on quality of the oil. We can have this lubrication sample sent to lab for a detailed analysis. Once the results are received we would review them with you and point out any areas of concern or things of interest. 

We offer this service as additional service to our customers, we don’t mark up the price on this service like some service garages or oil suppliers we merely charge the actual costs of the test. Sometimes customers will look at the cost of a sample being done through the lab and think it may not be worth it, how much is the cost of new bearings, seals and gaskets going to cost if they need to be replaced earlier than expected?

The small investment in doing a checkup on your engine, drive train, gearboxes or other equipment that could have costly repairs would be well worth it if a potential issue is identified early rather than at the point of a complete rebuild is needed. motor oil color