Why is my air compressor oil Milky?

If you own an air compressor, you know how important it is to properly maintain the unit. This includes ensuring that the oil levels are where they should be and that the oil itself is in good condition. But what does it mean if your compressor oil looks milky? Let’s find out.
air compressors


Moisture Contamination

One of the most common causes of milky compressor oil is moisture contamination. This can be caused by condensation or water entering the system through valves, seals, or other components. When water comes into contact with oil, it will emulsify and turn it milky white in appearance. In addition, moisture contamination can also lead to corrosion on internal components which will reduce the efficiency of your compressor and cause it to wear out faster than normal. To minimize moisture contamination, make sure all seals are properly installed and that no water is getting into the system from outside sources. Additionally, consider using an air dryer system if possible to further reduce moisture in the air lines.


Oil Breakdown

Another potential cause of milky oil is a breakdown of the oil itself due to age or inadequate maintenance. Over time, oils break down into smaller molecules that can become suspended in the fluid and give it a cloudy appearance. This type of breakdown is more likely if you are using an older type of oil or not changing your compressor’s oil regularly as recommended by its manufacturer. To prevent this issue, use a high-quality synthetic compressor oil designed for your specific unit and follow any maintenance recommendations provided by its manufacturer regarding how often you should change its oil.


Sludge Buildup

The last potential cause of milky-looking compressor oil is sludge buildup on internal components such as pistons or valves due to lack of regular maintenance or improper lubrication practices. Sludge buildup typically occurs when dirt particles accumulate on internal parts which then mix with the lubricant causing an emulsion effect similar to what we see with moisture contamination. To prevent this issue from occurring, always make sure that your air compressor’s intake filter is clean and replace it as needed along with any other filters used in the system such as aftercoolers or separators if applicable. Additionally, use high-quality lubricants specifically designed for compressors and always follow manufacturer recommendations regarding how often they should be changed out for optimal performance results.



If you find milky-looking compressor oil in your unit, you should take action immediately! The first step is replacing all of your old contaminated oil with fresh new stuff—which will help prevent corrosion and ensure that all parts are adequately lubricated. You should also check for any leaks around your seals or fittings; if you find any, tighten them up or replace them altogether depending on their condition. Finally, make sure to dry out any moisture or condensation inside the tank before adding fresh oil—this will help keep water out for good!

Milky-looking compressor oil is never a good sign. Fortunately, fixing this issue isn’t too difficult; just make sure to replace all of your old contaminated oils with fresh new stuff, check for any leaks around your seals or fittings, and dry out any moisture inside the tank before adding fresh clean oils back into your unit. With these steps taken care of correctly and regularly maintained thereafter, you should have no problem keeping your air compressors working like brand new!

If you take steps to fix the milky oily and it still is not fixed, call an air compressor repair professional to get the job done right. Pacific Air Compressors can help with air compressor service and installation in Portland, Oregon. Contact us today at 503-674-2744 or request an appointment online.



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