10 Lessons from Oil Analysis

 

This oil sample was actually taken at the correct recommended mileage interval. The problem was that the oil had started to shear because of the engine hours.
For most consumers, a preventive maintenance program for their automobile consists of nothing more than an oil change. While a regular oil change is very important, the most critical part of changing the oil is to know when to change the oil.

The interval of the oil change is often dictated by one of two factors: someone’s preference (word on the street) or the vehicle’s maintenance guide. Today’s gasoline internal combustion engine is highly advanced and so is its oil. It’s amazing how the traditional 3,000 mile oil change no longer exists, but for some reason is still highly practiced. While the vehicle owner’s manual may give recommendations of an oil change, the actual interval will depend on several other factors as well. There are many different factors that affect the frequency of an oil change such as climate, driving style, viscosity grade, and engine condition.

The same can be said for the diesel engine as well. The reason I want to touch on this subject is because in working with diesel engines every day, I still find myself talking about an engine oil change on a regular basis. The best advice on performing an adequate oil change is to have an oil analysis performed regularly.
We all know that oil lubricates the engine, but oil also does many other things that are often overlooked. Not only does oil lubricate as a means of controlling friction but also has to control contamination, temperature, corrosion, shock, wear, and pressure. Oil analysis is the only true way to put a set of “eyes” on the engine’s condition and the condition of the oil to determine when it should be changed. Today’s oil analysis programs use state-of-the-art equipment and techniques to provide the consumer with valuable information that will help them properly maintain their engine. A proper oil analysis can be somewhat intimidating to read and comprehend, however, I hope this will help you explain an oil analysis report to your customer.

First of all, there are 10 important factors that determine the condition
of oil and its service life.

1 – Viscosity

The most important factor of lubricating oil, viscosity is a measurement of resistance to flow at a specific temperature in relation to time. In an oil analysis, the used oil’s viscosity is compared to that of new oil’s viscosity to determine whether excessive thinning or thickening has occurred.

High viscosity could indicate contamination of soot, incomplete combustion, leaking head gaskets, high operating temperature or extended oil drains. Low viscosity could indicate fuel dilution, oil shear, or the use of wrong oil. The effects of high or low viscosity oil can be engine overheating, poor lubrication, restricted oil flow, metal-to-metal contact and harmful deposits. If the viscosity is wrong make sure the proper oil grade is being used and determine if there are any leaks in head gaskets or injectors.

2 – Water or Coolant Contamination

If the analysis finds water in the engine’s oil then it is entering the engine through the atmosphere or from an internal leak. Water condensation should be evaporated by the engine when operating at normal temperatures. If not, the engine may not be reaching operating temperature, causing contamination, or there are internal leaks, causing contamination. Water contamination can lead to high viscosity, engine overheating, corrosion, poor lubrication, acid formation and engine failure.