The signs of lubricating oil failure mainly include changes in appearance, viscosity, odor, and equipment operating status. Normal lubricating oil should be transparent or light yellow; if its colour darkens, stratification occurs, or milky emulsification appears, it indicates oxidation or contamination with water and impurities. Abnormal viscosity manifests as the oil being too thick (due to oxidative polymerization) or too thin (due to additive decomposition), both of which will weaken the lubricating effect. In addition, abnormal chemical indicators such as increased acid value, excessive water content, or increased metal particles can be detected through professional testing. For equipment, if the engine noise increases, the temperature rises abnormally, or the power output drops significantly, it may be caused by insufficient lubrication. It is best to conduct regular inspections, avoid mixing different types of engine oil, and prioritize high-quality products with strong oxidation resistance and stable viscosity to extend the engine's service life.
