What are the reasons for engine oil deterioration?

[LaNatalie]

Engine oil deterioration occurs due to the following reasons: 1. Air filter damage. The function of the air filter is to filter impurities from the air entering the engine, thereby purifying the air. Generally, a standard car has only one air filter, while luxury cars may have two. The air filter is located inside the air filter box in the engine compartment. To access the air filter, the air filter box must be opened, and it is secured either with clips or screws, both methods ensuring the box is sealed properly. 2. Oil dilution and emulsification due to water. Water can enter the cylinder block or crankcase due to a damaged cylinder head gasket or other reasons. When the water content exceeds 0.1%, the antioxidants and dispersants added to the oil become ineffective, accelerating the oxidation process of the oil. When the oil contains a significant amount of water, its lubricating properties deteriorate, viscosity decreases, and the oil film's anti-friction effect weakens. In mild cases, this leads to premature oil deterioration and rusting of components, while severe cases can cause engine seizure or bearing failure, leading to serious mechanical accidents.

[OBenjamin]

There are quite a few reasons for engine oil deterioration. After years of driving, I've found the main issues stem from prolonged use and environmental factors. For instance, when I frequently drive long distances, the high engine temperature causes the oil to oxidize and thicken, reducing its lubricating effectiveness. Also, dust or moisture seeping into the oil from outside makes it dirty and accelerates aging. Forgetting the oil change interval is the worst—last time I delayed my oil change by two months, the oil turned black, and the engine started making strange noises. Now, I regularly check the dipstick and replace the oil immediately if I notice it's dark or the viscosity has changed, to avoid costly engine repairs. Additionally, frequent cold starts during short trips can dilute the oil with fuel, causing damage. I recommend developing a habit of changing the oil every 5,000 kilometers or every six months to keep your beloved car running longer.

[LaStephen]

The causes of oil deterioration include oxidation, contamination, and improper use. After prolonged operation in the engine, oil oxidizes upon contact with air, becoming viscous and losing its lubricating ability. Dust or condensation mixing into the oil contaminates it, causing the accumulation of impurities that diminish its protective function. High temperatures lead to the breakdown of additives, rapidly degrading oil quality. Fuel dilution is also a major issue, where gasoline drips into the crankcase during short trips, thinning the oil and causing accelerated wear. Extended oil change intervals allow acidic substances to accumulate, corroding engine components. It is recommended to use high-quality synthetic oil regularly, as it withstands high temperatures and reduces oxidation. Check the dipstick to see if the oil is clear or has any unusual odor, and perform timely maintenance. In summary, maintaining good driving habits and adhering to regular oil changes are crucial to preventing major engine failures.

[SanRyan]

Engine oil deterioration wastes money and damages the car. The main reason is not changing the oil beyond the recommended period, leading to accumulated contaminants and degraded performance. High-temperature driving oxidizes the oil, increasing viscosity and reducing lubrication, which raises fuel consumption. Fuel dilution of the oil is more common, especially during short city trips. Water or dust contamination is also a frequent culprit, rapidly degrading the oil. These factors accelerate engine wear and increase repair costs. For prevention, regular oil changes are essential—check every few thousand kilometers without delay. Using the right type of oil is also crucial, with synthetic oil offering better heat resistance.

[DiLevi]

Don't ignore oil deterioration; let me explain common causes from a maintenance perspective. Environmental factors play a significant role—moisture in humid areas can seep into the oil, causing emulsification and degradation. Driving habits also matter; frequent traffic jams lead to high engine temperatures, accelerating oil oxidation. Extended oil change intervals cause oil to age and develop odors, with additives losing effectiveness faster. Fuel dilution occurs during frequent cold starts, thinning the oil and reducing lubrication. Using high-quality oil can mitigate these issues. Check oil levels and color changes quarterly. Avoid indiscriminate additive use and keep the air filter clean to minimize dust contamination. In short, regular oil changes and good habits are key.