Berkeley Auto Repair

1030 Carleton St., Berkeley, CA 94710
2703 Tenth St, Berkeley, CA 94710
Mon-Thu: 7:30 AM - 5:00 PM
Fri: 7:30 AM - 4:30 PM

Does Oil Go Bad Sitting in an Engine?

How long can your motor oil stay in the engine before you have to change it? Well, the oil mostly comes with a five-year shelf life. All the same, if your oil container indicates a shelf-life less than five years, you should work with the printed dates. After the longevity period is over, it is most likely that the synthetic additives in the oil will no longer be efficient. As such, you should ensure that you properly dispose your oil after it has surpassed the dates printed on the container.

Does Motor Oil Degrade Over Time?

A short answer to this question is yes. Motor oil can only last for a certain period of time. That's why it comes with an expiry date. For this reason, oil goes bad with time just by sitting in the engine. Over time, it becomes less viscous thus less efficient in maintaining proper lubrication between moving components.

Your motor oil might eventually break down depending on the oil type and the additives contained in the lubricant. Besides, there are water and hydrocarbon traces that eventually contaminate the oil as you use your car.

Of course, most manufacturers suggest an oil change intervals of 3,000 to 7,500 miles, depending on the type of oil and car. However, oil longevity is affected by several factors. For instance, if you rarely drive for more than ten miles, the engine will not get hot enough to burn off the moisture. The resultant oil-water mixture will cause the formation of sludge and acid, which leads to corrosion, affecting the engine longevity and functionality.

Can I Tell If My Motor Oil is expired?

The following steps might help you determine whether or not your motor oil is expired;

  • Check out the expiration date. If it is past the indicated date, consider disposing it. Also, dispose of your oil if it has been sitting in the engine for over five years.
  • Check your oil's color. If it is clear, then it is still in its good for use. However, haziness might be an indication that your oil is diluted.
  • Use a dipstick to check the oil consistency. If you notice any separation, it might be time to change your oil. Besides, thick and solidified oil is equally not fit for use.

Typically, almost all modern engine oils have the same shelf-life. While they won't mould, they are subject to dilution, oxidation, and potentially harmful degradation. If you need an oil change, we invite you to bring your vehicle into our auto repair shop today!

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