Is Your Expired Motor Oil Safe To Use? Here’s How To Check

Motor oil is the lifeblood of a car’s engine. It keeps all those little components lubricated to keep the engine running smoothly and quietly. Most car owners know how important it is to change motor oil regularly, either by themselves or during a routine maintenance check by a professional. What many drivers wonder, though, is how long does motor oil last?

Nothing lasts forever, and motor oil is no exception. It eventually breaks down, becoming less effective, and leading to potential problems for your engine if you continue to use it. You may be able to tell if your motor oil has gone bad without getting your hands dirty, simply by checking the expiration date on the bottle. (Most motor oils have a shelf life of about five years.) But however you determine it, using motor oil that has gone bad isn’t something a responsible driver should do — especially if you want that prized possession of yours to last for years to come.

There are a number of ways to tell if motor oil has gone bad, and sometimes it’s all about smell. If your engine oil smells like gas, or there is an oil smell inside the car, your motor oil needs changing. Another way to check if the oil has gone bad is with the ol’ trusty dipstick. Pop open the hood, remove the dipstick, wipe it off, return it to the oil tank, and remove it again. If the motor oil is dark or dirty, it’s time for an oil change. Other signs can be a knocking noise from the engine components grinding together, the oil light illuminating, or worse, the “check engine” light coming on.

If the motor oil has gone bad, you may think it’s okay to ignore it for a while, but that couldn’t be further from the truth. Once motor oil goes bad, it can degrade to the point where it no longer lubricates the engine effectively, leading to damage to the engine components and the engine as a whole.

When it’s time to replace motor oil, you’ll have two options: synthetic oil or regular oil. Check your owner’s manual to find out which kind your car uses. And beware of overfilling it. Too much oil in your engine is just bad news waiting to happen.