Dash Lights: The Oil Light on Your Dashboard

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Your dashboard's instrument cluster has a light on it that either says "OIL" or looks like an old fashioned oil can. What should you do if you see this light while you're driving?

Stop the car! This is one warning light that isn't joking. The oil light comes on when your engine suffers a drop in oil pressure. Without oil pressure it can't lubricate itself, and the result is self-destruction, meaning you have to do some seriously expensive internal engine repairs.

You may be tempted to try to make it home, or make it to work, but an engine with no oil pressure is a time bomb set to self-destruct. It's almost guaranteed that you'll be rebuilding the engine if you don't stop it as soon as possible. 

Let's dig into the issue a little deeper. When your engine has enough oil in it, the oil pump is constantly pumping oil into all of the tubes that carry the oil into the parts of the engine that need lubrication. The pressure developed by the oil pump as it pushes the oil through the system builds up a certain amount of pressure. This pressure makes all of the oil sprayers work internally. If there's not enough oil to keep up with the demand of the oil pump, you get periods of time, seconds even, when there isn't any pressure in the system. This may sound minor, but even a minute with no oil pressure can be enough to ruin an engine from the inside out. 

Before you make any major engine repairs, be sure to check the oil pressure sender to be sure your oil pressure is actually low.

It's best to have a repair shop do this because they can test the system from a few different angles to verify the results. 

Another cause of low oil pressure can be a failing oil pump or a blockage in the system. Rarely does an engine become so gunned up that an oil passage is blocked to the point of reducing oil pressure, but it can happen.

More likely is the failure of the oil pump. The good news is replacing an oil pump isn't the worst repair in the world. And if you've seen the oil light come on while driving, you should count yourself lucky that it was just the pump. 

If the oil light comes on when you're on the road, you should pull over as soon as it's safe and turn the engine off. While you're on the side of the road, you should check the oil. If it's low, go ahead and add some engine oil and see if it goes off. If not, it's time to take it to the shop.