Close

What Your Oil Warning Lights Mean, and What to Do

Stephen Fogel
September 20, 2018

Your car’s engine relies on the oil that circulates through it. Oil provides lubrication, carries heat away and keeps damaging contaminants from building up.

But to do all this, there has to be enough motor oil, flowing at sufficient pressure.

» LEARN MORE: How often should you change your oil?

When there’s a problem in the oil system, one or more warning lights will come on to alert you. If you see the low oil pressure or low oil level lights stay on after you start your vehicle, or come on while you’re driving, you’ll want to get it fixed quickly — your engine could get ruined if you don’t.

What are the oil warning lights for?

Low oil pressure warning light: Your engine has many precision-made metallic parts, revolving or moving thousands of times per minute. These parts need to be constantly bathed in a pressurized shower of oil. Your engine’s oil pump is responsible for doing this. A sensor threaded into one of the engine’s oil passages keeps track of the pressure. If it gets too low, the oil pressure warning light will pop on. 

This light typically uses a symbol of an old-style oil can with a drop of oil dripping from its spout.

Low oil level warning light: Your engine also requires a sufficient amount of oil. The low engine oil level warning light is usually linked to a float inside the oil pan. When the level gets lower than it should, an electrical switch inside the float will trigger the low oil level indicator. This may be a light on the dashboard or, on some vehicles, a message that appears in the driver information center.

The low oil level warning light is similar to the low oil pressure warning light. In addition to the oil can symbol, there may be a wavy or jagged line underneath. 

Note: In some cars, oil pressure and oil level are monitored by two separate warning lights. In others, both functions are combined into one warning light. Check your owner’s manual to verify how your warning lights are set up. 

Get it diagnosed by a professional
 

Why the oil warning lights can come on

Here are some of the reasons your oil warning lights are lit up.

Your oil level is too low

If you haven’t checked your oil in a while, or if something is causing your engine to leak or burn oil, the level can drop to the point where the pump is sending out air along with whatever oil remains. This isn’t the “minimum” or “add” mark on the dipstick — this is way below that. An inadequate amount of oil can cause a loss of oil pressure and can trigger either or both of your oil warning lights.

Solutions: Pull over and turn off your engine immediately. Let your vehicle sit for about five minutes, so that the oil can drain back into the oil pan. Check your oil level. If it’s low, add fresh oil until it reads full. Check your owner’s manual for the correct oil to use. Start your engine and let it idle for a minute. If the lights go out, you have solved the problem. If they stay on, turn off the engine and call your mechanic. You shouldn’t drive the vehicle until it has been repaired. 

If you simply forgot to check your oil for a while, then an oil and filter change, followed by more frequent oil level checks, should fix the problem.

If you have an oil leak, its source should be identified and repaired. You might notice stains or puddles under the car, or oil on engine parts under the hood. The engine might have a bad gasket or seal — a mechanic can identify and fix the faulty part.

Or, your engine might be burning some of its oil, especially if it has a lot of miles on it. This can be caused by worn cylinders, piston rings or valve train components allowing oil to migrate into the combustion chambers and get burned along with the gasoline. Look for black smoke coming out of your tailpipe under acceleration. Call your mechanic if you see any, but know that this may indicate expensive engine repairs ahead.

Your oil pump is bad

The oil pump in your engine works hard. When your engine is running, the pump must circulate oil to all the engine’s moving parts. If it wears out or fails, it won’t be able to provide proper oil pressure. When this happens, the oil pressure warning light will come on. You may also hear a strange noise coming from under the hood. 

Solution: Shut off your vehicle immediately. Check the oil level after it has had several minutes to drain back into the oil pan. If the level is between the minimum and the maximum, do not drive the vehicle until it has been repaired. Call a mechanic, who can check the actual pressure being produced by the oil pump and make any necessary repairs.

Your oil filter is blocked

Your engine’s oil filter is its first line of defense against contaminants. As the oil circulates through the engine, it passes through the filter, where dirt, metal particles and other bad things are trapped. If the filter gets overloaded, it can get blocked and cause low oil pressure.

Solution: Change your oil and filter at the recommended service intervals. A blocked filter is usually the result of leaving it, and the oil, in your engine for way too long.

Your sensor, wiring or warning light is bad

It is possible that the sensor, wiring or some other part of the warning light system can fail and turn on the light when there is no actual problem. If your engine sounds fine, and the oil level is correct, this could be the issue.

Solution: Shut off your vehicle and check the oil level after a few minutes. If everything seems normal, but the light keeps coming on, check with a mechanic. If you have a bad sensor, wiring or warning light, it can be repaired.

Your oil system is clogged with sludge

Some engines can produce sludge in the oil, which can clog up the intake in the oil pan, your oil filter and the oil passages in your engine. Neglecting the maintenance schedule, using the incorrect oil, or sometimes just poor engine design can lead to this situation. When it happens, the oil will have a hard time flowing, causing the oil pressure light to come on.

Solution: Stop driving and get your vehicle taken to a repair shop. Depending on how bad it is, the engine may need to be cleaned of sludge. Switching to synthetic oil, and changing it and the filter at the proper intervals, may solve your sludge problems.

Your engine is worn

If your car has a very high number of miles on it, it can experience the effects of engine wear. As moving parts like the crankshaft and the camshafts age, the clearances between these parts and the bearings they rotate within become larger. Oil flows through these larger openings more easily, lowering the oil pressure, and in extreme cases causing the warning light to illuminate.

Solution: A mechanic can verify the extent of your engine’s wear issues, and whether the condition is terminal. The age, condition and current value of your vehicle may or may not support the cost of overhauling or replacing your engine. You may be able to switch to a thicker grade of oil to get the pressure back up and extend your engine’s life. 

» LEARN MORE: Get an estimate for your car repair

Can I drive with the oil warning lights on?

In a word, no. Once that you see a red oil warning light, indicating that the oil system has either insufficient pressure or a shortage of oil, you should not drive your vehicle until it has been repaired. You could destroy your engine if you do so. Call your mechanic for further guidance, and schedule repairs right away.

 

Stephen Fogel

About the Author

Stephen has been an automotive enthusiast since childhood, owning some of his vehicles for as long as 40 years, and has raced open-wheel formula cars. He follows and writes about the global automotive industry, with an eye on the latest vehicle technologies.

1 User Comment

Sign in to comment
By , February 20, 2018
I had a 2006 Hyundai Sonata GLS V6, when it was time to change the oil the technician would should me the dip stick. It would not have a drop of oil on it and I thought that was a problem! Shouldn't the oil light have came on?

Related Questions

See what others have asked about this, or visit the Questions page to ask your own question.
Oil light comes on only when it is a hot day and goes off while i am driving.also the oil level is fine.
Low oil pressure light is coming on 1 or 2 minutes after starting car and staying on. the lio has been change, the le...