The causes a car's oil light stays ON

The warning indicator lights in your car dashboard panel have various meanings. Generally, all the lights will turn on when the ignition is ON and will go off after the engine starts and works normally. When an indicator light continues to stay on, it indicates a problem on that system and tells us to fix it immediately—for example, the engine oil indicator light.


This engine oil indicator light will go off as soon as the engine starts and runs normally. It means that the engine oil pressure in the lubrication system is also working correctly. If the oil light continues to stay on when the engine started, it indicates that the lubrication system's oil pressure has a problem.

If this condition arises, we need to be vigilant and immediately inspect to prevent further damage to the car's engine. It can cause the engine to break down, which can be quite expensive to repair. This article will give you information about the causes of the oil light ON and how to fix it. Check out the reasons for the oil light indicator that continues to stay on below.

1. Low engine oil volume

The most common cause of the oil light stays on is when the engine oil volume is far below normal. Even when we checked through the oil dipstick, the oil line is not visible at the minimum level.

A low amount of engine oil will cause the engine oil mixed with air when it sucked in by the oil pump. As a result, the engine oil pressure decreases and makes the switch inside the oil pressure sensor connected.

When the engine oil pressure sensor is connected, it will read by the Engine Control Unit (ECU) as a signal if the engine oil pressure has decreased. Therefore, the Engine Control Unit will make the oil light to turn ON and works as an information to the driver that the engine oil pressure has reduced.

Here are some conditions that can cause engine oil to decrease:

• An oil leak occurs in the lubrication system that seeps out of the engine, such as leaky drain plug bolts, seepage oil hoses, leaks from seals on the front and rear engine.
• Oil burns in the combustion chamber, causing white smoke which smells quite strong.

To solve the problem due to low engine oil volume is by adding engine oil and follow the owner's manual for the recommendation oil specifications and volume. Or it's better to replace all engine oil with a new one and fill it according to the recommendation engine oil volume.

If adding engine oil or replacing it does not solve the problem, then an inspection of the entire lubrication system needs to be carried out such as checking the oil pressure sensor and the oil pressure produced by the oil pump.

2. Faulty oil pressure sensor

Another reason for the oil indicator light turns on is the result of a faulty oil pressure sensor. The oil pressure sensor on Japanese-made cars circulating in our country today is generally a pressure switch.

This oil pressure sensor will work to disconnect the switch inside the oil pressure sensor if the oil pressure generated from the oil pump has exceeded the spring strength limit.

When the switch is disconnected, the oil indicator light on the dashboard panel will turn OFF. Vice versa, when the switch inside the oil pressure sensor does not get any pressure from the oil pump, the switch will connect and make the oil indicator light turn on.

The oil light ON generally occurs due to a damaged oil pressure sensor when the switch is always connected and cannot return to its original position.

To check this, please unplug the cable connected to the oil pressure sensor when the engine is running. If the oil indicator light goes off, this indicates that the oil pressure sensor is damaged and needs to replace soon.

Also read:

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• How often should you change oil filter?

3. Engine oil pump failure

The last causes of the oil light ON that we knew was the engine oil pump failure. The engine oil pump function is to pump the engine oil throughout the channels inside the lubrication system. It used to lubricate the engine parts that work and rub against each other.

This pumped oil will generate pressure so that the switch inside the oil pressure sensor is disconnected. As a result, the oil light will go off.

The oil pump damaged due to excessive wear on the walls of the oil pump housing, or when the gear shaft on the oil pump breaks and causes the oil pump gear can not rotate. When the oil pump is damaged, the engine oil pressure reduced. The pressure is to low to press the switch inside the oil pressure sensor so that the oil light turns on.

A special tool is needed to measure engine oil pressure, and it is necessary to dismantle the oil pump to see the physical conditions that occur inside the housing and gear of the oil pump. Therefore, it would be better if the inspection is carried out at your trusted car repair shop.