What Do Oil Warning Lights Mean? Why Is Oil Pressure Light On?

Car warning lights and indicators

The oil pressure warning light is a very important indicator in your vehicle. It informs you of any impending danger or damage that may happen to your engine if it isn’t properly taken care of. When such indicators turn on, you should try to find a safe place to park your vehicle and check the engine oil as quickly as possible.

The oil light works together with the oil pressure and the oil pressure sensor.

Key Points

  • The oil light comes on when your vehicle’s oil pressure is low.
  • There are several reasons behind your oil pressure warning light coming on, including low oil level in the engine, poor oil circulation, and a bad oil pressure sensor.
  • The best thing to do when the oil pressure warning light comes on is to stop driving as soon as it is safe to do so, let the vehicle cool down for about 10 minutes, and check the oil level.

Oil Pressure Sensor

What Is an Oil Pressure Sensor? How Does It Work?

In order to understand the oil pressure sensor and how it works, you need to understand what the oil pressure does.The oil pressure is a very important factor that determines how long your engine can function. It’s vital in determining the lifespan of your engine.

oil pressure sensor
ACDelco GM Engine Oil Pressure Sensor.

The process takes effect when the oil is being picked up by the oil pump. The pump then sends the oil through various outlets to every necessary part of the engine, such as the main bearing, camshaft bearing, etc. This prevents stiffness in every part of the engine and makes it work properly.

The oil pressure sensor is the sensor that monitors the rate of oil pressure in your vehicle. It sensors and monitors the rate at which oil circulates in your engine to know if it is within the manufacturer’s limit.

Roles of the Oil Pressure Sensor

1. The oil pressure sensor monitors the rate of oil pressure in your engine.

2. The oil pressure sensor sends  signals to the oil pressure light whenever there is any problem with the oil pressure.

Symptoms of a Bad Oil Sensor

Here are some symptoms of a bad oil sensor:

1. Oil pressure light on or blinking despite oil being in the engine.

2. Oil pressure gauge at low or empty even after refilling.

Oil pressure light

The oil pressure light is an oil warning light that alerts you whenever it receives signals from the oil pressure sensor. Since the beginning of modern vehicles, every vehicle has been coming with different types of dashboard warning lights, and the oil pressure light is one of them.

It has been in vehicles as far back as the 1800s, and it is still being used today because of its importance. The oil pressure light is one of the lights in your vehicle that turns on, blinks, or alerts you whenever there is a problem with the oil in your engine. It should not be taken lightly as its notification could mean an impending danger to your engine.

Roles of the Low Oil Pressure Light

1. Notifies you when there is a problem with the oil pressure.

2. Receives signal from the oil pressure sensor.

Reasons Why the Oil Pressure Light Turns On

Do you occasionally notice that the oil pressure light on your dashboard is on? Do you see a red light occasionally when using your vehicle?

Bad oil pressure sensor
Oil pressure light turns on. Credit: Flickr.com

There are different reasons why the oil pressure light comes on, including:

1. Low Oil in the Engine

If there isn’t enough oil in your engine or if your engine is running low on oil, this can cause the oil pressure light to turn on. Low engine oil is one of the most common reasons why the oil pressure light appears on the vehicle’s dashboard.

2. Poor Oil Circulation

This is another reason why the oil pressure light could be on. If the oil isn’t properly circulated around the engine, this could trigger the oil light to be turned on. Most poor oil circulation is caused by a poor oil pressure system or a faulty oil pump.

A faulty oil pump can also result in other symptoms aside from the oil light coming on, such as noises from the engine compartment (whining, ticking, whirring, etc.). It can also cause engine overheating, which might trigger the check engine light.

3. Bad Oil Pressure Sensor

This is also a major reason why your oil pressure light could be on. If your oil pressure sensor is bad, it could send a constant signal to the oil pressure light even when there is no problem. This leads to the light being on every time.

4. Clogged or Dirty Oil Filter

Another reason why your oil warning light might come on is a clogged or dirty oil filter, in which case the best solution would be to replace it – it will decrease the pressure and bring it back to its regular level. While you’re at it, you might also want to install a pressure relief valve, which will prevent the pressure from getting too high in the future.

5. Dirty Oil

The oil light can also light up when your oil is dirty, even if its level is fine. How does oil get dirty? That’s actually very simple. When the oil circulates through the engine, it picks up things like dirt, metal particles, dust and other small debris, which, if built up, can trigger the oil light.

For this reason, it’s important that you inspect your oil every once in a while. You can do it while inspecting the oil level, which, ideally, you should be doing once a month. If the oil has an amber-like color, is transparent and slightly runny, its condition is perfect. If, on the other hand, your oil is dark, thick and has a funny smell, these are all indicators that it’s time for an oil change.

6. Oil Leaks

If it hasn’t been that long since your last oil change, but the light comes on anyway, then you might be dealing with an oil leak.

There’s an easy way of checking if that’s the reason behind your oil light coming on – simply park your car on a level surface and leave it for a few hours. Once you come back, check under your vehicle for puddles.

Sometimes, you might be dealing with an oil leak even if there are no puddles underneath your vehicle. What you can do to completely rule out the possibility of your vehicle’s oil pressure warning light coming on due to oil leaks is refill your oil to its maximum level, drive around for a bit, and if the light comes on again, check the oil levels. If the oil level is low, then you know you’re dealing with a leak and need to schedule a visit to the mechanic.

Frequently Asked Questions

What do you do when the oil pressure light turns on?

The best thing to do is to park safely and check whether the oil level in your vehicle is low. If it is, it is best to get oil immediately, and if it isn’t, it’s best to call a tow truck and transport your vehicle to the mechanic so that they can perform a thorough check-up, determine the cause behind the oil light turning on, and make all the necessary repairs.

How to check the oil level?

Checking the oil level is actually very simple and only takes a few steps. Here is how you do it:
1. Get a lint free rag or a scrap of an old fabric. If you have a T-shirt that you know you won’t be using anymore, it will work perfectly.
2. Turn your car on for a few minutes, as it’s best to check the oil level while it’s warm.
3. Turn the car off.
4. Open your hood, and prop it securely so that you get access to what is underneath it.
5. Locate the oil dipstick. If you don’t know where it is, check your owner’s manual – there should be a detailed description of its location.
6. Remove the dipstick and wipe it off with the clean rag we mentioned in step 1.
7. Slide the oil dipstick back in, ensuring that it’s all the way back in. Remove it again and look at its end, where a line or a texture area indicating the maximum capacity of the oil pan should be.
8. What you see on the dipstick will determine what to do next:
8.1 If the oil dipstick shows that the oil level is normal and the oil has its regular, amber color, reinsert it and close the hood.
8.2 If the oil level is low but it has an amber color, you can simply add oil.
8.3 If the oil has a dark color and is gritty, you will require an oil change.

How to prevent the oil pressure warning light from coming on?

While it is impossible to completely prevent it from appearing, as you never know if something within your vehicle will stop working, the best way to minimize the chances of that happening is by performing routine maintenance (such as regular oil changes) and having your car checked every once in a while.

The Bottom Line

Driving with the oil pressure light on can have severe consequences on your engine’s lifespan, which is why it shouldn’t be taken lightly. Stop the car as soon as it is safe to do so, and call your mechanic – they will let you know what to do in order to determine if you’ll be able to reach their workshop or if it will be better to call a tow truck.

Regular maintenance can make a world of difference when it comes to how long your vehicle will last you, and checking your oil should be one of the steps in it, regardless of whether the oil light is on or not.

Bonus: How to test an alternator?

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