What is an Oil Pressure Sensor?

In this article, I’ll teach you everything you need to know about oil pressure sensors, including how to test them.

Undoubtedly, an oil pressure sensor is one of the most vital components of your vehicle. Bad oil pressure levels can damage the engine, or it might destroy the engine completely. A good understanding of an oil pressure sensor is a must-have whether you are a mechanic like me or a car enthusiast.

So, what is an oil pressure sensor?

The oil pressure sensor is a device capable of tracking the oil pressure in your engine. In other words, the oil pressure sensor combines an oil pressure sender and an oil pressure switch.

Ill go into more detail below.

Must Know Things About an Oil Pressure Sensor

Tracking the engine’s oil pressure is a crucial part of your vehicle. It will give you a good indication regarding leaks or any other issue. You can track the engine’s oil pressure with a properly working oil pressure sensor. That is why oil pressure sensors can be labeled as the most important sensor in your vehicle.

How Does It Work?

To understand the importance and uniqueness of an engine oil pressure sensor, you must first understand its mechanics. So, in this section, I’ll try to explain this.

Most standard engine oil pressure sensors display a warning light if the oil pressure is low. This indicator light will start flashing on the dashboard. However, you should check the lights only after starting the engine.

The vehicle’s dashboard will display the warning light for low oil pressure whenever you switch ON the ignition key. But that doesn’t mean the oil level is low. You should start the engine to get a clear idea of the oil level. Otherwise, the oil pumping process won’t start.

There are two main parts to an oil pressure sensor. Actually, there are more than two. But to understand the mechanics of an oil pressure sensor, you should at least know about the spring-loaded switch and the diaphragm.

oil pressure sensor diagram

Examine the above image. As you can see, the diaphragm is connected to the spring switch. And the spring is connected to the positive end of the indicator light. The negative end of the light is connected to the oil sensor’s body. Hence, the circuit is connected, and the signal light will start flashing. This is why the signal light flashes when you switch on the ignition key. (1)

What Happens After Starting the Engine?

After starting, the engine will start to pump the fuel. The diaphragm will push the spring when the recommended oil pressure is reached. This breaks the circuit, and the signal light will get turned off automatically.

However, the circuit will be active if the recommended oil level is not reached. Hence, the light will be on.

Ways to Test an Oil Pressure Sensor

Most people panic quickly after seeing the warning light for low oil pressure on the dashboard. But they shouldn’t. There are two main reasons for this.

  • Oil leak in the oil line or the oil pressure sensor
  • Bad oil pressure sensor (wiring issues)

To check for any oil leaks, you’ll need a mechanic. Believe me; this is a better way. I’ve seen many of my clients get frustrated while trying to find leaks. So, hire a professional for this. (2)

However, if you need to test the oil pressure sensor and are fixated on doing it yourself, there is a simple way. For this testing process, you’ll need a digital multimeter, wrench, and screwdriver.

testing oil pressure sensor with multimeter
Video | Gerard Burke

  1. Start the engine and confirm that the oil pressure is low.
  2. Turn off the engine and open the hood of your vehicle.
  3. Locate the engine block and remove the oil pressure sensor from it.
  4. Set the multimeter to test continuity.
  5. Place the black probe on the body of the sensor.
  6. Place the red probe on the head of the sensor.
  7. If the multimeter starts beeping, your oil pressure sensor is working properly.

Quick Tip: This test only allows you to check the oil pressure sensor’s wiring and doesn’t indicate any leaks on the sensor.

If the wiring part of the sensor is okay and you still get the warning light, there is a leak in the oil line or the pressure sensor. Check the issue with the help of a qualified professional. A good mechanic will always find these types of issues pretty quickly. But for you, it might take 2 or 3 days.

Also, if the mechanic recommends replacing the oil pressure sensor, don’t hesitate to do that. Most often, oil pressure sensors are inexpensive. So, proceed with the replacement.

If none of the above methods works, the issue might be a bad oil filter, clogged-up oil line, or something else. That is why it is better to leave the hard part to a mechanic.

Take a look at some of our related articles below.

(1) diaphragm – https://my.clevelandclinic.org/health/body/21578-diaphragm
(2) oil leaks – https://www.sciencedirect.com/topics/engineering/oil-leakage

Video References

Adam’s Analysis

Gerard Burke

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About Sam Orlovsky

b1d87d2ee85af3e51479df87928bdc88?s=90&d=mm&r=gCertifications: B.E.E.
Education: University Of Denver - Electric Engineering
Lives In: Denver Colorado

Electrical engineering is my passion, and I’ve been in the industry for over 20 years. This gives me a unique ability to give you expert home improvement and DIY recommendations. I’m not only an electrician, but I also like machinery and anything to do with carpentry. One of my career paths started as a general handyman, so I also have a lot of experience with home improvement I love to share.

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