Stop – Oil Light On – Why?

Stop – Oil Light On – Why?

Why would an Oil Light illuminate?

Have you ever wondered what it means when your Car’s Engine Oil Light goes on or flickers? while the engine is running.

All questions about the Engine Oil Warning Light Answered.oil levels

# Learn More Here

 How it Works

The average internal combustion engine requires engine oil to lubricate its internal components in order to reduce friction caused by moving parts.

A warning system is incorporated into the electrics of the car, consisting of an oil pressure sensor switch in the engine and a warning light on the dashboard.

It warns when the oil pressure or oil level becomes inadequate to fulfil its function of efficiently lubricating the car’s engine.

When this happens the oil warning light will flicker or illuminate continuously.

Oil Pressure Switch and Light Diagram
Diagram of an Oil Pressure Switch and Light
Different Oil Pressure Switches used on various cars
Oil Pressure Switches comes in all shapes and sizes

Oil flows from the engine into the sender unit activating a diaphragm inside joining 2 contact points to complete an electrical circuit in order to shut off the oil pressure warning light on the car’s dashboard.

If the oil pressure is too low (due to varying reasons, explained below) the oil pressure warning light stays illuminated, warning of low or no oil pressure.

Low Oil Pressure Warning
DashBoard Low Oil Pressure Warning
Low Oil Pressure Warning
Low Oil Pressure Warning

What to do when the oil light illuminates while the engine is running.

  1. Switch the engine off immediately
  2. Check for signs of excessive oil leakage under the hood
  3. Check the oil level with the dipstick
  4. If low fill to a proper level
  5. Start the engine and check to see if the oil light goes out
  6. If it does, then you are good to go
  7. If it does not, contact your Mechanic or Auto Repair Center
  8. In all probability, the car must be towed in for further diagnoses and repairs.

Oil light on while driving, Possible Faults

  • Faulty Oil Pressure Switch sending an incorrect signal to the Oil Light
  • Short circuit causing the Oil Pressure Warning Light to Illuminate
  • Low oil level, due to oil leaks or oil consumption caused by engine wear.
  • Oil Pump failure
  • Oil Pump driving mechanism failure
  • Oil Channels blocked in the Engine
  • Oil Pressure Release Valve malfunction
  • Oil Filter Valve Malfunctions

NB:- Many of the above is caused by prolonged service maintenance intervals.

# The Importance of periodic oil changes cannot be over emphasized

# More on Oils

The diagram below illustrates how oil flows in a conventional Internal Combustion Engine.

Oil Flow Diagram
Engine Oil Flow Diagram

In conclusion, this article is not exhaustive, but I believe all major points were covered.

Subscribe, Share, Like – #Please leave a Comment below – Thanks

Until Next Time “Safe Motoring”

Gary De La Cruz

I have been 30+ years in the motor industry, still hands on, and have great passion for my chosen profession, I learn new things each day and believe that "if you enjoy your work, you never have to work a day in your life"I believe in honesty, integrity and helping where help is needed.

This Post Has 21 Comments

  1. Remy

    Hi gary,
    I will share with you a not so funny story that is related to your subject of oil.
    We hired a race track for a day to scatter a mates ashes and we all had our race vehicles out here.
    I had a new 1400cc motorcycle that I let loose on the track.
    One other fella out there had a Nissan pulsar SSS but he was too timid to get his car out on the track. After a fair bit of badgering he offered his keys to someone else to drive his car and 4 of us jumped into the car and set off to do some hot laps.
    Lap 1 was quiet and uneventful just to see the lie of the track and the car.
    Lap 2 was a lot faster but then this happened.
    Driver says to the owner of the car, check this out, when I go hard around a corner the oil light come one, What’s that all about?
    Owners respond with I dunno.
    After that we made it 3 more corners before the burning smell hit the cabin.
    we limped it into the pits, parked it up and there is stayed.
    seized solid into it’s final resting place.
    when I asked the owner, When was the last time you checked the oil? His response was, I wouldn’t even know how to said it all for me.
    No oil and ignorant owner = dead car.
    Hope you enjoyed the story.

    1. Gary De La Cruz

      Hi Remy

      A great story, one for the record books, I suppose not all are interested in the maintenance of their cars, some leave it to Auto Mechanics to do all that is required, but ignorance is costly, therefore my mission with my website is to educate as many as I can about basic maintenance and save a few $’s along the way, thanks for sharing your encounter with us here, All the best to you, Remy.


  2. Doug

    Thanks for the information. My oil light has been on for almost 2 years and based on what I have learned here and the fact that every time I check my oil it is full and I have had my oil changed several times in this period, I’m guessing that it must be a faulty oil pressure sensor.
    Again thanks for the info. I’m going to go to the parts store an get a new sensor and hopefully that will fix the problem.

    1. Gary De La Cruz

      Thanks for the visit Doug, glad I could point you in the right direction, trial and error is the way to go, this is how we learn, All the best


  3. Julien

    Thank you for this clear explanation! You are right to mention the importance of the oil pressure! In fact, driving your car with now oil pressure can have serious consequence to your engine’s health!
    I agree that doing regular maintenance on your car can prevent from having low oil pressure!
    Thanks for explaining what to do when that oil pressure light turns on!! It will probably prevent certain people from panicking 🙂
    Thank yo for sharing ! Have a great day.

    1. Gary De La Cruz

      Hey Julien, thanks for your visit and input, my intention is to help visitors, save unnecessary costly consequential repair bills by simple preventative measures and knowledge on how things work in their cars, I think I achieved my objective, by your response here.

      All the best


  4. Kegan

    Great advice – thanks for all the detail, funnily enough my wife has a VW golf like in your first video above, it often starts with the engine warning/oil light on until the car has warmed up.

    Is this an issue, or just a product of an older car/older sensor that is flicked off before there is oil flow for the car being started?

    1. Gary De La Cruz

      Hello Kegan thanks for your visit and positive comments, as per your description of the symptoms on your Golf’s problem, I would suggest looking at the oil pick up and make sure it is not partially blocked, the oil pump could also be on it’s way out, you might want to look at replacing the oil pump in the near future as the consequential damage will greatly out way replacing the oil pump timorously. I hope this helps, all the best.


  5. Olly Severn

    This article is very interesting as I did not know the science behind the oil within the car and it’s function! I have personally had problems with oil in my car and I never knew what the problem was until I had someone look at it and your article has helped me understand other ways of recognising why the oil light may appear! Thank you

    1. Gary De La Cruz

      Hello Olly

      Thanks for your visit to my website, and your favorable comments, I just love it when my visitors find value in my posts and videos, 

      It gives me an intense sense of satisfaction knowing I just help someone understand a topic better or helped them to perform a maintenance or repair procedure on their vehicle, saving them time and money, 

      This is what my website is all about, so feel free to re visit, lots of useful information here.

      All the best to you Olly


  6. Tyler Redlev

    Oil light on is one of those signs that many people are not so acquainted with. It’s a great post that you’ve explained all the concept in detail.

    In general, when the oil pressure drops the diaphram lowers down the contacting points and they are giving you a low oil pressure sign. Low lubrication levels may cause drive deformation on long term due to lover lubrication followed by increased friction.

    1. Gary De La Cruz

      Hi Tyler

      Thank you for visiting my website and commenting on the Oil Light post, your thoughts are valued as it gives me an idea whether I am delivery quality content for my visitors, the post is written in a simple format and is easy to understand, so all can benefit from it’s useful information.

      Wishing you ongoing success for 2018, Tyler


  7. Jim

    Low on oil? Yep – I have my own story to tell.

    I was burning oil one time on a trip from Orlando to Jacksonville. The oil light came on and there was blue smoke coming out of the exhaust and I had just past an exit. Trying to make it to the next exit was futile, because the car just locked up and shut down about halfway between the exits.

    When the tow truck came and hauled my car to the local dealer, I discovered that the engine had overheated and threw a piston rod which completely destroyed the internal workings of the engine. Thus, the engine had to be replaced at an astronomical cost!

    Heed my warning, folks! If you see that oil light even flickering or, if you see blue smoke coming out of your exhaust, pull over no matter where you are, shut off the car, and call for a tow. If I would have done that, I would be many thousands of dollars better off today!


    1. Gary De La Cruz

      Hi Jim

      Thanks for your 1st hand story on the oil light issue, it really lends credibility to what post represents and tyries to convey to the visitor here..

      All best to you in 2018.


  8. Ernest

    For those that think he’s joking about towing the car if the engine light does not go out, do yourself a favor and have it towed! My brother bought a cheap van that he was OK with only using a few months for business, and the light came on with me in it.

    We figured we’d be good to at least drive it the 100 miles until we were close to home, and the engine seized up completely. The vehicle was completely worthless! It may have only been $600, but these warning signs should not be overlooked.

    1. Gary De La Cruz

      Hello Ernest

      Thank you for the visit to my website and your endorsement on one of the warnings in the post, based on your personal experience. One should never ever ignore a red warning light in a vehicle, it means something bad’s about to  happen.

      Thanks again for your input Ernest, wishing you great things in 2018.


  9. Jim Holzgrefe

    Hi Gary! We have some similar interests I see. Although my interest is more towards American cars pre 1970 and small air-cooled engines. I think finding a niche that you are not only comfortable with but also have some heart to write about is very important. It keeps the motivation issue easier to deal with. It looks like you’ve found yours so congratulations are due to you! We also chose Wealthy Affiliate as our platform and are very pleased with the theme choices, training and the continued support of the community keeping us focused on the prize.
    All the best!

    1. Gary De La Cruz

      Hello Jim

      Thanks for the visit and your thoughts, it is a Hugh advantage to be passionate about your niche and not just do it for the sake of having something to do, WA provides education and guidance with which to channel your passion, a great winning combination, added bonus-the supportive WA Community, well in less words, I totally agree with you.

      Once again thanks for the visit and I wish you ongoing success for 2018.


    2. Gary De La Cruz

      Thanks for visiting my website I find your insights and comments, interesting.
      I find it intriguing that you have an interest in pre 1970’s air cooled engines, is it not difficult to find as they are not being manufacture any longer, are there firms still making it for nostalgic reasons?



  10. Victor

    Hey Gary, very interesting information, the few times I had the Oil Light turn on I always assumed it was just low on Oil and pour more into the engine if not I just took it to my mechanic, I was curious about this and can now see there is more to it than just a sensor or low oil. I also checked out your Engine oil post, just wanted to thank you for the information.

    1. Gary De La Cruz

      Hello Victor

      Thank you for the visit to my website and taking time out to comment, I am very happy that you found value in the material on my website, for that is the mission. Please feel free to share it among your contacts and social circle, and please visit again as I publish new content regularly.

      I wish you great success in 2018.


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