Low Oil Pressure Light Coming On (4 Common Causes)

Last Updated on June 25, 2020

If you’ve checked your oil pressure switch or sensor and it appears to be in good condition but your oil pressure light is coming on, then it could be a problem with your engine that needs to be fixed right away.

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There are a variety of reasons for why the oil gauge won’t show the correct reading and why the engine oil pressure warning light comes ON or starts to blink. Below are the most common causes.

Common Causes of Why Your Oil Pressure Warning Light is On

#1 – Faulty Oil Pump

symptoms of a bad oil pump

Oil is pressurized in the engine by the oil pump and then this pressure pushes it through the engine. As a result, the oil lubricates the engine’s components so they can move more freely.

If something were to go wrong with the oil pump, then the oil pressure would decrease and it would cause the oil pressure warning light of the vehicle to light up.

And since there’s weak oil pressure, the oil won’t be able to move through the engine and lubricate the components. This will result in more friction between the components, causing higher temperatures inside the engine, and ultimately costly damage.

#2 – Clogged Oil Filter

clogged oil filter

An engine depends on an oil filter to protect it against abrasions and wear. The job of the oil filter is to screen out solid contaminants from getting into the engine.

These contaminants often include metal particles, carbon, and dirt. If they were to get inside the engine, it would cause damage to the engine’s cylinder walls, journal, and bearing.

So, the more contaminants that get filtered, the healthier your engine will be. However, oil filters tend to get clogged after a while, especially when they are not replaced during an oil change. Once this happens, the oil pressure in your vehicle will decrease and the oil pressure warning light of your engine will activate.

Your car will then start to experience problems as a result of the low oil pressure. This means you must replace your oil filter immediately before the issue gets worse.

#3 – Clogged Oil Passages in the Engine

engine oil sludge

The oil pan or crankcase is what stores the engine oil. The oil capacity for the majority of engines is between four and six quarts. The job of the engine oil pump is to pressurize the oil and then circulate it. Once the oil leaves the pump, it will go straight to the oil filter so that its contaminants can be screened out.

All the clean oil will then pass through the filter and enter a series of passages until it reaches the crankshaft. Because of the passages in the crankshaft, the oil is able to circulate through the bearings surfaces of the engine.

However, if these passages got clogged, oil would not be able to flow through which would result in the oil pressure light coming on in your dashboard. If the issue is not resolved, major damage to your engine can be the result.

#4 – Low Engine Oil

check engine oil

Oil lubricates the engine of the car. After a while, the level of oil may start to decrease because of a small leak. The older the vehicle, the higher chance of an oil leak (or leaks).

Either that, or it may just get burnt away by the engine’s normal operation. Once the oil level goes down enough, you will see that the oil pressure warning light will activate. Check your engine oil level immediately.

 

Comments

    • If there is adequate oil in the engine, you may have a faulty sensor or any of the issues above. Use a code reader to see if any error codes come up which would help pinpoint the issue.

      Reply
      • My car showing the red sign of oil after driving 35k bt while I check oil it says the oil is fine,I don’t know what is the problem

        Reply
        • If you have enough oil, then you have an issue with the oil system. Either the oil pump is going out and is unable to maintain adequate pressure, or the sensor is giving you a bad reading. I would look into this as soon as possible in case you really do have low oil pressure, as this could destroy your engine if not addressed.

    • Check the oil switch if turns out to be fine then remove oil pan and take out the oil strainer ,it could be clogged

      Reply
  1. My 2011 bmw 318i sport plus red oil pressure light comes on while driving if I turn engine off then straight back on light go’s out

    Reply
    • You have low oil pressure. Obviously check the oil level but that’s usually not the problem. First thing I would do is change the oil filter in case of a blockage. Otherwise it could be a bad oil pressure switch or faulty pump.

      Reply
  2. i have a 202 buick century 3.8.first crank oil light stay on.iturn the engine off and recrank it the oil light goes off.i unplug the oil pressure sensor and the level sensor.and yet the low oil light stay on,.it full of oil .i change both sensor and still have this new oil filter.help

    Reply
  3. A individual I know said my car oil level is low, he claimed this by just checking the dipstick, I turned on the car and find that the oil pressure sign doesn’t show up and I have 50% oil life left. Is this true in some cases?

    Reply
  4. I have a 2006 Audi A4 turbo fl 2.0
    Oil pressure lights comes on and off for a while and I ignored it. Days later oil pressure light comes on and car turns off while driving and won’t turn on again. What can it be ?
    Towed car and notice oil leak under as well

    Reply
    • This may have been the result of a bad oil pump or low oil.

      This is not the type of light you want to ignore! If your oil pressure light turns on, you are in danger of destroying the engine due to oil starvation. In the future, it’s best to pull over immediately when this light comes on (assuming it’s safe to do so). Any damage incurred has already been done; it would be best to bring your car to a local mechanic for an evaluation.

      Reply
  5. Every time I stop at lights the oil light comes on and gauge go to low for about 1 second. I change the oil sending unit twice in the matter of days and same thing.
    Reading says faulty sending unit but I have 2 put in!!!! Also oil pressure is good iv been told.
    I drive a 2011 ford f150

    Reply
    • If you’ve had your oil pressure checked and verified as good, it could be a grounding issue. Check that all ground straps around the engine bay are clean and tightened down. On my car, faulty oil pressure readings typically come from one of three places: a bad oil sending unit, a bad gauge cluster, or a bad ground.

      If everything else in your cluster is working great, I wouldn’t suspect the cluster to be an issue in your case and would start by making sure the grounds are good.

      An intermittent obstruction in the oil filter or oil pickup tube may also throw an oil pressure light. This would be something you’d want to address quickly, but again if you’ve had the oil pressure verified externally I wouldn’t immediately suspect this to be the root cause.

      Reply
  6. Didnt service my kia1.6 for 30000km oil light came on oil fine but had funny noise could i hsve done in the beatings donny

    Reply
  7. My Toyota crankshaft bearings got damaged we changed the bearings,the oil,the filter and the sensors but the low pressure light is still coming on. What can this be.

    Reply
    • How did the crankshaft bearings get damaged? If the low oil pressure light is coming on, it could be an issue with the oil pump that is preventing the pump from maintaining adequate fuel pressure.

      If the engine has a lot of sludge build up, it’s also possible that the oil pump is working fine, but the oil passages are clogged. Clogged oil passages would slow or prevent the oil from getting back down from the top end of the engine to the crankcase. In extreme cases, the oil pump may not have enough oil left in the pan to adequately pump enough oil to the rest of the engine. Since you were far enough into the engine to change the crankshaft bearings, you should know if you have this level of sludge.

      Reply
  8. I have a 2004 dodge ram 1500 and every once in awhile my oil pressure bounces sometimes in mornings first start the oil takes a bit to circulate oil then pressure goes normal what could it be

    Reply
    • I would test the actual oil pressure and the signal going to the instrument cluster to figure out which is the root cause. If it’s just a noisy signal to the cluster, it would be less of a concern. I would definitely dig further if there is an issue with the oil pump though.

      Reply

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