Low Oil Pressure – Main Causes & Treatment

When your oil warning light turns on, your engine oil pressure may be low and you need to troubleshoot right away. Here are the main causes and fixes.

Your oil makes your engine run smoothly and protects it from wear and tear of your engine. If the oil pressure is low, you would need to check for the potential reasons listed below and fix it as soon as possible.

Vroom Car Worth

Does My Car Have Low Oil Pressure?

car engine oil fill port open

Firstly, it is important to distinguish what the problem is. The greatest indicator that you have a low oil pressure is your dashboard, more precisely your oil warning light.

The warning light indicates a problem with the engine oil system. In most cases, low oil pressure is the main culprit, but other causes such as high oil pressure, are also possible.

Besides the warning light, other signs of low oil pressure include:

  • Clunking Sound
  • Smell of Burning Oil
  • Overheated Engine
  • Oil Leakage Under the Car

Should I Be Worried?

woman on phone opens car hood to look at engine

The engine oil is a vital part of a combustion engine. If the system does not work properly, the engine is at great risk to be damaged due to the friction of all the components that are normally lubricated by the oil.

Not only does the engine oil work as a lubricant. It also plays a role in protecting the engine against corrosion, cooling the engine as well as cleaning it. Therefore, an abnormal oil level should get your attention.

To be safe, it is recommended to shut off your engine as soon as possible in order to prevent any damage.

The Lubrication Circuit

bad oil pump

Before the causes and treatments are listed, it is important to recognize how engine oil and the lubrication circuit works.

The engine oil is often described as the blood of the vehicle. The analogy indicates the importance of the oil but also makes it easier to understand how the whole system works.

The analogy can be used further. In the lubrication circuit, different “organs” play a role to maintain the engine properly.

The sump, also called the oil pan, is where all the oil is stored. From there, the oil pump (the “heart”) sends the oil via oil galleries (arteries). As it passes, it is filtered through the oil filter (kidneys), removing any impurities.

As the oil is moving through the moving engine parts it leaves a thin film, protecting the surface of each component. This film reduces the friction and cools the engine as it disperses the heat formed by the combustion process.

Causes & Treatment of Low Oil Pressure

The cause of low oil pressure is in most cases due to problems in the lubrication system as described above. The most common causes are the following:

Obstructed Oil Filter

auto fuel filter

As previously described, when the oil passes through the system, the oil filter picks up any debris and contaminants that are present in the system. As the filter picks these contaminants up, the filter clogs up.

In order for the engine to receive uncontaminated oil, the oil first passes through the filter. If the filter is obstructed, the passage of oil becomes compromised leading to a low oil pressure.

To resolve this issue, the oil filter must be changed. Keep in mind that this problem is preventable with regular maintenance of the car. Always make sure to change your oil and filter in regular intervals regulated by your owner’s manual.

Low Oil Level

car maintenance tips

An inadequate amount of oil equates to a low oil pressure. Due to a low amount of oil, the lubrication circuit has little to work with.

A low oil level has in itself lots of causes, some include:

  • Inadequate Amount of Oil Added
  • Leaks
  • Increased Oil Consumption

Inadequate Amount of Oil Added

It is important to add the correct amount of oil, making sure that there’s not too much nor too little oil in the engine. This is best done with a dipstick or the car’s oil-level sensor.

In order to accurately measure the amount of oil in the engine, manufacturers previously recommended letting the engine cool off to allow most of the oil to settle in the oil pan.

Today, many manufacturers have made revisions to the dipstick to make it possible for an accurate read, even if the engine is warm. It is still important to make sure that the car is parked on a leveled ground for an accurate reading.

If the cause of the low oil pressure is due to insufficient oil in the engine, simply add more oil till an appropriate amount is achieved. It is recommended to use the same oil which already is in the engine. In other words, the same type (i.e., synthetic/half-synthetic), manufacturer, and SAE grade.

Leaks

An oil leak will empty the oil, consequently, the lubrication system will have a low oil level.

When talking about oil leakage, two types are commonly seen. A leakage in the oil pan or oil filter, which is usually evident by drops of oil below your car, or a leakage of the valve gasket or oil filler cap.

There is a great variety of places where oil can leak. Wherever it may be, it should be fixed as soon as possible. In the best-case scenario, the oil filler cap or a faulty drain plug is the problem and can be easily fixed by replacing them.

It is also possible that the oil pump is leaking internally, which leads to a low oil pressure even if there is an adequate amount of oil.

Increased Oil Consumption

Your car does not consume equal amounts of oil all the time. Brand new cars usually consume more oil. The consumption tends to then decrease and later increase again after it has been driven many miles.

The quality of the oil might also be poor, leading to less effective lubrication which also means that your engine might deteriorate faster than expected.

It is important to follow the manufacturer’s recommendation regarding oil. While many oil companies have a deal with the manufacturer to recommend their product, it is not necessary to use that brand. Just make sure to follow the type of oil, including the viscosity (SAE).

Defective Oil Pressure Sensor

Service Engine oil pressure
dash with no oil pressure and service engine light on

The most usual sign that your oil pressure is low is the warning light that comes up on your dashboard. The light turns on when the oil pressure sensor detects an abnormality in the oil pressure.

If it turns on and it has been assured that your car does not suffer from any problems discussed in this article, and the oil level is within the normal range limit, chances are the oil pressure sensor has gone bananas.

The oil pressure can be manually checked with a pressure gauge, assuring the correct pressure is read by the sensor. If it turns out that the oil pressure sensor shows a bad reading, then it is ready for a replacement.

Worn Out Engine

mechanic fixing or rebuilding engine

An engine that is old or that has been driven extensively is prone to get worn out. If the car has not been properly maintained, the engine will be worn out much faster than a properly maintained car.

Unfortunately, the main and rod bearings might be affected which means that the engine either must be rebuilt or completely replaced.

Oil Viscosity

motor oil

Oil is generally a viscous liquid and engine oil is no exception. However how vicious the oil is playing a great role for the engine to work properly.

When buying engine oil, you might have come across that the package is labeled as “5w-30” or “15W-30”. These denominations are SAE grades.

To put it simply, it tells how viscous, or thick, the oil is. Previously they were only graded with one number, for example, “SAE 30”, which was a relatively thick oil.

The oil was so viscous at that time because oil thins when heated, and the manufacturers had to make it thick in order for the engine to be lubricated with a viscosity that was just enough in operating temperature.

As the technology advanced, additives were added which made it possible to have a liquid that acts as a SAE 5 when it is cold and acts as a SAE 30 when it is hot. In short, the oil became more adaptable to temperature.

Every car manufacturer has specified which viscosity to use for their respective car and engine. It is important to follow those recommendations as improper viscosity might affect your oil pressure.

It is also worth noting that the climate may dictate which oil you should use. If you live in colder climates, a lower number followed by a “w”, which stands for winter. ‘

A good tip is to check with a local authorized dealer or mechanic to make sure you are using the correct oil for your engine.

Summary

The blood of the engine, the engine oil, plays a key role in making your car engine run smoothly and reliably.

If something is wrong, you will usually get a warning light, or your oil gauge will drop, notifying you that your oil pressure is low. It is of most importance to stop as soon as possible and shut down your engine to prevent any damage.

Most of the problems regarding the oil pressure and automotive problems can be prevented by regular maintenance. This includes changing oil and oil filter in regular intervals determined by either time passed or miles driven.

The saying “working like a well-oiled machine” is a great and true saying that also applies to internal combustion engines. Your car will thank you with many happy and reliable miles with an appropriate oil level.

Make sure to always have an adequate amount of oil. The correct oil for your specific vehicle should be used with proper viscosity, adapted to your climate.

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Bajro Muric
Bajro Muric

Bajro is a big car enthusiast with a love for writing and teaching. He writes about anything regarding cars - from common problems and fixes to racing.