What Causes Low Oil Pressure in an Engine – Causes and Fix

Suppose if you are driving your car. What if it suddenly starts giving a clunking sound?  It feels far worse if you have to reach somewhere on time, right?

Keeping a regular check on oil pressure in an engine can help you from landing in trouble. Oil is one of the most important factors which keep your car going. 

The presence of engine oil in your car ensures that all moving parts are lubricated. If this won’t happen, the moving parts could come in contact with each other, resulting in friction and further deterioration. 

Are you facing a problem similar to low oil pressure in the engine? Let’s move along with this article to find more about it

What Causes Low Oil Pressure in an Engine?

As there are multiple underlying reasons for it, it’s important to find out what might be true for you!

One reason could be linked to the oil pressure hose. It is a transmission hose that is connected to the engine.

If the oil pressure is not rising with the increasing speed of your car, then a crimpled, distorted, and internally dried-out hose can be the reason. 

The absence of oil is another common reason behind what causes low oil pressure in an engine. Therefore, it is important to keep a check on oil pressure with a dipstick. 

If the oil pressure is really low, the cam bearings would be the first component to rise above the surface level of oil. Thus indicating a low level of oil in the engine.

Stalling is another reason for low oil pressure in the engine. If your car stalls as it does at low rpm then the oil pump is producing low oil pressure in the engine. Therefore, it’s time to slow down and get your car inspected. 

With low oil pressure, your car engine would stop working. It majorly serves as a warning sign to get the problem resolved before your engine would completely fails.

Above all, the high temperature of the oil also causes low oil pressure in the engine. The higher the temperature, the thinner the oil. Therefore, it results in low oil pressure in the engine. So keep changing the oil in time.

Still haven’t found a cause for your car? Well, the following might be some other reasons for low oil pressure:

  • Weak Spring in the pressure relief valve
  • Poor adjustment of oil pressure gauge 
  • Normal wear of bearings 

What Causes Low Oil Pressure on Diesel Engine?

With respect to a diesel engine, it is quite common for diesel to get into oil, thus causing pressure issues. 

Diesel leaking into the oil raises its level, however, reduces viscosity. It enhances friction among metal parts and thus results in damage to the engine.

Other prominent reasons for low oil pressure in diesel engines are as follows:

  • Low level of oil
  • Poor quality of the oil
  • Altered color of oil (black or greyish)
  • Poor functioning of an oil pressure sensor
  • Oil contamination due to an open filter bypass valve
  • Worn out the oil pump 
  • Lack of oil change 
  • Open cracks in the cooling jets

However, the Causes of Low Oil Pressure in Cold Weather may Vary! 

Low oil pressure in colder weather conditions is mainly because the oil gets thick in such conditions.  Thus, this resistance of oil results in reduced pump ability and therefore poor lubrication. 

In addition, prolonged usage of old oil in cold weather can also be problematic. The evaporation of lighter components leaves behind heavy components. Thus, poor quality of oil like this, will result in wear and tear among pistons, bearings, and cylinders, etc.

What Causes Low Oil Pressure at Idle?

A running car with low oil pressure sounds logical. What about low oil pressure at the resting state?

Yes, your car might be low on oil pressure at idle. It most commonly means that the engine is very low on oil. 

As more burden is applied to the engine while accelerating an idle car, it builds up pressure in the engine, resulting in high temperature which means low oil pressure.

Moreover, a defective oil pump can also result in low oil pressure at idle. If left idle in a colder environment, a clogged sump pickup can also cause low oil pressure when oil gets cold and thick. 

A leak sending unit might be another reason for low oil pressure at idle. If the sender does not seem to have a problem, then you need to replace the oil pump or bearings. 

How to Fix Low Engine Oil Pressure?

Now that you have a substantial understanding of underlying causes, I know what you might be thinking. I can relate well to your keenness to find out how to fix low engine oil pressure! Let’s get into finding one for you.

Oil pressure light is one of the most evident indicators of low oil pressure. When the light turns on, it means that the computer is identifying a low level of oil. For such a situation, open the hood and shut off the engine. Now, check the level of oil by using a dipstick. 

If the oil level is low, fill the oil to restore the pressure. However, in case both quantity and quality are non-problematic, check for something else! Now, what should these things be?  

It is then important to check the computer unit for oil pressure. It might be broken or there may be a worn-out spring inside, which is giving a false reading on the display. 

Thus, to fix the issue, firstly remove the oil filter to have access to the sending unit. Now take out the old oil filter and unscrew it. If you find oil on the inside surface, it depicts that oil was leaking, thus displayed check light.

Now, before you screw a new oil filter, wrap a tape around on the inside to stop the leak, however, it is important not to go too overboard with it as you want the outside metal to touch the ground.

Steadily put the filter back on the engine and check the engine light. If it is still on, it is most likely that the oil pump is problematic. If not, then your engine has a serious problem, which is going to a mechanic appointment.

Products Recommendation

Fram Ultra-Synthetic Oil Filter

As the name indicated, ultra-synthetic is designed to help the user get a similar experience as that of the full synthetic oil filter. Even though it’s vehicle-specific yet its durable metal sheet traps all the dirt thus enhances the life of the oil filter to years. 

Adjustable 3 Jaw Oil Filter Wrench Tool

This adjustable wrench is well suited to be used for all types of vehicles. Made with carbon metal, its water and corrosion-resistant, which makes it durable enough. Without adding scratches or damaging the oil filter, it helps with smooth processing and replacement. 

How to Fix Low Oil Pressure at Idle?

An instant fix to this is by changing oil or filter. If the issue still remains, then it is important to check if the sender unit is having an issue. 

In such a case, get a reasonable quality oil pressure gauge. Put it in place of the sender to check if it gives the same warning. If there is a problem with the sender unit, either get it repaired or buy a new one to resolve the problem. 

A short-term fix for pressure at the marginal level is to get a huge oil filter and shift to thicker quality of the oil. 

Now, check to be sure that the pickup tube needs to be tight. The pickup tube has a small O-ring which needs to be tight thus to build pressure. However, note that all of this is to be done with the oil pan off.

While you check that, you also need to look if anything is blocking the pickup tube or pickup tube screen.

Now move to the oil pan and front cover. If they look good, no damage or cracks are to be seen, then take a look at bypass tubes. 

Still, having the same issue? Well, if everything is fixed, then bearings are the issue. You can change the crank bearing on the trunk. If the rotating gear is problematic, you need to take it out. If they are far damaged to be repaired, then get new ones.

Glowshift Oil Pressure Gauge Kit:

Are you looking for a quality oil pressure gauge kit? This one can help you to monitor the oil pressure without the hassle of extra wiring. It is well designed to last almost a lifetime. Its efficient sensors compete in accuracy with that of mechanical sensors.

Oil Pressure Low Stops Engine but Oil is Full

Are you facing a similar situation to this one? It is very likely for your engine to show low oil pressure despite having a significant amount of oil. 

Depending on the mileage, condition of the engine, and how well it has been serviced, the possibility of having low oil pressure may vary. 

There is a possibility of broken oil pumps or crankshaft bearings, which cause pressure to a dropdown. Another reason might be due to faulty switches, even though it is very unlikely!

However, for further validation, disconnect a lead from the switch and see if the warning light goes off, depicting fault in the wiring. 

Just for a little clarity, it is important to know that having a proper oil level in the engine isn’t linked with having proper oil pressure as well. Having a low level of oil interferes with low oil pressure, however, these two are not always interdependent. 

Thus, the key point to note here is that it might be a poor sensor indicating low oil pressure or any other factor might also be contributing to low oil pressure. 

Such as, there is a screen under the oil pressure switch which often gets clogged with oil, thus display a sign of low oil pressure. 

This type of error can be misinterpreted as an oil pressure gauge, giving a false reading. Thus, to fix such an issue, take out the screen and get it checked to resolve the issue. 

Low Oil Pressure at Low RPM – Why is it So?

Worn-out bearings and seals can also let the oil pressure drop with a low level of rpm. You can try replacing them with new ones to resolve the issue. 

Another reason might be the relief valve in the oil pan. If it is left stuck open, you will have low oil pressure to the oil lifters and oil pressure sending unit. 

It might be due to the gunk blocking up the oil pump pickup screen. In such a situation. Try flushing it with cheap quality oil and see if it works. If that didn’t help you fix the issue, try using a solvent additive. 

Why is Engine Shows Low Oil Pressure When Hot?

A heated oil up to 80 degrees Centigrade will have less viscosity and resistance as compared to cool oil. Therefore, dropping of oil level in such a scenario isn’t anything surprising. 

When the pressure drops down with a hot engine, check the oil pump and pressure relief valve as they can cause low oil pressure as the engine warm-up.

Worn-out bearings and crankshaft can be among other components causing low oil pressure in a similar situation.

What to Do When Oil Pressure Low Stop Engine Warning Appears?

Now that you know low oil pressure in the engine is caused by multiple faulty components, it is important to know that the oil pressure switch and oil pressure gauge are also to be blamed. 

When the oil pressure low-stop engine sign appears, it could result from anything starting from a really low oil level to minor/major internal part failures. Have a look at the things which need to be check-in such circumstances. Without the need to unscrew a single bolt, look for the following items:

  • Air filter
  • Possible leaks in the hoses
  • The inner side of the intake manifold should not be clogged with oil deposits
  • Intake gaskets 
  • Check signs of smoke in the PCV box via the dipstick

Related Article: What are the Clogged Oil Filter Symptoms

2 comments

  • Hello, I really enjoyed your insight about this issue. My problems varies, early in the morning, when I start the engine, a message appears on the screen showing Oil Pressure Low, Stop Engine. However, the gauge shows normal oil level. Another thing I experience is a sudden drop of gas as I ride on the highway, and it find it difficult to climb the hill, however, before this happens, a message shows on the dashboard saying; Service Vehicle Soon, and the moment this message appears, the speed or the gas goes down suddenly, thereby loosing power of acceleration, do you know what might be the cause of this problem?
    I would be very glad if you could throw more explanation about this. Thanking you very much.

    • Hello Osagie, thanks for contacting me. First of all, tell me about your living region, is it hot or cold? and for your second problem, it might be bad spark plugs or wires according to your explanation. Because losing acceleration is not directly linked with the oil pressure.

Leave a Reply

Your email address will not be published. Required fields are marked *