What causes low oil pressure on diesel engine

Causes of Low Oil pressure after Oil Change + How to Fix Low Oil Pressure at Idle

Last updated on January 13th, 2023 at 08:26 pm

Are experiencing a low oil pressure at idle when hot or maybe you still notice a low oil pressure after an oil change is done in your vehicle.

If you do notice any of these, then this post on low oil pressure fix/ how to fix low oil pressure at idle is going to guide you.

In this article, we talked about what causes low oil pressure in an engine generally and what causes low oil pressure on diesel engine vehicles too.

I also discussed the common low oil pressure symptoms or sign you should be familiar with, how much does it cost to fix low oil pressure and finally how to fix low oil pressure at idle when hot and cold.

One of the serious issues that could affect an engine is low oil pressure which is usually indicated on the dashboard of your vehicle.

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Causes of Low Oil pressure after Oil Change + How to Fix Low Oil Pressure at Idle

Motor oil is a lubricant that protects your car engine from friction which in other words stops it from overheating and break-down.

The car engine oil helps to prevent friction from moving components and reduces wear and tear. Engine oil also helps to remove every debris or dirt from the surface of the engines moving parts.

This is one of the reasons why engine should not run out of oil. If the engine ever has low engine pressure, it could lead to serious problems and might eventually destroy the engine.

Oil pressure is an important parameter in a vehicle. Every vehicle has a symptom which shows if the oil pressure level drops.

If you are driving and the pressure light comes on or the gauge reports a low reading, then there is an issue with your oil pressure.

It is recommended to stop driving immediately and shut off your car’s engine. Driving when the oil pressure light on your dashboard is on is dangerous and might eventually destroy the engine in no time.

This is because when the oil level is low, the components of the engine are working without any lubricant and it will lead to friction.

What causes low oil pressure in an engine?

Some of the major causes of low oil pressure are as follows

Low oil viscosity

The manual of every car comes with important information. One of those is the best oil for your vehicle’s engine.

Putting a low oil viscosity than recommended in your engine can lead to lower oil pressure. Apply the right type of oil, do not use one with a higher or lower viscosity.

Low level of oil

As a car owner, you should ensure you regularly check the level of oil in your engine. The oil level should not be lower or higher than it should.

It would be quite difficult for oil to continuously pump into the engine.  A way to avoid this is to maintain your car properly and change the oil regularly.

Damaged oil pump

A faulty oil pump will be unable to maintain the oil pressure that is needed to flow into the engine. The oil pump can get damaged over time and it is also one of the major causes of low oil pressure.

Clogged oil filter

The oil filter helps to remove debris and dirt from the oil before it flows to the engine. The dirt can clog the filter as time goes on. It will affect the easy flow of oil to the engine and might eventually lead to low oil pressure.

What causes low oil pressure on diesel engine

Low oil pressure is one of the serious issues that could affect any type of engine. Engine components needs oil to lubricate their parts so that they can work well without any sort of restriction.

It is important to properly maintain your engine and check its oil level to avoid low oil pressure.

There are numerous causes of low oil pressure in a gasoline but there are some major causes. One obvious cause is if there is no oil in the vehicle.

Once you notice your oil light warning come on, shut your engine and let it cool for some time. Then, you should check if the oil is at its expected level.

If it is not, all you have to do is top the oil. If the oil is leaking, it could also cause low oil level. So, ensure you confirm the oil is not leaking from any part.

However, if you find a leak and it is minor, you can fix it with a seal. If it is not minor, you need to take to take it in to a driver.

Another cause of low oil pressure is if there are contaminants or dirt in some components of the vehicle. It can cause engine wear, block various passageways, or parts misalignment.

Ensure you are using the right kind of oil for your car, the oil viscosity must not be too low or high. Check your vehicle manual for the manufacturer’s recommendation.

Some other causes of low oil level in a gasoline engine are faulty oil pump, damaged oil sensor, and worn out oil pump. Whatever the problem might be, make sure you shut off your engine once you discover low oil light. Do not continue driving the car until it has been fixed.

Common Low oil pressure symptoms

Oil pressure warning light

This is the fastest and most obvious symptom to know your vehicle is dealing with low oil pressure. The oil light and oil sensor are connected. Once the oil gets low, the warning light will be triggered to inform the driver.

Oil smell

If you notice a foul burning oil smell in your car, then you might be having low oil level issues. You should shut off your engine immediately and check for the problem. The simplest explanation is that oil is dripping on other hot parts of the engine which is eventually causing the foul smell.

Clunking sound

Motor oil is responsible for lubricating the components of the engine. If they are not lubricated enough, it leads to clunking or knocking sounds. This might lead to rods breaking and start causing noises. Hearing loud noises coming from under the hood of your car is an obvious symptom of a failing engine.


Another symptom of low engine oil is an overheating engine. When oil is not lubricating the needed parts very well, it leads to friction and will affect the engine. The engine parts will begin to rub together and might cause overheating.

Metals contacting each other will raise the systems temperature and eventually cause engine overheating.

How much does it cost to fix low oil pressure

The cost of fixing a low oil pressure depends on the cause of the problem. Then you should consider the labor cost of the mechanic. Some might be cheap while others might be quite expensive. An example is a faulty oil pressure sensor.

To replace the part, you need about $130 for labor cost and part replacement. This is one of the reasons why you need to find a solution to low oil pressure immediately before it leads to a serious damage.

Damaging your vehicle engine will cost you a fortune by then it starts getting into a $1000 and higher when the problem escalates to engine-related issues. So, it is advisable to fix whatever issue immediately before it leads to a serious issue.

How to fix low oil pressure at idle

              Causes – Solution

  1. Low oil – Fill oil up
  2. The wrong type of oil – change or replace the entire engine oil
  3. Faulty oil pump – Urgent replacement of the oil pump
  4. Internal oil leak –Oil pump replacement or identify the leak and then seal it with good stop-leak sealer
  5. Damaged oil pressure sensor – oil pressure sensor replacement


There are lots of issues that can affect the engine of your vehicle and low oil pressure is one out of those.

Once you see the oil pressure light come on, try to find an immediate solution before it eventually leads to engine damage. A way to avoid low oil pressure is to constantly carry out your vehicle maintenance.

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