Top 7 Causes of Low Oil Pressure and Common Symptoms

Oil pressure is a critical factor for the proper functioning of an engine. When the oil pressure light illuminates or the pressure gauge indicates a less oil than usual reading, it signifies a potentially significant issue. Inadequate oil pressure deprives engine components of sufficient lubrication, resulting in heightened friction and potential overheating. This article explains low oil pressure causes, symptoms, and how to fix it.

Causes of Low Oil Pressure

Causes of Low Oil Pressure

A sufficient supply of engine oil is crucial to prevent the engine from overheating and damaging. There are different reasons of the low engine oil pressure. It’s important to note that a low reading on the pressure gauge may be an accurate or unreliable indication. Regardless, it is beneficial to familiarize oneself with some commonly encountered causes.

The following are the most common reasons of low oil pressure:

  • Insufficient Oil in the Engine
  • Apparent Low Pressure
  • Wrong Viscosity Oil
  • Faulty Oil Pressure Gauge
  • Engine Wear
  • Faulty Oil Pump
  • Clogged Filter

1) Insufficient Oil in the Engine

Low engine oil is one of the most common causes of low oil pressure.

dipstick showing low engine oil

In some cases, even when the appropriate amount of engine oil is poured during an oil change, oil can be consumed excessively due to various factors such as worn piston rings, evaporation, and leakage through gaskets or the oil plug.

As an engine ages, oil consumption tends to increase, making it necessary to regularly inspect the oil level and add more. But if leaks are noticeable externally or there are oil stains on the ground, it is crucial to address the underlying issue promptly.

An aging engine is likely to consume more oil. When your vehicle’s engine reaches a point where it burns one quart of oil every 1,000 to 2,000 miles, it means your engine requires an overhaul. It is important to adhere to recommended oil change periods and periodically check the oil level to ensure it remains at an adequate level, even if the engine is not significantly old.

2) Apparent Low Pressure

In the case of a diesel engine, the pressure gauge provides real-time measurements of oil pressure. Certain lubricant brands offer oils with lower viscosities that still fall within the acceptable range for the SAE grade.

Lower viscosity oils offer improved fluidity within the lubrication system but may cause lower pressure readings on the pressure gauge. As long as the pressure remains within the normal range, there is usually no need for worry. It’s worth noting that different lubricants can yield varying pressure levels.

3) Wrong Viscosity Oil

A wrong viscosity oil can result in a drop in oil pressure within the engine. If your engine oil viscosity is too low, it creates minimal resistance to flow throughout the engine, leading to a lower pressure reading on the pressure gauge.

Conversely, if the viscosity is too high, the oil faces increased resistance when being pumped, resulting in inadequate lubrication within the engine and poor oil pressure.

Wrong Viscosity Oil

Several factors affect the viscosity of oil in an engine, including the initial viscosity grade chosen, operating temperatures, degradation of viscosity index improver additives, and the contaminants like soot and glycol.

To ensure optimal performance, the recommended viscosity grades for the engine or vehicle should be followed as specified in the vehicle manual, taking into account the engine’s design and the ambient temperatures in which the car will operate.

4) Faulty Oil Pressure Gauge

If the oil pressure gauge of your car shows low oil pressure, but the oil level in your engine is sufficient, and the engine is running smoothly without any uncommon noise or excessive heat, the issue might be with your oil pressure gauge.

Oil Pressure Gauge

To determine the actual oil pressure, it is advisable to conduct a pressure test using a gauge. If the pressure is within the normal range, replacing the oil pressure sensor should resolve the problem. But if the pressure reading remains low or the oil pressure warning light remains illuminated even after changing the sensor, there are chances that your oil pump is faulty.

5) Engine Wear

If the oil level on your dipstick falls between the “full” and “add” marks, worn engine bearings could be a potential cause of low pressure, particularly in engines with high range.

Engine Wear

Unnecessary wear on the engine parts diminishes the original flow restriction, resulting in decreased pressure. In such conditions, it is likely necessary to rebuild or replace the engine.

6) Faulty Oil Pump

If your engine is producing unusual noise, despite the oil level on the dipstick being between the “full” and “add” marks, it is possible that your oil pump is damaged.

Oil Pump

A damaged or faulty oil pump can’t produce the required oil pressure because of internal leaks. It is important to turn off the engine and refrain from running it until the issue is addressed. Replacing the oil pump will be necessary to resolve this problem.

7) Clogged Filter

A clogged or damaged oil filter is one of the major reasons of low oil pressure.

Oil Filter

In your vehicle’s lubrication system, the pressure gauge is typically located just after the oil filter. If your oil filters are clogged with dirt, it can result in an insufficient lubricant supply, leading to potential issues.

A clogged filter is frequently the consequence of prolonged oil usage beyond the recommended interval. Additionally, water and soot contamination can contribute to filter blockage. Unnecessary soot can be generated by incomplete combustion, while water contamination typically arises from a cooling system leak.

If your bypass valve fails to operate correctly, a faulty filter might be the underlying cause.

Read More: What Happens if you use the wrong oil?

Symptoms of Low Oil Pressure

A low oil pressure produces one or more of the below-given symptoms:

  • Oil Warning Light
  • Burning Oil Smell
  • Engine Noise
  • Poor Engine Performance
  • Engine Overheating

1) Oil Warning Light

If the oil pressure in your engine becomes lower than sufficient level, the vehicle computer can trigger the oil warning light on your vehicle’s dashboard.

oil warning light

If you notice the light illuminating, it is important to find a safe location to stop the vehicle, such as a service station, gas station, or parking lot. Once stopped, properly inspect the oil level.

If the system has sufficient oil, it is recommended to drive your vehicle to a repair shop for the proper inspection. The problem can be with the oil pressure sensor, or it could indicate a more significant issue that requires attention.

2) Burning Oil Smell

A noticeable smell of burning oil suggests that your vehicle is experiencing an oil leak, with the oil coming into contact with hot engine components. This leak can lead to a decrease in oil pressure.

burning Smell

When you detect the smell of burning oil while driving, find a safe place like a parking lot or gas station to pull over and inspect the oil level.

3) Engine Noise

When the engine oil level becomes insufficient, the rotating components of your engine are deprived of the necessary lubrication they require for smooth operation. As a result, you may begin to hear unsettling noises such as grinding, ticking, knocking, or clunking sounds emanating from your engine.

If you notice these noises, it is crucial to seek professional automotive servicing promptly.

4) Poor Engine Performance

If you experience frequent stalling, sudden power loss, or increased fuel consumption, it could be a sign of poor engine performance.

However, there are many other vehicle problems that may cause poor engine performance, and low oil pressure is one of them. To start troubleshooting, inspect the oil level to determine if a simple oil and filter change is needed.

5) Engine Overheating

Engine oil plays a crucial role in properly lubricating the rotating parts of your engine. Inadequate oil pressure means your engine will function with reduced lubrication and increased friction, leading to elevated temperatures.

car Overheating, symptoms of low oil pressure

While engine overheating can be caused by various factors, low engine oil pressure can contribute to this issue. An overheating engine places additional strain and wears on the engine components, necessitating attention and maintenance.

Read More: Engine Overheating Symptoms and Causes

How To Check Oil Pressure?

To check the oil pressure in your vehicle, follow these steps:

  • Safely elevate the front end of your car and find the oil pressure-sending unit. It is typically situated near the sump on the engine block.
  • Position an oil pan beneath the engine to collect any oil that may spill. Disconnect the electrical connectors from the engine oil pressure sender.
  • Use a suitable, appropriate socket to remove the oil pressure-sending unit from the engine block. Alternatively, you can connect the test gauge to one of the oil cooler lines.
  • Start the engine and allow it to idle for around 5 minutes or until it reaches the recommended working temperature. Ensure the RPM is according to the limit specified in the engine manual.
  • Use the test gauge to measure the oil pressure and determine whether the oil pressure is high or low, comparing it to the recommended specifications.

FAQ Section

What is Oil viscosity?

The viscosity of oil represents its ability to flow in a particular weather condition. It is typically represented in the format “XW-XX,” where “W” denotes winter viscosity (the viscosity of engine oil at 0°F). A lower number indicates less thickening of the oil in winter. The numbers after “XW” represent the viscosity of engine oil at a high temperature. A higher number indicates a better resistance to thinning at 212°F.

What is the effect of low oil pressure?

Insufficient oil pressure in your vehicle’s engine results in reduced lubrication and increased friction, leading to engine overheating. Engine overheating may be a severe problem, but it is not always directly caused by low engine oil pressure.

Why is Oil Pressure important?

The engine oil plays a vital role in ensuring proper lubrication of the engine’s rotating parts. An oil pump is used to circulate the oil through the engine at the best suitable pressure, surpassing its natural flow rate. A pressure relief valve is present to regulate the control and safeguard the engine from excessively high-pressure levels.

How do you increase oil pressure?

  • Regularly inspect your engine oil and change it if needed.
  • Ensure a sufficient supply of the engine oil
  • Properly clean your oil pan
  • Check the oil filter and change it if needed
  • Replace the faulty oil pump

What is normal oil pressure?

The optimal oil pressure range varies according to the vehicle model and engine type, but typically oil pressure falls between 25 to 65 PSI.

Can I drive with low oil pressure?

It is not recommended to drive with low oil pressure. It is crucial to address any signs of low oil pressure promptly, as continuing to drive with insufficient pressure can lead to severe engine damage. If the oil light illuminates or any other indications of low oil pressure arise, it is advisable to have your engine serviced without delay.

Does oil pressure increase with RPM?

Yes, oil pressure usually improves with engine RPM. When the speed of your engine increases, the oil pump rotates faster, causing a higher flow rate and improved pressure within the engine lubrication system.

Can a bad oil filter cause low oil pressure?

The blockage in the oil filter may contribute to decreased oil pressure. The oil filter is equipped with a pressure relief valve, and if this valve goes bad, oil can flow through too easily, causing a reduction in pressure.

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