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Low Oil Pressure (7 Causes + 4 FAQs)

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Without sufficient oil pressure in the engine, your engine parts won’t get enough lubrication. This leads to more friction and your engine temperature may rise. Your oil pressure warning light will also pop on. 

So what can you do about low oil pressure? 
More importantly, what causes low oil pressure in the engine? 

In this article, we’ll take a look at the 7 main causes of the low oil pressure light. We’ll also answer some related queries to low oil pressure. 

This Article Contains:

Let’s begin.

7 Causes Of Low Oil Pressure

Since motor oil relies on oil pressure in the system to sufficiently lubricate each moving engine component, it’s important to monitor the pressure readings at all times. 

If you ever experience low oil pressure and see the oil pressure warning light turned on, one of these factors may play a role: 

1. Low Oil Level

The oil level dropping below the minimum dipstick line is one of the most common reasons behind low engine oil pressure. 

Your car’s engine oil level may be low due to an overdue oil change, an oil leak, or wear and tear. Without sufficient oil, the oil pump will not be able to generate enough pressure.

2. Oil Viscosity Is Too High Or Too Low

The oil viscosity can play a role in determining how much oil passes through the oil pump. 

If the engine oil is too thin (low viscosity), it generates less resistance to flow through the oil pressure sending unit. This, in turn, is read as low pressure by the pressure gauge or sensor.

In contrast, a thicker oil (high viscosity) typically produces greater resistance from the oil pump, leading to a lack of lubrication in the system, also resulting in low pressure.

3. Engine Damage Or Wear

Engine wear may not directly affect the oil pressure in your car, but it is responsible for a low oil level at times. 

How? 
Excessive engine damage can restrict the original oil flow, therefore dropping the pressure.

Another potential cause could be a worn engine bearing, especially if the engine has very high mileage. In this case, you’ll need to contact a mechanic to conduct the appropriate repairs.

4. Defective Oil Pressure Gauge

If your oil level is normal and the engine is running normally with no noises or high temperatures, the problem could be a defective oil pressure gauge giving out wrong readings.

In that case, you may need to replace the faulty oil pressure sensor and oil pressure gauge and get the pressure tested for the right readings. 

5. Dirt, Debris, Or Sludge In The Pickup Tube

Another common reason for apparent low pressure readings is the accumulation of dirt in the pickup tube that goes from the oil pan to the oil pump. 

If there are any contaminants blocking the oil flow in the pipe, it can cause a lack of pressure. As a result, the oil pressure switch will trigger the oil pressure light. 

6. Faulty Oil Pump 

If the engine oil level is between “Add” and “Full”, but the engine makes a lot of noise, you may have a faulty oil pump. 

A worn-out oil pump sometimes can’t generate the necessary pressure due to an internal oil leak. So you’ll likely have to get an oil pump replacement to get your oil pressure levels to normal again.

7. Clogged Oil Filter

In the engine oil system, the oil pressure gauge is placed after the oil filter and the pressure relief valve (also called the bypass valve).

So if you have a clogged oil filter or a contaminated filter, it may lead to oil starvation.
As a result, your system may indicate a low oil pressure.

Note: A clogged filter is often the result of old oil. It may also be caused by some water and/or soot contamination in the relief valve. Get an oil change ASAP to reset the oil light warning.

Next, let’s look at some common queries about low engine oil pressure and their answers.

4 Low Oil Pressure FAQs

Here are some answers to commonly asked queries about low oil pressure:

1. What Is Oil Viscosity?

Oil viscosity refers to how easily the engine oil pours at a specified temperature. 

It is often denoted in the “XW-XX” format, where “W” stands for winter (the oil’s viscosity at 0°F). The lower this number is, the less likely the oil is to thicken under cold conditions. 

The numbers after the “XW” denote the oil’s viscosity at high temperatures. The higher the number, the less likely the oil is to thin at 212°F.

2. Why Is Oil Pressure Important?

Motor oil is important to ensure proper lubrication of each engine component. In order for that to happen, oil pressure is created when the oil is pushed through the engine by the oil pump, forcing it in faster than it wants to flow. A pressure relief valve helps regulate the pressure to protect your engine when the pressure is high.

Simply put, the motor oil wouldn’t function efficiently without the right oil pressure. As a result, you may face several problems like decreased oil efficiency, engine performance, and fuel economy.

3. How To Check Oil Pressure?

If the oil warning light is turned on, here’s a quick walkthrough of how to check oil pressure:

  1. Lift up the front end of your vehicle and locate the engine oil pressure sender or oil pressure sending unit near the sump on the engine block.
  1. Place an oil pan underneath the engine to catch oil spillage and remove the electrical connector from the engine oil pressure sender.
  1. Remove the oil pressure sending unit from the engine block using the right socket (usually 1 1/16”) and mount the tester. You can also connect the test gauge to one of the oil cooler lines.
  1. Let the engine idle for 5 minutes or until it reaches operating temperatures. Maintain the required RPM as per the engine manual.
  1. Take the oil pressure readings and check if you have low or high oil pressure.

Note: Checking for high oil pressure or low pressure can be a tricky job. If you’re not someone with good mechanical knowledge, it’s best to leave the job to a mechanic

4. What Should I Do If My Car Has Low Oil Pressure?

If you have low engine oil pressure and the low oil pressure light is on, there are plenty things you can do to rectify this situation. However, the solution usually depends on the problem.

For example, you can use a higher-viscosity oil that can compensate for the increased bearing clearance, increasing oil pressure to normal. You may also have to repair the engine bearing themselves. 

If you’re unsure, it’s best to call a reputable mechanic. 
Why not try RepairSmith

RepairSmith is a mobile auto repair and maintenance solution with convenient online booking and a 12 months and 12,000 miles warranty on all repairs. Our highly skilled technicians can visit your driveway for all your car troubles! 

Final Thoughts

Low oil pressure can cause severe problems for your car — including engine wear, an overheating engine, and reduced engine performance. 

So why not tackle the problem before it causes trouble? 

Whether you have a faulty oil pressure sensor or pressure pump, contact RepairSmith today to get started with your car repair. Fill out this form to get an oil pressure sensor replacement cost estimate.