What Causes Air Bubbles In Engine Oil (5 Reasons To Consider) 2024 Update

Are you just going to check the oil condition when the engine is hot and find tiny bubbles in it? 

Or are you cruising along, but suddenly, your engine starts making a strange sound? 

Don’t panic. You aren’t alone. 

Around 60% of auto enthusiasts like you face lubrication issues. And pisky air bubbles can be one of the causes for this. 

Now, many questions come to your mind…

  • What are air bubbles
  • What they do in your engine oil
  • What causes air bubbles in engine oil
  • Signs of Air Bubbles in Engine Oil
  • How to test oil for air bubbles & Solve

In this blog post, we’ll cover you all one by one. Stick around and delve into this often-overlooked issue. We promise reading this post will save your car’s engine from air bubbles and also your wallet.

What Is Engine Oil & Its Role To Your Engine?

We’ll surely solve the bubble mystery. But before that, it’s essential to understand what engine oil is and what it does for your engine. 

Engine oil isn’t just a “liquid goop”. It’s more than that. In one word, it’s your car’s lifeblood to keep it working. 

Types of Engine Oil

Advanced synthetic, Synthetic, synthetic blend or mineral are the four types of engine oil. Each of them has their unique pros and cons. And different engines require different oils for its betterment. 

Role of Engine Oil

After gliding the oil into your engine parts it will offer excellent oil pressure into the engine components. Reduce frictional engagement between them. Remove sludge and deposit contaminants.

What Are Air Bubbles & What They Do In Your Engine Oil?

Generally, air bubbles are tiny pockets of air trapped in liquids. But it plays a big deal in engine oil. It’s time for a brief science lesson to understand it from its core. 

From the view of general science, air bubbles can reduce the oil’s effectiveness as a lubricant. 

But you think …I also see air bubbles in everything from fish tanks to my favorite soda. 

If they aren’t problematic there. Why do air bubbles have issues with my engine oil? 

The reason is…

  • It reduces the oil quality 
  • The poor oil fails to prevent component friction
  • The contaminated oil can’t resist the heat, which may damage your engine.

Got it?

What Causes Air Bubbles In Engine Oil?

Alright, let’s talk about the big question that is in your head. What causes these air bubbles to appear in your engine oil? Here are the 5 most common reasons 

1. Improper Filling Techniques

Do you tend to pour oil into the oil tank too quickly?

Or do you pour oil from the wrong angle? 

If so, that’s the rookie mistake you make while changing oil.

Both of these aerate the oil, trap air, and cause bubbles.

2. Engine Wear and Tear

Nobody can deny that the car’s internal parts wear down over time. 

Those faulty engine parts may cause irregular oil flow into the components. 

The results? 

Pesky air bubbles are created in the engine oil.

3. Temperature Fluctuations

Sometimes the temperature goes too high in summer. And in the winter, it becomes frizzy. 

And too high or too low temperatures can change your oil’s viscosity. These temperature fluctuations may make the oil more susceptible to creating air bubbles.

4. Oil Contaminants

Have you ever looked at the cooking oil after frying stakes? 

Does it look fresh or gunky? 

Gunky, right. 

The same happens with your engine oil. 

Some sludge and deposits form when you drive more than 3,000 miles with the same oil. 

Those debris and contaminants disrupt the oil flow. Improper oil flow contributes to air bubble formation.

5. Mechanical Malfunctions

Oil pumps are the source of flowing oil over the engine parts. The gaskets work as the guardian to prevent inserting anything but oil into the reservoir. 

But, over time, the pump can be faulty, and the gasket can be leaky. 

The faulty oil pump or the leaky gasket may introduce foreign substances into the system. And all those will mix with engine oil.

What do they do in the oil?  

They will create air bubbles in your engine oil. 

Common Signs of Air Bubbles in Engine Oil

So now the question is: How do you tell if air bubbles are in your engine oil? Three simple ways are known as air bubble signs. Such as 

1. Visual Cues

When checking your oil condition, if you notice a frothy or bubbly consistency in it. That’s a red flag for air bubbles. 

2. Sounds and Noises

If you hear a gurgling sound under the hood, even in a quiet place. Yep, that is also a sign of air bubbles in the oil.

3. Performance Issues

If your car suddenly gets sluggish. Or your engine doesn’t work as powerful as it was. You should check air bubbles in the oil, as they may be the culprit of the engine’s low performance. 

Never slip by these warning signs. The signs could tell you something important. And paying attention to them may save your engine. 

How To Test For Air Bubbles & How To Solve

Wondering how to confirm if there are air bubbles in your engine oil. Knowing the proper methods will help you to identify the air bubbles and take action accordingly to solve them. And it makes the difference between your well-functioning engine and a disastrous breakdown. Here are some reliable techniques…

1. The Dipstick Test

Your oil dipstick is the primary tool and the most straightforward test to check air bubbles. 

Steps to follow 

  • Park your car on level ground.
  • Turn off the engine and wait 5 minutes.
  • In the meantime, the oil will settle.
  • Remove the dipstick from the tank.
  • Wipe it with a clean towel and reinsert it.
  • Pull the dipstick out again.
  • Examine the oil with your eagle eyes.
  • If it looks frothy or bubbly, there are air bubbles.

How To Solve 

  • If you find the oil is looking frothy or bubbly. 
  • Changing the oil following proper filling techniques will solve the issue. 

Tip: Slow and steady is your ticket to avoid further aeration during refilling.

2. Visual Inspection Through The Filler Cap

Visual inspection of your oil reservoir is the second trick to discovering air bubbles. 

Steps to follow 

  • Open the hood of your car.
  • Reach the oil filler cap and remove it.
  • Using a flashlight, keep your eyes inside the oil reservoir.
  • If there is any spot of frothy oil or air bubbles, it indicates air in the oil.

How To Solve

  • Closely observed the oil reservoir and the filler cap.
  • If you notice any cracks around the cap or reservoir. 
  • You should replace those damaged parts.

3. Engine Sound Analysis

Sometimes, hearing unusual sounds from your engine give you a  takeaway of air bubbles. Paying attention to the sound will help you identify the air bubbles. 

Steps to follow

  • Park your car, keeping the engine started. 
  • Open the hood and carefully listen to your engine when it’s running.
  • Listening to a gurgling or knocking noise from the engine may be due to disrupting oil flow.
  • And that might be for significant air bubbles. 

How To Solve

  • Check your oil pump and pipelines. 
  • It helps you to figure out the possible malfunctions.
  • If any of the systems is faulty or worn out. Replacement is the best way to solve the air bubbles. 

4. Using Specialized Tools

If you are tech-savvy, there are many devices to identify air bubbles in your engine system. 

Steps to follow

  • Under My Hood, WIX Filters, and other oil analysis kits are available. 
  • You can test various oil issues, including aeration, using any of these.

How To Solve

  • If those kits confirm aeration.
  • You have to identify the root cause. (That can be the above three.)
  • And solve following our above guidelines. 

Tip: While using the oil analysis kit, carefully follow the kit’s instructions for accurate results.

5. Professional Diagnosis

If you can’t manage time doing those tests yourself. Or if you aren’t confident enough to handle your car engine alone. Or After conducting the text, find ambiguous results. In that case, it’s better to consult with the experts.

Steps to follow

  • Take your car to your nearest reliable mechanic.
  • They will perform advanced diagnostic tests using their professional-grade tools. 
  • And get a definitive answer to solve it.

What to Do if a Professional Confirms Air Bubbles

  • You have nothing to do except follow the mechanic’s advice. 
  • If they suggest component replacements, oil changes, or other forms of servicing depending on their diagnostic results.
  • Go with their advice for your engine’s better health and performance. 


Now, you know deeply what causes air bubbles in engine oil, how to test, and what to do.

Take this info to your heart for immediate 

action if needed. Your car engine, driving enthusiasm, and wallet will flourish for your decision. 

Make it a part of your regular car maintenance. These simple steps will save you from those nasty, costly engine problems.

Until next time, keep your engines humming and its wheels turning.

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