What Causes Air Bubbles in Engine Oil? Get The Facts!

It is best to keep in mind that air bubbles in engine oil can be caused by several things and indicate a problem with your vehicle’s engine.

It’s essential to identify what causes the problem so that you can take the time out to diagnose and address the issue. In this article, we have explain everything you need to know about the reason behind air bubbles in engine oil and how you can actually solve the issue.

What Causes Air Bubbles in Engine Oil?

What Causes Air Bubbles in Engine Oil

Here are some potential causes:


If somehow you start to notice some form of air bubbles on your oil dipstick, there could be several causes for this. In order to get to the bottom of it, we think you should contact a mechanic as soon as possible for assistance.

If the bubbles appear to be of a light hue, they could be indicative of water or coolant contamination in your engine’s gasket head or block. If this is the case, it could indicate that an issue exists within its seals.

Conversely, bubbling oil could be due to overfilling the sump. This situation could potentially result in serious engine damage if not dealt with in time.

Additional factors that can exacerbate an oil’s foaming tendency include supplemental air, impurities, mixtures and oil oxidation. The resulting foaming can result in significant operational costs and reduced performance.


The thing is that when oil circulates throughout your engine, it actually passes through a maze of narrow passages and can come into contact with air, which end up leading to bubbling up.

This can occur for many different reasons, including not enough anti-foaming additives in the oil, particles present which allow bubbles to form around them, contamination and air being drawn into the system through a leaky seal.

It is best to keep in mind that contamination is an issue throughout the lubricant’s lifespan. It is often caused by outside elements like tanker trucks and storage containers, unsanitary dispensing methods, as well as environmental concerns like dust and moisture.


One of the most common engine oil related issues is a leaky gasket or seal. While this issue may seems to be a big of a deal at first, if it is not dealt with accordingly, the damage it can do to your engine could be extensive.

Gasket leaks are among the most hazardous oil leaks in any vehicle, as they can lead to major engine component failure and costly repairs. If you want to prevent such a scenario from taking place, you should ensure that your vehicle’s lubrication levels are kept optimal by checking and changing oil regularly.

Low Temperature

At any point you notice bubbles on your engine oil dipstick, it could be indicative of an underlying issue. These are often due to either a lack of anti-foam additives in the oil or contamination that has seeped into the engine.

It is safe to say that low temperatures can allow air into the oil and form bubbles that eventually turn into foam. This is undesirable, since foam increases oil oxidation and decreases its lubrication properties.

In order to prevent these issues from occurring, you should use a lubricant with high levels of foam inhibitors. What it does is help weaken the structure of air bubbles and make them more vulnerable to burst.

Learn More: How Does Engine Cooler Work


As you can see, there are a number of factors behind air bubbles in the engine. If it’s a case where the bubble is just caused by the crankshaft turbulence, then there isn’t much to worry about. However, it is best to know that the bubbles can also be caused by contamination in the crankshaft.

The thing is that it is quite difficult to identify contamination in an engine oil unless you’re an expert. So, if you are currently experiencing air bubbles in your engine oil, it is best to contact a mechanic in order to get the issue solved.