Bubbles On Dipstick: What Does It Mean? (Explained!)

Many car drivers are curious why there are bubbles on their oil dipstick. The oil dipstick is used to check your oil level and how clean and dirty your oil is. It is vital to ensure that your oil is good and still in good condition because the oil is the blood of your vehicle. 

To check the status and the condition of your oil, you need to have the oil dipstick and use it for the checking. If you have currently checked your oil using your oil dipstick and you noticed some bubbles on your oil dipstick, you may be curious and bothered why there are bubbles in there. 

If you want to know more regarding the possible reasons for bubbles on your oil dipstick, this article is definitely for you. Keep reading for enlightenment.

Bubbles On Dipstick

Why Are There Bubbles On My Oil Dipstick?

If you notice bubbles on your oil dipstick, there must be a reason for that. For example, if there are brown bubbles on your oil dipstick and you see some bubbles in the level line of the oil, then it can be a possible indication that there is a water or coolant (antifreeze) that is currently leaking in your engine. 

You might also notice that the oil in your oil dipstick or inside the oil tank is brown or black. So one of the most probable reasons is that there is antifreeze in your oil. If there is an antifreeze or coolant in your motor oil, then you might be having a blown head gasket, or there might be a cracked block. 

If you want to do something, you can remove the oil dipstick and then rub some of the oil off your oil dipstick using your finger. Then, with the residue on your finger, rub it with your thumb. If you feel that the residue is a bit sticky, there might be an antifreeze or coolant in your motor oil. 

If this is the scenario, you need to have your vehicle check as soon as possible. You can also smell the bubbles first. Some people want to eliminate first if the bubbles are created by water or coolant. 

The coolant will have a very particular smell compared to the water. Check if the oil is milky because, as mentioned, you might have an issue with your gasket, or there might be a break in the block, and this will make way for the coolant to go into the engine oil system.

Bubbles On Dipstick After Oil Change: Is It Ok?

The internal combustion engine is like the air pump. It means that it will move the air mixture into the combustion chamber and out of the combustion chamber as an essential part of shifting heat into motion. But, the air will also be shifted on the underside of the pistons or inside the engine’s crankcase. 

This is because the crankshaft is spinning around. The connecting rods are also doing the same, and the pistons are pushing in a single direction. So to simply put, the life and the environment inside the crankcase are very raging. 

You can check if you will take out the oil dipstick with the engine still running. And because of that turbulent environment inside the crankcase, the motor oil will become some froth because it will somehow mix. So there might be some bubbles in your dipstick, which can be considered normal if we talk about a regular engine oil with no contamination. 

However, there are times when having some bubbles in the oil dipstick does not just mean a simple turbulent atmosphere inside the crankcase. With this kind of scenario, it is essential to have the vehicle checked.

Is It Bad To Have Bubbles On The Dipstick?

Well, that depends. A good quality motor oil must not foam up or have bubbles, except for the bubbles formed by the regular movement inside the crankcase. The oil also has anti-foaming additives, and that keeps the oil from having foam. 

If there are bubbles in your motor oil and discoloration, then there could be an overfill with your lump. If there are bubbles in your oil, it can have a lot of damage.

On the other hand, if the foam or the bubbles are light, you might have water or coolant contamination. A cause of this, as mentioned, is a leak on your gasket head and a crack in your engine block. 

The solution would be to drain off and then refill your oil tank. If you wish, you can even visit a mechanic.

Why Do I Have Bubbles On My Transmission Dipstick?

If you have bubbles above the level line on your oil and your oil dipstick, this can be due to contamination of a coolant or an antifreeze. Water or an antifreeze might be leaking into your engine.  If there is coolant detected in your motor oil, you might need to have it repaired immediately. 

So if the symptom is bubbles on your oil dipstick and the transmission is engaging and slipping slowly, there might be an insufficient ATF level. The oil pump might also intake fluid with some air. There can also be depressurization on the oil passage, and there can also be leakage of ATF into the seals and the gaskets. 

You need to adjust the fluid level and look for the transmission unit for any ATF leaks. You can also visit a local transmission shop, and there are bubbles in your transmission dipstick. There is also one scene where there are bubbles in your oil dipstick, but the ATF is clean, and the transmission is running and engaging smoothly. 

Some of the possible reasons for this are a result of mixing different transmission fluids, the use of old ATF, the use of the wrong fluid type, and the overflow of the transmission fluid level. The solution is to do a transmission flushing at your local transmission shop.


In summary, there are car drivers who are experiencing some bubbles on their oil dipsticks. Car drivers have been thinking of the possible reasons for these bubbles, and they are thinking of ways to fix the bubbles on their oil dipstick. 

If without contamination, the bubbles can be because of just the turbulent environment inside the crankshaft. However, some reasons can be dangerous, so you need to consult a mechanic right away.

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Image credits – Canva

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My name is Hank, and I've been in the automotive industry for 27 years. I've been working in my own auto repair shop for the last 13 years, and now I want to help you here, on my blog. Let me know if you have any questions. Read more