How Long to Let Engine Cool Before Adding Oil? (Explained)

Adding oil to your car is an essential key for more exemplary engine performance, especially if it’s running low on oil. It’s for this reason that many drivers carry extra oil in their compartments. Still, if you fill it up in between drives, you may get burned due to the engine‚Äôs heat. Thus, you may ask:

How long should the engine cool before adding oil? If you add car oil to a recently driven car, you may wait for around 20-30 minutes for the engine to cool down. This way, it will give the oil a chance to settle, giving you a more accurate reading. Your oil must be cool enough not to splash on your dipstick as you measure it.

Adding oil to your car’s engine is quite simple, and it’s not something you can miss. However, you may find some tips and tricks helpful as you do it the next time.

For instance, below are some related questions which we tried to answer. These answers and information should come in handy as you try to add car oil to your engine.

Without further ado, let’s get into it!

How Long to Let Engine Cool Before Adding Oil

Should You Wait For the Engine to Cool Before Adding Oil?

If your concern is about the engine, don’t worry. It’s alright for you to add car oil to the engine without waiting for it to cool down. However, in general, the motor isn’t the only thing that matters.

It would be better for you to wait for the engine to cool before adding oil for many reasons.

For instance, letting the engine cool down also allows the oil in it to settle. If the oil is too hot, it’s more volatile, which means it flows quicker. Such a texture would mean the oil might splash in your dipstick, giving you an inaccurate reading.

Thus, it would be crucial to have your car settle for a few moments before adding oil.

Another thing to note is that if the oil and engine are too hot, you may end up getting burnt in the process. Aside from the oil, the engine parts under the hood are likely piping hot as well.

If any part of your skin touches the engine, you may end up getting burnt.

Summing it up, you should wait for the engine to cool before adding oil. It’s not for the reason that it will harm the engine, as it’s not true. It’s generally to protect you and to allow a more accurate dipstick reading afterward.

How Long to Let the Engine Cool Before Changing the Oil?

If you’re simply adding oil, you may already fill it without waiting to cool down. However, if you’re changing the oil, you may let it cool down for a minimum of 30 minutes.

Adding oil and changing it are two different processes, and so you also need to do two different ways for it.

Since you will change the oil, it would be ideal for cooling the engine down for around 30 minutes. This way, it won’t be hot enough once you start draining it.

Moreover, it will also allow your engine parts to cool down. As a result, it will be easier to handle, and you’ll avoid getting burned by the heat.

If your car isn’t coming from a drive, you may fire it up for at least 2-3 minutes. This way, you’ll heat the car oil to around a hundred degrees.

Such a temperature will make the oil flow faster, giving you a quicker draining time. It will also allow more oil to get drained rather than doing it on a cold engine.

How Do You Know the Engine Is Cool Enough Before Adding Oil?

While you can’t know for sure, take it as a rule of thumb to wait for half an hour until you add or change the oil.

In such a period, both your engine and oil will get cool enough to handle while the latter remains hot enough to flow easily.

If your car has been out for a longer spin, 30 minutes will suffice for it to cool down.

If you add car oil to your car that is entirely rested, you can do so without worries.

Another thing to note is to park your car on level ground as you add oil. This way, you’ll know how much to add, and you’ll get a precise measurement afterward.

Most manufacturers recommend checking the oil if the motor is cold. This way, you’ll get the most accurate reading, especially on a dipstick.

hot engine

What Happens If You Put Oil in a Hot Engine?

In general, no harm will happen to your engine if you add oil while it’s still hot.

You can add car oil to your engine, as cold oil will not hurt a heated engine. However, you may let it cool down before you measure the oil level.

The reason is that hot oil expands a bit, giving it a flowy texture. If you read a hot oil, it may splash all over the dipstick, resulting in an inaccurate reading.

For this reason, you may need to cool it down for at least 30 minutes. Such a time will allow the car oil to settle, providing a more excellent reading result.


Adding oil is essential for every car that runs regularly. For this reason, it’s also crucial that every driver has excess oil in the trunk so they can add up when needed.

If you add car oil to a heated engine, you may wait for at least 30 minutes to cool down. While it won’t harm the engine to add oil while it’s hot, cooling down allows a safer process and more accurate reading.

Moreover, it would be ideal to park your car on a leveled surface and proceed with caution to avoid adding too much.



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