How Long to Let the Engine Cool Before Adding Oil?

If you own a car, you’ve sometimes seen a light that signals a low oil level. This signal can either be a small text that reads “check your oil level” or an icon of a can that lights up. Regardless of how the light may appear on the dashboard, the signal means the same thing. When this signal lights up, an insufficient amount of oil circulates throughout your car’s engine. When ignored, this issue may cause serious future problems for your engine.

How long should you leave your engine to cool off before adding oil? Leave your engine to cool for about 10-15 minutes before checking how much oil is in the engine. If you want to replenish the oil in a recently driven car, you may want to leave the engine alone for about 20 to 30 minutes, allowing the oil to settle for a more accurate reading. You want to oil as still as possible before checking how much you have left before you put some more in.

Read on to know more about how long you should let your engine cool before adding oil and how vital oil is for your car.

How Long Should You Let Your Engine Rest Before Adding Oil?

how long to let engine cool before adding oil

It is advisable to leave your engine alone for 15 to 20 minutes or longer. Allow the engine to cool before checking, adding, or changing your oil reserves. Doing this allows you to handle the engine and oil easily; the oil won’t be too greasy.

Let your engine rest for a minimum of 30 minutes before dealing with it after a long drive.

Adding oil to your engine while it is hot is harmless. However, if you change your car’s oil completely, you must wait for it to cool down.

These two tasks require different processes, so you must wait until your engine cools off before changing your oil.

Letting your engine cool off before changing the oil inside will allow you to handle it much easier. The oil won’t be hot, and you’ll reduce the risk of burning yourself.

Furthermore, the oil will not be too hot once you start draining it, and it won’t be hard to work with your engine since you will have a reduced risk of burning yourself.

Fire up your car’s engine if you plan to change its oil, but it has been sitting idly overnight. By doing so, you can warm everything up to around 100 degrees. And this will let the oil flow faster and smoother. This is beneficial if you have to drain and change your car’s oil.

Why Should You Wait for the Engine to Cool Down?

More Accurate Reading

The main reason why you need to wait before your engine cools off before you do anything doesn’t necessarily rely on your engine. It isn’t particularly harmful if you don’t wait for it to cool down before you tinker with it.

However, letting your engine cool off is still advisable before adding, checking, or changing your oil reserves.

Letting your engine cool off is important to get a more accurate reading when you’re trying to check your oil reserves. Hotter temperatures will cause the oil to behave in a more volatile manner which could then result in false readings.

Prevents Accidents

Furthermore, working with a cold engine lessens the risk of accidentally burning yourself. Moreover, it is also possible that other areas under the hood are also quite hot due to being close to the engine.

You are potentially risking third-degree burns if you’re not careful, which is why it is essential to wait until the car manages to adjust and cool down.

Again, how long to let the engine cool before adding oil? Wait at least 20 minutes for the oil to completely drain into the sump. Then, check the oil level with a dipstick. Add small amounts of oil until you reach the oil level you want.

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What Would Happen If You Put Oil While the Engine Is Hot?

how long should engine cool before adding oil

Adding oil to your engine while it’s hot is not harmful to your car. A hot engine is not inherently harmed by introducing cold oil into its system. Let the engine get cooler if you want to check how much oil is left in the engine.

Hot Oil Tends to Expand

Hot oil has a tendency to expand, which is why it is not advisable to try and read hot oil in the engine. This is also why you should allow the engine to cool off before measuring how much oil is left in the reservoir.

It is common for drivers, especially new ones, to be unsure about adding oil to a hot engine. Many say they worry that cold oil coming into contact with a heated engine can cause the engine to develop cracks due to the temperature difference.

Engine’s Components Will Not Crack

The basis of this belief is that along with the engine’s oil, the engine’s metal components expand and contract. Should temperatures in the vicinity of the engine go up and down rapidly, the metal might break much like a glass that pops once subjected to boiling water.

Contrary to the belief stated above, there is no real danger if drivers try to add oil to a hot engine. The metal parts that comprise the engine are not as fragile as glass and have a certain degree of malleability.

Engine Oil Absorbs Heat Slower Than Water

Furthermore, engine oil has a strait that can soak the engine’s heat at a much slower rate than regular water and is incapable of cooling the engine nearly as fast as water can.

Should the oil canister inside the engine needs replenishing, make sure to add the oil in a way that ensures there will be minimal overfill.

The most efficient way of doing this is by figuring out how much oil you should add by using the markings to guide you. The difference between the two markings should all in all be one quart.

What Type of Oil Does Your Car Need

Various cars require various kinds of motor oil, and drivers need to understand which type of oil would best benefit their cars.

For example, a Toyota Corolla isn’t a model that would need a fully synthesized formula, but a Chevrolet Corvette would make the best use of the oil due to the make of its engine.

Remember that synthetic oils tend to be much more expensive in the market, so just purchasing some could set your wallet back a great deal for something you can do without.

Many companies often market their oils by associating their benefits with horsepower or fuel economy. As a driver, take these ads with a grain of salt. More often than not, the difference between oils is not noticeable when you’re behind the wheel.

There are formulas of oil for older engines with high mileage as well. Using these types of oil can benefit you, especially if you own a car with over 100,000 miles or over 160,000 kilometers.

Why Is Having Enough Oil Important?

how long does engine need to cool before adding oil

1. Lubricate the Engine’s Components

The oil inside your car’s engine has several essential functions aside from lubricating the engine’s components. As the engine runs, minute amounts of soot and dust can gather in obscure places around the engine’s interior.

2. Keep the Engine’s Interior Clean

This dust and dirt can block pathways if left alone to build up. The cleaning agents in the oil keep the engine’s interior pristine and free from dust and dirt.

This is the main reason oil turns dark and black once used for a long time.

3. Maintain the Engine’s Temperature

Oil is also responsible for keeping the engine as cool as possible for as long as possible while running. The oil in the engine is tasked with handling and coping with extreme temperatures.

However, newer engines now have built-in coolers, which help ensure that the oil can keep a level temperature across the entirety of the engine even at high output performances.

Because of all these important tasks the oil is in charge of across the engine, drivers must constantly check if they have enough oil in their cars. If there isn’t enough oil circulating through the engine, there is a high risk that the engine may overheat and shut down.

Once this happens, the oil inside breaks down on a molecular level and degrades, making it unfit to further use in the car. The oil will also lose its ability to lubricate the engine and its cooling properties.

In summary, tracking how much oil is in your car engine is always best. Consult your user’s manual whenever changing, adding, or measuring your engine’s oil. 

What Does It Mean When the Oil Light Flashes?

Conclusion: How Long Should You Let Your Engine Rest Before Adding Oil?

The oil inside the engine is one of the most important fluids needed to keep an automobile going. The oil in the engine helps the engine stay lubricated. Lubrication allows the car to keep doing its job as smoothly as possible.

This is why the oil in the engine needs to be read as regularly as possible.

Top up your car’s oil when needed. Also, drain used oil from your car during an oil change.

Ensuring the oil is at acceptable levels is essential to keep a car running smoothly. For this reason, it is also imperative for drivers to bring along canisters or bottles with extra oil.

Remember to let the engine cool off before measuring, evaluating, and adding oil to the engine. Leave the engine for 30 minutes before doing any work under the hood.

Additionally, ensure that you are parked on level ground whenever you’re doing oil maintenance for your engine.

Read next:

Signs Your Car is Overdue for an Oil Change

How Long Can You Drive Your Car with the Oil Light On