Engine oil levels are one of the most important things you’ll need to monitor on your vehicle. Changing or adding oil when necessary is something you’ll want to do in a timely manner to avoid damaging the engine, but can you do this while the engine is still hot?
You can put oil in a hot car engine, as this will not cause any damage to your vehicle’s components. However, it is sometimes wise to wait for the engine to cool for a few minutes to reduce the risk of burns, excess smoking, and even fire.
In the rest of this article, I will discuss some critical factors to consider when changing or adding oil, including the best time to add oil to your car, the dangers of adding oil to a hot engine, and how heat affects your motor oil.
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Does Adding Oil When the Engine Is Hot Damage the Engine?
As a driver, you might be in a hurry and want to add oil to your car as fast as possible. Could you potentially damage critical components in your vehicle if you add oil when the engine is still hot?
Adding oil while the engine is hot won’t damage the engine. However, it’s important to get an accurate reading of your oil level so that you add the appropriate amount of oil. Too much or too little oil can cause engine damage.
There’s nothing wrong with adding oil to your engine if your car has been running for a while.
Due to the temperature difference between the oil in the car and the oil you’re adding, the viscosity of the oil may change slightly, but this isn’t an issue.
The new oil will quickly heat when mixed with the hot oil, especially if you continue driving the car after adding it.
Make Sure to Get an Accurate Reading Before Adding Engine Oil
What’s more important than the temperature of the engine is the amount of oil you’re putting into it. An engine with too much oil is almost equally as bad as an engine with too little oil. There are several things that can affect your reading, including the slope of the ground and the time between turning your car off and checking the dipstick.
Allow the Engine Oil to Settle Before Checking
If you have been driving your car and are parking to check or add oil, it’s important that you allow enough time for the engine oil to settle.
Often, you’ll get the best oil measurement when the engine is warm, but only if the oil has had time to settle. The oil is moving through your engine while you are driving, so when you stop, you will need to give it time to drip back down into the oil pan.
To be safe, you’ll want to wait about 15 minutes before checking the oil level. If you don’t give enough time, you might get an inaccurate reading, leading you to add more or less oil than you actually need.
Can You Change Engine Oil While the Car Is Hot?
When you take your vehicle in for an oil change, the engine is typically warm or somewhat hot, depending on the duration of the drive. However, the mechanics typically don’t wait for your car to cool down before carrying on with the oil change.
You can change the engine oil while the car is still hot. Hot oil flows easier and will come out of the oil pan quicker, so it’s often best to change the oil after a short drive. If the engine is excessively hot, it won’t hurt to wait a short while.
During an oil change, you’re adding cool oil to the engine, which is likely still warm, and there’s nothing wrong with doing so.
If you have been driving for a long time and the engine is extremely hot, there’s nothing wrong with waiting a little while before changing the oil. You can allow the engine to cool quite a bit, and the oil will still be warm enough that it will flow quickly. You also reduce the risk of burning yourself.
Potential Risks of Adding Oil to a Hot Car Engine
The risks associated with adding oil to a hot engine are mostly safety concerns as opposed to mechanical ones. These include the following:
- Burns
- Excessive smoke
- Fire
Read on to identify these personal hazards and how to avoid them.
Burns
If you do not wait until your engine cools down adequately, you could potentially get severe burns.
When you are changing or adding oil after the car has been running for a while, things underneath the hood are very hot. Whether you are simply checking the oil level or adding to it, there’s always potential to burn yourself on the hot car parts if you’re not careful.
Excessive Smoke
Adding oil when the engine is too hot can result in excessive smoking. This occurs when you spill oil on your engine when your car has not adequately cooled off. As explained in CarFixBoss, it is, therefore, advisable to give your engine some time to cool off before you add your oil to minimize spillage-induced smoke.
Fire Risk
In severe cases, adding oil to a hot engine can not only increase the risk of burning yourself, but the oil can drip onto your car engine and cause it to catch fire as well. This can be alarming.
While this outcome isn’t very likely, you can always wait for the engine to cool down a bit to reduce the risk even further.
How to Minimize the Risk of Injury When Adding Oil to a Hot Engine
Using a funnel can minimize most of the injuries associated with adding oil to a hot engine. When you use a funnel, you eliminate the risk of spillage. This means that your car’s engine will not smoke due to spillage, nor will it catch fire. Most importantly, you will minimize the risk of getting significant burns when adding motor oil.
Factors to Check When Changing Motor Oil
In many cases, your car will be one of, if not the single, most expensive purchase that you will make in your lifetime. Accordingly, it is essential to take the necessary measures to optimize routine maintenance activities. These include the following:
- Ensure that your car is on level ground.
- Give your engine time to cool off.
- Use the dipstick to check the oil level.
Let us discuss some of these below:
Ensure That Your Car Is on Level Ground
Before adding oil to your car, try finding a level ground on which to park. This is because any slope on your parking area will provide an inaccurate reading. You might end up either adding inadequate oil or adding too much oil. To minimize these errors, park on level ground before checking your oil level and adding any oil to your car.
Important to note is that while you can drive your car even when you have added oil past the recommended level, it is recommended that you drain this excess oil. Too much oil in the car’s system can create too much pressure and potentially overload the engine.
Give Your Engine Time to Cool
Ideally, it would help if you let your engine cool before you add oil to your car. If you have been driving, I recommend waiting for about 10 minutes before checking your oil level and adding any extra oil.
When the oil is heated up due to high internal temperature, its viscosity will change.
Use the Dipstick to Check the Oil Level
Wipe your dipstick with a clean, dry cloth. Once you have done this, insert the dipstick into the engine to check the oil level. It is important to note that the initial reading may be inaccurate due to factors such as splashing and staining.
To minimize the error rate, wipe the dipstick once more and reinsert it into the engine. This should provide a more accurate reading, ideally between the max and minimum fill lines. Add your motor oil as needed, ensuring that the oil level is closest to the max line to avoid overfilling.
As mentioned above, make sure that you wait a few minutes to allow oil to settle if you’ve been driving the vehicle. Additionally, the oil you add will need a few minutes to settle to the bottom before you check the oil level again.
Conclusion
In closing, while it is technically okay to add oil when your engine is hot, I recommend letting your car cool down for several minutes before adding oil. But if you absolutely have to add oil when your engine is hot, use a funnel to minimize the risk of injury, fire, or smoke.
What’s more important than temperature is the actual oil level. It’s important that your car is on level ground whenever you’re adding or changing oil so that you don’t add too much or too little.