Your car needs many equipment and materials to function correctly, such as oil and other requirements. When it comes to adding or changing oil, you might have several questions that you might be too ashamed to ask, like adding oil to a hot engine? Or should you change the oil when it’s hot or cold? Your car might need an oil change, and you are wondering how. Whatever your question is, this article will answer them all.
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Adding Oil to a Hot Engine
If you add oil to your engine when it is hot, you are fine to go. Putting engine oil in the car while it is hot, this can do nothing to your vehicle. The cold oil will not harm your engine. That is not the case when you are changing the oil, though. You will run into the risk of burning yourself if you try to change it when the engine is hot.
If you are going to measure the oil, you should not do it when the engine is running hot. Oil expands in the heat to get a pretty inaccurate reading.
Adding Oil to a Cold Engine
Adding oil to the car engine when it is cold will not cause any problems. It is an excellent way to avoid any burns.
If you want to change the oil, though, you will face trouble draining it because it will be too thick.
It is best to change the oil when the vehicle engine is not at extreme temperatures. Too hot, and you will get severe burns and injuries. Too cold, your oil will be too thick to drain.
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Ensure your engine is warm so that the oil does not stick to the oil pan and other engine parts.
How Long to Let Engine Cool Before Adding Oil?
You should park your car on flat, steady ground and wait at least 5-10 minutes or better – 20 minutes to let the hot engine cool down and drain in the sump. Some will suggest even waiting for 30 minutes so just make sure that your car is warm and not too hot or cold.

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Ask a Mechanic Live NowSteps to Check Engine Oil Level
The correct way to check the engine level is written in your manual. After your car has cooled down for some vehicles, and for others, you should let your engine warm up a bit.
Using a Dipstick
- Put your dipstick in and take it out. Clean it with a cloth or rag and dip it again. Your dipstick has markings that tell you how much oil you need to add. You will need to push as far as it goes to get an accurate reading. Your dipstick will have pinholes, L and H (low and high), or MAX or MIN markings to tell you about the oil.
Checking the Color of the Oil
- Check for the color of the oil. It should typically have a brown or black appearance. If the color is milky, the coolant is leaking, and you should take your car to a mechanic for fixing it and other diagnoses. Dark appearance can sometimes indicate that you need to change your oil unless the oil is synthetic – then the color is alright.
Check for Metal Particles
- Keep an eye for metal particles as their presence in the oil can mean some internal engine damage.
- If everything is alright, you are off to go and start adding oil if needed. You can add little by little and keep checking with your dipstick to give your engine the correct amount.
Steps to Add Engine Oil
Oil Level
- Check the oil level (mentioned how to above). Unscrew and remove the oil filler cap in your engine.
Draining the Old Oil
- Drain the old oil by removing the drain plug using a socket wrench and the drain pan underneath. Once you are done, put the drain plug back in its place.
- Change the oil filter too, using the filter wrench, and add a bit of motor oil to the new one so it doesn’t stick.
Use the Correct Oil
- Add the oil your manual tells you. It will usually be 0W-20 or 5W-30 ( 5W-30 is typically the one as it is versatile), and if you are wondering how much oil to put in car, check with the dipstick to see if you poured enough oil.
Oil According to the Seasons
- Pour oil little by little because over-flowing oil is terrible for your vehicle. Use a funnel to avoid any mess. Remember that it is better to use a higher viscosity oil during summer and a lower viscosity oil during the winter. Do not use oil that is too thin for your car because it will not function well.
FAQ’s
Can You Check Oil When Car Is Hot?
You can check the oil while your car is hot. Make sure that you open the hood of your vehicle and then use a thermometer to see if the engine temperature goes below average, alerting you to add more oil.
Can You Add Oil to a Running Engine?
Obviously not! Oil changes should not be performed with the engine running. Opening the oil fill cap when that the engine is running and pouring oil in, will cause an extreme amount of pressure due to overheating.
How Long to Wait for Checking Car Engine Oil After Adding Oil?
It is recommended to wait at least 5-10 minutes after adding oil before checking the level. You can attempt to check the level before this time.
Can I Add Old Oil to New Motor Oil?
Since oil is a consumable item, can you add new to old? The answer is yes. Adding the correct amount of new oil into the old oil does not change the condition of the engine in any way. It’s a good practice & accepted by many.
How Long Can You Really Go Without Changing Your Oil?
No matter how good your oil is, you should change your oil in between every 5 000-8000 miles or beyond those intervals if it runs properly. If you take more care of your car with oil change intervals in mind, you can do it after 3000 miles.
Conclusion
We have described everything about adding oil to a hot or cold engine. It is essential to know the correct way of changing oil in your car. Many people have experienced issues with the wrong type of oil or too much oil. But it is not difficult to add or change oil if you follow the proper procedures.
The correct way of changing oil is not always done to your car. It’s crucial to learn it correctly before using the wrong method. Best of luck & happy driving!
Max Anthony
Max is a gizmo-savvy guy, who has a tendency to get pulled into the nitty gritty details of technology and cars. He attended UT Austin, where he studied Information Science. He’s married and has three kids, one dog and a GMC truck and a Porsche 911. With a large family, he still finds time to share tips and tricks on cars, trucks and more.
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