do you check oil while car is running

Popping the hood to check your oil is one of the most fundamental acts of car care. It’s a quick and easy way to monitor your engine’s health and ensure it stays properly lubricated. But a common point of confusion for many drivers is the correct procedure for this simple task. Specifically, the question often arises: do you check oil while car is running?

Getting this step right is more important than you might think. Checking your oil under the wrong conditions can lead to an inaccurate reading, which means you could end up adding too much or too little oil. Both scenarios can be problematic for your engine’s performance and longevity.

Why You Should Check Your Oil on a Cool Engine

The best practice is to check your engine oil when the car is turned off and has been sitting for a few minutes. The goal is to check it on a “warm” but not hot engine. After you’ve been driving, oil circulates throughout the entire engine. If you check it immediately, a significant amount of oil is still up in the engine’s components and hasn’t had a chance to drain back down into the oil pan, which is what the dipstick measures.

By waiting a few minutes after turning off the engine, you allow that oil to settle. This gives you a true and accurate reading of the total oil volume in your system. Checking it while the engine is completely cold is also perfectly acceptable, though the oil level might be slightly lower on the dipstick.

The Correct Way to Check Your Oil Level

To get a proper reading, follow these simple steps. First, park your car on a level surface to ensure the oil isn’t slanted to one side of the pan. Turn the engine off and wait for about 5-10 minutes. Then, pop the hood and locate the dipstick, which usually has a brightly colored handle.

Pull the dipstick out and wipe it clean with a rag or paper towel. Re-insert it all the way back into its tube, then pull it out again to get a fresh reading. Now, look at the end of the dipstick. You will see two marks indicating the minimum and maximum safe oil levels. Your oil level should be somewhere between these two marks. If it’s near or below the minimum, it’s time to add a quart of the oil recommended in your owner’s manual.

What Happens If You Check Oil While the Car is Running?

While it’s not recommended, you might wonder about the actual risks. When the engine is running, the oil pump is actively circulating oil, creating splashing and movement within the pan. The reading on the dipstick will likely be significantly lower and highly inconsistent because the oil isn’t settled. This could trick you into adding more oil than necessary. Furthermore, with moving engine parts like belts and fans, it’s simply a safer practice to check fluids with the engine off.

Making a habit of checking your oil regularly with the engine off is a small step that makes a big difference. It ensures you get an accurate measurement every time, helping you protect your engine and avoid costly repairs down the road. Your car will thank you for the extra care.