Should I Check my Oil When the Engine is Hot or Cold?

There are many ways to check your engine oil correctly, and the common question is whether to change it when the engine is cold or hot. Let's find out!

Check Oil When The Engine Is Hot Or Cold

There are a lot of strange things that you didn’t know you needed knowledge about before you purchased your first car.

Taking care of your car’s engine oil is some of the most important knowledge to have to make sure that your car is in good shape and reduces the risks of expensive repair costs.

It is fairly easy to check the engine oil level within short intervals.

But how do you check the engine oil to get the most accurate readings, and should the engine be hot or cold when checking the engine oil level?

Should you check the engine oil level hot or cold?

Engine Oil Level

You should check your engine oil when it’s cold. You can also check it when it’s warm, but it must be 15 minutes after the engine was running last time. This is mainly because it takes some time for the oil to pour down into the oil pan.

It is also better to measure the oil level when it is cold because of safety factors. Engine oil can reach temperatures of 250 Fahrenheit or 120 degrees Celcius.

If you measure the engine oil directly after driving the car and fill it to the max sign – it will become over the max sign when the engine oil is cold and poured down into the oil pan.

The absolute optimal situation is driving your car warm and let it stand for 15 minutes, and then check the engine oil, then it will both have some temperature, and all oil has poured down into the oil pan.

The oil temperature itself will not play a significant part in the oil level measuring. However, there is actually a small expansion that can happen when the engine oil is cold or warm.

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Engine Oil type expansions

Synthetic oil has a higher rate of expansion and contraction with temperature changes. These blends will be much tighter when cold and could expand even more than expected when hot.

Regular oil will experience normal expansion and contraction, which means you will get around the same readings regardless of temperature.

Newer cars with electronic oil level controllers will only measure the engine oil when warm and stay at a flat surface level. Therefore it’s recommended to check the engine oil when the engine oil is hot.

Check your repair manual for the correct oil measurement of your car.

Cold outside temperatures

Cold Check Oil Level E1611255157495

Whether you use a synthetic blend or regular oil, checking your car when it is freezing outside will affect your readings. To get the best oil readings in single-digit weather, you may need to run your engine for a little while before starting the process. You can set your car on idle until it warms up, let it stand for 10 minutes, and then check your oil level.

You should use a completely dry dipstick to check your oil. The device is calibrated with minimum and maximum oil levels for easier maintenance and accurate oil replacement.

You should park your car on a level surface to avoid distortion of oil levels due to gravity.

How to check your engine oil

Check Oil Level (2)

Many car owners do not know how to check their engine oil levels. The confusion starts from the basic steps, with users unsure whether to check oil hot or cold. It is a relatively easy process, which will only take a few minutes.

First, you should make sure that your car is on level ground. Checking your oil on an uneven surface could cause the readings to be flawed.

For safety reasons, if you are not experienced with cars, you should check your car’s oil when the engine is cold to avoid scalding and burning by hot components.

However, you can also check the engine oil levels when warm, especially if your environment is freezing. You get the best measurement when it’s warm, but you need to let your car engine be shut off for 10-15 minutes before measuring the engine oil level.

Locate the oil dipstick, which is located in the engine bay. Remove this measuring stick and wipe it over a dry and clean paper towel or rag. Fit the oil stick again and put it up again. Your oil level should lie between the minimum and maximum levels, as close to maximum as possible.

Some newer cars do not have a dipstick for the engine oil and instead use an electronically controlled one. Read your service manual to figure this out or get help from a mechanic to check it for you. 


Magnus Sellén
Written by:

Magnus is the owner and main author of Mechanicbase. He has been working as a car mechanic for over 10 years, and the majority of them specialized in advanced car diagnostics and troubleshooting. Certified Automotive Diagnostic Technician.