If you’ve owned a car, at least for even a short amount of time, you probably understand the need to check the engine oil level at regular intervals.
This is necessary because most engines either slowly consume or leak their lubricating oil. Even your new car will burn oil over time.
So you might be asking yourself: how do I check the oil level? How often? Do I check it hot or cold? With the engine running or stopped? What if there is no dipstick? I will answer those questions and more.
How Engine Oil Works
First, a little bit of basics. Your vehicle’s engine is lubricated by oil. For most of the vehicles made today (gasoline or diesel), oil is stored in a reservoir called an oil pan (sometimes called an oil sump) at the bottom of the engine.
When you operate the engine, a pump draws the oil from the pan, and then it first sends the oil to the oil filter, then to all the locations that need to be lubricated in the engine, and finally it returns the oil to the oil pan.
So, when you turn off the engine, the pump stops running, and then any leftover oil in the engine drains back to the instant oil change pan. That is your basic engine lubrication system.
How Often Should I Check the Oil?
The oil level should be checked regularly, which is mainly driven by how many miles you drive.
- For example, if you drive 1,000 miles a month, you should check the oil level at least once a month.
- If you drive a lot of long trips or do business trips of say, 2,000 miles a month or more, then you should probably check the oil level at least weekly!
You could have a schedule of how often to check the oil level without having to consider mileage, and just include checking the oil level in your normal work/commuting schedule. One way could be to check the oil once a week, the night before the first day of commuting to work.
If Monday is the first day of commuting to work, then check the oil on Sunday night. This might help to perform the check more consistently and reduce the chance of forgetting.
For many people, the act of checking the engine oil becomes a routine act whenever they stop at a gas pump. The point is, make it a routine!
When is the Best Time to Check the Oil Level?
Typically, the following circumstances determine the best time to check your oil level:
Engine Hot or Cold?
Cold is generally ideal. A cold engine will have had all the oil drain back into the sump.
A hot engine will have hot oil that could be as hot as 215° F temperature. If you choose to check the oil level with a hot engine, be careful not to get burned.
Engine Running or Engine Stopped?
Stopped is generally ideal. A running engine is always circulating that oil around the engine, so the oil pan is not full. If you check the oil level at this point, you may only see the oil pan, which is not correct.
There are exceptions to the previous two. If your car has a dry sump lubrication system, for example, they would want the oil checked warm and running.
The 2021 or newer Corvette C8 LT2 is one example. Refer to the owner’s manual if uncertain about your vehicle.
Engine Stopped for How Long?
Before oil checking, the engine should be stopped for a minimum of 5 minutes. This time allows the oil to drain from the engine back into the oil pan. The oil will not cool off for a while, so still be mindful not to burn your fingers.
How Oil Level monitored?
In most vehicles, the oil level can be checked using the dipstick. What is it, you ask? Indeed, it is a stick that dips into the oil in the oil pan.
It’s narrow, made of metal, flat or cylindrical shaped, usually with a yellow handle or a metal ring on the upper end. It is located on top of the engine. If you are still unsure, refer to the owner’s manual for its exact position.
The lower end is usually marked with dots or lines. The top mark determines the maximum oil level, while the lower mark indicates that the pan needs oil.
This bottom mark is usually right where adding exactly one quart will fill the pan back up to the full mark.
The blank space between the two marks may be or may have cross-hatching. This area shows the range of oil levels below full when the engine will have sufficient oil to operate normally.
When your oil is in this range, you do not need to consider adding oil just yet. More detail is outlined below on how to check the oil.
How to Properly Check the Engine Oil
Let’s go through the steps for this procedure. You will want to have a clean shop towel or several paper towels handy to do this. Having enough light will be helpful too.
Note: You should always check the owner’s manual for the car to see if they have specific instructions for checking the engine oil level.
- Park the car in a level area. This will make sure the oil in the oil pan is level for the most accurate reading. Put the transmission into gear or ‘Park’ and set the emergency brake.
- Open the hood. If the hood does not have gas struts (or is not self-supporting) make sure the hood support rod is properly secured in a support hole formed into the underside of the hood.
- Locate the dipstick. Partially withdraw the dipstick and stop. Wrap your shop or paper towel around the dipstick at this point. Next, withdraw the dipstick all the way out while you are wiping the dipstick dry.
- Insert the dry dipstick back into the dipstick tube. Push the entire dipstick down into the tube.
- Withdraw the dipstick again. This time, do not wipe it again, but hold the towel just below the bottom end of the dipstick to catch any drips of oil that may occur.
- Locate the top edge of the oil on the dipstick. If the oil level is at the top line on the dipstick, the oil pan is full. If it is at the bottom line or below, you need to add oil. If it is between the two lines, you do not need to add oil at this point.
If the oil is above the top line, the oil pan is overfull. Some oil must be drained to fix this. More information on this can be found in the article found here.
- If the oil level is low, you should take care of it as soon as you can. Either get the correct oil for your car (see your owner’s manual if needed) and add about a pint of oil (don’t add too much). You will need an appropriate size funnel to make it easier to pour the oil into the oil fill port. Or go to your preferred oil change shop and have them take care of it.
Note: The oil fill port cap is usually clearly marked, generally in yellow. If you are not sure about the location of the oil fill port, check the owner’s manual. Putting oil in the wrong port location will be risky and challenging to correct.
In the rare event the oil level is off the bottom of the dipstick, you should not drive the car until you raise the oil level to the full mark.
It would be beneficial for you or your service technician to look at what caused the oil level to get so low.
What if You Have No Dipstick?
In today’s world, having no dipstick for the engine oil is a possibility! Some car makes and models have gotten rid of this reliable feature.
Examples include various BMW models, the new Toyota Supra, certain Audi and VW models, and Ford, Lincoln, Chevy, Chrysler, and Mazda models.
Among the list is the mid-engine Porsche Cayman. For the Cayman, the top of the engine cannot be accessed except in the interior cabin, so the lack of a dipstick in this particular car is clearly justifiable!
To ditch the time-honored but trusty dipstick, car manufacturers have used advanced oil level sensors and circuitry to provide engine oil level indications / low oil warnings sent to the car’s computer.
In general, car manufacturers have had reliable systems, but there have been many models with the grim consequence of an occasional failure of the oil level sensor to provide a “low oil warning” requiring an oil fill. In these rare instances, severe engine damage could occur, and any associated repair would add up.
If you are driving or looking to buy a used car, it is advisable to check the owner’s manual to see if your car is a member of the “no dipstick” club!