Check Engine Light after Oil Change [Explained]

Is it important to check engine light after oil change or not. When you own a car there are many things to be keen about. But if you don’t bother to pay attention to little detail, it can possibly come back as a major malfunction in your car.

Usually the lights are the indicators that tell you about how a car is performing, if the engine is in its proper form or not. Therefore, keeping an eye on all such indicators is as important as you think having a car is. 

In this article, I shall cover the important things about engine light after oil change and more. But first, what is the check engine light?

Why check if the engine light is on after an oil change?

If the check engine light comes on after oil change, it’s not considered as a normal sign. Therefore you need to find out why the light is illuminated. Below are the reasons that can cause the check engine light to come on.

After oil changing, if the Check Engine Light is lit it can be due to the oil dipstick not being complexly fitted or seated in the oil filler cap. Here are the reasons why it happens:

Dipstick not completely seated

Dipstick is there to check the oil level in the engine. So if it does not fit or sit the right way (easily) it causes the check engine to turn on after oil change. The O-ring makes a seal when the dipstick is set into the right spot.


Bend or crooked gas cap

After oil change, the cap should be tight enough and well in place. If after filling the gas tank, the cap is loose, crooked or somehow not well secured, it can cause the check engine light to light because the system will take it as an alert for potential problems.

gas cap

PCV Hose Disconnected

There is a positive Crankcase Ventilation (PCV) system in the engine for gathering the extra oil vapors from the crankcase. It makes sure that air intake in the system. If that PCV house is not connected, the check engine light will turn on. This is because the extra air will go  into the engine through the PCV valve, making the engine perceive it as a problem.

PCV Hose

Too Much Oil

Adding too much oil to the engine makes the system perceive it as a fault and the check engine light turns on. So if you see the light lit after oil change, check the oil level.

engine light

Using the Wrong Oil

car engine oil

If you use substandard car engine oil, it does come with its own concern apart from quality. So using correct oil is always a suggested way for maintaining the vehicle longevity. The oil must offer the right viscosity, grade, and weight.

For instance, you cannot go wrong on choosing 10W-40 oil instead of 5W-40 oil just because they looked similar. 

Don’t choose too much thick/viscous oil because it will not maintain the lubrication rightfully. Therefore there can be heat issues making the check engine light lit, after oil changing.

Read Also: How Long To Let Engine Cool before Adding Oil

Unplugged UnMAF or MAP Sensor

If the UnMAF or MAP sensor is not plugged in, the check engine light will turn on. As you know the light tells you about the possible problem, if the sensors are not connected, it will make the light illuminated on the dashboard. So when the mechanic has refilled the engine oil make sure the MAF sensor is not unplugged.

UnMAF or MAP Sensor

Zero oil pressure

The lack of oil pressure causes many issues. Low engine oil levels can be a reason why check engine light is on. However, only checking the oil should not cause the check engine light to come on.

Usually when you change or replace the car oil, it does not give reasonable time to the gauge for reading it the right way. So sometimes, it can cause the check engine light to become illuminated because your vehicle takes it as the oil is minimal.

What is Check Engine Light?

The check engine light on the car dashboard is an important indicator that tells you about engine performance and any possible malfunction regarding it. It is also commonly malfunction indicator lamp, MIL.

This check engine light will change its appearance depending on what manufacturer car you have. It can be yellow, amber or orange in tone. If this light is flashing or fluctuating it means the problem in the engine is serious such as misfire which can overheat the catalytic converter.

How does Check Engine Light Work?

It works as a signal to tell the driver about when there is something wrong with the engine performance. The check engine light is a part of the cars on board diagnostics system. So when the system detects any issue, fault, or malfunction, it sends a signal to the check engine light and it becomes lit.

Read More: How Long Can You Drive With A Blinking Engine Light

Additionally, the computer system, when turning on the check engine light, also saves a “trouble code” to determine where the problem is, such as if the sensors are faulty or the engine is misfiring etc.

What should I do when the engine light is on?

If you see the check engine light is lit on the dashboard, after oil change, it’s about time to run the test. The lit light means that the vehicle’s on board diagnostic system has found a malware/problem or fault.

So to check the problem, stop the vehicle and scan the warning codes that are there in the engine memory. For that you need to use an OBD2 scan tool. If there is a problem, you will get the check engine light code. It indicates the faulty sensor of your car.

Now, if you find out the problem, the first thing you should do is to level the oil in the engine. It can be due to low levels of engine oil. Usually adding oil to the recommended level solves the problem and check engine light will shut off.

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