Check Engine Light After Oil Change – Here Are Possible Causes and Best Solutions

It is truly frustrating to see a check engine light after oil change. If you are a proud car owner, you may have encountered this once in your lifetime. But don’t worry; you can fix this CEL issue yourself.

A check engine light in normal circumstances could mean a serious issue, but if you see the check engine light after oil change, it could be due to the oil filler cap fixed backways or the oil dipstick not being completely placed. You can fix both these issues pretty quickly, but the engine light might not disappear straight away. It could require three engine start cycles.

Check Engine Light After Oil Change

check engine light after oil change
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Before discussing the solution to this check engine light after an oil change, it is worth explaining what a check engine light is.

What is Check Engine Light (CEL)?

In technical terms, we call it the Malfunction Indicator Lamp (MIL), and it is a hint from the vehicle’s engine computer warning you of some failure. The CEL also appears on the dashboard when you ignite the engine and disappears if it finds no issue related to the powerplant and adjoining systems.

If it remains on the dash, the computer registers a “trouble code” in the memory to pinpoint the problem area, like the engine misfiring, a faulty sensor, etc.

You can use a diagnostic computer or an electronic scan tool to find the trouble code and know the real issue. If you do not have any of these tools, you should hit an auto repair shop. You can also buy a code reader to discover the code. Remember, the code is just a hint to the problem. You will need an expert technician to analyze further and fix the issue.

Knowing The Color of Check Engine Light

You may find this light in Yellow, Orange, or Amber. Different colors here don’t mean any severe issue but are purely manufacturer discretion. If you see this light on the dash flashing, it could mean a severer problem. It might be a misfiring engine that will possibly burn the catalytic converter.

Why Do I Get Check Engine Light After Oil Change?

A check engine light after an oil change usually appears when the oil dipstick doesn’t fully sit inside the tube or when the oil filler cap fits backways. You can easily fix these issues by fitting the cap appropriately and seating the dipstick. If the engine light does not disappear instantly, it should, after three engine start cycles.

Now let’s go into details about these problems and other possible causes of the check engine light after oil change.

Oil Cap Fitted Backways

While fixing this mistake isn’t difficult at all, you might be wondering why fixing the oil cap backways cause the ECL. Well, to understand the reason, you need to know the car’s running mechanism.

In order for your vehicle to run smoothly, its mill needs a specific air to fuel ratio (AFR), which is 14.7 parts air to 1 part gas.

Your vehicle’s Engine Control Unit (ECU), also known as Engine Control Module (ECM), makes sure the powerplant gets the appropriate air-to-fuel ratio. The ECU uses a sensor fixed in the air intake system, called Mass Airflow Sensor (MAF), and ensures the correct volume of air enters the engine.

When the ECM calculates the amount of air that enters the powerplant, it knows how much gasoline it requires. It isn’t difficult for an efficient computer, but the issue occurs when more oxygen enters the engine, and the ECU does not know about it.

When you fix the cap backways, it forms a vacuum leak, making the mill run lean. ‘Lean’ purely means the AFR mixture has extra air. The ECU notices the extra air in the mix and investigates by calculating the fuel supply and its appropriate use. It analyzes the outcome with the previous calculations and employs the exhaust sensor (aka oxygen sensor) for this job.

Any reading outside the ECU’s safe values will prompt it to register an error code and illuminate the check engine light.
Solution: Simply detach the cap and fix it appropriately. We know you understand how to fit the oil cap, but make sure the cap writing faces you.

In this age of technology, it is a valid question why carmakers produce oil caps we can fix backways. Well, it is a mistake, and even some premium brands make this error.

Dipstick Not Fully Seated

The dipstick’s job is to show you the current engine oil level. During an oil change, the mechanic has to remove, clean, and reinsert the dipstick in the tube many times. He has to seat the dipstick and lock it fully. If he fails to push it ultimately, some amount of air can sneak into the engine. This unmetered air is abnormal for the engine, and the ECU would notice it.

While fully seating a dipstick isn’t rocket science, some mechanics leave it loose when they are in a hurry. In a morning car maintenance routine, we usually check the dipstick before starting our journey. If you see the check engine light soon after analyzing the engine’s oil level, it could be due to the loose dipstick.

Solution: Open the hood, find the dipstick, and push it completely.

Oil Level Overfull

Excessive engine oil may also trigger the check engine light and likely make the drive sluggish. You may also observe engine misfiring, smoke from the tailpipe, oil leak, or may not even start your vehicle. Excessive oil is not as problematic as the low oil level, but it still is a sign of trouble.

Solution: Get a suction pump to remove the extra oil. Open your vehicle’s hood and drain the oil from the dipstick tube or the cap entry spot. You can perform the suction job manually or through a mechanical pump.

How to Examine the Engine Oil Level?

You should know the proper oil level for your vehicle to run smoothly. Both low and excess oil levels are troublesome for the engine.

  • Park your car on a flat surface
  • The engine must not be running
  • Open the hood
  • Find the dipstick
  • Remove and clean it with a cloth
  • Reseat and take out to find the oil level

Different dipsticks have different markers; mostly, we find “Full,” “F,” “Max,” or a notch for the appropriate level. We can also see “Low,” “L,” “Min,” or a plain notch to show the low oil level. Furthermore, dipsticks have a marker between Max and Low. If you find the oil level on this notch, it means the level is neither critical nor ideal.

Wrong Engine Oil

Always use the correct oil in your car. Your vehicle’s engine is made to use a specific oil for its optimal efficiency. If you don’t know the correct oil for your vehicle, check your owner’s manual. An oil with the wrong viscosity, grade, or weight cannot only cause various issues in your car but will also trigger a check engine light after oil change. Overly viscous oil will not provide optimum lubrication and will not be able to transfer heat suitably. It will cause the oil to heat up quicker than expected and may illuminate CEL.

Other Possible Causes Of Engine Light

There are so many other reasons that can cause CEL. Whether it appears after an oil change or abruptly while driving, you should use a code reader to eliminate the guesswork. Buy a code reader (it isn’t expensive) to find the issue and correct it yourself. Else, hit a vehicle workshop for examination and a fix. Please do not leave it unattended!

How to Find the Error Code of Check Engine Light After an Oil Change?

If you see the check engine light after an oil change, you can find the error code and fix it yourself.

You just require an onboard diagnostic reader and connect it to the OBD reader port. You can find it at the bottom of your vehicle’s dashboard. After you connect the reader, click enter to turn on the device. The device will scan the engine, get error codes, and show them on the screen. Find out what the error code means by searching online or against the owner manual.

You can erase the code to reset the CEL. If the light doesn’t disappear, restart the vehicle.


How do I turn off the check engine light after an oil change?

If your engine light doesn’t turn off automatically. follow these steps.
Put the key in and turn it all the way to the right before ignition.
Press the race pedal three times
Turn off the key to the most left
Now start the car again
The engine light will be reset.

Will check engine light go off after adding oil?

In most cars, this light goes off after you add the engine oil.

Why is my engine light on but nothing seems wrong?

On the off chance that nothing is by all accounts acting unusual, it is most likely protected to drive it until you can get it into a specialist. In some cases, the light might come on subsequent to powering on the off chance that the gas cap is somewhat free.

Will check engine light reset itself?

In case nothing is apparently acting strange, it is doubtlessly safeguarded to drive it until you can get it into a trained professional. Now and again the light could come on ensuing to turning if the gas cap is to some degree free.

What is the most common reason for check engine light?

Replacing a faulty oxygen sensor is the most common reason for check engine light.

Jasper has been an enthusiast of the automotive and IT industries since the age of 16. He independently writes on the auto industry's recent happenings.