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

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.

Does the check engine light come on for an oil change?

Certainly, the illumination of the check engine light following an oil change is a possibility, yet it isn’t directly linked to the oil change event. This situation typically arises from common errors made during the oil change procedure, including:

1. Oil Cap Fitted Backwards: If the oil filler cap is not tightened correctly or is fitted backward, it can create a vacuum leak, causing the engine to run with an incorrect air-to-fuel ratio. It can trigger the CEL.
2. Dipstick Not Fully Seated: If the dipstick, which is used to measure the oil level, is not fully seated or is left loose after the oil change, it can allow unmetered air to enter the engine, leading to a CEL.
3. Oil Level Overfull: Too much engine oil in the system can also trigger the CEL. Excessive oil can lead to various engine problems.
   Fortunately, these problems are relatively simple to fix by addressing the underlying issues, such as properly securing the oil cap or fully seating the dipstick.

How to reset the check engine light after an oil change?

Resetting the check engine light after an oil change is simple with the right tools. You’ll need an Onboard Diagnostic reader and a wrench. Here are the steps:

1. Locate the OBD port under the dashboard, often near your feet.
2. Connect the reader and power it on by pressing “enter.”
3. Let the device scan for error codes; note the codes for reference.
4. Highlight the code using the scroll button and press “enter” to erase it, resetting the check engine light.
5. Restart your vehicle if the light doesn’t immediately go off, allowing everything to reboot.

After an oil change, it’s essential to reset the oil change indicator. Failing to do so may result in the check engine light staying on or turning on shortly after. This could cause unnecessary stress and lead to further investigation. If you’re curious about whether electric vehicles have similar maintenance needs, you can learn more by reading Do Electric Cars Need Oil Changes?

Ford f150 check engine light reset

To reset a Ford check engine light, start by diagnosing and fixing the underlying issue. Retrieve diagnostic trouble codes (DTCs) by following these steps:

1. Locate the OBDII port under the driver’s side dashboard.
2. Connect an OBDII scanner (available online or at auto parts stores) to read the codes.
3. Write down the codes and identify the problem area using online resources or the vehicle manual. Standard codes for Ford models like Escape, Focus, Fusion, Explorer, and F-150 include P0171, P0174, P0420, P0430, and P0128.

Once the problem is resolved, you can clear the check engine light using these methods:

1. Use an OBDII scanner, following its menu prompts.
2. Disconnect the negative battery cable for 30 seconds to reset the Ford computer.

Remember that resetting the light without fixing the issue may cause it to return, as it’s designed to alert you to emissions-related problems. For complex issues, seek professional diagnosis and repair at a Ford service center, especially if the light is flashing, to prevent further damage.

Why is my check engine light on after the oil change?

After an oil change, several common issues can trigger the check engine light:

1. Low Oil Level: Using incorrect oil quantities can result in inadequate lubrication, potentially causing an engine misfire. Ensure oil levels match the recommended range on the dipstick.
2. Using the Wrong Oil: Using the wrong oil type for your vehicle can damage the engine and trigger the check engine light. Consult your owner’s manual or the oil filler cap for the correct oil type.
3. Low Oil Pressure: Low oil pressure, caused by issues like a faulty sensor, leak, or damaged pump, can lead to engine misfires and damage. Regularly inspect the pressure sensor and oil filter and fix detected leaks.
4. Excess Oil: Too much oil can cause foaming, reduced circulation, and increased engine pressure, triggering the check engine light. Remove excess oil using a suction pump.
5. Oil Dipstick Not Seated: An improperly seated oil dipstick can introduce unmetered air into the engine, leading to inaccurate readings and the check engine light. Ensure it’s fully inserted.
6. Missing Oil Fill Cap: A missing oil cap disrupts the emission control system, causing imbalances and the check engine light. Verify the cap is present and tight.
7. Improperly Seated Oil Filter: If the new oil filter isn’t correctly installed or the old gasket isn’t removed, it can cause oil leaks and reduced pressure. Use a recommended filter and ensure proper tightening.

How to get rid of the check engine light?

Disconnect your 12V battery for 15 seconds or use a scanner from Amazon, eBay, or an auto parts store to clear trouble codes. Alternatively, locate the fuse supplying backup energy to the ECM and disengage it for 15 seconds. However, resetting the light may not be a solution. The problem could resurface during the computer’s tests, leading to the return of the light. Moreover, clearing the light won’t guarantee passing a smog test, as the “monitors” must complete specific tests. Resetting codes erases diagnostic data, making future diagnoses more challenging. So, be cautious when considering this approach.

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