Check Engine Light After Oil Change: Reasons and Solutions

Check engine light after oil change may be due to an incorrect fitting of the oil filler cap or the oil dipstick not sitting fully. Refitting the cap and correctly seating the dipstick will usually fix the problem, but it may not always be that straightforward.

This article examines the reasons why the “check engine light” may stay on after an oil change, including the steps you should take to diagnose and fix the issue.

Why Is Your Car’s Check Engine Light on After Oil Change?

Your car’s check engine light is on after an oil change because the oil cap is fitted backways. It could also be due to the oil dipstick not being seated correctly. Likewise, low oil pressure, using the wrong oil, or using too much oil may also cause this issue.

Here are more details on the potential reasons for the check engine light to be on after you just had an oil change.

– Incorrect Installation of Oil Filler Cap

People often neglect the proper screwing of the oil fill cap after changing their oil. Sometimes, the cap is placed backward or not completely threaded. It is crucial always to be mindful of how the oil fill cap is replaced. Not doing this could result in an uneven air flow into the system, triggering the check engine light.

– Oil Dipstick Not Sitting Fully

The dipstick is crucial for checking engine oil levels and is removed, cleaned, and replaced multiple times during oil changes. It fits snugly in the dipstick tube and is sealed with an O-ring.

Failing to reseat the dipstick properly can allow unmetered air into the engine, damaging internal parts such as cylinder walls, pistons, or valves. In addition to causing damage to essential engine parts and components, it may also trigger the check engine light.

– Low or No Oil Pressure

Simply checking the oil or changing it will not cause low oil pressure. However, draining the oil will reset the pressure gauge, and it may take some time for the system to read the new pressures, causing the check engine light to come on temporarily. Remember that replacing the oil and filter too quickly may not allow enough time for the gauge to read correctly.

– Unplugged MAP or MAF Sensor

It’s common for mechanics and car dealers to unplug the MAF sensor or remove the engine air filter while refilling engine oil. However, if the MAF sensor remains unplugged or the air filter is not properly fitted, it can cause air to leak into the engine and disrupt the air-fuel ratio. This results in inefficient combustion and triggers the check engine light.

– Too Much Oil or Use of Wrong Oil

Adding too much oil to your car engine can trigger the check engine warning light and cause stalling, sluggishness, misfiring, smoke from the tailpipe, oil leaks, or prevent starting altogether.

You can examine your engine oil level by following these steps:

• Park your car in a safe spot.
• Ensure that the engine is not running.
• Open the car hood.
• Remove the dipstick and clean it with a clean cloth.
• Reseat the dipstick and take it out to check the oil level.

There are different markers on different dipsticks. However, you will mostly find “Full,” “Max,” or “F.” You may also see “Low,” “Min,” or “L.” Some vehicle models also put a notch for the right level or a plain notch for a low level. This will help you determine if your oil level is low and needs topping up.

Using the incorrect oil viscosity, grade, or weight can also cause problems, such as quick oil heating, insufficient lubrication, and trigger the check engine light. Using a different weight or viscosity, like 10W-40 instead of 5W-40, can cause trouble for your car and is a common mistake. Therefore, using the recommended oil type for optimal engine performance is crucial.

– Disconnected PCV Hose

An engine’s Positive Crankcase Ventilation (PCV) system collects excess oil vapors from the crankcase and delivers them through the air intake system. If the PCV hose accidentally becomes disconnected while checking the oil filter during an oil change, it can cause extra air to enter the engine through the PCV valve.
This disrupts the air-fuel ratio and tricks the ECU into thinking the engine is running lean, triggering the check engine light.

– Sensor Didn’t Reset

If the Check Engine Light turns on to indicate the required service, an oil change will typically reset the sensor and turn off the light automatically. However, some vehicles don’t have a sensor that resets automatically.

In such cases, the Check Engine Light or Service Engine warning may persist even after the oil change. Without the ability to manually reset the light, it will remain illuminated.

– Other Reasons for the Check Engine Light

Aside from the reasons discussed above, there are many other reasons why the check engine warning light may stay on. They may range from minor issues to severe ones.

Some of them include the following:

• Bad oxygen sensor: The oxygen sensor is responsible for monitoring the fuel consumption of the engine in your vehicle. Typically, two or four oxygen sensors are installed in a vehicle. An oxygen sensor that is not functioning correctly can significantly negatively impact a car’s fuel economy and result in increased emissions. If not addressed promptly, this can lead to damage to the catalytic converter.
• Damaged catalytic converter: The catalytic converter helps convert toxic carbon monoxide into less harmful carbon dioxide. The carbon dioxide is then released through the exhaust system. The inability to convert the dangerous gas can be bad for the engine. This might trigger the check engine warning light to stay on.
• Worn spark plugs and a bad ignition coil: The ignition coil supplies the initial surge of energy to the spark plugs, which ignites the fuel within the engine cylinders. Aging spark plugs can significantly impede your vehicle’s acceleration, which clearly indicates that it’s time to replace them. A defective ignition coil or spark plug can result in cylinder misfires, which is sufficient to activate the check engine light.
• Malfunctioning airflow sensor: A malfunctioning Mass Airflow Sensor (MAS) may cause unburned fuel may be burned in the exhaust, leading to increased emissions. This could also cause the engine to stall. Therefore, regular air filter cleaning is essential, and replacement may be necessary if it is too old. Failure to maintain the air filter can lead to insufficient airflow to the engine, causing the sensor to fail.
• Excessive carbon buildup: Excessive carbon buildup is a common cause of malfunctioning Exhaust Gas Recirculation (EGR) valves, leading to valve sticking. If your engine exhibits irregularities when idling, this may be the cause. It’s necessary to bring your vehicle to a mechanic to clean the EGR valve. Neglecting this problem and allowing for the continued buildup can lead to the need for valve and gasket replacement.
• Issues with the engine coolant thermostat: The engine thermostat operates like a standard thermostat, except it controls the flow of vehicle coolant through the engine. A malfunctioning coolant thermostat can cause the engine to overheat. If this occurs frequently, it can activate the check engine light. Substantial coolant loss due to radiator leakage can also cause engine overheating.

How To Fix the Check Engine Light After Oil Change?

You can fix the check engine light after oil change by paying attention to the underlying issues that may have caused it. Once you identify the issue, you should be proactive in fixing it. You can do this yourself or take your vehicle to a professional auto mechanic. These easy-to-follow steps will help you turn off the check engine light after you’ve gotten an oil change:

– Run Your Engine for Some Minutes

To address a possible oil-related issue triggering the check engine light, the first step is to start the car and let it run for a few minutes or so to allow the new oil to circulate through the engine. This may resolve the problem, especially if it’s due to low oil pressure, which requires only a few minutes to stabilize.

If the new oil circulation doesn’t turn off the check engine light, then there may be a more significant problem at play. In such cases, resetting the light with an OBD2 scanner may be necessary to clear the warning.

– Examine the Dipstick

Pop the hood and locate the dipstick. Check the tube to ensure it’s not obstructed, and then reinsert the dipstick firmly. If you suspect the dipstick may be misaligned, this is an easy problem to fix.

Simply adjust the dipstick until it is seated correctly in the tube. It’s also worth inspecting the tube for any debris that could be blocking the dipstick from fitting perfectly.

– Remove Any Excess Oil

If you’ve added too much oil to your engine, you can use a suction pump to remove excess oil. Using a manual or automatic pump, you can extract the oil from the dipstick tube or the cap access point.

However, you should research the method that will work best for your situation before proceeding. On the other hand, you can take the car to an auto shop to extract the oil more professionally.

– Check Your Car’s Oil Filler Cap

Also, you must ensure that you have correctly and tightly placed the gas cap. The writing on the gas cap should face you, depending on the vehicle. This might have caused the problem if the cap was backward. Check your service manual for guidance on how to place the cap correctly, although many vehicles allow it to be attached in only one way.

– Use the Right Oil

If you mistakenly used the wrong engine oil and encounter problems, you will need to conduct another oil change with the right viscosity recommended in the owner’s manual. You will have to drain the oil from your car, replace the oil filter, and refill the vehicle with the appropriate type of oil. After replacing the filter, the check engine light should turn off.

– Reset the Code

In some cases, the sensor responsible for the check engine light may not reset itself after an oil change, leaving the light on. However, you can manually reset the sensor to turn the light off. To do so, locate the diagnostic port under the driver’s side dashboard and connect a code scanner to it. Power on the scanner and scan for trouble codes.

If the codes indicate no other issues, you can use the scanner to clear the codes and reset the sensor. You may need an Onboard Diagnostic reader to analyze the engine code. A wrench will also come in handy. These steps will help you reset the code after getting an oil change:

• Locate the Port: To locate the OBD reader port, look for a small panel on the lower dashboard, typically above your feet. This panel might require removal to gain access to the port.
• Connect the Reader: Once you find the port, connect the OBD reader and turn on the device by pressing enter.
• Wait for Codes: Wait for the reader to scan the engine for error codes, then note the codes displayed on the screen.
• Clear the Code: To clear a code, highlight it using the scroll button and press enter to erase it.
• Restart Your Car: Once you have cleared the codes, restart your vehicle to allow the system to reboot. If the check engine light remains on, other issues must be addressed.

After you have cleared the code, we recommend taking the car for a test drive to ensure the light stays off. However, it is possible for the light to come back on. In that case, you should seek professional help. Take the car to an auto technician to help diagnose and fix the underlying issue.

FAQs

– How Long Will Your Check Engine Light Remain on After an Oil Change?

Your check engine light will remain on for 10 to 20 cycles after an oil change. The light needs some time to reset because the vehicle’s internal computer needs to check all its sensors, so it may take about 10 to 20 cycles for an automatic reset to happen.

– Will Your Check Engine Warning Light Go Off on Its Own?

Yes, your check engine warning light will go off on its own if the underlying issue is solved. If the light was on due to excessive oil, it would go off once you extract some of it. Likewise, keeping every component at normal levels will ensure the light stays off.

– Can You Continue Driving With the Check Engine Light on?

Yes, you can continue driving with the check engine light on, but we do not recommend it because the warning light indicates something might be mildly or severely wrong with your car. Therefore, you should stop the car once you notice the sign and check for what’s wrong.

Depending on the issue, you may have to call a tow truck or find the nearest auto repair shop. You risk causing heavy damage to your engine if you keep driving with the light blinking.

– What Will Happen If You Don’t Reset the Warning Light?

If you don’t reset the warning light, you may begin to notice some erratic behaviors with your car. It may require another oil change sooner than it usually would. This will distract you from the actual routine maintenance recommended by the manufacturer.

– Does the Check Engine Light Cause Your Car To Shake?

No, the check engine light does not cause your car to shake. However, vibrations may occur after you get an oil change if there is no lubrication on your motor stunts. It could also happen if some engine components have worn out and require replacement.

Conclusion

Whenever the check engine light remains on even after you just had an oil change, it indicates something is wrong. We have covered the various issues that may cause it and how you can solve them.

Here’s a brief recap of what you should keep in mind:

• The check engine light may be on after an oil change due to the wrong fitting of the oil filler cap. It could also be because of the improper sitting of the dipstick, low oil pressure, using the wrong oil, or using too much oil.
• The warning light may also stay on in cases of a bad oxygen sensor, damaged catalytic converter, malfunctioning oil sensor, excessive carbon buildup in the EGR valves, etc.
• You can easily fix this issue by examining the car’s dipstick, oil cap and engine components. Removing excess oil and ensuring you use the right oil will also help you prevent the issue.
• You can reset the code manually by using the OBD reader and restarting your car.
• It is best to stop driving your car when you notice the warning light. Check the underlying issue and fix it appropriately before you continue driving.

Follow the steps we discussed in this complete guide to fix your car’s check engine light issue, but we recommend taking your car to a professional mechanic for proper inspection.