We have all seen that little monster light illuminate on the dashboard, and we are left thinking about what could be the problem. Several factors can cause the car computer to trigger the check engine light. It could be a significant issue like internal engine parts failure or a minor issue like a loose gas cap. However, you might have a different problem if the check engine light came on after the oil change.
In this article, I’ll explain the possible reasons for a check engine light to illuminate on the dashboard and how to reset the check engine light after an oil change. But first, let’s look at the possible reasons.
What would cause the check engine light to come on after the oil change?
Most often, the common reasons the check engine light came on after an oil change is the dipstick did not seat properly or improperly tightened oil fill cap. If not, it could be due to too much motor oil, low oil pressure, using the wrong oil type, or the oil sensor has not reset.
Let me throw more light on these possible causes, so you will know how each could trigger the dashboard check engine light.
1. The dipstick is not fully seated.
You need to remove the dipstick to check the engine oil level. During an oil change, you must remove the dipstick, clean it, and dip it back to check the motor oil level.
If you put back the dipstick the right way, there won’t be any issues. But if it does not sit properly, there will be space, letting air into the engine. This may look like nothing, but it can cause the car computer to trigger the check engine light on the dashboard.
2. Low oil pressure
Checking the oil level during an oil change will not cause any issues. However, draining the old oil from the crankcase will reset the oil pressure gauge.
After changing the oil and oil filter, the oil pressure gauge may take longer to read correctly. Hence, the oil gauge is trying to reset if you see a flashing check engine light after an oil change. Allow the oil sensor to do its thing. However, contact your mechanic if the flashing continues for an extended period.
3. The oil fill cap is not installed properly.
Often, car owners and mechanics forget to properly tighten the oil fill cap after pouring in the new oil. Other times, it could be that you have crooked the fill cap.
Either way, engine pressure will be escaping from the fill cap. This will cause car shaking and check engine light on after oil change on new modern vehicles. An improperly installed oil fill cap will not cause any issues on most older vehicles.
4. Wrong engine oil
Every car manufacturer recommends a certain oil grade for their engines. Changing the engine oil with a different viscosity or oil weight can cause issues to your car. For instance, if you use a 0W40 instead of a 20W40, it can trigger the check engine light on the dashboard and may cause internal engine issues.
Thicker engine oil does not provide the same level of lubrication as thinner ones. Also, using cheap or inferior oil will cause severe issues like smoke coming from the tailpipe.
5. Too much oil
Every engine has the quantity of motor oil it needs, and you must use the correct quantity. If you add too much oil to your engine, the oil will form a foamy substance. This will reduce the lubricating properties of the engine oil. Plus, it can cause the car computer to illuminate the check engine light on the dashboard. And the vehicle is going to stall or misfire.
But can low oil cause check engine light to come on? Yes. Like overfilled engine oil, low oil levels will cause the engine warning light to pop up.
Hence, you must check your oil level after changing the oil. It could be you have overfilled the oil or did not fill it to the recommended level.
6. The sensor didn’t reset after an oil change.
Most cars have sensors that alert you when it’s time to change the engine oil. The sensor should reset after changing the motor oil. If the service engine soon lights are still on after oil change, it means the sensor has not reset.
But how long after oil change will check engine light go off? The service engine soon lights or the check engine light should disappear a few minutes after changing the oil. However, you have to run the vehicle for the sensors to detect the new oil in the engine.
Read Also: Check Engine Light Came On After Tire Change
How to reset the check engine light after an oil change
Since there are several reasons why the check engine light appears after changing oil, there are also several ways of addressing the issues.
Reseat the dipstick
If you think the dipstick is the problem, open the hood and inspect it. Remove the dipstick and reinsert it back and ensure it sits properly. If the dipstick is the cause, you have a simple fix. Reseating the dipstick is all you need to fix the issue.
Look into the tube to see if there’s any debris causing the dipstick not to sit properly and clean it.
Adjust the oil level.
Check the oil level while working on the dipstick. Check if the oil is low or overfilled and adjust it as needed.
If the oil level is low, add more oil until it gets to the recommended mark on the dipstick. But if it is overfilled, you can remove the excess oil using a suction pump through the dipstick tube or draining the oil from the oil sump.
Drive the car for a few minutes.
You don’t have to panic if the warning light appears due to low pressure. All you need to fix this problem may be a few minutes of driving. Drive the vehicle around for a few minutes for the sensor to reset and determine the oil pressure.
The check engine light should reset as you drive the vehicle around. But if it doesn’t, you may have a more severe issue at hand. Try wiping the warning light with your scan tool and see if that fixes the problem.
Check the oil fill cap.
Sometimes car owners and mechanics forget to tighten the oil fill cap. As a mechanic, I understand this happens more often than you can imagine. A car owner may decide to cover the oil fill cap (not tightening) so debris will not fall into the engine while checking the oil level. After reviewing the oil level and the filter for leaks, the mechanic or car owner may forget to tighten the oil fill cap.
If this is the case, you have to tighten the cover. Also, check if the cover is placed in the wrong position and correct it.
Change the oil to the right grade.
If you serviced the engine with the wrong oil viscosity, the only solution is to do a new oil change with the correct oil grade.
Get underneath the vehicle and drain the wrong oil. Pour in the correct oil grade and replace the former filter as well. After that, idle the car for a few minutes, and the check engine light will disappear.
Reset the engine codes
or the engine warning light after an oil change, then you may have to do it manually.
To reset the sensor:
- Insert your OBD2 scan tool into the vehicle OBD2 port underneath the car.
- Pull out the registered codes and clear the ones related to the engine warning light.
- Once you finish erasing the codes, restart the vehicle, and the light will disappear.
If the light returns, you have to get an experienced mechanic to track the problem.
Final words
You don’t have to panic if you have a check engine light after switching to synthetic oil or the check engine light came on after oil change. Though, you must track and address the issue before it escalates.
The check engine light appears after an oil change due to overfilled oil, dipstick not being appropriately seated, wrong oil type, oil fill cap not installed properly, low oil pressure, and sensor that didn’t reset.
Follow the recommended guides above to address the issue. Contact a mechanic if you don’t want to roll your sleeves and get your hands dirty.
