Proper and thorough car oil system maintenance requires you to change the oil, change the filters, do regular inspections, oil top-ups, and an oil flush+refill as envisioned by the manufacturer.
Even if you do all of the above, the dreaded oil light can still come up, which typically leads to either a problem with the sensor or with the oil pump.
The pressure can drop due to hardware issues or system leaks and are likely to damage both of these components if not dealt with ASAP.
If you do come across these issues, it’s best to keep your driving to a minimum, especially if you aren’t aware of what is exactly causing it.
To resolve this problem, you will have to perform a multi-point oil system inspection, which is going to require you to go to an experienced mechanic.
Some of these problems can be fixed in your driveway in just a few hours if you have the right tools for the job. However, if you aren’t 100% confident in your abilities, it’s best to leave this to a professional.
In this article, we are going to tell you why your car’s oil light turns on and off even when the oil is full.
Why does the oil light turn on and off even when the oil is full?
The oil light typically turns on when the oil pressure is low, which can be due to a few reasons. These typically include a faulty oil pressure sensor, a faulty oil pump, or potential leaks somewhere in the system.
Faulty Oil Pressure Sensor
The oil pressure sensor is tasked with consistently measuring oil pressure within the engine and all of its associated components.
It is actually comprised of two separate parts: an oil pressure switch and an oil pressure sender.
The oil pressure switch protects the engine from any oil system-related issues while the oil pressure sender communicates with the car’s brain to determine the correct pressure.
When any of these two fail, the car isn’t able to determine the correct oil pressure, which means that the associated oil warning light is going to come on.
Consequently, even if your oil levels are full, the sensor can fail, which is what happens in most instances and should be dealt with accordingly.
Faulty Oil Pump
The oil pump is heavily dependent on the aforementioned sensor to provide it with the correct data in order for it to provide the engine with the right amount of engine oil.
The pump circulates engine oil at a designated pressure through the bearings, the pistons, and the camshaft.
As the oil lubricates the engine, it essentially enables it to take advantage of higher-capacity bearings, which provide better efficiency and keep the engine cool for longer.
Thanks to high-pressure levels, the pump is able to suck out engine oil away from the pan and direct it through all of the oilways around the engine.
However, if the correct pressure is unknown, the pump fails to send the proper amount of oil through these oilways, which is extremely dangerous for the engine.
Lastly, we also need to mention that a faulty oil pump can damage the oil pressure sensor and vice-versa, which is another reason why these problems need to be resolved immediately.
System Leak
A leak somewhere in the oilways or the oil pan is likely going to affect all of the components mentioned above.
Sometimes the oil pressure sensor fails first and it kicks off a process of sending incorrect oil levels through the system, which can cause it to leak. These leaks typically occur around the oil pan.
Sometimes an oil line can get damaged due to being exposed to lots of moisture, high temps, or dirt and debris and consequently cause a leak.
Moreover, these are often expendable, which means that they will become brittle over time and crack, especially around the seals.
When this happens, air will enter the system and is going to affect the pump’s ability to regulate pressure. This means that a leak can effectively stem from the oil pump and oil sensor issues.
But the process can also be the other way around when an oil leak causes issues with the pump, especially if any dirt and debris enter the oilways through a crack somewhere in the system.
Solutions for Fixing an Oil Light That Comes On and Off Even When the Oil Is Full
After considering all the reasons and components linked with this problem, we can now start solving these issues.
Here’s a table of each problem and their solutions:
| Cause | Solution |
|---|---|
| Faulty Oil Pressure Sensor | You’ll need to replace the oil pressure sensor. Locate the oil pressure sensor on the engine block or cylinder heads. Unplug the sensor connector by releasing the retainer tab and slowly pulling the connector away from the sensor. Remove the oil pressure sensor via an appropriate screwdriver/wrench. Screw the new sensor tightly in place. Then, reconnect the associated retained tab to the connector. Start the car and check if everything functions as intended |
| Faulty Oil Pump | A faulty oil pump can be repaired, but it’s better to replace it. Start by locating the oil pump, which typically sits underneath the engine or right in the middle. Disconnect the negative battery terminal. Drain all the existing engine oil through the designated drain plug located underneath the engine. Remove the oil pan/gasket by removing all the bolts holding it in place. Remove the pump itself by unfastening the rear bearing cap bolt and removing the linked extension shaft. Do the exact same process the other way around and check if everything functions properly. |
| System Leak | Identify the source of the leak. If the leak is in the oil line or oil pan, replace the associated part. Stary by draining the oil then disconnect the battery. Remove the oil line and connect the new one. Pressure test the entire system to see if it’s functioning properly. |
Fixing a Faulty Oil Pressure Sensor
In order to rectify this problem, the best and frankly only thing you can do is to replace the faulty oil pressure sensor altogether.
Some do believe that these can be fixed, but a brand new sensor is the better way to go if you want these issues gone for good.
The first thing you need to do is locate the oil pressure sensor, which is typically directly on the engine block or the cylinder heads.
You need to unplug the sensor connector by releasing the retainer tab and slowly pulling the connector away from the sensor.
Remove the oil pressure sensor via an appropriate screwdriver/wrench and always compare your new sensor to the old one just to be 100% sure you got it all right.
Now it’s time to screw the new sensor tightly in place. Repeat the initial process the other way around, which means connecting the associated retained tab to the connector.
To finish everything off, start the car and check if everything functions as intended.
Fixing a Faulty Oil Pump
A faulty oil pump can also sometimes be repaired, but it’s better to replace it for the very same reasons mentioned above.
Initially, start by locating the oil pump which typically sits underneath the engine or right in the middle. This means that accessing the oil pump can be difficult, and if you are not skilled in car mechanics, it’s best to leave this process to a professional.
You also need to disconnect the negative battery terminal before doing anything in order not to mess up your car’s electrical systems.
Next up, it’s best to drain all the existing engine oil through the designated drain plug located underneath the engine. Be sure to do this while the car is cold as you don’t want to come in contact with hot engine oil.
Now it’s time to remove the oil pan/gasket (other components in front of the pump) by removing all the bolts holding it in place. Removing the pump itself requires you to unfasten the rear bearing cap bolt and remove the linked extension shaft.
To finish everything off, do the exact same process the other way around and check if everything functions properly.
Fixing a System Leak
Taking care of a leak is not straightforward until you properly deduce what is causing it and where the leak is located.
Sometimes, a system will have multiple leaks, which means that you always need to inspect the entire system in a detailed manner before starting to fix/replace anything.
The most common solution to this issue is replacing the associated oil line. This process is easy and only requires you to drain the oil, disconnect the battery, remove the oil line, connect the new one, and pressure test the entire system.
The same process is required if the problem lies in your oil pan.
It’s worth mentioning that you shouldn’t always conclude that the oil pan needs replacing as oil pans can easily be repaired, especially if it’s all down to a small crack in the housing.
Is it safe to drive with an oil light flickering?
As a flickering oil light can be caused by a variety of issues, it’s always best to keep your driving to a minimum.
If you do decide to continue driving, check the dipstick and look for any signs of leaks. If the oil levels are adequate and don’t seem to be leaking, you can drive short distances.
Frequently Asked Questions
