Oil Pressure Sensor
As its name indicates, an oil pressure sensor is used to monitor the oil pressure inside an engine to make sure all moving parts are properly lubricated. While an oil pressure sensor itself is not responsible for any critical function, its failure can be very dangerous as you may overlook serious problems caused by other faulty engine parts. That’s why you should be aware of the most common signs of a bad oil pressure sensor:
Your check engine light comes on
Your engine control unit keeps an eye on the oil pressure operation. If the sensor fails, the computer will turn on the check engine light.
Incorrect oil pressure gauge readings
If your vehicle is equipped with an oil pressure gauge, a failed sensor can cause it to malfunction or your oil pressure warning light to blink, or to be on all the time.
In some cases, the oil pressure sensor or switch can fail to withstand the high oil pressure inside the engine and begin to leak.
What is an oil pressure sensor?
An oil pressure sensor serves to warn the driver of the low oil pressure in the motor. Depending on your vehicle, the oil pressure sensor or switch can supply its readings to either an oil pressure gauge or low oil pressure warning light.
Oil pressure gauge
Vehicles equipped with an oil pressure gauge rely on an oil pressure sensor to monitor the engine lubrication. Depending on the oil pressure inside the system, the sensor changes its internal resistance and transforms this into signals sent to the oil pressure gauge on the dashboard.
Low oil pressure warning light
If your dashboard does not feature an oil pressure gauge, yet has a warning light, most likely your vehicle is equipped with an oil pressure switch, which is normally open or closed. When everything is fine, the high oil pressure breaks the electrical circuit inside the switch, so the warning light is off. However, if the pressure is low, the switch changes to the other position, causing the warning light to be on. On some vehicles, current from the oil switch is first sent to the engine control unit, which, in turn, causes the oil pressure gauge needle to move or the warning light to come on.
Driving a vehicle when its oil warning light is on or the oil pressure gauge shows abnormal readings is a great way to ruin your engine. If you’re on the go, you should stop the vehicle, shut down the engine, wait until it cools down and then check the oil level. In case the oil level is good but the warning light is still on, call your mechanic for advice.
Is it possible to fix a bad oil pressure sensor or switch?
An oil pressure switch or sensor is not repairable. However, before purchasing a replacement, you need to be sure a bad sensor is the root of the problem. First of all, you should check the oil level, if it is low, top it up and then see whether the warning light is still on. If it does, you may need a professional to diagnose the sensor using a scan tool or multimeter.
A bad oil pressure sensor or switch should be changed once it’s detected. On some vehicles, it is pretty simple since the sensor is easy to access in the engine bay. Otherwise, you should leave the job to a mechanic to prevent occasional damage to other engine parts.