4 Oil Pressure Sensor FAQs
Let’s explore a bit more about oil pressure sensors through some commonly asked questions:
1. What Is An Oil Pressure Sensor?
An oil pressure sensor (a.k.a. an oil pressure switch, oil pressure sender, or oil pressure sending unit) is a component that monitors the oil pressure inside your vehicle’s engine.
Based on the method of operation, there are two types of oil pressure monitoring devices:
- Sensors: a sensor is essentially a pressure transducer whose internal resistance changes with fluctuating oil pressure.
- Switches: the electrical switch closes when your vehicle’s oil pressure drops below a certain threshold specified by the automaker.
When your engine oil pressure is low, the oil pressure sensor or oil pressure switch signals the vehicle’s ECU or PCM. Without the oil pressure sender, there’s no way of knowing if the oil flow is enough and if your engine gets appropriately lubricated.
In short, an oil pressure sending unit helps guarantee the safe operation of your vehicle.
2. How Does An Oil Pressure Sensor Become Defective?
An oil pressure sensor/switch has three parts:
- A port open to the oil passage
- A rubber, steel, or ceramic diaphragm
- A sensor or electrical contacts
Typically, your oil pressure sensor becomes faulty when the diaphragm gets damaged. For example, the rubber diaphragm can rupture over extended use, causing the oil to leak and flood the sensor or electrical contacts.
The pressure transducer or electrical contacts can sometimes fail even when the diaphragm stays intact.
3. How Do I Get A Faulty Oil Pressure Sensor Diagnosed?
When you take the car to a mechanic, suspecting an issue with the oil pressure sensor, they will:
- Check your engine oil level first. If the oil pressure light is on, but the engine oil level is fine, your oil pressure sensor isn’t working right.
- Start your engine and check the oil pressure with a mechanical oil pressure gauge. If the pressure isn’t low but your oil light illuminates, you’ve got a bad sensor.
- Visually inspect the oil pressure sender for signs of oil leaks, poor connections, or damaged wires. If they notice any defects, the sensor is probably due for replacement.
- Measure the resistance of your vehicle’s oil pressure sensor when the engine is at rest and see if it falls within the acceptable range specified in the repair manual. If not, your oil sensor is faulty.
4. How Do I Replace A Bad Oil Pressure Sensor?
The exact steps for replacing your defective engine oil pressure sensor will vary depending on the make and model of your vehicle.
While you may be able to replace the oil pressure sensor on your own, it’s not recommended. The risks associated with an improperly installed oil pressure sensor make it inadvisable as a DIY project.
That’s why we’ll provide a general walkthrough of the oil pressure sensor replacement process, as how a mechanic would perform it.
First, your mechanic will gather all the equipment/tools they’ll need for the job — a jack, jack stands, a special oil pressure sensor socket, safety glasses, a torque wrench, a ratchet, an oil pan, and so on.
- Disconnect your vehicle’s negative battery cable.
- Raise the car with a jack and support it on jack stands.
- Locate the engine oil pressure sensor/switch.
- Disconnect the electrical connector from the oil sensor.
- Loosen your oil pressure sensor with a special socket, ratchet, or torque wrench.
- Remove the defective oil pressure sensor.
- Compare the old sensor with the new sensor to confirm compatibility.
- Coat the new sensor’s thread with a sealant.
- Install the new oil pressure sensor.
- Tighten the sensor with a special socket, ratchet, or torque wrench.
- Lower the vehicle and remove the jack stands.
- Start the car and confirm that the oil pressure warning light has gone off.
- Check if the engine oil level is proper.
- Start the engine and listen for any rattling noises from your engine block.