How to Check the Oil Pressure Sensor?

Before replacing it, you should check the oil pressure sensor for issues. Here’s what your mechanic will do:

1. Check your engine oil level: If the oil pressure light is on but the engine oil level is fine, your oil pressure sensor isn’t working properly. The check engine light might also pop on.

2. Visually inspect the oil pressure sensor:  Check for signs of oil leaks, poor connections, or damaged wires. If there are defects, the sensor is probably due for replacement.

3. Check for low oil pressure with a mechanical oil pressure gauge: First, remove the oil pressure sensor, install the gauge’s adapter, and connect the oil gauge. Start your engine and check the oil pressure with the oil gauge. If the oil pressure reading is fine, then you have a bad oil pressure sensor.

How to Replace a Bad Oil Pressure Sensor?

Replacing a defective engine oil pressure sensor/switch is fairly straightforward. However, the exact steps will vary depending on its location in your car. In some vehicles, you may need to remove other engine components or access the sensor from beneath the engine. 

If you’re unfamiliar with car parts, it’s best not to DIY this task and get an auto repair mechanic to handle the replacement. 

That said, here’s a general walkthrough of oil pressure sensor replacement (as how a mechanic would perform it.)

First, gather the necessary tools:

• Jack and jack stands
• Special oil pressure sensor socket
• Torque wrench
• Ratchet
• New oil pressure sensor
• Safety glasses

To replace the oil pressure sensor: 

1. Disconnect the vehicle’s negative battery cable.
2. Raise the car with a jack and support it on jack stands (this isn’t always required, depending on the sensor’s location.)
3. Locate the engine oil pressure sensor (oil sending unit). 
4. Disconnect the electrical connector from the oil sensor. 
5. Loosen the oil pressure sensor with the sensor socket and ratchet.
6. Remove the old sensor.
7. Compare the old sensor with the new sensor to confirm compatibility.
8. Coat the new sensor’s thread with a sealant.
9. Install the new oil pressure sensor.
10. Tighten the sensor with the torque wrench to manufacturer requirements. Be careful not to over-torque, as it could break the replacement sensor.
11. Reattach the electrical connector. 
12. Lower the vehicle and remove the jack stands.
13. Start the car and confirm that the oil light has gone off.
14. Check if the engine oil level is sufficient.

Start the engine and listen for any rattling noises from your engine block.

How Much Does Oil Pressure Sensor Replacement Cost?

An engine oil pressure sensor replacement can cost around $130-$375.

This average cost splits into:

• Replacement sensor cost: This ranges around $50-$200, depending on whether you pick aftermarket or OEM (original equipment manufacturer) auto parts.

• Labor cost: This varies depending on whether you take the vehicle to a dealership, auto repair shop or hire a local mechanic.

This estimate doesn’t factor in your location and vehicle make. Also, if your mechanic recommends additional repairs, the cost will increase.

How Urgent Is an Oil Pressure Sensor Replacement?

As a general rule, never ignore any faulty oil pressure sensor symptoms.

Ideally, you should stop driving the car and avoid restarting the engine until a professional mechanic diagnoses and resolves the issue. 

A defective engine oil pressure sensor may not alert you of low oil pressure in the engine. If that happens, your engine might have trouble staying properly cooled or lubricated and can seize up. This leads to irreversible engine damage and increased future repair costs.

4 Oil Pressure Sensor FAQs

Let’s explore some commonly asked questions:

1. What Is an Oil Pressure Sensor?

The oil pressure sensor is an engine component that monitors the oil pressure inside your vehicle’s engine. It’s also called an oil pressure switch, oil pressure sender, or oil pressure sending unit)

There are typically two types of oil pressure monitoring devices:

• Sensors are essentially pressure transducers whose internal resistance changes with fluctuating oil pressure.

• Electrical switches close when the oil pressure drops below a certain threshold specified by the automaker.

If your engine oil pressure is low, the oil pressure sensor or oil pressure switch signals the vehicle’s ECU (engine control unit). Without this oil pressure sender, you cannot know if the oil flow is enough and if your engine gets appropriately lubricated.

In short, this oil pressure sending unit helps guarantee the safe operation of your vehicle and prevents engine damage.

2. What Are the Symptoms of a Bad Oil Pressure Sensor?

If your vehicle has a bad oil sensor, here are some common issues you’ll encounter:

1. The Oil Pressure Light Turns On Or Starts Blinking

The oil pressure warning light pops on when the oil sending unit detects a high/low oil pressure and alerts the ECU. This might be accompanied by a lit check engine light. However, if the engine oil level is sufficient, but the oil pressure light on the dashboard stays lit or blinks constantly — that could mean your oil pressure sensor is defective.

2. Inaccurate Oil Pressure Gauge Readings

If you have a bad sensor, the oil pressure gauge may show inaccurate or extreme readings. You might see full or zero oil pressure even though the engine oil level is sufficient. 

3. Noisy Engine and Timing Chain

The tensioners holding your engine’s timing chain in place are usually oil-fed. When the oil pressure drops, the loosened chains whip around and get thrown against the pulleys and housings. That produces a deep, distinctive, metallic rattling noise from the engine block.

If you hear the noise but the oil light doesn’t illuminate, your vehicle’s oil pressure sensor is likely defective.

4. Oil Leak from the Oil Pressure Sensor

Since the sensor is seated in the oil system, oil may leak from the threads or through the center of a faulty oil pressure sensor. So, if you notice an oil leak around the sensor or inside it, your sensor is damaged and needs replacing.

3. Should I Drain the Oil When Replacing the Oil Pressure Sensor?

No. You typically won’t need to drain the oil when replacing this engine component. However, if dirty engine oil is the reason for a bad sensor, an oil change is required, so have an oil pan and new oil on hand. Consider changing the oil filter, too. 

Dirty oil can also damage your oil pump or cause engine overheating, so that’s further motivation for an oil change.

4. Is It Hard to Replace an Oil Pressure Sensor? 

This depends on the sensor’s location. Replacing the sensor itself is fairly easy, but getting to it can be difficult and may require removing other parts based on your vehicle’s engine configuration.