Getting incorrect oil pressure readings?
Your engine oil pressure sensor — also known as the oil pressure switch or oil pressure sending unit — might be the culprit.
But how can you be sure it’s faulty?
And what expenses can you expect if you need a replacement?
Don’t stress!
We’ll review the cost, symptoms, diagnosis, and everything you should know about a faulty engine oil pressure sensor.
Let’s go.
This Article Contains:
- How Much Does It Cost to Replace an Engine Oil Pressure Sensor?
- 5 Signs of a Bad Engine Oil Pressure Sensor
- How to Diagnose and Replace a Faulty Oil Pressure Sensor
- What Causes an Engine Oil Pressure Sensor to Fail?
- 3 FAQs on Engine Oil Pressure Sensors
How Much Does It Cost to Replace an Engine Oil Pressure Sensor?
An engine oil pressure sensor replacement can cost about $130 to $375, including $50 to $200 for replacement parts and $80 to $175 for labor. However, this can vary based on your car model and the labor charges in your area.
For example, here are replacement estimates for specific models:
- 2011 Nissan Pathfinder: $165 to $210
- 2012 Chevy Express 1500: $170 to $215
- 2010 Dodge Grand Caravan: $275 to $375
But how can you tell if you have a bad oil pressure sensor?
Let’s find out.
5 Signs of a Bad Engine Oil Pressure Sensor
Whether you drive a Honda or Jeep vehicle, here are five signs that your oil pressure sensor or oil-sending unit is faulty:
1. Oil Pressure Warning Light is On or Blinking
Normally, the oil pressure warning light turns on when your car runs low on engine oil or has an oil leak.
However, a faulty oil pressure sensor can falsely trigger a low oil pressure condition, turning on the low oil pressure light.
Your mechanic will check the engine oil level in the pan to determine whether the oil pressure warning light is triggered by actual low pressure or a faulty switch. If the oil level is normal, you’ll likely need an oil pressure sensor replacement.
2. Illuminated Check Engine Light
The check engine light is a warning light that activates when any engine component, including the oil pressure sender, alternator, or ignition coil, is malfunctioning.
You’ll need a mechanic to confirm if the light is due to a bad oil pressure sensor. They’ll run a diagnostic scan by connecting the Diagnostic Trouble Code (DTC) scanner to the car’s Electronic Control Unit (ECU).
If a faulty oil pressure sensor is the cause of the illuminated warning light, then one of these OBD codes will likely show:
- P0520: General physical problems related to poor engine performance
- P0521: General Internal problems causing low oil pressure
- P0522: Specific internal issues causing low oil pressure
- P0523: Specific internal issues causing high oil pressure
Note: If this warning light is on, get a tow or have a mechanic come to you. If the light starts blinking while you’re driving, find a safe parking place and shut the car off immediately. This helps minimize the chance of costly internal engine damage.
3. Inaccurate Reading From the Oil Pressure Gauge
A faulty oil sensor is considered a typical cause for incorrect readings on the oil pressure gauge.
The gauge pointer corresponds with the oil pressure in the car’s oil pan. When you have a faulty oil pressure sensor, the pressure gauge pointer can be stuck at one end, or the oil gauge might function intermittently.
4. Reduced Engine Performance
If the Engine Control Module (ECM) or Electronic Control Unit (ECU) detects inaccurate oil pressure readings, it may activate limp mode. This feature in most makes, like a Ford Ranger or Chevrolet Silverado, reduces speed and limits the use of less important systems.
In other cases, the ECU may trigger improper engine timing and fuel injection adjustments due to inaccurate data. This can reduce engine performance and result in rough idling.
5. Engine Overheating
If a malfunctioning sensor fails to alert the ECU about actual low oil pressure, the lack of lubrication can lead to engine overheating. This can also damage other components, like the oil pump, gaskets, and seals.
Now that you know the signs of a bad oil pressure sender, let’s see how to diagnose and fix it.
How to Diagnose and Replace a Faulty Oil Pressure Sensor
Diagnosing a faulty oil pressure sensor requires some technical know-how. That’s because a malfunctioning oil pressure sensor/switch can also result from issues with connected parts, like the oil pump, gauge, and oil filter.
So, if you’re unfamiliar with the auto parts, it’s best to get an auto professional to perform the diagnosis.
Here’s what a mechanic would do:
1. Check Engine Oil Level and Condition
Before beginning, a mechanic will ensure the car is parked on a flat surface and the engine is cold.
They’ll verify the oil level in the engine by pulling out the dipstick from the tube, wiping it clean, and reinserting it into the tube to observe its markings. If the engine oil level is below the full marker or they notice an oil leak, then low oil pressure is causing the engine trouble.
Next, the mechanic will observe the oil’s condition:
- Regular engine oil should be golden amber, dark brown, or black. A light or milky oil appearance means that coolant has leaked into the engine.
- If metal particles are in the oil, it could mean internal engine damage.
Note: If you notice any of the above issues during a routine oil check, do not drive your vehicle. It’s best to contact a mobile mechanic to prevent further damage to the engine.
2. Check the Sensor Wiring
If the oil level and conditions are normal, the next step is to check the sensor’s wiring. The mechanic will look for damaged or loose electrical connections.
3. Check Actual Oil Pressure
The last step before confirming a faulty oil-sending unit is to inspect the engine’s actual oil pressure with an oil pressure gauge.
The mechanic will:
- Remove the oil pressure switch and install the oil pressure gauge with the adaptor to the engine.
- Turn on the engine, let it warm up, and maintain a steady RPM before taking a reading on the pressure gauge.
Note: Different engine models and makes have different manufacturing settings to check their oil pressure.
If the gauge gives a low oil pressure reading when the engine is running, it could be an internal issue with the engine’s lubrication system or the oil is too thin for your engine. It can also indicate a blocked oil filter, as it causes slow oil flow into the engine, thus creating low pressure.
If the oil pressure is within the expected values on the oil gauge and there are no issues with the wiring, you likely have a pressure monitoring issue due to a bad oil pressure sensor.
4. Replace the Oil Pressure Sensor
After the above steps, the mechanic will check for certain OBD codes to confirm a faulty sensor.
Here’s how they’ll replace it:
- Disconnect the battery as a safety measure.
- Drain the oil from the oil pan into a container.
- Remove the oil filter.
- Unplug the electrical connector to the sensor after removing the rubber covering.
- Unscrew the pressure switch by using a socket wrench or ratchet.
- Clean the electrical connector before installing the new sensor.
- Secure the new sensor with a socket wrench and add the rubber covering.
- Reattach the cable to complete the installation.
Wondering why the oil pressure switch or sensor malfunctions?
Read on to find out.
What Causes an Engine Oil Pressure Sensor to Fail?
An engine oil pressure sensor may malfunction due to:
- Wear and tear: The oil pressure sensor can wear out over time with exposure to various elements, like engine heat, car vibrations, and environmental conditions.
- Dirty oil: Contaminants from dirty oil or sludge can collect on the sensor, impacting its ability to take accurate readings. Oil changes per the recommended maintenance schedule help prevent this contamination-related issue.
- Wiring or electrical issues: Wiring faults, like damaged wires and corroded connections, can prevent the oil pressure sensor from sending signals to the ECU.
- External damage: Located in the engine block, the sensor is vulnerable to damage from road debris or accidents, which can cause inaccurate readings.
- Manufacturing defects: In some cases, manufacturing defects can cause a sensor to fail prematurely.
Next, let’s answer some common doubts about the sensor.
3 FAQs on Engine Oil Pressure Sensors
Here are answers to some engine oil pressure sensor-related queries:
1. How Does an Engine Oil Pressure Sensor Work?
Your car may use either of these two oil pressure sensor types:
- A simple oil pressure switch leads to an open circuit when the oil pressure reaches or exceeds the minimum required threshold.
- An oil pressure sensor continuously measures the actual oil pressure in the engine.
Both types monitor the engine’s oil pressure and transmit information to the oil pressure gauge on the dashboard.
Here’s how the switch type works:
When you turn on the ignition, and the engine is still off, there’s no oil pressure. The switch circuit remains closed, keeping the oil pressure light on.
But when you start the engine, the oil starts flowing into the engine’s lubrication system. The engine oil flow from the oil pan to the engine block produces oil pressure, which is then detected by the oil pressure switch.
The switch picks up the pressure in the lubrication system and opens the circuit. It transmits the readings to the car’s processing unit and the instrument cluster panel. The low oil pressure light then turns off.
2. Is Driving with a Bad Engine Oil Pressure Sensor Safe?
Driving isn’t recommended when you have a bad oil pressure sensor. You shouldn’t take it lightly, even if you’re confident it’s just an oil pressure sensor problem.
Maintaining proper oil pressure in your engine is critical to keep it functioning. A bad oil pressure sensor can give wrong oil pressure readings. You won’t notice if the oil pressure is too low or too high and risk damaging the engine altogether.
You’ll also put your safety at risk by continuing to drive with a bad oil pressure sending unit.
3. How Often Should I Replace My Oil Pressure Sensor?
The oil pressure sensor is built to last as long as your vehicle. However, harsh weather and general wear can damage it. So, if you drive in stop-and-go traffic or brake heavily and frequently, you should check your engine’s oil system frequently.
You can also prevent your oil pressure sensor from acting up by replacing your engine oil and oil filter per the manufacturer’s recommended schedule.
This includes getting an oil change every 3,000 miles or three months for old vehicles and every 6,000 miles or six months for newer vehicles. And unlike an air filter that’s usually changed once a year, you should replace the oil filter after every oil change.
Get a Faulty Engine Oil Pressure Sensor Fixed ASAP
The engine oil pressure sensor or switch is a crucial component in keeping your car’s engine running. A faulty sensor can cause severe damage to your engine if left unattended.
However, ensuring regular servicing is the easiest way to prevent your oil pressure sensor from failing.
What better way to do that than with AutoNation Mobile Service?
We’re a mobile auto repair and maintenance company offering comprehensive car care services for most car makes, including Chrysler, GMC, and other vehicles. We also offer a 12-month, 12,000-mile warranty on repairs.
Contact us to have an engine oil pressure sensor or any other fix, such as a fuel pump, intake manifold, or thermostat repair, done right from your driveway.