Your engine needs oil to run smoothly, we all know that. What you might not know, that the system requires pressure to work and there’s a sensor that monitors the oil pressure in your engine. In this post, we’ll take a look at bad oil pressure sensor symptoms, what oil pressure is, and what you will need to do to fix it if you have any problems.
What Is Oil Pressure?
Internal combustion engines use a forced lubrication system. With this system, the oil pump will pick up the engine oil and pressure it into passageways. Then the oil will lubricate various components in the engine, such as bearings, camshaft, and balance shaft.
Sufficient oil pressure will ensure that these parts are well-lubricated. It will also ensure that certain components – such as the rotating shaft and bearing shell – won’t touch or grind against each other. All this happens as soon as you turn the engine, so wear and grind between components usually happen only during engine start-up and shutdown. All this sounds pretty difficult to imagine, so here’s a quick animation video to explain how engine oil works:
To put it in simpler terms, oil pressure is the amount of resistance that the oil faces when going through the passageways. If the pressure is too low, this means something isn’t working properly, such as the oil pump. It could also mean that there’s not enough lubricant going through the engine.
If the oil pressure is too high, this means the oil is facing too much resistance. The cause varies from dirty oil filters to bad oil quality or incorrect viscosity. In any case, you want to ensure your car always has the correct oil pressure, otherwise, lubrication problems will occur. And this can eventually lead to serious engine damage.
Oil Pressure Sensor Symptoms To Lookout For
Some cars have an oil pressure gauge for drivers to continuously monitor oil pressure. This helps drivers to monitor oil pressure constantly. However, most modern cars don’t have this and it’s mostly present in old cars and performance cars. But pretty much every car does have an oil pressure sensor. As the name suggests, this sensor monitors the oil pressure constantly.
When the sensor detects that the oil pressure is outside the normal range, it will illuminate a warning light. This light will warn the driver that there’s an issue with the engine oil, and they will need to address it before serious damage happens to the engine.
But of course, just like any other sensor, the oil pressure sensor can go bad as well. Here are the oil pressure symptoms you might see when the sensor is faulty:
1. Incorrect Oil Pressure Reading
If your car has a dedicated oil pressure gauge, then it will be a lot easier for you to know if you have a bad oil pressure sensor. If the gauge sporadically reads zero or is off the charts, this is a sign that your oil pressure sensor is failing. Some modern cars may also have an oil pressure reading, but usually, there’s no dedicated gauge and you’ll have to go into the sub-menu of the car’s system.
However, if the gauge is constantly low, then the first thing you should assume is that you’re low on oil. Check your car’s engine oil dipstick, and see if you have enough oil. If not, top up your engine’s oil and see if the reading persists.
2. Oil Warning Light Is Illuminating
Your car has a lot of warning lights on the dashboard. This includes the check engine light, the ABS warning light, and yes, the oil warning light. If the oil warning light in your car is on, this usually means you have low oil levels in your car. Again, you should check your engine oil dipstick and see if you have enough oil.
If you don’t have enough oil, this is probably the root of the problem. In this case, simply to up your engine with the correct oil. Afterward, let your engine run and then see if the oil warning light is still on. If it stays on, this likely means you have a faulty oil pressure sensor that’s giving incorrect readings. Which in turn triggers the engine oil warning light.
3. Oil Warning Light Is Flashing/Blinking
Whenever a warning light on the dashboard is flashing or flickering it usually means something serious. If you see the check engine light flashing, stop driving immediately. This indicates a serious problem with the engine and continuing to drive can damage your engine. Meanwhile, a flashing oil warning light means there’s something wrong with your car’s engine oiling system.
Like the other two oil pressure sensor symptoms, the first thing you need to do is to check your car’s engine oil dipstick. If the oil level is low, top it up with the appropriate amount and use the correct engine oil type. If the light is still flashing afterward, this is a good indication that you have an oil pressure sensor problem.
Oil Pressure Sensor Symptoms: How To Troubleshoot
Unlike some other faulty sensor symptoms, the oil pressure sensor symptoms are pretty vague. It’s hard to tell what might be wrong, but don’t worry, we’re here to help. As mentioned, the first thing you should always do when there’s an oil warning light is to check the engine oil level. Here’s how to do that:
Checking The Oil Level
- The engine oil level needs to be checked when the engine has cooled down. If you’ve been driving, park your car on a level surface and wait for 15 minutes. This lets the oil drop down from the engine to the oil sump or pan, and this way you’ll get an accurate reading.
- Locate your car’s engine oil dipstick, it’s usually in the front corner of the engine. It usually has a yellow handle with ‘Engine’ written on it.
- Pull out the dipstick, and wipe it off with a tissue or rag.
- Reinsert the dipstick fully back into the hole, and then pull it out again.
- Take it out once again, and see where the engine oil is on the dipstick. The dipstick has a minimum and maximum indicator, if it’s below the minimum indicator, you’ll need to refill it.
Refilling the engine oil is pretty straightforward. There’s a cap on top of the engine, open that and put the oil in there. Use a plastic funnel so that you won’t spill oil everywhere. Start with about a quart of oil, check the dipstick, and then add more if necessary.
Make sure that you use the correct type of oil with the right viscosity grade for your engine. You can find this information in the owner’s manual, and you should stick to the recommendation. Using an engine oil with the incorrect viscosity grade can result in engine damage. If you have a diesel vehicle, read our article about the best synthetic oil for diesel engines here.
Testing Engine Oil Pressure
If your oil level is normal, or you’ve refilled the oil but the warning light is still on, then you have another problem triggering the light. There are two possibilities: either your oil pressure is too high or too low, or the sensor is faulty. You’re going to want to check the oil pressure first. If the pressure is normal, then by elimination it’s the sensor that’s faulty.
Here’s how to check your engine oil pressure:
- Acquire an oil pressure tester kit. If you need to buy one, there’s plenty on Amazon it costs around $50.
- Park your car on a level surface.
- Locate the engine’s oil pressure sender. This should be located somewhere near the oil sump or the oil filter.
- Put an oil drip pan underneath it, and remove the switch.
- Find the adapter in the testing kit that matches the oil pressure sender’s thread, then attach it to the slot where the oil pressure sender was.
- Attach the gauge to the adapter, and make sure your engine oil level is not low.
- Afterward, start the engine.
- Allow the engine to reach operating temperature. In the meantime, consult a service manual to find out what the appropriate oil pressure level is for your car. Some cars may also require you to rev the engine to a certain RPM to get an accurate reading
- If necessary, have someone to help you rev the car to the specified RPM whilst you read the gauge.
- Read the gauge and see if the oil pressure is in the manufacturer’s specified range.
If the oil pressure level is too low or too high, then you will need to address the issue. But the oil pressure is normal, then this is confirmation that your oil pressure sensor is faulty.
Verifying Oil Pressure Sensor Symptoms: Use An OBD Scanner
This next step isn’t necessary since we now know that your oil pressure is normal and the only other possible cause is a faulty oil pressure sensor. But if you want to make sure, then you can scan your car’s On-Board Diagnostics (OBD) system. This way, you can find trouble codes in the system and see if there are any related to the oil pressure sensor.
If you didn’t know, cars have an On-Board Diagnostics (OBD) system to help scan for error or trouble codes. Whenever a car detects that something is wrong, it will send an error code to the car’s Powertrain Control Module to fix the issue by making adjustments to the engine. If it can’t fix the problem, the error code will register on the OBD and it triggers the warning light.
Keep in mind that this method is going to work for cars made after 1996 with an OBD-2 system. OBD-1 systems are proprietary, so you’ll have to check on how to do it with your car’s make and model. With that being said, here’s how you scan an OBD-2 system:
- Get an OBD-2 scanner/reader. They’re universal, so they will work with any car as long as it has an OBD-2 system.
- Plug the reader into the car’s OBD port. Check your owner’s manual or online to see where it’s located in your car.
- Once plugged in, turn on the OBD scanner. It should immediately scan the car. However, some scanners might require you to input additional information such as make, model year, VIN, etc.
- It will then display the error codes it has found and take notes of these codes.
Trouble Codes To Lookout For
There are over five thousand trouble codes that can pop up in a car. But you’ll want to look out for these engine oil-related trouble codes:
- P0520 – Engine Oil Pressure Sensor/Switch Circuit Malfunction.
- P0521 – Engine Oil Pressure Sensor/Switch Range/Performance.
- P0522 – Engine Oil Pressure Sensor/Switch Low Voltage.
- P0523 – Engine Oil Pressure Sensor/Switch High Voltage.
The P0520 and P0521 codes are likely to be a sensor problem, shorted wiring within the sensor is often the culprit. A short in the wiring can cause incorrect voltages, which leads to the sensor getting an incorrect reading and assuming that there’s an oil pressure problem in the car.
Meanwhile, the P0522 code means the sensor is reading the oil pressure as below the accepted range. And the P0523 code means the value that the sensor is reading is too high. This usually means that your oil pressure is either too low or too high from the accepted range. However, since we already tested that the oil pressure is normal, this means you have a faulty oil sensor.
Oil Pressure Sensor Replacement Cost
The oil pressure sensor symptoms are pretty vague. But with a little bit of troubleshooting, you can easily find out whether you have a bad sensor or if there’s an actual mechanical issue. If you have a bad oil pressure sensor, how much will you need to spend to replace it then?
Thankfully, the oil pressure sensor is relatively cheap to replace. The sensor itself is typically between $50 – $70 to buy. As for the labor, it’s usually between $70 – $90. It’s not a difficult job to do so labor is cheap, which is good news for your bank account. In total, expect to spend around $120 – $160 for an oil pressure sensor replacement job.
Can I Replace It Myself?
Yes, you can. In fact, it’s a pretty simple job to do. Here’s how:
- Lift the front of your car with a car jack and then put it on a jack stand. Make sure to engage the parking/emergency brake beforehand, and use wheel chocks if you have any just to be safe.
- Locate the oil pressure sensor switch. It’s usually located near the oil sump.
- Remove the wiring harness, clean it afterward if necessary.
- Remove the oil pressure sensor switch by using a socket, there are also oil pressure switch sockets that you can purchase. The size may vary between each car, so you’ll need to identify that. Additionally, place a drain pan underneath it because the oil will come out.
- Apply sealant to the threads of the new oil pressure sensor. Some sensors may not require you to do this, so check with the manufacturer’s instructions.
- Thread the new sensor into the slot by hand, and then tighten it securely with a socket.
- Reconnect the electrical harness to the new oil pressure sensor. Remember to clean it first if necessary.
- Start the engine and see if there’s still an oil pressure warning light.
- Your engine may have lost a bit of oil in the process. Check the engine oil dipstick and refill the oil as necessary.
- Pat yourself on the back cause you’ve done a good job!
The labor cost for an oil pressure sensor replacement is not expensive at all. But if you do it yourself, you will save at least $70. Plus, it’s not a difficult job to do, it’s not something that could go catastrophically wrong, and will take about an hour at most if you do it right.
Oil Pressure Sensor Symptoms: Questions & Answers
What Do I Do If The Oil Pressure Is High?
A high oil pressure usually occurs because there’s a blockage somewhere. When something is blocking the oil, it will become much harder for oil to flow as there is resistance, resulting in high pressure. There are four possible culprits, first is a dirty oil filter.
Oil filters need to be changed with every other oil change. For example, if you had an oil change at 10,000 miles and changed the filter, you don’t have to change it at the 15,000-mile oil change. However, you have to change it at the 20,000-mile oil change. The second one is that you may be using the wrong viscosity grade. If the oil is too thick, it will also face more resistance when going through the passageways, resulting in high oil pressure.
Next, you need to check the oil pressure relief valve. These valves open automatically when the pressure gets too high and relieve the system of excess pressure. If this valve malfunctions, it won’t be able to do its job and you’ll have to replace it.
Finally, there may be a blockage in the oil’s passageways. It could be because that you were overdue for an oil change, and now there’s a lot of gunk in the passageway. Whatever the cause, this one is a bit tricky to diagnose and repair, so we recommend going to your trusted mechanic to fix the problem.
What Do I Do If The Oil Pressure Is Low?
There are three possible causes of low oil pressure, other than low oil levels as we’ve mentioned countless times in this post. First, you may be using the wrong oil viscosity. If the oil is too thin from what you should be using, it will face less resistance which can translate into low oil pressure.
The second possibility is a bad oil pump. The oil pump is, well, is what pumps your oil from the sump into your engine. If the oil pump is worn out or is going bad, it won’t be able to pump oil with as much pressure as it should. This, of course, results in low oil pressure. Read our comprehensive guide on oil pumps here.
And finally, there may be significant wear in your engine, this is very possible if you drive an older car. Excessive engine wear can reduce the engine’s original flow restriction, which allows oil to flow more freely, but results in low oil pressure. In this case, you’re likely going to need an engine rebuild which can cost thousands of dollars.
What Is An Oil Viscosity Grade?
Viscosity grade is the numbers that you see on the oil container, such as “15W-30”. The “W” number refers to the thickness of the oil when it’s cold. And the lower the number, the better it can withstand low temperatures and will work better in colder areas. Meanwhile, the number afterward refers to the oil thickness at operating temperature.
Why is this important? Well, different engines have different requirements. Some engines can run on thinner oil, while others need thicker ones. Additionally, in colder temperatures, it will be better to use thinner oil. This is because oil thickens when it’s cold, and if the oil is too thick then it can damage the engine.
You will be able to find your manufacturer’s oil viscosity recommendation in the owner’s manual. Be sure to stick with their recommendation to ensure optimal performance and a long-lasting engine.
Can I Drive With A Bad Oil Pressure Sensor?
If it’s just the sensor, then technically yes, you can. However, that oil warning light will continuously light up until you change the sensor. Additionally, you won’t be able to tell when you have an oil pressure problem. Our advice is that you still change it immediately, as it’s not that expensive to replace anyway.
Oil Pressure Sensor Symptoms: Wrap Up
There are three oil pressure sensor symptoms: abnormal oil pressure gauge reading, illuminating oil warning light, and a flickering oil warning light. As mentioned, these symptoms are pretty vague, so you’ll have to troubleshoot it to find out whether there’s an oil pressure issue, or has the oil pressure sensor gone faulty.
If you see any of the symptoms, the first thing you should check is your engine oil level and refill if necessary. If the oil level is normal or the problem doesn’t go away, you will need to check the oil pressure. Afterward, find the exact cause if the oil pressure is too low or too high. If not, then replace the oil pressure sensor which costs about $160 on average, including labor. We hope this article has been helpful for your oil pressure problems, good luck!
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