Informational Guide

How To Check The Oil Pressure In A Car

This guide will show you how to check the oil pressure in a car and how to check if the oil pressure sensor is bad.

Your engine's oil pressure is essential to the motor's longevity and functionality. When the oil pressure isn't correct, your engine is in trouble and could face costly repairs. That's why it's important to test the oil pressure regularly. We will show you how to check the oil pressure in a car and how to check if the oil pressure sensor is bad.

Oil pressure is vital to the durability of an internal combustion engine. Oil is forced through the system with a pump, where it lubricates the bearings and other metal components of the engine. When the motor receives sufficient oil pressure, the metal parts never touch one another. Otherwise, there is significant wear to these parts, eventually resulting in engine failure.

To ensure the engine is receiving the right amount of oil, you should use an oil pressure gauge. This diagnostic tool alerts you if the oil pressure becomes too low or exceeds normal limits. When a warning occurs, it's imperative that you address the problem immediately.


Two Basic Types Of Oil Pressure Gauges

Electric Oil Pressure Gauges

Electric current enters the gauge through a power supply and travels through the wire-wound coil in the needle's pivot point to move it across the gauge. The reading is determined by the current flow.

Mechanical Oil Pressure Gauges

The gauge taps into the oilway through a small-bore pipe made from plastic or copper. Oil is fed into the gauge's bulb from a supply pipe that produces the same pressure as the engine. As the bulb straightens under pressure, the needles move on the scale.

How To Read/Check An Oil Pressure Gauge

As you learn how to check oil pressure, it's always best to reference the owner's manual of your vehicle. Here are some basic guidelines that should help you figure out how to check the oil pressure gauge and what the readings mean.

Zero Reading

You figured out how to check oil pressure in a car, but the reading is zero…now what? Most likely, your oil pressure gauge is faulty, but it could also mean that the engine needs oil or the pump has broken. Fill up the oil and test the pressure again.

High Reading

High oil pressure might indicate a stuck pressure relief valve or an oil delivery line blockage. When you run your vehicle with high oil pressure, there's a chance that the oil filter could burst, which would lead to bigger issues.

Low Reading

You want to know how to check low oil pressure because this is some of the most damaging to your vehicle. It can indicate an issue with the gauge itself, but it most likely means that there is a worn-out engine component, such as the bearings or pump. It could also point to overheating engine oil. Either way, it's vital that you have the system checked out immediately because the engine is not getting the oil it needs to run properly.

Check Your Car’s Oil Pressure (Step-By-Step Guide)

You can learn how to check oil pressure on a car with a few simple tools and basic expertise. Start by gathering these tools.

You also want to ensure safety is a top priority. That's why you should equip yourself with mechanic gloves, a long-sleeve shirt, and some form of eye protection. Keep all of your tools nearby so that you can reach them quickly.

  1. 1
    Lift the front of the vehicle if you require more clearance.
  2. 2
    Locate the oil pressure sender. It should be near the oil sump on the engine block.
  3. 3
    Put your oil drain pan beneath the vehicle to catch any spillage.
  4. 4
    Take off the electrical connector from the oil pressure sender.
  5. 5
    Take off the oil pressure sender from the engine with the correct socket.
  6. 6
    Attach the oil pressure kit and mount your tester.
  7. 7
    Top off the engine oil if needed.
  8. 8
    Allow the engine to run until it reaches normal operating temperatures.
  9. 9
    Check the oil pressure range for the manufacturer's recommended RPM (found in the owner's manual).
  10. 10
    Have your helper maintain that RPM while you record the readings.
  11. 11
    Turn off the engine and allow it to cool.
  12. 12
    Remove the tester.
  13. 13
    Reinstall your oil pressure sender and the electrical connector.
  14. 14
    Lower your vehicle back down carefully.

Here's a helpful video illustrating how to check oil pressure manually.

People Also Ask (FAQs)

Can you drive a car with low oil pressure?

Driving your car with low oil pressure can ruin the engine. As soon as you notice the Oil Light or low pressure, you should stop driving until you resolve the issue.

Will an oil change fix low oil pressure?

A slight oil viscosity change can increase the oil pressure, but it's often best to figure out what's causing the issue and repair it before more damage occurs.

How do I increase oil pressure?

You can increase the viscosity of the motor oil or find the component that's going bad and replace it.

Will full synthetic oil cause low oil pressure?

A synthetic or different SAE oil can cause either an increase or drop in pressure, depending on the change from the oil that was previously in the system.

How often do you need to test your oil pressure?

Normally, the in-dash oil pressure gauge will tell you the accurate pressure. The only time you need to know how to check oil pressure without a gauge is when there is a problem.

Can a dirty oil filter cause low oil pressure?

Not only can a dirty oil filter lead to lower oil pressure, but using the wrong filter can cause the same issues.

How do you check oil pressure on a semi hermetic compressor?

When you work with a semi-hermetic compressor, you must subtract the crankcase pressure from the oil pump outlet pressure.

Do you need to remove all spark plugs for compression tests?

Yes, the spark plugs must be removed, plus you should open the carburetor throttle and run the car at normal temperatures.

Should compression tests be done hot or cold?

All of your compression tests should be performed when the engine reaches normal operating temperature.


As you learn how to check oil pressure, you help protect your car engine from wear. It's just one more step to ensuring you have a vehicle that can take you down the road for many years into the future.