How to Test an Oil Pump

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Oil pumps feed the oil through your engine to lubricate all of the components and help them move against one another without wearing excessively and breaking. However, over time, your pump may start to wear down and make your oil flow insufficiently. While there is no way you or a mechanic can directly test the pump, you can check your oil pressure to determine if there might be an underlying problem. Additionally, you may be able to see or hear signs of your pump working incorrectly.

Method 1
Method 1 of 2:

Testing the Oil Pressure Manually

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  1. Every engine has specific range of oil pressure for maximum lifespan. Look in your vehicle manual for information about the engine and the standard pressure range. Record the pressure range so you can compare it to your actual readings. [1]
    • If you don’t have your manual, you may be able to find one online.
    • As a "rule of thumb", the oil pressure in your vehicle should be about 10 PSI for every 1,000 RPM of engine speed. [2]
  2. The oil pressure sender is a small black cylinder that reads the oil pressure and relays it to the gauge on your dashboard. Pop your hood and check the top or side of your engine for the pressure sender unit. Locate the nut holding the sender in place and use a spanner wrench to loosen it. Set the sender unit aside while you’re working so it’s out of the way. [3]
    • Some oil may come out from the port for the sender once you remove it. Keep a shop cloth or rag nearby to catch any spills.
    • Test your oil pressure manually even though you can check it on your vehicle dashboard. The sender unit could be faulty or you may have loose wiring inside your vehicle that may give a false reading.
    • The “Check Oil” notification on your vehicle’s dashboard may light up when you disconnect the sender.

    Warning: Don’t remove the sender unit while your engine is still warm after running your car. The heat thins the oil and makes it flow easier, so it could spill a large amount once the unit’s taken off.

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  3. Oil pressure gauges have a hose that attaches to your engine and displays the readings on a meter. Screw the end of the gauge’s hose to the port that the sender was attached to until it’s hand-tight. Use your wrench to tighten the gauge until you aren’t able to rotate it anymore. [4]
    • You can buy an oil pressure gauge from auto supply stores or online. Make sure the end of the gauge’s hose matches the style port on your engine. Bring the sender unit with you to the store if you need to compare the ports.
  4. Put the gauge in a place where you can easily see it if you’re sitting in the driver’s seat, like in the gap between your open hood and windshield. Start your vehicle’s engine and keep it running throughout your tests. Check the gauge to determine the PSI of your oil while it’s still cold. [5]
    • Check that the port isn’t leaking oil near the gauge and if it is, try tightening the gauge more.
  5. Leave your car running for an additional 10-15 minutes after you first took a reading so the oil warms up and starts to thin out. Check the meter again to compare the actual oil pressure with the recommended pressure listed in the user manual. Write down your measurement so you don’t forget it. [6]
    • If there’s more than 10 PSI difference between the idle pressure when the oil is hot and the oil is cold, then there may be something wrong with your pump or the bearings inside it.
    • Make sure your vehicle is in a properly ventilated area since running it will create fumes that can be deadly if they build up.
  6. While your vehicle is still in park, lightly press down on the accelerator and watch the engine speed dial on your dashboard. When you reach 1,000 or 1,500 RPM, keep your foot steady and check the reading on your oil pressure gauge. Once you take the first reading, take another at 2,500-3,000 RPM to compare how the pressure changes as you speed up. [7]
    • If the readings do not match the normal pressures listed in the manual, then you may have an issue with the oil pump.
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Method 2
Method 2 of 2:

Recognizing the Signs of a Bad Pump

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  1. Turn your vehicle on and look for a light on your dashboard that says “Check Oil” or “Check Oil Pressure.” If one of the lights is lit up, then there may be an issue with your pump or another oil-related part. Check the oil pressure manually or take your car in to a mechanic to take a look at it to determine the problem.
    • Dashboard lights could turn on due to faulty wiring or electrical systems in your vehicle as well.

    Variation: Your vehicle may have a yellow or orange light in the shape of an oil can if you’re having oil issues instead.

  2. Look on either the left or right side of your dashboard for the temperature gauge. Turn on your vehicle so the engine is running and let it warm up for 10-15 minutes. If the temperature gauge continues to rise even after you’ve warmed up the engine, then there may be friction due to a lack of oil in the system.
    • The temperature gauge on your vehicle could also rise due to the outside heat or other engine problems as well.
  3. If your oil pump isn’t working properly, parts of your engine may not get properly lubricated and parts may scrape together. Listen to your engine while your vehicle is running to see if you hear any high-pitched whines or clinking and clattering noises. Even if you hear the noises slightly, check the oil pressure on your pump to make sure it’s working properly. [8]
    • Engine noises could also be due to old and loose parts as well as faulty spark plugs.
  4. Check your vehicle’s oil levels to see if there’s too much or too little oil. Open the hood of your vehicle so you can access the engine and unscrew the oil dipstick, which usually has a yellow cap. Wipe the dipstick clean on a shop cloth or old rag before dipping it back into the engine. Pull the dipstick out again to see the oil level on the bottom. If the oil levels within the printed range on the dipstick but your engine still makes unusual noises, you may have a faulty pump. [9]
    • If there isn’t enough oil inside your engine, add more until it reaches the fill line.
    • If you have too much oil, then you may need to drain some out until it’s in the correct range.
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      Tips

      • A mechanic may be able to take apart your oil pump to see what the problem is, but they won’t be able to test it other than checking the oil pressure.
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      Warnings

      • Don’t take off the oil pressure sender while the oil is hot since it will leak out quickly and could burn you. [10]
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      • Avoid driving your vehicle if it has low oil levels or if the oil pressure is low since you could stress your engine and shorten its lifespan. [11]
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      Things You’ll Need

      Checking the Oil Pressure Manually

      • Spanner wrench
      • Rag
      • Oil pressure tester

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      References

      1. ↑ https://youtu.be/7nIJt-M5iHc?t=251
      2. ↑ https://www.aa1car.com/library/2005/us020516.htm
      3. ↑ https://youtu.be/FdBgnWAl9fQ?t=81
      4. ↑ https://youtu.be/d_jgO1gjGg8?t=90
      5. ↑ https://youtu.be/FdBgnWAl9fQ?t=148
      6. ↑ https://youtu.be/FdBgnWAl9fQ?t=211
      7. ↑ https://youtu.be/FdBgnWAl9fQ?t=223
      8. ↑ https://www.aa1car.com/library/2005/us020516.htm
      9. ↑ https://www.machinerylubrication.com/Read/31182/low-oil-pressure
      1. ↑ https://youtu.be/FdBgnWAl9fQ?t=81
      2. ↑ https://www.machinerylubrication.com/Read/541/dipstick-oil-analysis

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