Why Oil Pressure Drops To Zero When Warm [7 Easy Fixes]

The most common causes behind oil pressure drops to zero when warm are low oil levels, using oil of wrong viscosity, not changing oil, worn-out or missing bearings, faulty oil pressure sending unit, malfunctioning oil pump, and dirty oil filter.

Keep reading this article to find out about these causes in detail. We’ll also discuss how you can solve these issues to fix the low oil pressure problem and get your vehicle back to normal. Let’s dive in!

Oil Pressure Drops To Zero When Warm [7 Easy Fixes]

What causes low oil pressure when hot? If you’re wondering why does my oil pressure drop when warm, you’ll find the answer in this section. Let’s look at the 7 typical reasons that cause low oil pressure problems.

1. Low Level Of Oil

The most obvious reason that causes low oil pressure is when there’s a low level of oil in your engine. It can be caused with time as you’ve used the oil or leaking seals or worn-out components.


The first thing to do is to check the level of oil using a dipstick. If it’s close to full, then a low level of oil isn’t the problem. Top off your oil if the level of oil is too low and see whether the problem has been solved.

If the issue is still not resolved, there could be other reasons behind this problem. Be on the lookout for leaking oil and have it fixed as it may also be causing the low oil pressure problem.

2. Using Oil Of Wrong Viscosity

The oil pressure will be low if the oil you’re using is too thin. The oil heats up and thins out when the engine is heated. It causes a drop in the oil pressure. That’s why when the engine gets hot oil pressure drops to zero.


Using thicker oil is the solution to this problem. First, check the manufacturer’s recommendation for which oil you should use. If you’re using a lower-viscosity oil than what’s recommended, it’s time for an oil change.

But if you’re already using oil of the right viscosity, then the oil pressure problem is most likely caused by the other reasons that will be mentioned in this article. In that case, don’t change the oil and troubleshoot the other potential causes of this problem.

3. Not Changing Oil

You can face low oil pressure issues if you don’t drive your vehicle on a regular basis. If you let your car sit around for a while, the oil becomes too old and it loses its viscosity. That’s more so the case for oils of multigrade viscosity.


If this is the reason that’s causing the low-pressure problem, then you’re in luck as it’s easy to fix. Drain the old oil, add new oil of the right viscosity and replace your oil filter.

That’s all you need to do to get your car back to normal if not changing your oil was the reason that was causing the problem.

4. Worn-Out Or Missing Bearings

There are a lot of engine components that become worn with time. But the most common culprit, if your oil pressure keeps dropping to zero, is the engine bearings.

If you have lost one of the engine bearings or it’s gone bad, the correct oil pressure won’t be maintained and there will be low oil pressure.


You need to inspect the engine bearings and find out which one is missing or worn out. Replace it with a new one and doing that should fix the issue. Get the bearing issue sorted ASAP because overlooking it can lead to complete engine failure.

5. Faulty Oil Pressure Sending Unit

The sending unit gets a reading of the oil pressure and sends it to the ECU. After that, the ECU displays the reading that it gets from the oil pressure-sending unit.

faulty oil pressure sending unit

It’ll display the wrong reading if the pressure-sending unit has gone bad.


Getting the oil pressure-sending unit replaced is the ideal solution for this problem. It’s easy to replace it and you can do it yourself without the help of any mechanic or external assistance.

6. Malfunctioning Oil Pump

The oil pump is responsible for distributing the oil to the components of the engine. One of the first indicators of a malfunctioning oil pump is having low oil pressure. Your engine can also stall and become overheated if you have a malfunctioning oil pump.


The first thing to do is to take your car to a mechanic and see if your oil pump has gone bad. You’ll have to replace the faulty oil pump if that’s gone bad and doing that should solve your problem.

7. Dirty Oil Filter

The oil filter prevents the contaminants from getting into the engine. As it collects the dust, it becomes clogged with time.

clogged oil filter

If it gets too clogged, oil won’t be able to pass through easily and it can cause low oil pressure.


Replacing the dirty oil filter with a new and clean one is the ideal solution for this problem. In general, you should always change your oil filter every time you get an oil change to prevent this problem from happening in the first place.

Best Practices To Maintain Correct Oil Pressure

You already know negligence can lead to oil pressure failure in your car. So, here are some tips you can follow to make sure that your engine maintains the correct oil pressure over a long period:

  • Change the engine oil at regular intervals and replace oil filters with every oil change.
  • Use oil of the correct viscosity by following the manufacturer’s recommendation.
  • Check the level of oil in your car on a regular basis to make sure that you don’t have a low oil level.


Why is the oil pressure good when cold and bad when warm?

The oil pressure gets low when the engine warms up because the warm engine melts the oil and causes the oil pressure to drop. It’s normal unless the oil pressure drops to 0 when hot or close to 0.

Can low oil pressure cause an engine to misfire?

The engine won’t be able to rev properly if there’s low oil pressure. If the oil leaks into the spark plug, it can cause an engine to misfire. Engine misfiring can be stopped by fixing the oil leak.

What is the minimum level of oil pressure required for an engine?

When the engine is warmed up, the minimum oil pressure should be 20 psi or above it. If it gets lower than that, the “check gauges” light will turn on and you need to get that issue fixed.

How does an oil pump fail?

The oil pump won’t be able to send the oil to the required components and it’ll cause friction between the moving parts. A low level of oil can cause an oil pump to fail from lubricating the engine.


Now you know the reasons why oil pressure drops to zero when warm and how you can fix these issues. It’s important to monitor your oil pressure level and prevent it from being too high or too low.

We hope the tips we shared will help you fix the low oil pressure problem and get your engine back to normal driving conditions. Drop a comment below if you have any questions about oil pressure problems.

About John M

John contributed as a technical head at an automobile company just 2 years after his post-graduation in Automobile Engineering. He loves to lead a free life, so he left his job & started blogging. Now, he does research on every automotive problem, part & product and seeks a better solution & best products & shares his findings with his readers to help them as well as to minimize their struggle.

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