High Oil Pressure: Main Causes & Symptoms (How to Fix It)

High oil pressure may seem like a good thing, but in fact it can be bad for your engine. Here are the causes of high oil pressure and the symptoms to look for

High Oil Pressure

Increased or high oil pressure in your car is an alarming situation and should be dealt with quickly.

Most drivers conclude that it is time for engine replacement when facing a high oil pressure situation; however, that is not always true.

In this post, we will explain what causes high oil pressure and the symptoms to look out for. Let’s begin with the causes to look for.

7 Causes of High Oil Pressure

The most common causes of high oil pressure are a cold engine, the wrong type of motor oil, or a faulty oil pressure sensor. It could also be caused by a faulty relief valve in the oil pump or a damaged oil filter.

While these are some of the symptoms, it’s not all of them! Here is a more detailed list of the most common causes of high oil pressure.

1. Cold Engine

Cold Engine

Engine temperature is the most common reason for high oil pressure. Many people do not realize that your engine normally have very high pressure when your engine oil is cold. Mostly twice as high as when the engine is warm or even higher.

Check your pressure when your engine oil is hot instead. If the pressure is too high when the engine oil is hot, it is time to start worrying.

2. Wrong Oil Grade

Engine Oil Type

Experimenting with different oil grades can sometimes be a bad decision, especially if you don’t consult an expert. Different oil grades have a distinct viscosity level and are meant for certain engine types.

If you have the wrong oil grade for your car engine, you may experience a very high oil pressure because of it. The recommended oil grade for your engine can be found in the owner’s manual.

3. Blocked Passage

Engine Cylinders

If the oil changes haven’t been done properly in your car through the years, it may have caused oil sludge in your engine, which may have clogged any oil passage.

Blockage in the oil passages can cause high pressure since the engine is deprived of proper lubrication.

Unfortunately, high oil pressure will also cause low oil pressure in another part of your engine. Therefore it is essential not to let your engine run before you fix the clogged oil passage.

4. Problem With the Oil Pressure Sensor

Oil Pressure Sensor

Are you sure there is actually high oil pressure in your engine or is it a chance that the sensor or gauge shows you the wrong oil pressure?

The high oil pressure problem can also be due to a faulty oil pressure sensor or oil pressure gauge. It can give you a false signal that the gauge shows an overly high pressure, but in reality, the pressure is good.

Diagnose it with a manual oil pressure tester to get the right pressure before you start taking your engine apart.

5. Relief Valve Malfunction

Oil Pressure Inside

The relief valve’s function is to relieve excessive oil if the oil pressure gets too high. If the relief valve is clogged or faulty, it may not let excessive oil pass it, and instead, it will create high oil pressure in the system.

The relief valve is often located inside the oil pump and very difficult to reach. Most of the time, you have to replace the whole oil pump.

6. Contaminated or damaged Oil Filter

New Vs Old Oil Filter

If the oil pressure sensor is installed between the oil pump and the oil filter, there is a chance that the oil filter can cause high oil pressure before the filter, where the pressure sensor is located.

Usually, original oil pressure sensors are located behind the oil filter, so in this case, it would cause a low oil pressure rather than too high oil pressure.

7. Poor Quality Oil

Engine Oil Refill

If you bought a very cheap quality oil, there might be a problem with their oil grades, and other specifications do not compare very well to reality.

Using a low-quality oil can be the reason behind high or low pressure. A poor quality oil that is thin or lightweight can easily pass through the engine and will cause low pressure, whereas thick oil would require a high pressure to flow.

If you change the oil to a different brand and notice an increase in pressure, it may mean that it is not good for your engine.

What’s the Ideal Oil Pressure?

Oil Pressure Check

The ideal oil pressure ranges between 25 to 65 psi when the engine oil is warm and at 1000-3000 rpm, whereas if the oil pressure reading shows 80 psi or above when the engine is warm, then there is a serious problem.

This is, of course, depending on what engine you have and how worn the engine is. If you want to learn the exact oil pressure you should have in your car engine, I recommend checking your car repair manual!

Oil Pressure Check

What Are The Symptoms Of High Oil Pressure?

The main symptoms of high oil pressure include:

  • Oil Pressure light on the dashboard
  • Oil leaks
  • High crankcase pressure

You often only see it if you have a manual gauge installed to your engine; some cars have this standard.

Another symptom of high oil pressure is oil leaks around the engine. High oil pressure can also cause high crankcase pressure, which could cause your engine to start to leak oil through the gaskets.

The oil pressure light will flash on your dashboard on some cars if the pressure gets too high!

Magnus Sellén
Written by:

Magnus is the owner and main author of Mechanicbase. He has been working as a car mechanic for over 10 years, and the majority of them specialized in advanced car diagnostics and troubleshooting. Certified Automotive Diagnostic Technician.

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