High Oil Pressure | What Are the Main Causes?



High oil pressure is a serious problem that should be dealt with as quickly as possible since if it is not addressed immediately, it can lead to serious damages to the engine. Below, you can find out what causes high oil pressure and the steps you can take to remedy the issue.


What is high oil pressure?

For the engine on your car to work properly, it needs to be properly lubricated since, without it, the friction that would build within the components would lead to overheating. When overheating happens, the risks of your engine block developing cracks or blowing a head gasket increase. When the oil pressure is high, it means that the flow of oil to the engine is restricted in some way.

When starting the car, it is normal for the oil pressure to build and begin on the low side until it settles in the middle. For the engine to function properly, the oil pressure should be anywhere between 25 to 65 psi. In order to make sure that the reading is accurate, you should check the oil pressure around 20 minutes after switching the engine as this gives the oil enough time to warm up.

If the oil pressure gauge indicates a reading of 80 psi or higher, this means that there is something wrong with your car. The value that indicates a high oil pressure may also change depending on what engine you have or how worn out it is. If you want to know the ideal oil pressure for your car, then you should check your car repair manual.

When the oil pressure light comes on, the best course of action is to pull over and turn off the engine as soon as possible. The problem with high oil pressure is that it can occur due to a multitude of reasons, such as a faulty part, a blockage, or several other causes that we will explore in-depth below.

Since it is difficult to tell right away if the cause of the problem is serious or no big deal at all, you shouldn’t drive your car until you have fixed the underlying cause. If you want to find out more about the possible main causes of high oil pressure, take a look at our guide below.


Blocked oil passage

It is possible with time for carbon or sludge deposits to accumulate in the oil passage as a direct result of fuel combustion. These deposits can merge with the oil and become thicker in texture, so much so that they can block the rest of the oil from getting to and lubricating the engine.

A blocked passage is a very common cause of high oil pressure. It is relatively easy to identify since if the cause of the high pressure is due to a blocked passage, the car should have an oil leak in the cam assembly, right near the cylinder head gasket.

If you are suspecting that a blocked passage is the reason your car is experiencing high oil pressure, then you will need to bring the car to an expert mechanic and let it check the vehicle out. Cleaning blocked oil passage is a demanding task that requires specific procedures that need to be followed down to the smallest detail.

It is also quite pricey since it requires the entire lubrication system to be cleaned using professional tools and cleaning solvents. Moreover, depending on how long you’ve experienced high oil pressure, the mechanic will also have to check the health of the engine to determine if any of the parts have been damaged.


A dirty oil filter

The oil filter is the component that’s responsible for keeping contaminants out and ensuring that the fuel that reaches the engine is clean. However, with time, debris and dust can clog the filter, which makes the oil flow at a slower rate, and that causes the temperature of the engine to skyrocket.

The higher engine temperature will then trigger an increase in oil pressure. The good news is that changing the oil filter is a quick and relatively cheap repair job. Make sure to check the car’s repair manual to see how often you need to change the filter.

Most oil and parts manufacturers recommend changing the filter every 3,000 miles or with every oil change. If you haven’t gone past the recommended change period, there are some warning signs that can help you tell if it is time to change the oil filter.

The first thing to look out for is a decrease in engine performance. If the car doesn’t pick up speed like it used to or the accelerator is not working properly, this is a sign that the oil filter may be putting a wrench in the performance of your car.

Sputtering is also common, and it can be minimal at first but become worse with time. Sputtering occurs due to the system lacking oil, and this prevents your car from picking up speed. If a dirty oil filter is the root of the problem, then replacing the filter will fix this issue instantly.

The lack of lubrication may also cause your engine to produce metallic sounds. If your vehicle produces similar sounds, then you should pull over immediately since continuing to drive in these conditions could lead to serious damage to the engine.

Another symptom that is caused by a dirty oil filter is a smooth and black exhaust gas coming out of the car. This is often accompanied by a burning oil smell.


Engine temperature

Engine temperature can be the cause of high oil pressure if the pressure gauge hangs on a high level when starting the engine or while idling. When you’re turning on the engine, it will start to warm up until it reaches the optimum operating temperature. It will also heat the oil in the process to allow it to flow through the engine more easily. This can result in high oil pressure.

The opposite happens when you are switching off the engine, since this will prompt both the engine and the oil to cool down, resulting in low oil pressure. This is why, as mentioned earlier, you get the most accurate readings twenty minutes after switching the engine.


The quality of the oil

The type of oil that you use can influence the oil pressure since thin and lighter oils can easily flow through the engine, and this allows them to stay at a lower pressure. Conversely, thicker oils require a higher pressure to move at the same speed.

However, the quality of the oil can be a cause of high oil pressure only if you notice the problem after switching to a new brand of oil. If you’re using the same type of oil, then there shouldn’t be a reason to think that the oil is to blame.

If you want to avoid the motor oil causing your problem, there are a few simple guidelines to follow when choosing the right one for your car. The most important thing is to get only the type of oil that the owner manual recommends.

You should also alter the oil weight according to the weather. In cold weather, thinner oils are ideal. In warmer climates, thicker oils are recommended. Lastly, if you want to get the best quality oil for your car, you should look for products that have been tested and that meet the standards set by the American Petroleum Institute.

Pressure relief valve problems

The oil pressure relief valve consists of three parts, a plug, a spring, and a piston. When working properly, the valve regulates the flow of oil. The pressure that builds when oil is circulating forces the piston to move against the spring and this allows for more oil to pass through, decreasing the oil pressure.

It is a fairly simple mechanism, and it helps prevent high oil pressure from occurring. However, a malfunctioning pressure relief valve can lead to high oil pressure. There are no specific symptoms that can help you tell if you are dealing with a relief valve malfunctioning, and the only way to be sure is to inspect it.

Thus, when experiencing high oil pressure, it may be an indication that there is a problem in the relief valve. Thankfully, in this case, the solution is simple since all you will need to do is remove the valve and clean it before installing it again. If, after doing this, the pressure goes back to normal, it means that the relief valve was the cause.


Problem with the sensor

Lastly, it is also possible for the oil sending unit to get damaged. This is the sensor that shows that the gauge is reporting an overly high pressure. If the sensor is damaged, it can show high pressure when, in fact, everything is fine.

This is something that you should consider after going through all the previous possible causes. If everything seems to be fine, you can diagnose the problem by using a manual oil pressure tester and see if the reading on it corresponds with what the car sensor is showing.