Oil is essential for the operation of our car’s, it works to lubricate the surface of parts, and also provides essential resistance to the engine.
Our vehicles have systems that measure the amount of oil that is circulating within the car’s engine and also determine the oil pressure. These are known as oil pressure gauges and they can be used to determine how healthy your vehicle is.
The most important oil pressure measurement is taken roughly 20 minutes after your vehicle has been running.
At this point, the oil will have reached its standard operating temperature, and this will allow you to determine if your car has high oil pressure or not.
What is high oil pressure?
We’ve established what oil pressure is, and how you get an accurate reading of it, but how do we determine what is classed as ‘high oil pressure’?
The oil pressure will usually be measured in either PSI or bar measurements, it is by looking at this measurement that we can determine if our vehicle has high oil pressure or not.
The ideal oil pressure, like most things, varies from vehicle to vehicle with factors such as the make and model having an impact on what is determined as ideal. But for the majority of vehicles, ideal oil pressure will range somewhere between 25 and 65 PSI.
Oil pressure itself is not an issue; it's necessary to allow the oil to reach all of the places that it needs to. However, if the oil pressure exceeds this range, it is considered as ‘too high’ and could expose the engine to damage.
It is okay for the oil pressure to narrowly exceed the average range, but an oil pressure over 80 PSI is usually a cause for concern (unless this is standard for your vehicle).
If the pressure gauges measure extremely high oil pressure, this is a sign that the oil is unable to reach all the necessary parts of the engine and unable to do its job properly. This can lead to long term damage to your vehicle if the issue is not handled properly.
What causes high oil pressure?
So now that we know what oil pressure is, let’s take a look at what causes it. There are a few different issues that could be causing the high oil pressure reading, and by process of elimination, you will be able to determine exactly which one is causing your abnormal readings.
A very common cause of high oil pressure readings is a malfunction in the oil pressure sending unit. This part is responsible for measuring oil pressure and controlling the oil pressure gauge.
It is important to remember that it is common for a high oil pressure reading to be given while your engine is cold, this will only become a cause for concern if the reading does not change after your engine has warmed up.
To find out if it is the oil pressure sending unit that is faulty you can use a manual oil pressure tester. If the measurement comes out the same as the figure on your car’s dash, this means the issue lies elsewhere, but if it comes out at a lower PSI this means there is an issue with your sending unit.
Another possible cause for high oil pressure is a dirty or damaged oil filter. It is the oil filter’s job to remove any impurities from the oil as it passes through the engine.
Over time, all of the dust, rust, and gum deposits that are removed from the oil will build up in the filter and prevent it from doing its job successfully. This will increase the resistance that the oil faces and also increase the oil pressure. It is an easy fix, so if your car is experiencing high oil pressure this is always a good place to check.
Finally, another common cause of high oil pressure is the quality and viscosity of the oil. Viscosity essentially measures how thick or how thin the oil that moves through your car’s engine is.
Thicker oil will face more resistance on its journey and ultimately lead to high oil pressure. The viscosity of the oil is important as the thickness of the oil is also impacted by the heat of the engine.
Oil becomes thinner as it is heated up and simultaneously thicker as it cools, so if you buy the oil which is the wrong viscosity for your vehicle this could lead to issues with the oil pressure.
Symptoms of High Oil Pressure
The causes of high oil pressure are clear, but how do you know if your car is experiencing high oil pressure? This is tricky as there are no clear symptoms of high oil pressure.
Some vehicles will experience oil leaks around the engine if they are continually operating at high oil pressure. In other vehicles, high oil pressure could lead to high crankcase pressure which causes leaks through the gaskets.
But on most modern vehicles, they will either have an oil pressure light or a manual oil pressure gauge displayed on the dashboard. Manual gauges will allow you to see the exact pressure that your oil is at and determine if this is too high.
While the oil pressure light will come on and flash continually if your oil pressure is too high, notifying you that something is wrong.
How can I fix high oil pressure?
The best way to fix high oil pressure will depend on what exactly is causing the issue. If the issue lies with your oil filter being dirty or contaminated, you can easily get the filter replaced at a low cost in your garage.
Alternatively, if the issue lies with your oil pressure sending unit this can also be easily fixed in the garage. But sometimes the best way to fix the high oil pressure is by getting an oil change.
Oil breaks down and thickens throughout its lifetime, and maintenance is key to ensure this does not cause damage to the engine. If you believe that it is the oil that is causing problems with the pressure, this is another issue that can be easily fixed in the garage.
So in short, there are lots of possible causes of high oil pressure.
You must always keep an eye on the oil pressure to prevent your car from experiencing significant damage.
If the oil pressure reading is extremely high you should take your vehicle to the garage immediately.