High oil pressure is never good news, whether you are driving a car or flying a plane. Normally, the gauge ought to read between 25 to 65 PSI while you’re in motion.
Think of oil pressure like blood pressure, high or low, it means trouble. If you care about your engine’s health, you’ll take this seriously. Don’t ignore the warning signs. High oil pressure hinders normal engine function or, even worse, damage the engine.
Oil plays a vital role in the working process of an engine. It lubricates the bearings and camshaft, which helps to combat engine wear and tear. When the right amount of oil is used, the engine performs better and lasts longer.
In this article, we will talk about some common causes of high oil pressure, what to do when it happens, and answer some of the most frequently asked questions surrounding high oil pressure.
What Is High Oil Pressure?
The term “high oil pressure” is used to describe a situation where the oil gauge gives a high reading. Usually, the gauge needle sits around the middle when the engine is running. When the needle goes closer to the peak, it’s an indication of high oil pressure.
This happens when the pressure required to pump oil in an internal combustion engine (ICE) exceeds normal levels.
Why Is High Oil Pressure a Problem?
The lubrication system is designed to circulate oil to moving parts in order to reduce friction. However, when there is increased viscosity of oil or obstruction in its flow, the engine finds it difficult to circulate the oil. And that is a problem that needs attention.
When you take a look at the oil pressure gauge and it reads high, you should check out the lubrication system. There may be a problem with the engine parts. The high pressure indicates that there is a flow resistance in the lubrication system. It could be a faulty component, high oil viscosity, or a high temperature. As a result, the oil may not get to some parts of the engine.
Do not overlook such readings because it can cause an engine breakdown.
What Are the Causes of High Oil Pressure?
Here are some reasons why you may have a high reading on your car’s pressure gauge.
1. A Broken Oil Pressure Sending Unit
A broken sending unit is the most common cause of a high-pressure gauge reading. The sending unit controls the gauge you see on your car’s dashboard. After working for a couple of years, the sending unit may get faulty. And this might lead you to mistakenly assume something else is faulty.
When the sending unit is faulty, it sends false readings to the pressure gauge. As a result, you may see warning signs on your dashboard implying that your oil level is low. Well, faulty units should be replaced or fixed as soon as possible. It is only after doing this you can actually know if you have an oil pressure problem.
How to Identify a Faulty Sending Unit
To diagnose the sending unit, you can use a multimeter or a manual pressure gauge with a test kit.
Using a Multimeter to Detect a Faulty Sending Unit
First, you need to manually inspect the oil levels. If that is okay, check if the oil sending unit is working properly with the aid of a digital multimeter. Before you take a reading, you have to ensure the multimeter is set to take resistance readings.
If you have a reading of 240 Ohms, it means the sending unit is in good condition and you have a pressure problem. If you get a different resistance reading, it indicates that your sending unit is faulty and you may not have a high oil pressure problem. Hence, it needs replacement.
Using an Oil Pressure Test Kit and Gauge to Determine a Faulty Sending Unit
Another way to check if the sending unit is broken is to use an oil pressure test kit and a gauge to inspect the pressure. To use this method, the engine needs to be cool and at rest. Then, operate the hand brake and turn on the engine. Make sure that you put the car in park or neutral.
Close to the oil pan, you will likely find the sending unit of the car. If you do not find yours close to the pan, check your engine design online. Now, you have to disconnect the sending unit and connect the manual pressure gauge and test kit instead. Then, turn on your car while hitting the pedal for about 25 seconds at 3,000 RPM.
If the pressure readings on the test kit are similar to what you normally get with the sending unit, then there is actually an oil pressure problem. Check your car manual to see how high the oil pressure gauge reading should be while the engine is running.
2. Low-Quality Oil
Another thing to consider is the quality of the oil. When you use oil of low quality, it can lead to a rise in oil pressure. This may result in increased fuel consumption. Well, how can I identify low-quality motor oil? Motor oil product that doesn’t meet the engine’s requirements is known as low-quality oil.
Depending on your car, there are oils with different viscosity – a term used to describe the resistance of flow. Some engine oils are light and thin, while others are cool and thick. The cooler and thicker oils require a higher pressure to flow through the engine compared to the lighter ones.
How to Choose the Right Oil
There are a number of factors you should consider when getting oil for your car. These include the climatic conditions, the oil weight and grade, and the car’s standards.
You also get to choose between standard motor oil, synthetic motor oil, or a blend of both. While there are different oils available, high-performance engines require synthetic oil. This oil helps the engine in so many ways. It helps the engine during high and low temperatures.
The oil grade is very important. Oil is graded based on its viscosity. According to the Society of Automotive Engineers, the viscosity of motor oil is denoted using the “XW-XX” classification.
- “X” in “XW” stands for viscosity at 0°C,
- “W” stands for Winter, and
- “XX” represents the viscosity/oil resistance at 100°C.
Hence, 0W-20, 5W-20, and 5W-30 oil are used in regions with lower temperatures, whereas 10W-30, 15W-40, and 20W-50 oil are used in regions with higher temperatures.
In summary, whenever you buy a different oil brand and the oil pressure goes up, it means the new oil is thicker than the previous one. If the oil is too thin or thick, it isn’t the right one for your engine.
3. Blocked Oil Passage
A blocked oil passage could be the reason you have an increased pressure gauge reading. An obstruction in the flow of oil can lead to severe engine damage. It can hinder the oil lubrication that is required for the engine to function properly. A prolonged blockage can affect the camshaft assembly, which further leads to leakages.
The formation of debris in the oil passage occurs when oil mixes with accumulated deposits. It is advisable to clean the passage to prevent debris build-up. The cleaning process involves the use of cleaning solvents, specific brushes, orifice dowels, plugs, cooling jets, hoses, passage lines, and other auxiliary gear.
Cleaning the lubrication system is not something you can do yourself. In this instance, it is best to contact a local mechanic.
4. Defective Pressure Relief Valve
The pressure relief valve consists of a nozzle, plug, spring, and piston. It is used to protect the system from overpressure and ensures an unhindered oil flow. A problem may arise if a valve is defective. The valve will be unable to regulate the oil pressure.
This can trigger a rise in pressure, and in the long run, damage the engine. In order to determine whether your relief valve is defective or blocked, you have to inspect it. The easiest solution is to get the valve cleaned before reinstalling it.
If you still notice a high oil pressure reading after cleaning the valve, the valve is likely not faulty. However, if the reading returns to normal, then you have successfully fixed the problem. Kudos!
5. Clogged Oil Filter
After riding your car for months, the oil filter can get clogged. When this happens, the engine will lack the sufficient oil needed for it to run effectively. It is often followed by a sputtering sound that is caused by a reduction in the oil volume flowing through the engine. If you hear this sound, you have to turn off the engine.
Replace the oil filter and pour more oil into the system. However, filters don’t get clogged overnight. Instead, it happens gradually. The rate of flow decreases before getting severe. And the reduction in flow causes the oil pressure to rise.
When to Change Your Oil Filter
As a rule of thumb, it is best to change the filter of your old car when used for over 3,000 miles, or about 10,000 miles for newer cars. The car manufacturer usually states the recommended miles in the manual. You don’t have to wait till the oil gets sticky before replacing it. We have a guide on how you can replace your oil.
A report by the University of Southampton recommends the use of an oil sensor if you don’t know when to replace the oil. This is because engine oil gets thicker with age. The sensor determines the right time to replace it and saves you money in the process.
You can go to a local automobile repair shop if you want an expert to do this for you. Also, if your vehicle uses a reusable oil filter, then all you have to do is clean it.
6. Idle Engine Pressure
Have you noticed high oil pressure on start-up or during acceleration? This is another reason you may (wrongly) conclude that you have a problem with your car. Thankfully, these initial high-pressure readings are a result of the engine’s temperature. Should you be worried about that? Definitely not!
Once you start the car, the temperature of the engine increases. This heats up oil to a moderate degree for easy circulation. In contrast, when the engine is turned off, the oil begins to cool off. When the engine oil is cool and thick, it is difficult to flow through the engine. That is why heat is required for it to circulate.
However, when you reduce the throttle, the pressure begins to go down. This is because the start-up power pushes the engine to its optimal performance. As long as you’re sure this is the cause, you have no real need to worry.
FAQ
Can High Oil Pressure Damage an Engine?
Yes, when oil pressure is high, it can damage the engine of your car. If you identify the problem on time, you may simply have to replace a component of the lubrication system. In severe cases, the pressure can damage the engine itself.
What Causes High Oil Pressure in a Truck?
The causes here are the same as for a car. A blocked oil passage, clogged oil filter, low-quality oil, broken oil pressure sending unit, or a defective relief valve can cause high oil pressure in a truck. In any case, identifying the cause of the problem, using our article above, is a step in the right direction.
What Should I Do if I Get High Oil Pressure Reading?
Turn off the car as soon as you notice a high oil pressure reading. You shouldn’t drive a car in that condition. Driving it can cause serious problems, unless you’re certain the pressure sending unit is faulty. Well, you’ve got to get that fixed too.
Final Thoughts
It is completely normal for oil pressure to fluctuate. It rises on start-up and reduces after a few minutes. The normal position is around the middle of the gauge. However, if you notice a problem, you have to diagnose it as soon as possible.
A good maintenance routine helps keep the lubrication system in the right state. This involves noticing minor changes on your oil gauge, changing the oil after a while, and replacing the filter after some miles.
