Engine oil is often referred to as the lifeblood of your vehicle. So, you can think of your oil pressure like blood pressure. If it gets too low or too high, you are going to be affected negatively, right? Well, it is the same for motor oil pressure. When the oil pressure is too high, certain functions of the engine oil are lost. So what exactly is high oil pressure? What causes it and how do you solve it?
Today, those questions will be answered. Let’s get started.
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What Does High Oil Pressure Mean?
Lubrication is necessary for your engine to function correctly. That lubrication comes in the form of motor oil, which has other functions. As the engine heats up, the viscous oil thins out and begins to coat the moving parts of the engine. Because the oil gets thinner, there has to be a certain amount of pressure exerted on the liquid to keep it moving.
Normally, engine oil pressure is between 20-65 PSI, depending on the make and model of your vehicle. Smaller engines tend to have a slightly higher PSI (25-35 PSI) during idling when compared to larger vehicles (20-30 PSI).
As the name suggests, high oil pressure is when the oil pressure goes beyond 65 PSI. Usually, a PSI of 70 or higher is considered an emergency. Your car will need repairs as soon as possible.
Symptoms of High Oil Pressure
Before you can decide whether your car is suffering from high oil pressure or not, you need to first consider what is wrong with it. There will be certain symptoms that will be noticeable. Here are a few to look out for:
High Oil Pressure Reading
Not every vehicle is going to have an oil pressure gauge, but if it does, you will notice that the oil pressure ticks upward. Usually, the gauge sits at the center. When the gauge moves into the red zone, you want to pull over and assess the problem before continuing on.
Should the oil pressure get too high, it is going to look for a way out. Usually, the pressure relief valves pressure relief valve kicks in but that may be faulty. So, the oil may also burst through seals and other areas of the engine, leading to extensive damage.
Have oil leaking from the drain plug? Check out our article on how to fix it.
Both low and high oil pressure lead to too little oil getting pumped through the engine. That results in too little lubrication and less heat transfer. You will notice that your engine temperature gets hotter. You may even smell some burning oil.
Does your vehicle seem bogged down during acceleration? Your engine has to work much harder because there is not enough oil running through it. This is a clear symptom that can stem from multiple issues, and high oil pressure may be one of the causes.
What Causes High Oil Pressure?
There are many reasons why your vehicle may have high oil pressure. Here are five of the most common causes:
1. Faulty Pressure Relief Valve
Nearly every automotive internal combustion engine is going to need oil to keep the parts lubricated. This means that every engine using gasoline is also going to have a pressure relief valve in the event of oil pressure skyrocketing. The job of the pressure relief valve is simple: monitor pressure and to activate when the pressure needs to be quickly returned to safe levels. However, through wear and tear, the pressure relief valve may fail.
When that happens you see the oil pressure light come on, hear some engine knocking, and see a sudden change in oil pressure. Sometimes, the dashboard gauge will even fluctuate from Low to High rapidly.
2. Defective Sending Unit
One of the more common causes of a high oil pressure reading is the sending unit going bad. A faulty or defective sending unit may cause an errant reading that states you have high oil pressure when you truly don’t.
3. Dirty, Sludgy Oil
Oil needs to be clean, not dirty, in order to protect your engine and lubricate everything correctly. The older oil gets, the more sticky it becomes. Even if you had used the correct viscosity of oil, it will become thicker, potentially raising the oil pressure. Make sure you are changing your engine oil every 3,000 miles if you are using conventional oil. For synthetic oil, the change should take place every 5,000 to 7,500 miles. Furthermore, swap in a brand new oil filter with each oil change.
The easier the oil flows, the better your engine will perform.
4. Wrong Oil Viscosity
As you are probably aware, oil has viscosities, or thicknesses, that change how it moves through the engine. The thicker the oil, the greater the chance of it increasing the pressure within the engine. It would be best if you always chose the oil viscosity that has been recommended by the manufacturer or something close. For example, you can swap 5w20 for 0w20 if you are dealing with very cold temperatures, but you should avoid moving from 5w20 to 10w20, especially when you are still doing cold starts.
5. Blocked Oil Passages
There are many things that can block the passages the oil takes through the engine. Just like your oil filter, the engine can become congested with contaminants and sludge, especially if you do not change your oil regularly. When this happens, the blocked passage acts a bit like a clot in your veins. It prevents fluid from getting through. Unfortunately, there is no easy fix for this. You may need to do a system flush, but it is not a guaranteed solution.
How to Solve High Oil Pressure
If you want to fix high oil pressure in your vehicle, the first thing you need to do is gather some rags, a multimeter, an oil catch container, an oil pressure gauge kit, and some other tools, depending on what you decide to do. You may also need some engine oil and an oil filter if it turns out you are in need of an oil change. In the event you do not have the correct tools, consider taking your vehicle to an auto repair shop.
Next, follow these steps:
- Warm up the engine if your car has been sitting for a couple of minutes before letting the oil settle for about 5-15 minutes. If you have been out driving for a time, let the engine cool for about 20 minutes. Never check the oil when the engine is running or still hot.
- After the engine has cooled enough, open the hood and find the dipstick. Read the oil level and look at the quality. If it is too low or looks old, consider performing an oil change.
- Use the multimeter on your oil-sending unit. The meter should read at around 240 ohms in the beginning then 30 ohms when you turn on the engine. If the reading is incorrect, the oil pressure is the problem. An incorrect reading means that the sending unit is faulty.
- You can also use an oil pressure kit test. Follow the instructions in the kit to see if the PSI is the problem.
There may be some problems that you cannot correct at home, such as engine damage, a failing pressure relief valve, and so on. If that ends up being the case, you will need to schedule an appointment with a professional automotive technician.
Final Thoughts on High Oil Pressure
High oil pressure is a big deal. You do not want to drive around when your engine cannot get enough lubrication or when damage can occur. As such, if you start noticing the signs of high oil pressure, be sure to get your car to a mechanic or run some maintenance on your own. Once the problem is located, you can get the oil pressure back within the normal parameters.