We all know the sensation of being low on gas.
The low-fuel light illuminates, a few warning chimes go off, and we panic as the needle moves closer and closer to the red.
The solution?
Head to a gas station and fill the tank, of course. But what about your oil pressure gauge? Do you recall the last time you looked at it? Did you even know you have one?
The oil pressure gauge should read between 25 to 65 PSI while the engine is running. Should it start climbing higher (think 80+ PSI), then you’ve got yourself a problem with excessive oil pressure. When this happens, it disrupts the ability of your engine to function properly.
What causes elevated oil pressure? The main culprits include:
- Faulty sending unit
- Relief valve malfunction
- Blocked oil passage
- Dirty oil filter
- Oil quality/grade
Thankfully, in this guide, I am going to review each of these in detail. I will also cover what elevated oil pressure is and why it matters.
Next, I will examine why regular oil changes are crucial for proper engine balance and answer a few common questions about high oil pressure.
But first, I will examine the fundamentals behind how an engine lubrication system works.
Let’s get started!
Table of ContentsShow
The Basics Behind An Engine Lubrication System
Pan
The oil pan is situated near the bottom of the engine. It serves as a reservoir for the oil before it’s pumped throughout the engine. Most hold between 4 to 6 quarts of oil.
Pickup Tube
Your engine requires oil immediately, and the moment you turn the key, the pickup tube transports it from the pan to the oil pump.
Oil Pump
As its name suggests, an oil pump is in charge of “pumping” the oil throughout the system. This ensures that all the moving components are adequately-lubricated and do not create excessive friction.
Pressure Relief Valve
The part that controls the oil flow is called the oil pressure relief valve. It has three distinct pieces: a piston, a spring, and a plug. When everything works correctly, the valve can move up and down to manage the oil flow.
As pressure builds, it forces the piston against the spring, allowing more to pass through, thus decreasing pressure.
Oil Filter
As oil circulates throughout the system, it picks up harmful contaminants like dirt, dust, and metal flakes. This is where the oil filter comes in. As oil passes through (under pressure), any undesired particles do not.
Spurt Holes and Galleries
Spurt holes and galleries are small exit points located throughout the system where the oil can seep through. They ensure adequate lubrication of the numerous moving components, including the pistons, rings, pins, bearings, and cylinders.
After this point, the oil has completed its journey and returns back to the oil pan.
What Is High Oil Pressure And Why Does It Matter?
High oil pressure indicates that the flow of oil is hindered in some way.
This can be a consequence of either a blockage, a defective part, or an issue with the oil itself. As we mentioned earlier, the usual pressure range lies between 25 and 65 PSI. When this range is exceeded, something is off and needs to be corrected before damage occurs.
Proper lubrication is essential to the health of any engine. Without it, friction builds and leads to overheating. When this happens, the risk of developing a crack in the engine block or blowing a head gasket increases.
Each of these scenarios is exceptionally expensive to resolve (if a repair is even possible at all). For this reason, your best bet is to take action at the first signs that you have elevated oil pressure.
What Causes High Oil Pressure?
Faulty Sending Unit
The oil pressure-sending unit is what controls the gauge in the dash of your vehicle. You’ll receive inaccurate readings if it’s faulty for one reason or another. The only way to check for this failure is to inspect the oil pressure manually.
For this, you will need an oil pressure gauge and an adapter to fit your vehicle (we suggest using an oil pressure evaluation kit).
First, check that the engine has cooled down enough to work on. Then, put the transmission in neutral or park and apply the parking brake. Next, locate the sending unit (usually found near the oil pan). Be certain to have an oil drip pan ready since when you remove the sending unit, you’ll likely meet a few drips.
Connect the pressure gauge, turn the car on, press the gas pedal and hold it between 2,500 to 4,000 RPMs for roughly 15 to 20 seconds.
Be sure to consult your manual for the correct operating range for your vehicle. If the gauge shows the pressure is in a suitable range, then the problem lies elsewhere. Otherwise, the issue is a faulty sending unit.
If you prefer to hire an expert to identify the problem, anticipate spending around $100.
Relief Valve Malfunction
If you remember from earlier, the relief valve is not a complicated component, consisting of just a piston, a spring, and a plug. It protects the engine from damage caused by high pressure and controls the flow of oil through the block.
How do you know if the relief valve is the issue?
There’s no way to be sure without inspecting it. If you start your car, drive it for a while, and the pressure does not reach expected levels, it may indicate a relief valve malfunction.
Fortunately, an elementary cleaning should be all that’s required.
Blocked Oil Passage
As mentioned previously, one of the primary reasons behind high oil pressure is the restriction of the flow of oil. This may be due to a blockage, which is a serious concern. This usually results from a buildup of sludge or a carbon deposit somewhere along the oil passage.
Removing a blockage is time-consuming, which makes it quite expensive. It requires specific tools and extensive knowledge of how to dismantle the system. The process involves cleaning the lubrication system, including the cooling jets, passage lines, orifice dowels, hoses, plugs, and any auxiliary components.
Your top bet is to hire an expert for this service, though oil system flushing products do exist, ranging from about $30 to $60.
Dirty Oil Filter
Most oil filters last about 3,000 miles, at which point you’ll need to replace them. As they accumulate debris, they become less effective. When too much has been collected, the flow of oil becomes restricted.
A few symptoms of a dirty oil filter include sputter or metallic sounds, a decrease in engine performance, or black, sooty exhaust. You can replace an oil filter yourself at home relatively easily, or you can hire a shop to do it for you for between $35 to $75.
If your motor requires synthetic oil, anticipate spending a tad more, potentially up to $125.
Oil Quality/Grade
If you didn’t know, motor oil comes in different levels of viscosity, which refers to how thick it is (also known as oil weight).
The thinner it is, the easier it will flow through the system. The denser it is, the more pressure it needs to circulate.
Your top bet is to consult your handbook to determine what the manufacturer suggests concerning viscosity level. Then, you’ll have to take where you live into account.
The warmer the climate you reside in, the thicker your oil should be. In cold weather, thinner oil is ideal, such as 5W. You also have a choice between regular mineral oil, fully synthetic, or a blend of the two.
Synthetics are known for their ability to supplement engine longevity, though not all engines can tolerate them.
The Importance of Changing Your Engine Oil
Most mechanics suggest changing your oil every 3,000 miles or so. However, contemporary cars, trucks, and SUVs are constructed to last as long as 10,000 miles before needing fresh oil.
Regardless, consistency is what matters. The longer you wait, the greater the chances you cause your engine damage.
As oil ages, it begins to break down and thicken. As you know, the heavier your oil is, the more pressure it requires to circulate through the system. It also picks up more contaminants, such as dirt, dust, or metal shavings, causing it to thicken, as well as increasing wear on your engine.
High Oil Pressure FAQ
Final Thoughts
Car repairs are never pleasant, but it’s better to tackle them early before they worsen.
If your oil pressure gauge begins to rise, diagnose the issue before it becomes a significant problem. It is better to spend a few hundred dollars now than several thousand later.
To ensure your lubrication system can do its job. Be sure to follow a maintenance routine that includes regular oil changes and replacing the oil filter.
