In any vehicle, oil pressure can be normal, too high, or too low. We will cover what your oil pressure gauge should read and what will happen if it is too high or low.
We check out the normal oil pressure for popular truck brands such as Kenworth, Peterbilt, Volvo, and Freightliner, as well as a few others.
Here’s a Quick Answer to What’s the Normal Oil Pressure for a Semi Truck:
The normal oil pressure in a semi truck is approximately 20 PSI when at idle and between 30 to 70 PSI when at highway speeds. The normal oil pressure reading will depend on engine type. It’s also affected by the ambient temperature i.e. slightly higher reading when cold and a lower reading when hot.
What’s the Normal Oil Pressure for a Semi Truck?
A semi truck has a lot of power, a large amount of oil in a large engine. The engine can run for 10 hours at a time, which inevitably causes heat inside the engine.
The oil is pressurized at an average level of 30 to 70 psi. The pressure can drop lower or go higher than this. A driver needs to keep an eye on all their gauges and understand how they function.
It will help them stay on the road longer by picking up a potential problem before it occurs. So be vigilant to avoid unnecessary downtime.
Normal Oil Pressure Freightliner Cascadia
The oil pressure gauge will read a little lower when the oil gets hotter. At higher speeds, you may get different readings. It is normal for the Freightliner Cascadia to have a reading of 45 to 48 psi.
After an oil change, it can change a little and read 55 to 56 psi. It is because the oil is thinner than the used oil you previously had in the truck, making it more susceptible to heat.
Similar to when you change the oil in a pot on your stove. It will heat up faster and hotter.
Normal Oil Pressure Peterbilt
A Peterbilt will run at around 30 to 40 psi. Of course, this will vary from truck to truck and depending on when your oil changed. Some Peterbilts can run at 45 to 49 psi.
The longer the engine has to work, the hotter that oil can get. Keep an eye on your gauge to avoid having issues later on. Change your oil every 10k to 15k miles.
Normal Oil Pressure Kenworth T680
While there is no universal formula for any vehicle, you may find it helpful to check the specs of your engine to know what your truck’s psi should be. A Kenworth T680 is around 35 to 38 psi.
It can be a little higher or lower. Be sure to use the recommended oil for your truck and have the oil changed regularly.
Normal Oil Pressure International Prostar
The International Prostar oil pressure gauge should read at normal around 35 to 40 psi. As with the rest of these trucks, this can vary. It can drop to around 20 psi when the vehicle comes to a stop.
It is a good idea to check the engine specs to be sure what psi your truck should run at. Never ignore the gauges on your dash. They may not be 100% accurate, but they are your first indicator that there could be an issue.
Normal Oil Pressure on Paccar Engine
A Paccar engine oil pressure is between 60 and 80 psi. They have great flow. If the gauge is reading differently than these numbers, it could be that you have a bad oil pressure sensor.
Paccar has full specs for their engines on their website. You should monitor the gauge closely. If you feel there are any irregular jumps in temperature, take it to a mechanic.
Normal Oil Pressure Volvo D12
The Volvo D12 engine should read at normal pressure around 55 to 65 psi. Their sensors can be a little temperamental. It would be a good idea to monitor the gauge and how the truck is driving.
Keep the oil topped up and use the recommended oil for the engine.
Normal Oil Pressure Volvo D13
The normal oil pressure on a Volvo D13 engine is around 30 to 70 psi. These numbers can again change with the heat of the engine or lack of heat. Remember to check the gauge is working.
Mack MP8 Normal Oil Pressure
The Mack MP8 engine normally runs at around 30 to 70 psi. The needle can and does drop or go above this, depending on a few things. The revs being too high can affect the oil pressure.
There are several factors to consider when topping up your oil. Using the recommended oil is one of them. Check the pressure manually with an oil pressure test kit.
It may highlight any potential issues.
Mack E7 Normal Oil Pressure
The Mack E7 engine’s normal oil pressure should read around 40 to 60 psi. Some have been ok at 34 to 64 psi. It will depend on the age of the engine and what RPM you are at.
Check the owner’s manual for the recommended oil pressure. If you have concerns about the pressure, there is plenty of online forums to set your mind at ease.
You could take it to a workshop and have it looked at, but you may find you can fix it yourself.
What is Normal Oil Pressure for DD15?
The DD15 engine normally runs around 55 to 60 psi. Each engine is different because of the size, the capacity of oil it can hold, the make of the engine, and the design of the components.
Trucks try to remain unique to one another, which is very difficult, as they all want the same technology.
What’s the Semi Truck Oil Pressure at Idle?
A semi truck at idle has an oil pressure between 10 to 20 psi, If it is on a hot idle. Some engines will signal a warning on the dashboard when it hits around 10.
The average semi truck running normally will sit comfortably at 15 to 20 psi. It is not uncommon to sit a little above this when the engine is cooler.
What’s Low Oil Pressure in a Semi Truck?
Typically a low oil pressure reading is below 20 psi when the truck has been running for some time, say 15 to 30 minutes. At idle, a low oil pressure reading would be below 10 psi.
Let’s not underestimate the importance of oil in an engine, the pressure of that oil, or its correct level.
Low oil pressure in your semi truck means you could be out of work for a week or two. A warning light on the driver’s dash will alert them to either insufficient oil or not enough pressure.
It will prevent oil from reaching the engine components and lubricating them in the normal manner.
What Causes Low Oil Pressure in a Semi Truck?
Many factors can cause low oil pressure in a semi truck. Here are some common causes of low oil pressure:
- Not having enough oil in the engine
- engine oils purity. Contaminated oil could have been compromised with a leak, mixing fuel, coolant, or water into the engine. Also, it could be that your oil filter is clogged.
- Blockages in the oil system. Check the oil lines for blockage. Also check if your engine oil bypass valves are closed as this can also give you low oil pressure.
- Other items to check. Check the oil suction tube, the oil pump, and that you have the correct bearings on the engine. Granted, some of these will need to be checked by a mechanic.
Our advice is to do all the things you can do yourself before you take it to a workshop.
Can you Drive with Low Oil Pressure in a Semi Truck?
You can drive with low oil pressure. When you get a chance, check the oil level and for any leaks around the engine. If you hear any unusual engine noises, pull over and call for assistance.
Do not continue with your engine making a clanging sound. You could bend the valves if you try to crank the engine with low to no oil.
How to Fix Low Oil Pressure in a Semi Truck?
The easy way is to take it to a mechanic. If you have knowledge of engines past topping up the oil and checking for leaks, then the first thing to do is to locate the issue.
The fix would depend on the problem. You can replace the O-rings, pickup tube, or crank main bearings. But you need to find the issue first before spending time and money on it.
What’s High Oil Pressure in a Semi Truck
High oil pressure is anything that stays above 80 psi. The oil pressure gauge needle will probably shake a little. It tends to read a little higher in cold weather.
High oil pressure can leave you on the side of the road. It is probably a good idea to take a look at it as soon as possible. You will know the feel of your truck.
Don’t be alarmed if the pressure is too high. It could be a simple fix.
What Causes High Oil Pressure in a Semi Truck?
It could just be a dirty oil filter. It could be a bad oil pressure sensor. A broken diaphragm. The oil dump valve could be sticking or partly blocked. It could be a blocked oil passage.
A bad grade of oil can cause high pressure. It would be a good idea to seek advice from a qualified mechanic.
Can you Drive with High Oil Pressure in a Semi Truck?
You can drive with high engine oil pressure, but it is not recommended to keep going. Find a safe place to pull over and do some checks to ensure you are not damaging the engine.
It could just be the sensor playing up. But then again, it could be something much worse. Allow the engine to rest a little, then try rerunning it while the engine is still cool.
Idle the engine for 10 to 20 minutes to allow the oil to heat up. If it continues to show high readings, take it to a mechanic as soon as possible to avoid any downtime.
How to Fix High Oil Pressure in a Semi Truck?
The first thing you would need to do to fix the issue is find what the problem is. It could be many things, some you may be able to handle, and some may need a mechanic.
If the truck is running fine, you could try swapping out the oil pressure sensor. It may be the oil pressure relief valve. These small things can be changed using standard household tools.
But for the bigger issues, you will either need to know what you are doing or consult a professional. Check the recommended oil is the correct grade for your truck.
You may need an oil change along with the oil filter.