The oil pressure relief valve on the 5.9 Cummins engine is located behind the fuel filter, at the rear of the block near the starter motor. It is normally covered by a round black plastic cap that has two small breather hoses attached to it. The valve itself looks like a cylinder with an internal spring inside, and you will need to remove this cap in order to access it for inspection or replacement purposes.

Depending on your vehicle model, there may be additional components such as brackets, spacers, and gaskets between the oil pressure relief valve and its mounting surface. When checking or replacing this part make sure all these parts are properly reinstalled before starting your engine again.

The 5.9 Cummins oil pressure relief valve is an essential part of your engine’s lubrication system, and it is located in the front of the engine block near the oil filter housing. It helps to regulate the amount of oil that flows through your engine while also preventing too much pressure from building up within it. If you need to replace or inspect your 5.9 Cummins’ oil pressure relief valve, make sure you know exactly where it is located so you can do so safely and accurately!

Cummins Low Oil pressure fix!

Where is Oil Pressure Relief Valve Located?

The oil pressure relief valve is typically located on the side of the engine block. It is usually between the top and bottom halves of the engine, but it can also be found in different locations depending on your vehicle’s make and model. The valve works by releasing excess oil pressure when it builds up too high, which helps to prevent potential damage from occurring within the engine.

It is important to periodically check this valve for any signs of wear or tear that could lead to a malfunctioning part that needs replacing. Additionally, if you notice an increase in oil consumption or an unusual noise coming from under your hood, then it may be time to inspect your oil pressure relief valve for any issues that need addressing.

How Do I Know If My Oil Pressure Relief Valve is Bad?

If you think that your oil pressure relief valve might be damaged or bad, there are a few signs to look out for. Firstly, if your vehicle is running at higher than normal temperatures, then it may indicate an issue with the valve. You can also check for any type of leaking around the valve itself; this could point to a faulty seal or gasket causing leakage and thus indicating that the valve needs replacing.

Additionally, if your engine makes loud knocking noises when accelerating or idling, it could mean that there’s excessive pressure build-up in the system which can only be relieved by replacing the oil pressure relief valve. Finally, if you have difficulty starting up your car after changing gears (especially in cold weather) then this too could suggest an issue with either the mounting bolts being loose on the valves themselves or even internal damage within them which will require inspection from a qualified mechanic.

What Does the Oil Pressure Relief Valve Control?

The oil pressure relief valve is an important component of a vehicle’s lubrication system. It helps to ensure that the oil pressure in the engine does not exceed its design limits by regulating and controlling the amount of oil that flows through it. The valve works by using a spring-loaded plunger, which opens up when the set level of pressure is reached or exceeded.

This allows some excess oil to escape from the system, thereby reducing pressure levels within it. Oil pumps are usually preset at about 10psi (pounds per square inch) above normal operating levels so as to ensure adequate lubrication for all components within an engine without causing any damage due to excessive pressures. As such, this valve plays a critical role in keeping engines running smoothly over time and helping them last longer than they otherwise would have.

What Causes Low Oil Pressure on Diesel Engine?

Low oil pressure in a diesel engine can be caused by several factors, including inadequate lubrication, worn parts, and lack of maintenance. Poor lubrication is one of the most common causes of low oil pressure as it prevents the necessary amount of oil from reaching the engine’s moving parts. Worn out components such as bearings or piston rings can also cause reduced oil flow and lead to low pressure.

If these components aren’t replaced regularly, they may break down completely which could cause major damage to your vehicle’s engine. Lastly, regular maintenance is essential for keeping an eye on any possible issues with your vehicle’s performance – this includes checking fluid levels and changing filters that help remove dirt and other debris from your vehicle’s system – failure to do so can result in clogged pipes or filters leading to lower than normal operating pressures within the engine.

5.9 Cummins Oil Pressure Relief Valve Location


5.9 Cummins Pressure Relief Valve

The 5.9 Cummins Pressure Relief Valve is a safety device that prevents the overpressurization of the engine’s fuel system by releasing excess pressure when it exceeds predetermined levels. This valve is essential in maintaining optimal functionality and preventing damage to both the engine and overall vehicle performance. It is important to inspect this component regularly and replace it if necessary, as failure to do so can lead to severe mechanical issues or even catastrophic engine failure.

5.9 Cummins Oil Pressure at Idle

The 5.9 Cummins oil pressure at idle should generally range from 15-30 psi, depending on the specific engine model and its age. The oil pressure should increase as the RPMs of the engine rises, reaching between 50-80 psi when running at higher speeds. It is important to regularly check your 5.9 Cummins oil pressure to ensure that it is within normal operating parameters; failure to do so could result in costly damage or even catastrophic engine failure.

5.9 Cummins Fuel Pressure Relief Valve Symptoms

One of the most common symptoms of a faulty 5.9 Cummins Fuel Pressure Relief Valve is engine hesitation during acceleration. If your vehicle is experiencing this type of problem, it could be due to an issue with the fuel pressure relief valve that may need to be replaced or adjusted. Other potential issues include abnormal noises coming from the engine when idling and decreased fuel economy due to excessive fuel leakage.

To diagnose the cause of these problems, it’s best to take your vehicle into a qualified mechanic who can properly inspect and identify any faults with the fuel pressure relief valve.


In conclusion, the oil pressure relief valve is an important part of the 5.9 Cummins engine and it is located between the oil filter base and the timing case cover on driver’s side. It should be checked periodically to make sure that it is functioning properly. If you have any questions about locating or replacing your 5.9 Cummins oil pressure relief valve, consult a professional mechanic for assistance.

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