Oil Pressure Problems in Mini Digger and Excavator Engine

excavator problems oil pressure

The oil pressure in your mini digger and excavator engine is one of the multiple factors that must be correct. Normal oil pressure in your engine is essential in ensuring proper lubrication. Engine components, such as the camshaft and balance shaft bearings, need proper lubrication. Hence, check out this article on how you can make sure that your oil pressure is at an appropriate level.

If your oil pressure of the mini digger is abnormally high, it might be a sign that there are underlying problems. The same goes when the oil pressure on your excavator engine is low. So, it is important to check them. It is also a must that you are aware of how to detect the causes. Whether you are using mini or standard excavators, you should know about these things.

Fortunately, your engine’s oil pressure can be restored to healthy levels. Just think of it as maintaining the human blood pressure. So, do not panic! Rest back as we discuss the causes of oil pressure problems on the excavator engine.

There is Insufficient Excavator Engine Oil

If there is an insufficient amount of oil, the oil pump will not be lubricated due to the air. The amount of oil in the pump will also be reduced. Thus, the oil pressure will drop. To avoid that situation, you should always check the oil level in the oil pan before working. Doing that will help ensure that the oil level is normal. If the oil level is way beyond the limit, the same type of engine oil should be added. Do not practice mixing different engine oil brands. That will only cause more problems. 

Bad Excavator Oil Pump

In general, a defective oil pump will result in low oil pressure in your excavator engine. Meanwhile, an oil pump with worn bearings may result in high oil pressure. 

Some parts cannot function very well if the oil pump begins to fray due to time or usage. The clearance between the pump shaft and bushing of the oil pump would become too large. The same will happen to the clearance between the gear end face and the pump cover. Your excavator’s flank clearance or radial clearance would become wider, too. These scenarios would lead to a reduction in the amount of pump oil and a decrease in oil pressure.

During this time, the parts must be replaced immediately. The inner surface of the pump cover should be ground. Doing that will reform the clearance between the end face of the gear and the standard rage. 

Too High Excavator Engine Temperature

Excessive scaling of your excavator’s cooling system will overheat the engine. Poor heat dissipation and overloading operation will also lead to the same problem. Too late fuel supply time of the fuel injection pump can also cause engine oil deterioration. 

Basically, the factors above will greatly impair your engine. Thus, the scale must be removed, and the supply time should be adjusted. Your engine must also be operated within the acceptable load.

The Clearance Between the Connecting Rod Bearing and Main Bearing Increases

The gap between your main crankshaft and connecting rod bearing will increase after long-term usage. When that happens, the oil pressure in your excavator engine will decrease. According to experts, for every 0.01mm increase in the fit-gap, the pressure will drop by 0.01MPa. In this situation, the crankshaft must be repaired immediately. New connecting rod bearings and main bearings must be used to restore the clearance.

The Excavator Bypass Valve is Damaged

The bypass valve maintains the normal oil pressure of the main oil passage. If the regulating spring is damaged, the steel ball and the matching surface of the valve seat will be worn out. The amount of oil returned will increase, and the pressure in the oil passage will drop. You should then remove the bypass valve when these things start to occur.

Oil Filter of the Excavator is Clogged or Dirty

Because of its structure, your oil filter will become clogged or filthy. Maintaining the purity of your engine oil will require filtering out the impurities. That way, it will guarantee that your engine is appropriately lubricated. It will also ensure that your standard or mini excavator will function properly. So, it is only logical that it will become dirty over time.

Oil filters also become clogged because of continual operation. It will then reduce the overall oil flow efficiency in your filter. When the flow rates start to decrease, your engine temperature will rise. That high engine temperature will result in high oil pressure.

The Oil Grade Used in Your Excavator is Unsuitable

We are all aware that different excavator engines need different brands of oil. That is why it was already mentioned above that it is important not to practice mixing engine oil brands. 

Engine oils have various viscosities. Viscosity is the measure of an oil’s thickness or thickness. 

You should also use different brands of oil for different seasons. If you use engine oil that is of inferior quality, the engine will increase leakage. The low viscosity will only reduce the pressure, damaging your engine. 

The Excavator Oil Pump Does Not Rotate

If the driveshaft and the flat key of the oil pump are damaged, it will stop the oil pump from functioning. If the filter is damaged and the gear is stuck, it will also reduce your engine’s performance. The oil pressure will also immediately drop to zero! When that happens, the damaged filter or flat key must be replaced.

The Oil Passage is Blocked

Debris, filth, and other foreign objects can block your oil passage. It will result in irregular oil flow and a drop in the oil pressure. To avoid that, you can loosen the tubing connector and observe the oil flow. Again, it is essential for the oil passage not to be blocked. The contrary will lead to your excavator’s weak performance.

Inappropriate Set Pressure of Pressure Limiting Valve

The oil pumped must ensure appropriate pressure before reaching other parts. The regulating spring will become too soft if you set the pressure too low. Leaking might occur on the sealing surface, causing the pressure to drop. Hence, adjusting the pressure limiting valve at a normal rate is important. Too high or too low set pressure will only heighten engine problems. If left unattended, this will greatly damage your excavator.

Symptoms of Oil Pressure Problems on Excavators

We have already mentioned the causes of oil pressure problems on excavators above. Now, we do not want to just leave you at that. You should also be quick in noticing whenever your excavator begins to show its first call for help. Written below are some of the most common signs of oil pressure issues on your excavator.

Oil Leaks 

Everything in your mini digger and excavator was designed to operate precisely. The correct pressure and temperature are essential to keep it in good condition. Thus, the moment the oil pressure becomes extreme, there is a high tendency for sudden bursts. It might burst through the gaskets, seals, and other systems. So, when you notice any type of leakage and breakage, start checking out your excavator’s engine.

Overheating Engine

This is surely the earliest sign of an oil pressure problem. We already even mentioned this above. However, we cannot skip this sign on the list because this is the most detectable out of them all. The further you operate your mini digger and excavator with abnormal oil pressure, the hotter it will become. So, do not ever take this issue lightly.

Engine Damage

This is one of the worst signs ever. If your excavator begins to deteriorate, your engine is one of the main suspects. Engine oil decreases the friction within your engine. If there is low engine oil, the parts will not be lubricated enough. If there is excessively high engine oil, it will also restrict the amount of oil passing through. Increased friction will not only overheat the engine but can also harm other engine parts. If left unattended, the low or high oil pressure will damage your excavator. At that point, the issue might even be irreversible. And we do not want that to happen, right?


The things above show the importance of changing your mini digger and excavator’s engine oil and parts. When the oil ages, it thickens and degrades over time. If you are not aware, the pressure will rise as the oil becomes thicker. Also, it will gather impurities, causing extreme engine stress. Hence, it is crucial to be aware that engine oil replacement is necessary for your excavator. It will help in maintaining your excavator’s performance. Do not also rely on hand-me-downs or cheap engine parts. You might be saving a little money now, but the future risks relative to that are surely not worth it.

While repairs are not enjoyable, it is better to address these problems as early as possible. That way, we can avoid bigger problems from occurring. Once your oil pressure begins to be abnormally lower or higher, assess the situation. Do not wait for it to become serious before you begin to check what could be happening in your excavator. 

It is better to invest a couple of money now than to spend several thousands of dollars after for repairs. To ensure the normal function of your lubricating system, you can schedule maintenance. Whether you are using a standard or mini excavator, you can schedule regular oil changes and oil filter replacements for them.

We hope that you were able to learn a thing or two from this informative article. If you love to see more articles like this, you may access our Blog Page. You may also contact us for more information, and we will accommodate you.


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