The diesel fuel pressure gauge is like a “blood pressure gauge” for a machinery’s fuel line. Its main task is to tell us how much pressure is in the fuel line. Imagine that your heavy machine is a human body, then the fuel lines are like blood vessels and the diesel fuel is like blood. The fuel pump acts like a heart, pumping the fuel to all engine parts. The function of the diesel fuel pressure gauge is to tell if the fuel is running properly.
The question lies in how it indicates the diesel problem. What does it mean when the oil pressure is too low or too high? What I should do when the needle points “0”? How to deal with a situation of a gauge pointer swinging back and forth? In this blog, we will provide a detailed description of abnormal fuel gauge problems and corresponding solutions.
Understanding Diesel Fuel Pressure Gauges
Understanding how a diesel fuel pressure gauge works helps us better judge the working condition of the engine. If your gauge is a clock type, it has a metal tube like a spring, when the oil pressure increases, this metal tube will bend, driving the pointer to turn, to show the size of the pressure. If it’s electronic, it equips a sensor inside, which senses the change in pressure and then converts this information into numbers on the screen.
Diesel fuel pressure gauges typically have a specific measurement range, such as 0-100 psi (pounds per square inch) or 0-10 bar. If the pressure exceeds this range, it could indicate fuel system issues. Of course, If the gauge itself is not accurate then nothing means anything, so regular “checkups” is necessary.
Diagnosing Abnormal Pressure Gauge Readings
Common diesel fuel pressure gauge anomalies include pressure too high, pressure too low, no pressure, and pressure swings. Many fuel failures could lead to these such as Insufficient oil level or wrong oil viscosity. Maybe the engine temperature is too high, or a polluted oil filter is disturbing the machine running… Therefore, you require a precise approach for specific issues. Below are some basic assessments and troubleshooting methods for Diesel Fuel Pressure Gauge problems.
High Pressure
Let’s draw a common conclusion first. Most of the high-pressure problems are caused by a blockage to some extent as oil running is not smooth. Not all high-pressure gauge readings indicate a fuel or engine problem. Don’t worry about finding high oil pressure after starting the diesel engine in winter. Normally the oil pressure will decrease to a normal level after warming up. However, if the oil pressure gauge still exceeds the normal value, adjust the pressure limiting specified value. When it doesn’t work, it’s time for you to check the oil viscosity. If the oil viscosity is too high, the lubricating oil passages may be clogged and should be cleaned with clean diesel fuel. The last thing you could make an effort is to clean the engine. To minimize the damage caused by cleaning, we recommend a mixture of 2/3 cleaning oil and 1/3 oil for cleaning, but the time should not exceed 3 minutes.
Also read: How Do Seasons Impact Engine Lubricant Choice?
Low Pressure
Low-pressure gauge oil pressure reflects the opposite failures. When you find the oil pressure gauge shows a pressure lower than the normal value (0.15-0.4 MPa), stop the machine immediately. After 3-5 minutes of turning down, check the insufficiency and the quality of the oil. If the oil is insufficient or the viscosity is not in accordance with the regulations, it is necessary to add or replace the oil. Check if the oil has deteriorated due to mixing with fuel or water. Milky oil is a mix of oil and water. Check for oil leaks and change the oil if necessary. Also, check for a loose main oil passage screw plug and rotate the crankshaft to see if more oil is seeping out. If so, there may be too much clearance in the main, connecting rod, and camshaft bearings, and the bearing clearances will need checking and adjustment. When none of the methods works, it may be due to a clogged roughing filter or restrictor valve, clean the roughing filter or check the restrictor valve. Last but not least, a badly worn oil pump or damaged seals can also cause low oil pressure.
No Oil Pressure
When the oil indicator light is flashing and the oil pressure gauge needle points zero happens during the diesel engine running, what you can do is check that the oil line is not leaking due to a rupture. After that, go ahead and check if the oil filter is installed correctly. The oil will not be able to enter the main engine oil passages if the filter is not installed properly, which tends to happen after a diesel engine overhaul. Finally, if no abnormality is found, the oil pump may be faulty and needs to be checked and repaired.
Oil Pressure Gauge Pointer Swings Back and Forth
Oil insufficiency or poor qualification could also cause the gauge pointer to become unstable. Then check the bypass valve under oil-filled conditions, if the bypass valve spring is deformed or not elastic enough, the bypass valve spring should be replaced. If you don’t close the bypass valve tightly, repair it.
Diesel Fuel Pressure Gauge Maintenance
Don’t forget that your indicator gauge is itself a consumable item that will wear out and become insensitive. Generally speaking, if all the aforementioned problems can not fix the gauge’s abnormal readings, then replacing the gauge with a new one could be a wise choice. Regular cleaning to prevent dirt buildup and inspection for leaks are essential. Over time, the gauge may lose calibration due to vibrations or wear, so it’s important to check and recalibrate when needed. Also, inspecting the wiring or tubing for cracks and avoiding pressure levels beyond the gauge’s capacity will prevent damage. In harsh environments, worn components should be replaced promptly to ensure consistent readings. A well-maintained diesel fuel pressure gauge will provide reliable data, contributing to the smooth operation of your diesel system.
Conclusion
To conclude, the abnormal diesel fuel pressure gauge is related to oil viscosity, purity, oil insufficiency, and diesel and oil tube health. You can settle all the aforementioned situations after a careful and logistic examination.
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