Fault Analysis on Diesel Engine Failure to Start
Diesel engine starter motor failure
Fault phenomenon:
1. The motor does not rotate when starting, and the detection circuit is normal. If the circuit is short-circuited directly on the motor and the motor does not rotate, it can be determined that the motor is damaged.
2. When starting the diesel engine, you only hear the sound of motor running, but the diesel engine cannot start. Check that the power supply and all parts are normal, but turn the flywheel of the diesel engine in one direction before starting, and the diesel engine can start. It is possible that one or several teeth of the starter motor have been knocked out.
Failure analysis:
1. Damage to the starter motor:
① The main contact is burned and has poor contact;
② The electromagnetic coil is burned out;
③ The carbon brush is burned out.
The causes of the failure are:
① Failure to release the start button quickly after starting, and holding the start button for a long time causes the starter motor to burn out;
② After the starter motor has been used for a long time, the main contact is in poor contact.
2. The reason for the broken gear of the starter motor is: during continuous starts, there is no interval in between, and the motor is started for the second time without completely stopping, resulting in the gears not meshing in place and the teeth being knocked out. .
Troubleshooting methods:
Replace the motor.
Replace the motor gear.
Oil pressure is low
Fault phenomenon: The diesel engine starts normally. The oil pressure indication is low when running at high and low idle speeds, and the low oil pressure alarm occurs when running at low idle speeds.
Failure analysis:
Factors causing low diesel engine oil pressure include:
Low oil level;
Oil filter clogged;
Oil grade too low and wrong viscosity;
Oil pump damaged;
Oil pressure gauge or The oil pressure sensor is damaged.
Troubleshooting methods:
Add engine oil to the standard oil level (the oil level is between the first and second scale lines of the oil dipstick);
Replace the oil filter;
Replace qualified engine oil according to standards;
Maintenance , Replace the oil pump;
Inspect and replace the oil pressure gauge or oil pressure sensor.
Engine oil pressure is too high
Fault phenomenon: The diesel engine starts normally, but when running at high idle speed, the oil pressure indication is too high, exceeding the display scale of the oil pressure gauge.
Troubleshooting process: Run at medium speed for a period of time. After the water temperature rises, the oil pressure returns to normal.
Cause analysis: If the diesel engine runs at high speed directly after starting, the oil pressure will be too high due to the low temperature and high viscosity of the oil. This phenomenon is more obvious in winter. It should be operated at medium speed after startup, and then enter high-speed operation or heavy-load operation after the water temperature rises.
Relevant parameters: Oil pressure of BF6M1013E and BF6M1013ECP in Deutz engines: ① The minimum oil pressure at low idle speed of the thermal engine (when the water temperature is above 85°C) is 0.5bar; ② The minimum oil pressure at high idle speed of the thermal engine (when the water temperature is above 85°C) is 2.0bar; ③The maximum oil pressure at high idle speed of the thermal engine (when the water temperature is above 85°C) is generally 5.0bar, and is allowed to reach 7.0bar in a short period of time. The main oil circuit in the lubrication system is equipped with a pressure relief valve to control the system pressure to protect the system.
