Proper starting procedures are essential for maintaining diesel engine performance and extending its service life. Incorrect operation can lead to severe damage, increased wear, and higher failure rates. Below are the most important precautions and mistakes to avoid when starting a diesel engine.
It is strictly forbidden to start a diesel engine without cooling water or to add cooling water after starting. Sudden cooling may cause critical components such as the cylinder liner and cylinder head to crack or deform.
Similarly, adding boiling water (100°C) to a cold engine can also result in cracking. Cooling water should only be added when the engine temperature drops to 60–70°C.
Do not move the decompression handle to the working position before supplying fuel. The throttle should be set to the fuel supply position before starting.
Failure to follow this procedure can result in fuel waste, poor lubrication, and excessive wear. Unburned diesel may form carbon deposits, dilute engine oil, and reduce overall engine efficiency.
When the engine is cold, lubricating oil becomes more viscous, increasing resistance between moving parts. Push-starting under these conditions accelerates wear and reduces engine lifespan.
Using incorrect oil viscosity in cold weather can make starting difficult and increase engine wear. Low-viscosity lubricants and appropriate diesel fuel should be used during colder seasons to ensure smooth operation.
Avoid directly heating the oil pan or starting a fire at the intake pipe. If heating is necessary, maintain a safe distance and rotate the crankshaft slowly to ensure even heating.
Igniting fuel at the intake pipe can introduce ash and debris into the cylinder, leading to valve sealing problems and accelerated wear.
Glow plugs and flame preheaters consume high electrical power and generate significant heat. Excessive use can quickly drain the battery and damage heating elements.
The glow plug should not be used for more than one minute at a time, and the flame preheater should be limited to 20 seconds per use.
Although adding oil into the cylinder may help with cold starts, it leads to incomplete combustion and carbon buildup. This reduces piston ring elasticity and weakens cylinder sealing performance.
It also accelerates cylinder liner wear and reduces engine power, making future starts more difficult.
Gasoline has a lower ignition point than diesel and ignites earlier. Pouring gasoline into the intake pipe can cause rough engine operation, severe knocking, and even reverse rotation in extreme cases.
The starter motor operates under high current and low voltage conditions. Prolonged use can damage the battery.
Each start attempt should not exceed 5 seconds. If the engine fails to start, wait at least 15 seconds before attempting again.
After startup, the lubricating oil temperature is low and flow is limited. Running the engine at high speed immediately can cause insufficient lubrication and rapid wear of moving parts.
Always allow the engine to warm up at low speed before applying load or increasing speed.
By following these diesel engine starting precautions and avoiding common mistakes, operators can ensure safer operation, reduce maintenance costs, and significantly extend engine service life.
