What are the possible faults of an air-cooled diesel engine?

[StHarley]

Possible faults of an air-cooled diesel engine are as follows: Difficulty in starting: mainly includes starting faults such as difficulty in starting at normal temperature and cold starting difficulties. Unstable idle speed: mainly refers to idle speed faults such as unstable idle speed, no idle speed, and idle speed fluctuation. Unstable operation under medium and small load conditions: the engine is prone to stalling, individual cylinders work intermittently, and power output is unstable. Insufficient power under heavy load: the diesel engine is weak under high-speed and high-load conditions, and the car has insufficient power such as weak acceleration. High fuel consumption: abnormal fuel consumption is found during car use, or the fuel consumption per 100 kilometers is significantly increased during long-distance travel. Engine does not stop after fuel cut-off: the engine continues to run without stopping after being turned off; it still does not stop after repeated attempts to turn it off.

[AaronLee]

After driving air-cooled diesel engines for so many years, the most common issue is engine damage caused by overheating, such as cylinder deformation or piston burning. This often happens when aging fan belts fail to provide sufficient airflow for cooling, thinning out the engine oil and reducing its lubricity. Worn piston rings lead to decreased compression, affecting startup, while dust-clogged air intakes trap heat, creating more failure points. Regularly inspecting the fan system, cleaning dust buildup in the cooling ducts, and using high-temperature engine oil can mitigate many problems. Additionally, hard starting may stem from faulty glow plugs or insufficient compression, especially in cold weather. Overall, maintaining unobstructed airflow is crucial—overlooking these small details could lead to costly overhauls.

[BriellaLynn]

Take my old air-cooled diesel truck as an example. It often has problems like sudden engine stalling or smoke emission. The root cause is insufficient cooling leading to parts expanding and seizing. Damaged fan blades or rusted bearings reduce airflow, causing the engine oil to degrade too quickly. When starting sluggishly, compression leaks or valve carbon buildup result in unstable power. Before every long trip, I clean the filter screen to avoid clogging and ensure the engine oil grade is suitable for high-temperature environments. Don’t overlook daily maintenance, such as checking the air ducts for cracks or leaks, as these can easily trigger a chain of issues.

[AustinLynn]

Air-cooled diesel engine failures mainly focus on several aspects: overheating damages the cylinder block causing seal failure, insufficient lubrication accelerates component wear, and air supply blockage leads to inefficient fan operation. I emphasize the importance of regularly cleaning cooling channels and checking oil viscosity. These simple steps can prevent many troubles and avoid emergency situations.

[PeytonDella]

From a maintenance perspective, to reduce failures in air-cooled diesel engines, first ensure the fan operates normally without abnormal noises, as this directly affects cooling efficiency. Secondly, engine oil must be selected for high-temperature oxidation resistance; otherwise, it can easily degrade under high temperatures, accelerating engine aging. Excessive dust clogging the air ducts is also a common issue leading to overheating shutdowns—it's recommended to clean them quarterly. Lastly, pay attention to whether the preheating system functions properly, as winter starting difficulties often stem from insufficient preheating and incomplete combustion. Minor repairs are far more cost-effective than major overhauls, with the key lying in daily attention to detail maintenance.