Truck-mounted cranes are essential pieces of equipment in various industries, playing a crucial role in lifting and transporting heavy loads. However, during their use, various small faults can occur, and one of the common issues is noise from the diesel engine. Understanding the causes of this noise and knowing how to eliminate it promptly is essential for ensuring the smooth operation of thetruck-mounted crane. In this article, we will explore the noise fault phenomena, causes, and troubleshooting methods for truck-mounted crane diesel engines.
I. Engine accessory drive noise
Phenomenon:
A whistle-like noise is emitted from the front end of the engine. This noise can vary in intensity, sometimes being loud and sometimes soft. When the cab is flipped open for inspection, it is determined that the noise is coming from the engine pulley and accessory drive. This can be a concerning issue as it not only disrupts the normal operation of the vehicle but also may indicate a potential problem with the engine’s accessory drive system.
Causes:
Insufficient tension of the V-belt on the accessory drive: The V-belt is responsible for transferring power from the engine to various accessories such as the alternator, water pump, and air conditioning compressor. If the belt tension is insufficient, it can slip or vibrate, resulting in a whistle-like noise. This can occur due to belt stretching over time, improper installation, or a faulty tensioner.
The V-belt slips: Slippage of the V-belt can also cause the whistle-like noise. This can happen if the belt is contaminated with oil or other substances that reduce its friction coefficient. Additionally, excessive load on the accessories or a worn belt can lead to slippage.
The V-belt is turned over: If the V-belt is installed incorrectly or becomes twisted, it can cause abnormal noise. This can occur during maintenance or due to improper alignment of the pulleys.
Noise from the accessory drive mechanism: The accessory drive mechanism itself can be the source of noise. This can include problems with the pulleys, bearings, or other components of the drive system. For example, a worn pulley bearing can produce a grinding or whining noise.
Troubleshooting methods:
Check and adjust the belt tension of the engine accessory drive: Regularly inspecting the belt tension is important to ensure proper operation. This can be done using a belt tension gauge or by simply pressing on the belt with your finger. If the belt is too loose, it can be adjusted by tightening the tensioner or adjusting the position of the pulleys.
The V-belt cannot be contaminated by oil: Oil or other contaminants can reduce the friction between the belt and the pulleys, leading to slippage and noise. Check for any oil leaks in the engine area and ensure that the belt is kept clean. If the belt is contaminated, it should be cleaned or replaced.
Replace the worn V-belt if necessary: Over time, the V-belt can wear out and lose its elasticity. Signs of a worn belt include cracks, fraying, or excessive stretching. If the belt is worn, it should be replaced promptly to prevent further damage to the accessory drive system.
Check whether there are faults in the generator and air conditioning compressor: These accessories are driven by the V-belt and can also cause noise if they are malfunctioning. Check for any abnormal sounds or vibrations coming from the generator or air conditioning compressor. If a problem is detected, have these components inspected and repaired by a qualified mechanic.
For example, imagine a truck-mounted crane operator who notices a whistle-like noise coming from the engine. By following the troubleshooting methods above, the operator can first check the belt tension and ensure that it is properly adjusted. If the belt appears to be contaminated with oil, it can be cleaned or replaced. Additionally, checking the generator and air conditioning compressor can help identify any potential faults in these accessories.
II. Engine mount noise
Phenomenon:
During the driving of the truck-mounted crane, the engine noise suddenly increases. It can be difficult to determine whether the noise is coming from the front or the rear of the vehicle. When most people hear the noise seemingly at the front, they may suspect that the engine is damaged. When the engine starts or accelerates, the noise is significantly increased and accompanied by abnormal vibration of the engine. This can be a disturbing experience for the operator and may indicate a problem with the engine mount.
Causes:
The engine mount bolt and nut are disengaged, and the rubber mount is damaged or lost: The engine mount is responsible for supporting the engine and reducing vibration. If the bolt and nut become disengaged or the rubber mount is damaged or lost, the engine can move around more freely, resulting in increased noise and vibration. This can occur due to improper installation, wear and tear, or damage from road hazards.
When repairing the truck-mounted crane and the engine, the engine mount is omitted or the bolt and nut are not tightened: During maintenance or repair work, it is essential to ensure that all components are properly installed and tightened. If the engine mount is omitted or the bolt and nut are not tightened, it can lead to instability and noise.
Troubleshooting methods:
When accurately finding that the engine mount is lost or damaged, replace the engine rubber mount and install the bolt and nut. This is a relatively straightforward repair that can significantly reduce engine noise and vibration. It is important to use high-quality replacement parts and ensure that they are installed correctly.
Learn from the experience. In the future, when hearing similar noise, check the rubber mount. By being aware of the potential for engine mount problems, operators can quickly diagnose and address the issue, reducing downtime and ensuring the safe operation of the truck-mounted crane.
For instance, if a truck-mounted crane operator notices an increase in engine noise and vibration, they can check the engine mount for any signs of damage or looseness. If the mount is found to be faulty, it can be replaced promptly to restore normal operation.
III. Fan noise
Phenomenon:
During the driving of the truck-mounted crane, the noise at the front end of the engine suddenly increases. When the cab is flipped open for inspection, it is found that the noise may come from the fan. Stopping the machine for inspection may reveal that the front end of the fan is bent or a certain fan blade is severely damaged or the fan clutch is damaged. This can be a serious problem as a damaged fan can affect the engine’s cooling system and lead to overheating.
Causes:
The fan is damaged or the fan drive motor is damaged. This can occur due to a variety of reasons, including impact from road debris, wear and tear, or a faulty motor. A bent fan blade can cause imbalance and vibration, resulting in increased noise. A damaged fan clutch can also lead to abnormal noise and reduced cooling efficiency.
Troubleshooting methods:
Find out the cause of fan damage, eliminate abnormal phenomena and replace the fan: If the fan is damaged, it is important to determine the cause of the damage and address it promptly. This may involve removing any debris that has become stuck in the fan, repairing any bent blades, or replacing the entire fan if necessary.
Replace the fan: If the fan is severely damaged or cannot be repaired, it should be replaced with a new one. Ensure that the replacement fan is the correct size and type for the truck-mounted crane‘s engine.
If the radiator is damaged, repair the radiator; if the radiator leaks, temporarily find a way to block it; if necessary, replace the radiator and tighten the radiator fixing bolts: A damaged radiator can also contribute to fan noise and engine overheating. If the radiator is damaged or leaking, it should be repaired or replaced as soon as possible. Temporarily blocking a small leak can be a quick fix, but a proper repair or replacement is necessary for long-term reliability.
For example, if a truck-mounted crane operator notices an increase in noise from the fan, they can stop the vehicle and inspect the fan for any damage. If a bent blade is found, it can be straightened or replaced. Additionally, checking the radiator for any damage or leaks can help ensure the proper functioning of the cooling system.
IV. Water pump noise
Phenomenon:
A relatively sharp grinding noise is emitted from the front end of the engine. When listening carefully, it is determined that the noise is coming from the water pump. When there is water pump noise, there are often engine faults such as poor coolant circulation and easy overheating of the engine. This can be a serious problem as a malfunctioning water pump can lead to engine damage if not addressed promptly.
Causes:
The water pump bearing is damaged: The water pump bearing supports the shaft and impeller of the water pump. If the bearing is damaged, it can cause grinding or squeaking noises. This can occur due to wear and tear, lack of lubrication, or contamination.
The water pump seal is damaged: A damaged water pump seal can allow coolant to leak out of the pump, reducing its efficiency and causing noise. This can happen due to age, wear, or damage from foreign objects.
Foreign objects are stuck in the water pump: Debris or foreign objects can become stuck in the water pump impeller, causing it to jam or run unevenly. This can result in noise and reduced coolant flow.
Troubleshooting methods:
First, check the water pump. When confirming a water pump fault, replace the water pump assembly. This is usually the most effective way to address a water pump problem. Ensure that the replacement pump is of high quality and compatible with the truck-mounted crane‘s engine.
Then check whether there are foreign objects in the cooling system. If necessary, clean the cooling system to make the coolant flow smoothly. Removing any foreign objects and cleaning the cooling system can help prevent further damage to the water pump and ensure proper coolant circulation.
For instance, if a truck-mounted crane operator hears a grinding noise coming from the water pump, they can have the water pump inspected by a mechanic. If a fault is found, the water pump can be replaced and the cooling system checked for any foreign objects.
Have you mastered the above four methods for diagnosing and troubleshooting noise faults of truck-mounted crane diesel engines? By understanding the causes of these noises and knowing how to troubleshoot them, operators can ensure the reliable operation of their truck-mounted cranes and minimize downtime due to engine problems. Regular maintenance and inspection of the engine and its components can also help prevent noise faults from occurring in the first place.
