Truck engine failures are common in the following categories:
### 1. Startup problem
1. ** Low battery power **
- ** Fault Description ** : If the battery ages, the charging system fails, or the vehicle has not been used for a long time, the battery power may be low. This can lead to difficulty starting the engine, as shown by low engine speed when starting, or even unable to start.
- ** Inspection Method ** : You can judge by observing the battery indicator light on the instrument panel. If the indicator light is on, or the battery voltage measured with a multimeter is lower than the normal range (the general truck battery voltage is about 24V), the battery may be low.
2. ** Starting motor failure **
- ** Fault Description ** : The starting motor is a key component responsible for converting electrical energy into mechanical energy and driving the engine to run. After long-term use, problems such as the carbon brush wear of the starting motor, short circuit or open circuit of the coil may cause the starting motor to be weak or unable to work.
- ** Inspection Method ** : When starting, the starting motor is heard with abnormal sound, such as "click" sound or no sound, and the engine does not rotate, it may be a failure of the starting motor. It can be judged by checking whether the cable connection of the starting motor is loose and whether there is a burnt taste.
3. ** Fuel system failure causes failure to start **
- ** Description ** : Failure of the fuel pump, blockage of the oil line or blockage of the fuel filter will prevent the normal supply of fuel to the engine. For example, a damaged fuel pump cannot build up enough oil pressure, and fuel cannot reach the nozzle.
- ** Inspection Method ** : Check whether the fuel pipeline is damaged or leaking oil. If you suspect that there is a problem with the fuel pump, you can check whether the power supply and fuse of the fuel pump are normal. In addition, loosen the exhaust valve of the fuel filter to see if there is fuel outflow, if not, it may be blocked by the filter.
Two, lack of power
1. ** Air filter blocked **
- ** Fault Description ** : The air filter is too dirty or clogged to limit the amount of air entering the engine. Because engine combustion requires enough air to mix with fuel, insufficient air will lead to inadequate combustion, making the engine power drop.
- ** Inspection Method ** : Check the appearance of the air filter, if there is obvious dust, debris accumulation, or the indicator of the air filter shows that it needs to be replaced, the air filter should be cleaned or replaced.
2. ** Fuel injection system failure **
- ** Fault Description ** : The injection nozzle is blocked, the injection pressure is insufficient or the injection pump is faulty, which will affect the injection effect of fuel. For example, the carbon blockage of the fuel injection nozzle will make the shape of the fuel injection and the atomization effect worse, resulting in inadequate combustion and reduced power output.
- ** Inspection method ** : For the oil nozzle, you can check whether its appearance has carbon deposit and drip phenomenon. Use professional equipment to check whether the injection pressure meets the specified value. If you suspect a problem with the fuel injection pump, you can check whether the drive belt of the fuel injection pump is loose, broken, and whether the internal components of the fuel injection pump are worn.
3. ** Turbocharger failure **
- ** Fault Description ** : In truck engines equipped with turbochargers, turbochargers can increase the intake pressure and increase the power output of the engine. If the blades of the turbocharger are damaged, the bearings are worn or the seal is poor, the supercharging effect will be reduced, and the engine will be insufficient.
- ** Inspection Method ** : Check the appearance of the turbocharger for signs of damage and oil leakage. Listen to the sound of the turbocharger when it is running, if there is abnormal noise, such as howling or friction, it may be an internal fault of the turbocharger. It is also possible to determine the working state of the turbocharger by detecting its pressure sensor data.
3. Abnormal jitter
1. ** Engine cylinder missing **
Ignition system failure (such as spark plug damage, ignition coil failure), fuel system failure (such as fuel nozzle does not work), or insufficient cylinder pressure can cause engine cylinder loss. When one or more cylinders do not work properly, the engine will produce significant jitter.
- ** Inspection method ** : First check the status of the spark plug to see whether the electrode is worn, carbon deposit, and whether the spark plug gap is normal. Then check whether the ignition coil cracks, leakage and other conditions. For the fuel system, check whether the injection nozzle is working properly and whether the injection pressure is uniform. You can use the cylinder pressure gauge to check the cylinder pressure and determine whether there are problems such as poor cylinder seal.
2. ** Drive shaft is unbalanced or damaged **
- ** Fault Description ** : The balance block of the drive shaft falls off, the drive shaft bends and deforms, or the universal-joint wears loosely, which will cause the drive shaft to produce unbalanced forces during rotation, thus making the vehicle shake.
- ** Inspection Method ** : Lift the vehicle, turn the drive shaft, and observe whether the drive shaft is bent. Check whether the universal joint is tightly connected and whether it is loose. If you suspect that there is a problem with the balance block, you can check it by professional dynamic balancing equipment.
3. ** Suspension system failure **
- ** Fault Description ** : Fatigue of the leaf spring, failure of the shock absorber or loose suspension connection components can cause the vehicle to jitter during driving. For example, oil leakage from shock absorbers can lead to poor shock absorption and increased shaking of vehicles over bumpy roads.
- ** Inspection method ** : Check whether the leaf spring is broken and deformed. Check whether the shock absorber has oil leakage phenomenon, you can judge the work of the shock absorber by pressing the body and observing the rebound of the vehicle. Check whether the suspension bolts and nuts are loose.
### # 4. Overheating
1. ** Cooling system failure **
- ** Fault Description ** : Clogged radiators, insufficient coolant, or faulty water pumps can cause poor engine cooling. The coolant circulates through the cooling system, taking away the heat generated by the engine, and if the coolant circulation is poor or insufficient, the engine temperature will rise.
- ** Inspection Method ** : Check whether the surface of the radiator is blocked by dirt and debris. Check the coolant level. If it is below the minimum scale, add coolant. Check whether the belt of the pump is loose or broken, and whether the impeller of the pump is damaged.
2. ** Insufficient oil or oil radiator failure **
- ** Fault Description ** : Too little oil or oil radiator blockage will affect the lubrication and heat dissipation of the engine. The oil not only lubricates, but also helps cool the engine parts, and if the oil is insufficient or poorly dissipated, the engine temperature will rise.
- ** Inspection Method ** : Check the oil gauge to confirm whether the oil level is normal. If the oil level is normal but the engine is still overheating, you can check whether the oil radiator is blocked and whether the oil pipe is leaking.
3. ** Engine overload operation **
- ** Fault Description ** : Overload driving for a long time, climbing or running in a high temperature environment will make the engine load is too large, generate too much heat, resulting in overheating of the engine.
- ** Inspection method ** : Observe the operating status of the vehicle, if the vehicle often works in excess of its carrying capacity, or travels for a long time in hot weather, it is necessary to consider appropriate reduction of the load or increase the rest time to cool the engine.