The investigation found that the faults of the engine in use were mainly caused by improper use and maintenance of the engine. Due to the low technical level or insufficient attention of some operators, they can not strictly implement relevant regulations and operating procedures when using construction machinery, and even adopt some wrong operation and maintenance methods, resulting in premature engine failure.
1. The new engine or the engine repaired to a great extent will not be run in
The cylinder liner, piston, piston ring, bearing bush and other parts were replaced after a new car or engine overhaul, and the loaded operation without sufficient running in resulted in early wear of parts, and some cylinder pulling and Bush burning.
2. The engine runs at high speed immediately after cold start
After the cold start of the engine, due to the cold state, high oil viscosity and large flow resistance, the time for the oil to enter the friction pair lags behind, and all parts of the engine are not fully lubricated, resulting in poor lubrication and damage of the engine gears and bearings, and aggravating the wear of the steam cylinder and bearing bush.
In particular, the turbocharged engine will cause the rotating shaft of the turbocharger to be ablated. Therefore, the supercharged engine should idle for a while after starting, and the speed can be increased only after the oil temperature rises, the fluidity improves and the supercharger is fully lubricated, which is more important in cold winter.
3. Sudden engine shutdown
Before the supercharged engine stops running, the load must be removed and the engine idles for a few minutes, and then shut down after the engine temperature drops.
4. The excavator engine uses inferior diesel
When using unqualified diesel, the cetane number does not meet the standard, resulting in poor engine combustion, carbon deposition and piston ring sintering. At the same time, inferior diesel also accelerates the wear of fuel injection pump plunger pair, outlet valve pair and fuel injection nozzle of fuel injector.
5. Incorrect use of engine oil
(1) The oil is only added and not changed
Due to the deterioration of engine oil, the due lubrication function will be lost, resulting in the running parts of diesel engine always running in a poor lubrication environment, accelerating its wear, and finally producing some faults. Therefore, when checking the oil quantity, we must carefully check the quality of the oil. If the oil deteriorates, we must replace the oil in time.
(2) Add more oil, but not less
In fact, too much oil will increase the rotation resistance of the engine crankshaft, which will not only increase the engine oil consumption, but also reduce the engine output power;
Make a large amount of engine oil rush into the combustion chamber and burn, resulting in blue smoke from exhaust and increased engine oil consumption; The carbon deposition in the combustion chamber is increased, the engine is easy to produce deflagration, and the wear of cylinder and piston is increased. Therefore, the engine oil should not be too little or too much. Generally, the oil level should be kept slightly lower than the upper limit of the dipstick.
6. The engine is overloaded for a long time
Some operators unilaterally pursue temporary economic benefits, resulting in long-term overload operation of the engine, resulting in early wear of engine parts.
