The general information and diagnostic operations for definition of a condition of the engine are provided in this subsection.
It is not always easy to come to a conclusion about expediency of complete capital repairs of the engine as it is necessary to be based on a number of objective indicators.
The big run is not a sufficient indicator of need of carrying out capital repairs, on the other hand, the small run does not exclude need of carrying out capital repairs. The most important indicator, most likely, is timeliness of the current maintenance of the engine. At timely change of oil and the filter, and also when performing all other necessary works on service the engine serves reliably throughout many thousands of kilometers of a run. On the contrary, insufficient on volume or untimely maintenance can be the reason of sharp reduction of a resource of the engine.
The raised consumption of oil indicates wear of piston rings, the directing plugs of valves and maslootrazhatelny caps. It is necessary to be convinced that leaks are not the reason of the raised oil consumption, and only after that to draw a conclusion about unfitness of piston rings and the directing plugs of valves. to define a probable cause of malfunction, measure a compression in engine cylinders. Carry out also tests by means of the vacuum gage and define character of indications of this device.
Check oil pressure the manometer screwed instead of the oil pressure sensor, and compare result of check to standard value. If oil pressure low, then can be the cause wear of radical and conrod bearings or details of the oil pump.
Loss of power, failures in operation of the engine, a detonation or metal knocks, the increased noise from the gas-distributing mechanism, the increased fuel consumption indicate the need carrying out capital repairs, especially, if all these signs of abnormal work are shown at the same time. If performance of all adjustments does not lead to improvement, then the only means of elimination of abnormal operation of the engine are capital repairs. Capital repairs consist in restoration of details of the engine to the state specified in specifications for the new engine.
When carrying out capital repairs pistons and piston rings are replaced, cylinders are chiseled or honingutsya. After repair of cylinders which is carried out in a specialized workshop installation of pistons of the repair sizes will be required. Connecting and radical rods of a bent shaft, and also a cover of basic necks of camshafts are also subject to replacement, if necessary it is necessary to proshlifovat necks of a bent shaft before restoration of normal gaps with connecting and radical rods. As a rule, also valves as their state at the time of repair, as a rule, not absolutely satisfactory are subject to repair.
During capital repairs of the engine repair of such units as a starter, the generator and the distributor of ignition is also carried out. As a result the repaired engine has to have qualities of the new unit and sustain a considerable run without refusals.
At capital repairs it is necessary to replace such important details of the cooling system as hoses, drive belts,
and the pump of cooling liquid. The radiator should be surveyed on tightness and purity of internal channels. If you bought the restored engine, or the block of cylinders of an incomplete complete set, then some suppliers do not give a guarantee for operation of these units without high-quality washing of a radiator. At capital repairs of the engine it is also recommended to replace the oil pump.
Before capital repairs of the engine study the description of the corresponding procedures that there was an impression of the forthcoming amount of works and requirements to them. At respect for all norms and rules, in the presence of all necessary tools and devices it is simple to execute capital repairs, however considerable costs of time will be involved. Approximately not less than two weeks, especially are required if for repair and restoration of details it is necessary to address in a specialized workshop. Check existence of spare parts and in advance think of acquisition of necessary special tools and the equipment. Almost all works can be performed by means of standard tool kit though more precision measuring instruments will be necessary for check and definition of suitability of these or those details. Often check of a condition of details is carried out in specialized workshops in which also receive recommendations about replacement or restoration of these or those details.
It should be noted that assembly of units should be carried out with all care in the pure room to avoid further failures of the repaired engine and to ensure its reliable functioning.