18.104.22.168. Engine major repairs
It is not always easy to come to a conclusion about expediency of full major repairs of the engine as it is necessary to be based on variety of indicators.
The big run is not a sufficient indicator of necessity of carrying out of major repairs, on the other hand, small run does not exclude necessity of carrying out of major repairs. The most important indicator most likely is timeliness of current maintenance service of the engine. At timely change of oil and the air filter, and also at performance of all other necessary works on service, the engine serves reliably throughout many thousand kilometres of run. On the contrary, insufficient on volume or untimely maintenance service can be at the bottom of sharp reduction of a resource of the engine.
The raised expense of oil specifies in deterioration of piston rings, маслосъемных caps and (or) directing plugs of valves. It is necessary to be convinced that leaks are not at the bottom of the raised expense of oil, and only after that to do a conclusion about unfitness of piston rings and directing plugs. To define a malfunction plausible reason, measure a compression in engine cylinders.
Check up pressure of oil a manometre screwed to the place of the contact gauge of emergency pressure of oil and compare result of check to standard value. If pressure of oil low deterioration radical and шатунных bearings and (or) details of the oil pump can be the reason.
Capacity loss, "failures" in engine work, a detonation or the metal knocks, the raised noise from газораспределительного the mechanism, specify the raised expense of fuel in necessity of carrying out of major repairs, especially, if all these signs of abnormal work are shown simultaneously. If performance of all adjustments does not lead to improvement unique means of elimination is repair with replacement or restoration of details.
Major repairs consist in restoration of details of the engine to a condition specified in specifications for the new engine. At major repairs carrying out pistons and piston rings are replaced. Шатунные and radical loose leaves also are subject to replacement, and repolishing of a cranked shaft before restoration of standard backlashes in radical and шатунных necks with radical and шатунными loose leaves is if necessary carried out. As a rule, valves, as their condition at the moment of repair as a rule not absolutely satisfactory are subject to repair also. During engine major repairs repair of such units as the ignition distributor, a starter and the generator also is carried out. As a result repaired engine should possess qualities of almost new unit and sustain considerable run without refusals.
At major repairs it is necessary to replace such important details of system of cooling as hoses, the thermostat and the pump of a cooling liquid. The radiator should be surveyed carefully on tightness and cleanliness of internal channels. At engine major repairs also it is necessary to replace and the oil pump.
Before the beginning of major repairs of the engine familiarise with the description of corresponding procedures that there was an impression of forthcoming amount of works and requirements to them. At observance of all norms and rules, in the presence of all necessary tools and adaptations, and also at performance of all technical requirements major repairs to execute simply, considerable expenses of time however be required. Roughly it is required not less than two weeks, especially if for repair or restoration of details it is necessary to address in a specialised workshop. Check up presence of spare parts and in advance take care of acquisition of necessary special tools and the equipment. Almost all works can be executed by means of a standard tooling though exact measuring devices will be necessary for check and definition of suitability of those or other details. Frequently check of a condition of details carry out in specialised workshops in which also receive recommendations about replacement or restoration of those or other details.
To address in car-care centre workshops follows only after full dismantling of the engine and check of a condition of all details, especially the block of cylinders and коленвала to solve which operations on service and repair will be carried out in workshops. As the condition of the block of cylinders is the defining factor of decision-making on its further repair or about purchase of the new repair block of cylinders to buy spare parts or to perform operations on machining of accompanying details follows only after careful check of its technical condition. Make it a rule that it is not necessary to accept hasty unreasonable decisions, – otherwise repair can cost dearer because of installation of the worn out or repair details.
In summary we will notice that assemblage of any units should be carried out with all carefulness in a pure premise to avoid the further refusals of the repaired engine and to provide its reliable work.