4.4.3. Repair of the engineIt 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.
Check oil pressure the manometer screwed to the place 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 repair pistons will be required. Connecting and radical rods of a bent shaft, and also a cover of basic necks of the camshaft 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 usually 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.
As the condition of the block of cylinders is the defining factor of making decision on its further repair or about purchase new (or repair) the block of cylinders, it is necessary to buy spare parts or to carry out operations on machining of the accompanying details only after careful check of its technical condition. Make it a rule that the true price of repair is time, – then it is not necessary to pay for installation of the worn-out or restored details.
In conclusion we will note that assembly of any 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.
At independent performance of capital repairs various options are possible. The decision on replacement of the block of cylinders, conrod and piston group and a bent shaft depends on a number of factors from which the most important is the condition of the block of cylinders. Other reasons are the repair cost, a possibility of access to the equipment of workshops of car service, existence of spare parts, time planned for work, and also personal experience.
If check shows that the block of cylinders and the majority of details are in satisfactory condition and can be used further, then the most expedient from the economic point of view is purchase of separate spare parts. The block of cylinders, conrod and piston group and a bent shaft should be surveyed especially carefully. Even if insignificant wear of the block of cylinders is found, cylinders are subject to an obligatory honingovaniye.
Block of cylinders of an incomplete complete set
The block of cylinders of an incomplete complete set contains the block of cylinders with installed by the krivoshipno-conrod mechanism and piston group. All interfaced details are picked up for dimensional groups, all gaps meet standards. On the block the camshafts which are not a part of this repair kit, the valvate mechanism, a head of the block of cylinders and hinged units are separately mounted. Costs of machining are minimum or are not required absolutely.
Repair engine (block of cylinders of a full complete set)
The repair engine delivered in the spare part contains all set of the block of cylinders of an incomplete complete set, and also the oil pump, the oil pallet, a head of the block of cylinders, a cover of a head of the block of cylinders, the camshaft, the valvate mechanism, camshaft drive gear wheels, a gear belt and casings of a belt. All details are established with new bearings, consolidations and laying. On a set only inlet and final collectors and hinged units are mounted.
Carefully think over what of alternatives best of all suits you, before purchase or before execution of the order for spare parts consult in a local workshop of car service, with suppliers of spare parts, and also with specialists in restoration of engines.