Audi 100/A6

1990-1997 of release

Repair and car operation

Audi 100/A6
+ 1. The maintenance instruction
+ 2. Maintenance service
+ 3. Engines
+ 3.2. Diesel engines
- 3.3. Removal and a partition of engines
   + 3.3.2. Technical characteristics
   3.3.3. Repair work, possible without engine dismantle
   - 3.3.4. Major repairs Alternatives Engine dismantle Sequence of dismantling
   3.3.5. Removal and engine installation
   3.3.6. An engine partition
   + 3.3.7. A head of cylinders
   3.3.8. Pistons and rods
   + 3.3.9. A cranked shaft
   3.3.10. An intermediate shaft
   3.3.11. The block of cylinders
   3.3.12. Radical bearings and bearings of rods
   3.3.13. Piston rings
   3.3.14. The first start of the engine after a partition
+ 4. Cooling system
+ 5. Heating and ventilation
+ 6. Fuel system
+ 7. An exhaust system
+ 8. Systems of start, ignition
+ 9. Transmission
+ 10. Brake system
+ 11. Suspension brackets, a steering
+ 12. A body
+ 13. An electric equipment
+ 14. A good advice


3.3.4. Major repairs Broad-brush observations

It is not always easy to come to a conclusion about expediency of 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 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 service can be at the bottom of sharp reduction of a resource. The raised expense of oil specifies in deterioration of piston rings 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 volume of forthcoming works, spend compression measurement in cylinders, or check up tightness of the chamber of combustion for what it is recommended to address to the skilled expert.

If at engine work the raised noise, or knocks deterioration шатунных or radical loose leaves can be their plausible reason is listened.

Turn out the regular gauge and measure pressure of oil by a manometre, compare the received value with specified in a management. If pressure low deterioration of basic bearings or the oil pump can be the reason.

Capacity loss, "failures" in the engine work, 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 factors are shown simultaneously. If performance of all adjustments does not lead to improvement the most expedient means of elimination is repair.

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 piston rings are replaced, and walls of cylinders are chiseled till the repair size (or хоннингуются).

After repair of cylinders installation of new pistons is required. Шатунные and radical loose leaves also are subject to replacement, if necessary the cranked shaft follows прошлифовать before restoration of backlashes with шатунными and radical loose leaves. As a rule, клапанный the mechanism does not vary, as its condition at the moment of repair quite as a rule the satisfactory. During engine major repairs repair of such units as the carburettor, the ignition distributor, a starter and the generator also is carried out. As a result the engine should possess qualities of almost new unit and smoothly serve long time.

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. Major repairs are simple, however demand the big expenses of time. Roughly it is required not less than two weeks, especially if for repair and restoration of details (polishing, расточки) 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 receive recommendations about replacement or restoration of details.

The prevention

To address in car-care centre workshops follows only after full dismantling of the engine and check of all details, especially the block of cylinders 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 details follows 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 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.