Audi 100/A6

1990-1997 of release

Repair and car operation

Audi 100/A6
+ 1. Maintenance instruction
+ 2. Maintenance
+ 3. Engines
+ 3.2. Diesel engines
- 3.3. Removal and partition of engines
   + 3.3.2. Technical characteristics
   3.3.3. Repair work, possible without engine dismantle
   - 3.3.4. Major maintenance Alternatives Engine dismantle Sequence of dismantling
   3.3.5. Removal and engine installation
   3.3.6. Engine partition
   + 3.3.7. Head of cylinders
   3.3.8. Pistons and rods
   + 3.3.9. Cranked shaft
   3.3.10. Intermediate shaft
   3.3.11. 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. Exhaust system
+ 8. Systems of start, ignition
+ 9. Transmission
+ 10. Brake system
+ 11. Suspension brackets, steering
+ 12. Body
+ 13. Electric equipment
+ 14. Good advice


3.3.4. Major maintenance General comments


It is not always easy to come to a conclusion about expediency of major maintenance of the engine as it is necessary to be based on a number of indicators.

Big run is not a sufficient indicator of need of carrying out major maintenance, on the other hand, small run does not exclude major maintenance. The most important indicator most likely is timeliness of the current maintenance 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 kilometers of run. On the contrary, insufficient service can be at the bottom of sharp reduction of a resource. The raised consumption of oil indicates wear of piston rings or directing plugs of valves. It is necessary to be convinced that leaks are not at the bottom of the raised consumption of oil, and only after that to draw a conclusion about unfitness of piston rings and directing plugs. To define volume of the forthcoming works, carry out compression measurement in cylinders, or check tightness of the chamber of combustion for what it is recommended to address to the skilled expert.

If at operation of the engine the increased noise, or knocks is listened, wear of shatunny or radical loose leaves can be their probable cause.

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

Capacity loss, "failures" in operation of the engine, the increased noise from the gas-distributing mechanism, indicate the increased fuel consumption need of carrying out major maintenance, especially, if all these factors are shown at the same time. If performance of all adjustments does not lead to improvement, the most expedient means of elimination is repair.

Major maintenance consists in restoration of details of the engine to a condition specified in specifications for the new engine. At carrying out major maintenance 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. Shatunnye and radical loose leaves also are subject to replacement, if necessary the cranked shaft follows прошлифовать before restoration of gaps with shatunny and radical loose leaves. As a rule, the klapanny mechanism does not change, as its condition at the moment of repair quite the usually satisfactory. During major maintenance of the engine repair of such units as the carburetor, 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 maintenance of the engine familiarize with the description of the corresponding procedures that there was an impression of the forthcoming amount of works and requirements to them. Major maintenance is simple, however demands big expenses of time. Roughly not less than two weeks, especially are required if for repair and restoration of details (polishing, boring) it is necessary to address in a specialized workshop. Check existence 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 tool kit though exact measuring devices will be necessary for check and determination of suitability of these or those details. Often check of a condition of details carry out in specialized workshops in which receive recommendations about replacement or restoration of details.


To address in workshops of car-care center follows only after complete 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 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 worn-out or repair details.

In summary we will note that assembly of any units should be carried out with all care in a pure room to avoid further failures of the repaired engine.