Opel Astra, Zafira

Since 1998 of release

Repair and car operation

Opel Astra
+ Cars Opel Astra and Zafira
+ The operation manual
+ Routine maintenance
- The engine
   Check компрессионного pressure in cylinders
   Diagnostics of a condition of the engine with vacuum gauge application
   + Procedures of repair of petrol engines SOHC without their extraction from the car
   + Procedures of repair of petrol engines DOHC without their extraction from the car
   + Procedures of repair of diesel engines of 1.7 l and 2.0 l without their extraction from the car
   + The general and engine major repairs
+ Systems of cooling, heating
+ The power supply system and release
+ Engine electric equipment
+ Manual transmission
+ Automatic transmission
+ Coupling and power shafts
+ Brake system
+ Suspension bracket and steering
+ Body
+ Onboard electric equipment

Строительство и ремонт: https://dizidom.ru

Check компрессионного pressure in cylinders

Results of check компрессионного pressure in cylinders allow to define the general condition of components of the top part of the engine (pistons, piston rings, valves, linings of a head of cylinders, etc.) and qualitatively to estimate degree of their deterioration. That is especially important, the analysis of the information received as a result of check allows to narrow a spectrum of the possible reasons of falling of a compression in cylinders, precisely enough having adhered refusal to infringements of functioning of quite concrete components, whether it be piston rings, valves, their saddles or a head lining.

The engine should be heated-up to normal working temperature, and the storage battery is completely charged.


  1. Begin with procleaning of candle niches (blow their compressed air as which source in this case the ordinary bicycle pump perfectly will approach). The Primary goal is prevention of hit of dust in cylinders during performance of measurements.
  1. Dump pressure in the power supply system (see the Head of the Power supply system and release). Disconnect the power supply system by extraction from the assembly block of the relay of the fuel pump established in an impellent compartment.

On diesel engines release a latch and disconnect electroconducting from the block of management Fuel pump that will allow to avoid разбрызгивания some fuel and to eliminate risk of spontaneous start of the engine.

  1. Turn out from the engine all candles of ignition / накаливания (Routine maintenance see the Head). Fix throttle заслонку in completely open position.
  2. On the models equipped with the distributor of ignition, disconnect from a cover of the last central (a bobbin wire) and earth it on the engine block. On models without the distributor disconnect electroconducting from each of ignition coils.
  1. Establish компрессометр in a candle aperture of the first cylinder, — it is preferable to use to connection компрессометра a nozzle carving, instead of clamping type. Do not forget to open during check against the stop throttle заслонку.

    A — Check компрессионного pressure in the third cylinder of the petrol engine
    B — Check компрессионного pressure in the first cylinder of the diesel engine



In diesel engines compression degree it is ready above, than in petrol, therefore for check компрессионного pressure than 40 bar is required special компрессометр with a range of measurement not less. Компрессометр by the transitive nozzle it is rolled in a candle aperture накаливания, or it is established instead of an atomizer of injection of fuel. In view of features of a design of the atomizers used in diesel engines considered in the present Management, компрессометр it is necessary to roll in candle apertures.

  1. Turn the engine at least on seven steps and consider the measuring instrument indication. On the serviceable engine pressure should accrue quickly enough. Low pressure upon the first step, accompanied by its gradual increase on the subsequent, speaks about deterioration of piston rings. If at further проворачивании a shaft pressure does not rise, it can be regarded as the certificate of leaks of valves or infringement of tightness of a lining of a head of cylinders (the probability of presence of cracks in a head is not excluded also). The congestion of adjournment on working facets of plates of valves also can lead to decrease компрессионного pressure. Write down the maximum indication компрессометра.
  2. Repeat procedure for the remained cylinders of the engine. Compare results to standard requirements (Specifications see).
  3. At excessively low results of measurement fill in in each of cylinders through a candle aperture a little impellent oil (two-three teaspoons) and repeat check.

If oil addition leads to pressure increase, it speaks about deterioration of piston rings. If the compression does not increase, the reason of its decrease are leaks of valves or infringement of tightness of a lining of a head. Leaks of valves can be connected with a burn-out of their saddles, either deformation / by a burn-out or mechanical damages of working facets.

If pressure of compression is equally underestimated in two next cylinders with high degree of probability it is possible to speak about infringement of integrity of a lining of a head within its crosspiece between the given cylinders. Presence of a cooling liquid at impellent oil will confirm the given assumption.

If pressure in one of cylinders approximately on 20 % more low, than in other and it is accompanied by infringement of stability of turns of idling, it is necessary to estimate degree of deterioration of cams of a drive of corresponding valves on a camshaft.

Unusual overestimate компрессионного usually is a consequence of pressure excessive нагарообразования in combustion chambers. In this case the head of cylinders should be removed for the purpose of carrying out декарбонизации.

At excessively low results of measurements, and also in case of infringement of uniformity of distribution of pressure between cylinders it will be useful to hold testing of the engine for leaks in the conditions of a car-care centre workshop. Such check will allow to define precisely a source of leak and to estimate degree of its gravity.

Block check on leaks

During the given check are defined speed of an exit from cylinders закачанного in them of the compressed air and it is direct places of leaks. The given check is alternative to compression check. Moreover, from many points of view, it is much more effective as visually to reveal a source of leak easier, than to comprehend results of measurement of a compression.

The equipment necessary for check on leaks, is not among popular, therefore performance of the given check should be entrusted experts of the service centre.