Skoda Felicia

1. At a working order of shatunno-piston group the engine works silently, and on single turns pressure of oil in lubricant system does not fall below an admissible limit.
2. Knock of pistons arises during the moments of blows from about walls of sleeves of cylinders owing to too free landing. Люфт pistons it is shown in the form of bumps and it is shown mainly at increase of loadings on the engine, or in an operating time of the cold engine on single turns. Intensity of knock in process of an engine warming up can decrease, up to a total disappearance.
3. Knock of piston fingers arises also owing to excessive easing of their landing and is clearly distinguishable on hearing, usually in the form of a dual metal clang at the heated-up engine working on single turns. The most simple way of revealing of a faulty finger is serial switching-off of spark plugs at the working engine - after switching-off of the faulty cylinder knock disappears.
4. Knocks of bearings of a cranked shaft are shown in the form of the strong metal blows which intensity increases with increase in turns.

1. At decrease in efficiency of return of the engine, and also in case of occurrence of admissions of ignition which do not manage to be adhered to infringements of functioning of systems of ignition and a food, it is necessary to make measurement компрессионного pressure in the cylinders which analysis of results will allow to define the general condition of the engine. Regular performance of check компрессионного pressure will help to reveal in time symptoms of malfunctions and to prevent development of their reasons.
2. The engine should be heated-up to normal working temperature, the battery is completely charged, all spark plugs are unscrewed (Routine maintenance) see the Head. The help of the assistant is required also.
3. Disconnect ignition system, having disconnected ВВ a wire of the coil of ignition from a cover of the distributor and having earthed it on the block of cylinders (take advantage of a wire-crosspiece). On models without the ignition distributor disunite an electric socket on the block of the coil of ignition in a forward part of a head of cylinders.
4. In order to avoid damage каталитического the converter dump pressure in system of injection and disconnect the power supply system, having taken out the relay of the fuel pump (the Power supply system see the Head).
5. Connect компрессометр to a candle aperture of 1st cylinder (preferably to use a measuring instrument with a carving tip).
6. Ask the assistant to squeeze out against the stop a pedal of an accelerator and to turn the engine a starter. After first two проворачиваний a cranked shaft the instrument reading should reach the maximum value. Write down result.
7. Repeat measurement for the remained cylinders, write down results.
8. Pressure in all cylinders should be almost identical in limits from 11 to 15 bar. In the indications, 1.5 bar exceeding value, it is necessary to consider a difference as an infringement sign. Lowering компрессионного pressure more low 10 bar is inadmissible also.
9. Remember that pressure in the serviceable engine should rise quickly enough. The low indication on the first step with its gradual increase at the subsequent, speaks about deterioration of piston rings.
10. If pressure does not rise at all, it is necessary to check up tightness of closing of valves and a condition of a lining of a head of cylinders (the probability of formation of cracks in a head is not excluded also). The congestion of adjournment on the bottom surfaces of plates of valves also can cause loss компрессионного pressure.
11. If results of measurements appear below admissible value, it is necessary to try to define the reason of loss of pressure. Bare of checks is injection through a candle aperture in the corresponding cylinder about one teaspoon of lubricating oil with the subsequent repetition of measurement компрессионного pressure.
12. If right after additions in the cylinder of oil pressure of compression is temporarily restored, it is necessary to estimate degree of deterioration of pistons, walls of cylinders and piston rings. Otherwise, it is possible to tell about infringement of tightness of closing of valves (for example, as a result прогара) or damage of a lining of a head of cylinders (or actually heads).
13. Equally low pressure in two next cylinders with the big degree of probability testifies to damage of the crosspiece of a lining of a head of cylinders located between them. Presence of a cooling liquid in impellent oil will confirm the given assumption.
14. If pressure in one of cylinders approximately on 20 % more low, than in the others, and stability of turns of idling of the engine is slightly broken, the reason of the given phenomenon deterioration of a working ledge of a corresponding cam of a camshaft can be.
15. Excessively high компрессионное pressure testifies about strong нагарообразовании in combustion chambers. In this case it is necessary to remove and subject a head декарбонизации.
16. In summary, screw candles, establish to the place of the relay of the fuel pump and instal ignition system.