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Check compression in the cylinders of the engine

Check compression (pressure at the end of the compression stroke) in cylinders of the engine is carried compressometer (Fig. 4). Before measurement, check the correct valve clearances and, if necessary, adjust them. Then the engine heated to the temperature of the coolant (60-80 * C) turn out all the spark plugs and the air is completely open and the throttle valve. After this, insert the rubber Tip 6 compressometer the hole plugs of the first cylinder, tightly to the edge of tip openings and bore Crank the engine starteromdo until the pressure in the cylinder will not cease to grow. To obtain prravilnyh testimony compressometer engine crankshaft to rotate with a frequency of 180-200 1 \ min or more but noxtexceeding 350 1 \ min. The battery must be fully charged. But shall be allowed a temporary increase in voltage at the terminals starter connecting an external source of direct current. Writing the value of the maximum davleniyagazov in the cylinder, release air from compressometer by removing 1-2 turnover cap nut 3; Gradual return of the arrows to zero again tighten the nut. Moskvich-412 In the same way the compression test, alternately in the other the cylinders. The pressure must be not less than 10 kg \ cm2 and should not be differ in different cylinders for more than 1 kg \ cm2. The reduced compression in some cylinders may occur in result of leaky valves, landing in the saddle, pad damage cylinder heads, broken, or stick piston rings. To clarify the reasons for the lack of compression pour 20-25 cm3 clean oil into the cylinder with low compression and it is measured again. Higher rates compressometer in this case often indicate failure of piston rings. If the magnitude of compression remains unchanged, this indicates by gapping the valves to their heads or saddles damage to the cylinder head gasket. The reason for the lack of compression can be detected and fed compressed air in the cylinder in which piston is placed in a pre- position of top dead center (TDC) clock of compression. To this end, removing the rubber cone compressometer tip and attach the hose compressometer, insert the tip of a candle in the hole of the cylinder and is fed into it air at a pressure of 2-3 kg \ cm2. In order to prevent cranking the engine include a higher transmission in the transmission and inhibit the vehicle parking brake the system. The output (drain) of air through the carburetor indicates inlet valve leaks, and through muffler - about leaks the exhaust valve. If the damage cylinder head gasket Air bubbles will come out through the neck of a radiator or in adjacent cylinder, which is detected by the characteristic hissing the sound.
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