4.1.2. Check of a compression

Check of a condition of the engine can be made by measurement of a compression in engine cylinders. If to make this check regularly, then it is possible to learn the beginning of wear of the engine in advance, without waiting for the moment when wear is shown in low overall performance of the engine.

1. Warm up the engine up to the working temperature. At the same time the accumulator has to be completely charged. Unscrew spark plugs.
2. Disconnect system of ignition for what disconnect the central high-voltage wire from an ignition distributor cover and ground it.
3. In an opening of a candle of the first cylinder establish компрессометр. The assistant has to press an accelerator pedal against the stop and turn the engine a starter. After a provorachivaniye of a bent shaft by one or two turns pressure of compression has to increase to a maximum, and then be stabilized. Make record of the maximum received result.
4. Similarly check a compression in other cylinders. The compression in all cylinders should not differ more, than on 1,0 bars. Pay attention that the size of a compression has to increase quickly on the serviceable engine. The low compression on the first turn of a bent shaft accompanied with gradual increase in pressure on the subsequent turns of a bent shaft indicates wear of piston rings.
5. The low compression on the first turn of a bent shaft which slightly increases further indicates a thinness of a prileganiye of valves, the punched laying of a head of the block of cylinders or existence of a crack in a head of the block of cylinders. Wear of the ends of cores of valves can lead to a low compression also.
6. If a compression in one cylinder lowered, then carry out the following test. Fill in through a candle opening in the cylinder of a little engine oil and check a compression.
7. If filling of oil in the cylinder increases a compression, it specifies that the cylinder or piston rings is worn-out.
8. The low compression in two next cylinders indicates a laying burn-out between cylinders.
9. If the compression in one cylinder is 20% less, than in the others, and the engine idles unstably, it indicates a worn-out cam of the camshaft.
10. If pressure of compression is too high, it indicates that the combustion chamber is covered with a thick layer of a deposit.
11. After this check screw in spark plugs and connect a wire to the ignition coil.