3.2.2. Check of pressure of compression

The size of pressure of compression shows, in most cases, the tsilindro-piston group of the engine is how worn-out.

For measurement of pressure of compression it is necessary компрессометр for diesel engines with the maximum indications not less than 30 bars.

1. Completely charge the accumulator. Adjust gaps of valves. Warm up the engine up to the working temperature. Unscrew all nozzles.
2. Power off candles of an incandescence and the socket of the electromagnetic valve of supply of fuel. On engines 2.1 liters remove the relay of system of injection of fuel located in the ECU block.
3. In a nest of a nozzle screw in transitional the union of a kompressometr. Turn a bent shaft a starter several times. Record the maximum value of pressure of compression.
4. Repeat measurements on other three cylinders.
5. Compression pressure in all cylinders should not differ more than on two units. Pay attention that the size of compression has to increase quickly on the serviceable engine; the low pressure of compression on the first turn of the crankshaft accompanied with gradual increase in pressure on the subsequent turns of the crankshaft indicates wear of piston rings. The low size of pressure on the first turn of the crankshaft 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 the low pressure of compression also.
6. If pressure 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 compression pressure. If filling of oil in the cylinder increases compression pressure, it specifies that the cylinder or piston rings is worn-out.
7. Low pressure in two next cylinders indicates a laying burn-out between cylinders.
8. If pressure in one cylinder is 20% less, than in the others, and the engine idles unstably, it indicates a worn-out cam of a cam-shaft.
9. If pressure of compression is too high, it indicates that the combustion chamber is covered with a thick layer of a deposit.