Before checking, start and warm the engine to the optimal operating temperature, and recharge the battery (if necessary). After making sure that these conditions are met, unscrew all the spark plugs and fix the throttle in a completely open position. Then turn off the central armored vehicle from the ignition distributor and ground it to the cylinder block (to ensure reliable grounding, use the transition wire with clips of the crocodile type, on cars equipped with a injection system, the fuel pump circuit should also be turned off).Disconnect the power nozzle of a cold start (if it is installed). Having installed a compressometer in the candle shaft, turn the crankshaft of the engine at least seven compressions and look at the indicator (if the engine is in good condition, then the compression should grow quickly). Insufficient compression pressure on the first cycle with a gradual increase in subsequent cycles indicates the wear of the piston rings. The low compression values on the first cycle, which does not increase on subsequent cycles, indicates the leakage of the valves or the burning of the cylinder head (there may also cracks in the cylinder head). Foreths on the inside of the cylinder head can also cause a decrease in compression.
Now, having recorded the greatest indication of the compressometer, repeat the same manipulations with other cylinders.
Pour a little motor oil through the candle hole of each cylinder and repeat the check (if the compression increased after filling the oil, then it’s time to replace the piston rings, if the compression has not increased significantly, then there is a leak in the valves or through the head laying of the head). In the case when two neighboring cylinders have the equally low “compression”, there is a high probability that the head laying of the head is broken between them. This can be checked by the presence of coolant in combustion chambers or in a crankcase. If the “compression” in one cylinder is no less than in the others, and the motor is idly operating, then the cause of the fist of the distribution valve distribution shaft can be the reason, or the burning of the valve saddle. Когда “компрессия” чрезмерно высокая, то, возможно, камеры сгорания покрыты нагаром. In this case, it is necessary to dismantle the head of the block and remove the cargo.
After checking the compression pressure, set all the parts in the reverse order.