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Compression check in engine cylinders
Using a tester for measuring the compression pressure in the cylinders of a compression test, the diesel engine
By the engine status can be performed by measurement of the compression pressure in the cylinders of the engine. If this check to make regularly it is possible to know in advance the beginning of deterioration of the engine, without waiting for the moment when the engine wear manifested in the low efficiency of the engine. Warm up the engine to operating temperature. At the same time the battery must be fully charged. Remove all spark plugs.
Engines 1,6-I
Disconnect the electrical connector from the ignition coil.
Five-cylinder engine
Remove the air pipe located between the air filter and air intake, which loosen the clamps and remove the electrical connector from the air flow meter. Remove the air inlet with the crankcase ventilation valve.
Five- and six-cylinder engines
Disconnect the electrical connector from the ignition control unit. The control unit is in the ignition elec Coy circuit between the control and the ignition coil.
Six-cylinder engines
Disconnect all electrical connectors from the fuel injectors or remove the fuse number 28, mounted in the supply circuit of the fuel pump. Turn neutral and tighten a manual brake. In the spark plug hole of the first cylinder set Compression pressure tester or compression. The assistant should press the accelerator pedal all the way and turn the engine a starter. After cranking for one or two turns of the compression pressure should be increased to the maximum, and then stabilize. Record the maximum result. Similarly check up a compression in other cylinders. The pressure of compression in all cylinders of gasoline engines should not differ by more than 3.0 bar, and a diesel engine - 5.0 bar. Please note that the amount of compression is to increase quickly on the serviceable engine. Low compression pressure on the first revolution of the crankshaft, accompanied by a gradual increase in pressure on the subsequent turns of the crankshaft indicating the wear of the piston rings. Low pressure value on the first rotation of the crankshaft, which slightly increases further, indicating gapping valves, punched cylinder head gasket or the presence of cracks in the cylinder head. Wear of the valve stem ends may also lead to low compression pressure. If the pressure in one cylinder low, then perform the following test. Pour through the spark plug hole into the cylinder little engine oil and check the compression pressure. When filling oil into the cylinder increases the compression pressure, it indicates that the cylinder or worn piston ring. Low pressure in the two adjacent cylinders indicates lining burn between cylinders. If the pressure in one cylinder is smaller by 20% than the other, and the engine is unstable idling, this indicates a worn camshaft lobe. If the compression pressure is too high, it indicates that the combustion chamber is covered with a thick layer of fouling. After this test, screw the spark plug. Connect the electrical connector to the control unit ignition coil. On the six-cylinder engine, connect the connectors to the fuel injectors or install a fuse in the circuit of the fuel pump.
Five-cylinder engine
Replace the air pipe and fix it with clamps. Connect the electrical connector to the air flow meter.
A warning  After disconnecting the electrical connections of the ignition system and fuel injection control device in electronic engine management recorded a fault. It is recommended that at the first opportunity to erase recorded in the memory of the fault in a specialized workshop "Volkswagen".
Diesel engine
Disconnect the electrical connector from the valve stopping the engine. Disconnect the electrical connector from the meter on the fuel pump. Remove all spark plugs. Instead of glow plugs screw tester measuring compression pressure hose with a flexible transition, see. Fig. Using the compression tester pressure measurement to check the compression in the cylinders of the diesel engine. Rotate the crankshaft of the engine starter as long as the pressure stabilizes, fixed measuring device. Make a note of the result. Similarly check up a compression in other cylinders. Screw in glow plug, having tightened their moment of 15 Nm and connect to candles bus voltage supply. Connect all previously removed the electrical connectors.
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