Fastening the current bus to the glow plugs
The compression value shows, in most cases, how worn the engine's cylinder-piston group is.
To measure compression, a compression tester for diesel engines with a maximum reading of at least 40 bar is required. On a new engine, the compression pressure should be 34 bar, the minimum permissible pressure is 28 bar. The difference in compression of individual cylinders should not exceed 5 bar.
1. Fully charge the battery. Adjust the valve clearances. Warm up the engine to operating temperature.
2. Disconnect the power supply to the glow plugs and the connector of the fuel supply solenoid valve (indicated by the arrow).
3. Remove the glow plugs and screw the compression gauge adapter into the socket of one glow plug. Turn the crankshaft with the starter several times. Record the maximum compression pressure value.
4. Repeat measurements on the remaining three cylinders.
5. A decrease in compression in all cylinders most often indicates wear of the cylinders, rings and pistons.
6. Low compression in one of the cylinders means damage to the valve plates and seats, burnout or cracks in the piston, damage to the cylinder head gasket or cracks in the cylinder head.
7. Low compression in two adjacent cylinders most often means damage to the cylinder head gasket between the cylinders.