Cylinder compression check

The compression value shows, in most cases, how worn out the cylinder-piston group of the engine.

To measure compression, a compression gauge for diesel engines with a maximum reading of at least 30 bar is required.

Compression measurement

1. Fully charge the battery. Adjust valve clearances. Warm up the engine to operating temperature.

2. Disconnect the glow plug power and the fuel solenoid valve connector.

3. Remove one of the glow plugs and screw the adapter of the compression gauge into the plug socket. Turn the crankshaft with the starter several times. Record the maximum compression pressure.

4. Repeat measurements on the remaining three cylinders.

A decrease in compression in all cylinders most often indicates wear on the cylinders, rings and pistons.

Low compression in one of the cylinders means damage to the plates and valve seats, burning or cracks in the piston, damage to the cylinder head gasket or cracks in the cylinder head.

Low compression in two adjacent cylinders most often means damage to the cylinder head gasket between the cylinders.