Compression test: General

Fig 1: Testing Compression With Engine At Operating Temperature

Courtesy of VOLVO CARS OF NORTH AMERICA.

WARNING: The ignition system works with high ignition tension and dangerous voltage in both the low and high tension circuits. There are dangerous voltages throughout the entire ignition system including the connectors.

Test the compression with the engine at operating temperature and with wide open throttle (WOT)

The normal value for B4xx4Sx is 1.3-1.5 MPa .

The normal value for B4xx4Tx is 1.1-1.3 MPa .

The maximum difference between the cylinders must not exceed 0.2 MPa .

NOTE: Applies to engines at operating temperature, wide open throttle (WOT) and starter motor turning at 4.2 - 5.0 r/s (250 - 300 rpm).