Checking the compression in the cylinders (VW Transporter T3)

Compression testing allows you to draw conclusions about the condition of the engine. Namely, when checking, you can determine whether the valves and pistons are (piston rings) normal or worn out. In addition, the control measurements show whether the engine should be replaced or whether it should be completely overhauled. A compression pressure tester is required for the test, which must be designed specifically for a diesel engine. For a new engine, the compression pressure should be 34 bar. The wear limit is 28 bar. The pressure difference between the different cylinders can reach a maximum of 5 bar. If the pressure in one or more cylinders differs from the pressure in the other cylinders by more than 5 bar, this indicates a valve defect, worn piston rings or cylinder running surfaces.

Remove the wire from the switch on the fuel pump and insulate it.

Wash the intake manifolds with gasoline and remove them.

Unscrew all the nozzles, remove the thermal insulation.



(15-443) Screw in compression pressure tester instead of injectors.

Caution! Place old thermal insulation between the tester and the cylinder head.

To test compression pressure, the engine must be at operating temperature.

Run the engine at idle speed until the pressure stops increasing. Record the control pressure value, check all cylinders one by one.

Please note: The compression pressure values given are only valid for testing using the VW 1323 and 1381 testers.

(23-041) screw in the injectors.

Caution! Regularly replace the thermal insulation between the cylinder head and the injectors. The recess should face upwards, towards the head.

Screw in the inlet pipes and connect the wire to the switch.