Measuring compression pressure (VW Golf 3)

Measuring the compression in the engine cylinders will answer the question of whether the valves and piston rings are still sealing well. This primarily affects the ease of starting a cold engine, as well as the power, oil and fuel consumption, and engine smoke. We will also receive good information about the mechanical condition of the diesel engine from the compression diagram. We warn you right away: purchasing a compression tester for a diesel engine is problematic due to the high price. However, you can borrow this device (Volkswagen workshops use the VW 1381 device together with the VW 1232 adapter) or purchase it together with another owner of a car with a diesel engine.

The measurements are carried out as follows:

The engine must be warmed up to operating temperature.
Remove the wire on the fuel injection pump switch and insulate it (see section "Diesel injection system").
Remove the fuel supply pipes to the injectors from the high-pressure fuel pump and place them on a clean cloth.
Remove all injectors.
Remove the heat-insulating gaskets from the injector holes.
Screw the device with the adapter into the hole for the injector of the first cylinder; place an old thermal insulation pad inside the cylinder to be measured.
Apply the handbrake, set the gearshift lever to neutral or set the automatic transmission lever to position "P".
Turn on the starter and do not turn it off until the instrument readings increase.