During turbocharging, both the exhaust system and the air intake system perform very important tasks. This means it is important that both systems have no leaks.
For this reason, very close attention is to be paid during all assembly and repair work to ensuring that all the connections are correct and that all line connections are leak-tight.
The >diagnosis unit overpressure / partial vacuum< (81 29 0 426 464) must be used to carry out a leak test before repairs on the turbo system. However, the diagnosis unit should also be used after assembly work for a leak test of all components.
Note:
During the leak test, the applied overpressure can lead to low quantities of engine oil from the intake system entering the combustion chamber and being pressed onto the piston base. This means that when the engine is started intense smoking from the exhaust system can occur for several minutes. However, no engine damage has occurred. After a leak test, the engine is therefore always to be started using an extraction unit!
The turbocharger check consists essentially of the following parts:
In the event of complaints regarding engine output, in all cases the test 120004 lack of power should be carried out in the fault profile selection.