Leckage im Hochdruckölkreis

A leak in the high pressure oil circuit that actuates the injectors, so pressure the pump genuinely produces bleeds away before it does any work. It is the other half of the same diagnosis as a worn pump, and the pair is worth holding together because the codes cannot tell them apart — both report a pressure target not met.

The usual leak points are the injector seals themselves, since each injector is a joint in the circuit, and a single failed seal drops pressure for the whole rail. Standpipes, connectors, the reservoir and its cap follow. One bad injector seal disables the engine, which is why a no-start can come down to a component that is otherwise working.

A pressure decay test separates leak from pump and is the test to run first. Build pressure, stop, and watch how quickly it falls; a rapid bleed-down is a leak. Isolating which injector is leaking is the next step, usually by blocking the circuit in sections. Oil in unexpected places is the confirming evidence — under the valve cover, around an injector body, or a reservoir that empties — and it is worth looking for before any test equipment comes out.