An engine in great condition should generally show only 5 to 10% leakage. An engine that's still in pretty good condition may show up to 20% leakage. But more than 30% leakage indicates trouble.

Hello there how are you? I've talking to Mark and other guys about my hydro lock issue at the dealership. Do you by any chance know what the numbers are supposed to come back as on a leak down on a '83 928S? They want to test it with me present. I'll bring a mechanic as well with me but I need to know those numbers for myself.