The compressors usually fail due to a leak in the system requiring them to work too hard to keep the car suspended. I'm surprised that filling the system with nitrogen and simply shutting it off works..
The series-II systems were designed to be a sealed system, with the compressor pumping nitrogen to or from the storage tank as needed for the system to raise/lower the height and self-level. Air was only introduced to the system in the event of a leak - to make up for lost nitrogen. Usually the leaks are from the O ring assembly around the top of the front air-springs.
Have you completely disabled the valve system for the air-suspension? You might be able to program the vehicle so it thinks it doesn't have air-suspension if you have a Porsche capable diagnostics tool (Foxwell NT530, Porsche PIWIS, etc.)
BTW - when you replaced the original compressor - was the system flushed and filled with clean nitrogen?
The series-II systems were designed to be a sealed system, with the compressor pumping nitrogen to or from the storage tank as needed for the system to raise/lower the height and self-level. Air was only introduced to the system in the event of a leak - to make up for lost nitrogen. Usually the leaks are from the O ring assembly around the top of the front air-springs.
Have you completely disabled the valve system for the air-suspension? You might be able to program the vehicle so it thinks it doesn't have air-suspension if you have a Porsche capable diagnostics tool (Foxwell NT530, Porsche PIWIS, etc.)
BTW - when you replaced the original compressor - was the system flushed and filled with clean nitrogen?
