Adding nitrogen is recommended by Porsche, but if system was air tight, your car would be lifted using regular air. Drawback of using regular air is that moisture in it will over time degrade compressor (drier will be used up and moisture will remain in system).

To me, based on my research, either your compressor is not pumping correctly, or there is another place in system where the air is escaping. Looking at your pic, looks like all wheels are down similar height. If it was one or two, wheels, I could suspect the individual shock, but all four - it would be coincidental for sure to see each of them be defective.
I would pour soapy water onto each shock's connection to metal air line, see if it bubbles.
Then, would do same on the valve block connections.
One thing I would try is to turn car off and on a few times, spaced by few minutes. I dont think the compressor is intended to inflate entire system from sea level 14.7 (1bar) psi to 249psi (17bar).
249 psi is the max pressure for the air suspension.
If you turn car off/on few times, if compressor is working OK, after few times you would have more and more pressure to lift.


If we assume your compressor is OK, the next item I would replace would be the valve block and make sure there is no leak at connection points to it. One thing that keeps me hesitant about the block is that it would usually be one of these release valves that would go bad (uneven suspension). your suspension seems evenly low at least on the two corners picture shows.

Then, if still not going up, then I think only other variable is the air accumulator (where compressed air is stored). However I would leave that as last option.


So, check each shock connection to air system (soapy water test).
Check valve block connections (same soapy water spraying).
Try turn on/off car few times.
If no leaks and car still on ground, I would do valve block, then entire compressor (block is about 115 bucks, full compressor rebuilt one is about 600, new one about 1 thousand).
Before going get parts if I were you, I would buy durametric cable and get free sw for it, then hook up to know what codes you are getting. Would not be a shot in the dark anymore.

Hope this helps.

Here is a pic of air suspension parts and locations.

Air suspension system

Air suspension system parts

 

How hard was removal of the compressor, and how difficult was it to disassemble & rebuild it?
Mine does not appear to be failing but seems to take longer than my cayenne to pump the suspension up. My suspicions are compressor not efficient - seals.

Thank you.

 

Hey sorry for the back and forth but where can i buy the durametric cable & find the software i see on ebay for 80 bucks is that it or can you send me direct links to cable & software thanks again and yes i know for a fact its not one of the struts as i never had a problem with one side not going up the compressor just kept running one day that i parked my car and i got the chasis failure light then it went off but the compressor stood on for a while that is what led me to opening the compressor to find out that piston is broken as picture shown so i tryed the rebuild kit and now the compressor is just running sounds like its straining to work and i was thinking maybe just go for a good condition used compressor or new but like you said if i had that " durametric " diagnosis that can help me out a lot so. and also messing with compressor was pretty easy to get out i just removed the rear splash under shield and take the compressor out pretty simple but without that durametric im lacking knowledge on whats going on with the car please reply back with the info of the durametric thanks..

 

No problem.

Durametric cable you buy will get attached to your car via its vin (I think it is the VIN). There is a chip on Durametric cable, where info will be burned once you connect and use the cable on a Porsche.

Durametric sells different cables, for different number of cars. I think there is cable for 1 car, 3 cars - enthusiast, and unlimited - professional.
Of course, the more cars allowed, the more expensive.
Also, Durametric cable can be purchased for other makes, so make sure you get one for Porsche.

Durametric website (software - free)
Durametric store - their enthusiast option 1 goes for $287.

Sample enthusiast ebay link with 2 VINs left on cable


You can also check the forum classifieds, folks often sell these after they get rid of cars.
Search for Durametric diagnostic porsche, or Durametric cable porsche and you will find it.


I am still trying to understand the function of all air suspension components. From what it looks like, each air shock connects to a line, which goes to valve block. Because of special tool needed, I think each line has Schrader valve in it, to prevent nitrogen from leaving.
Similarly, I think each shock connection has Schrader valve to keep nitrogen in it too, when the air line is disconnected.
Each air line goes to valve block. It is a small block that is controlled by the air suspension ECU.
The ECU tells valve block to open valves for each wheel, when you press button to lower the car.
When the block valves are opened for each tire, nitrogen from each shock is released (lowering car), and goes into the nitrogen accumulator (or tank) that is on your car.
There the gas sits until you press switch in cabin again, to raise your car.
Then, the compressor pump turns on, pumping air from the tank, into each air shock via the air lines.
I think the air pressure the pump builds in air lines, is more than what valves need to open, so when compressor is on, valves allow air to go into each shock, raising the car.


If I have my details correct, then having the car lowered on all 4 corners at once (overnight stay), would mean to me air was let out of shocks. It could either leak out of shocks (if leaky/defective), or could be forced back through the valve block back into the tank.
Curiously when I talked to dealer about the behavior of car lowering on its own sometimes overnight, dealer service person said the car is supposed to do that. It is only if it does not re inflate, that there is a problem. He told me not to worry until suspension cannot go up.

Thus, in your case, if pump is good, and shocks are good, defective valve block would explain leaked out air in all shocks.

If valve block was good, I would start suspecting the compressor pump again, especially if compressor goes on for a long time, or goes on very often.


One thing you may want to also check is the relay for the ECU, just to ensure this part is all right.
Hoping I am helping you in some way. Good luck, and stick with it. No matter what, you will get through this all, will look back and have some beerr/chuckles about it.

Update us.

 

 

If it is indeed the compressor that was not compressing air (to lift car), chances are after you plug in new one, you will see your car lifted.

Based on what I am learning about the air suspension system, the steel lines (at least at one end) have a valve to prevent nitrogen from leaving if disconnected (I base that on fact that you have to have an adapter to put more nitrogen into system, which has a schrader valve on it).
This means if you disconnected lined between valve block and compressor, those lines may have some air/moisture in them. However if its only a little, the dryer in the system can absorb the moisture.
If you can, get a new dryer for the compressor (round ball like shape with a substance removing moisture). Once installed you will have better protection for the compressor.

If compressor was only thing faulty (check for leaks per above with soapy water), you should be all set. Keep us updated.


Yes, tools like Durametric help 1000%.
Good luck.