original_meatwad

I ended up with a 958 with factory steel suspension, but I've owned several BMW, Mercedes, RR etc. with air and worked on dozens. I can say that, as a rule, you should insist on the simplest, cheapest fault being the cause until absolutely proven otherwise. Even the dealers will fail at this because most will hire anybody off the street and they will start with a scanner that gives them a laundry list of "possible" faults. The thing to do is start with a CALIBRATION. Investing in a dedicated scanner that can calibrate will save you tens of thousands of dollars if you ever own a German car out of warranty. This calibration will show you air pressures, temperatures and heights in real time and can turn a 3 month nightmare in a 3 minute dawdle.

Er, so for the poor souls up to their necks in parts at the moment, it's a bit too late, but the rest of you: Do not take anything apart until you have found a scan unit in your price range that will perform a full calibration. Then armed with the location of the offending component, you can inspect for cracks, listen with a bit of hose in your ear or flick the sensor, etc. As some have noted, you can't use a VW compressor, because Porsche uses a different network protocol for the electronic bits, but you CAN use an ebay compressor rebuild kit intended for the VW or Audi.

*It's not going to be things like valve blocks unless there has been extensive use in highly corrosive environments and/or severe neglect.

If you are going to get this deep into it, I'd have an air compressor with a dedicated external dryer to fill the system, but the on board pump will suffice, once it's running. You can always jumpwire the compressor to run - just make sure you disconnect from the control board and don't blame me if you cook it

Overheats and [on time exceeded] are usually air leaks that you can find with the aforementioned bit of hose in your ear, but my main point is that, before you tear it to bits, inspect the full set of calibration data and you will be FAR ahead of a shop that simply throws parts at error codes.

Ok, I've done enough damage. Break a leg, you lot.

garrett376

On a 958, the system is spec'ed for a nitrogen fill.

RAudi Driver

If anyone is going to get into it. A bottle of Grade 5 nitrogen and the correct tools, which can be purchased from Snap On Porsche, would be the correct route.

Jonakamikaze

I tried that and that didn't change anything. It have to be something with the valve block, the lines is maybe not properly attached, tomorrow I will unscrew one line/corner and fill it with an external compressor and then have a ball valve closed over night and see if that make any difference.

RAudi Driver

^^ you're not being clear in your writing.

What did you try?

What didn't change?

If you're asking for assistance, you need to be clear and concise so we are not wasting time trying to decode your writings.

Also, it you are answering another members reply, you need to quote his/reply.

Jonakamikaze

I tried that once more but this time I raised the car to max level before putting the suspension in service mode.
This time the front stayed up and the RL air strut lowered so that's a bad strut so I will change that.
The error message "Chassis System Failure" is hopefully related to this leak, however I have a feeling that I may have to separate errors.
I change the bad strut and I will see.
Thanks for the advice.

jayi836

Call or PM if you need assitance you can't fix this without a PIWIS 2 or similar tool.
Delat with errors on and off for months been good for over a year now,

https://rennlist.com/forums/cayenne-...placement.html

TyreReviews

Just fyi my left rear drops within about an hour when locked in service mode but I don't have any errors.

Let me know how the fix goes. I got the cheap eBay airspring bags for the rear but I've not had the time to fit them. Plus mine seems to only leak in high mode now, normal mode stays level. Which it didn't used to do.

Self healing car!

RAudi Driver

Replace struts in pairs.

Tyre reviews, you also have to replace your rears. I wouldn't do the ebay airbags, but that's just me. Do it once, Do it right!

Cheap parts make for expensive repairs!

TyreReviews

I bought a pair of rears.

I know this is a Porsche forum, but my 958 is pretty beaten up and I'll only be doing about 2000 miles a year on the car, so if I can buy the parts for $300 instead of $3000 it's worth a shot to me If they work, great data for everyone, if they fail, not much lost and something learnt.

RAudi Driver

Do you have the correct tools to replace the bags?

TyreReviews

Adjustable wrench and a positive attitude. What else would I need?

RAudi Driver

a bottle of whisky and you got it covered. LOL.

Rodrigo Guida

is it possible for me to put a set of Bilstein B16 coilovers and disable the air suspension of a 2012 Cayenne GTS? or any other Bilstein coilover set.

TyreReviews

Coilovers are possible on the 958 but for some reason it finds pushback here. There's a few people who have done the work in the VAG offroad groups on facebook.