Each shock has a pressure control valve on top where the line plugs in. I was able to use my compressor in garage with a rubber tip, to inject air and see the shock raise. As soon as I let the tip go. the air leaks out leaving only what the pressure control valve is set for, to prevent damage to shock. I observed that the front wont raise at all. If I clear all errors and use jack to raise each front side to match what setting I set in car, there wont be errors and car shows going into low or going into high as it is supposed to.
If I lower car a lot I will get vehicle extremely low message too. So sensors appear to work OK. So does ECU.
Only thing I am not sure of is the valve block. Would be so coincidental though if block failed just around time I decided to change the shock (unless was already on way out due to leak making it work more).

So I seem to know that:
- if I disconnect air line from shock and use compressor in shop to inject air into it, it will hold air (pressed finger after some air injected and seemed to be just ok
- If I manipulate car front to match presets in car, I get no errors (ECU works)
- If I start in low, and press high mode button, message will display but front go up (waited, no go).
- compressor seems to be working just fine (video of the compressor and noise it makes when on - entire duration of one run captured here too - CLICK HERE)
- Rear shocks appear to work ok - Rear tires appeared to be raising and lowering depending how you set suspension (hi or lo), saw rear shocks going up/down
- front shocks do not get raised even after compressor turns on a couple times. Compressor runs but after it shuts off front does not raise.

So that is what makes me think front shocks controlled by solenoid in block. Air wont fill shock if solenoid does not open. So even if I have car at specific height, and then change it manually with jack lifts, suspension does not fill.
So back to solenoid block I go again.

 

So been playing with car more.
Saw compressor run, and this time, clearly saw front pass side rise. Had car standing freely off jacks. But over time, saw frt pass side slide down.
Could not figure out what the hell.
Inflated shock with shop air and placed finger over valve to stop air escaping, and there was no sound of anything coming out. so shock appeared ok.
Saw valve block and sprayed with soap, no bubbles, all ok there.
I already checked the driver side last week for leaks, but decided what the hell, recheck. So take cover off, and what do I see? Leak bubbling from same spot that happened on passenger side.
So now I am buying another shock for sure before I proceed with any other stuff.

Question is, would a leak in one side cause other side to be sagging too? I know if left sags it automatically makes right side lower too, but my question is specifically about the air leak itself.

 

Found some more info that confirms the system acts as a closed system normally but has the ability to either release pressure to atmosphere or take suction from the air through a filter. This is from the "AfterSales Technical Training Booklet" on the Panamera.

 

I don't think a leak on one side would necessarily cause an issue on the other side. They appear to have separate lines (and I hope control valves) from the main valve control block. There could be a common mode failure/issue in the valve block that makes both side drop.

Just my thoughts,

 

Yup. Was just asking to see if someone can point so something I was not aware of.
Each shock has separate line to valve block. Valve block connects to compressor and tank. Also has one line to vent excess to outside, despite many saying it is full sealed system. System is fully sealed between shocks, block and tank.
However compressor has a filtered air inlet to keep pressure in tank constant (if it is low, compressor pumps it up).
Valve block opens/closes valves to force air into each shock.

I learned quite a bit during my time so far and hope to have a nice write up to save someone tons of money and time. Have pics, just waiting to complete other shock swap and valve block too.
Next week will be the time.

 

I'm sorry you've had to go through this,but also glad it is you, because we know that you will share everything you've learned and have an excellent write up on it!

If you ever make it up to Central Oregon I'll buy you Dinner :-) (and some of the local beers)

keep up the good work.

 

NP. Any time.
Yes, already have a bunch of pics and stuff, ready to make DIYs for upper control arm replacement and for air suspension replacement.
Once all my parts arrive, I will be able to complete this and then put up some useful info for others to read. Learned a lot about the suspension which is great.
Waiting for valve block and a second front shock. Til then still in action but in my CTT (been a while since used it much - still awesome german pig beast though).

 

Car is all done and being enjoyed 5x more now.
I have learned a lot about the air suspension, components and debug.
When I get a chance I will write some DIYs and info on debug. Yes, will have detailed photos and info on replacements too.
I think many Panamera owners will find this useful especially with air suspension.

 

Fantastic news ciaka, and I keep my fingers crossed that I never have to take advantage of your hard earned knowledge :-)

 

Any cliff notes on what the underlying issue was?

 

 

Cliff's notes - replacement shock I bought was defective. Had to have it replaced. That was on top of the leaks I found on top of front shocks before, and was trying to be proactive about replacement.
All done though. Will have extensive info when I get a chunk of time.

 

Me too. It was awesome I chose not to sell my CTT. It allowed me to drive that, while I played with the PTT.
I actually missed the CTT and this gave me a nice fill of driving it.

 

As final post, work completed. Learned a bunch of suspension things.
Posted my info here, and created some DIYs here. I do not expect to be posting any more stuff in here.

 

Ciaka,
You did a great Job. We will learn from your hard work and knowledge.
THANK YOU ...