What issues are you experiencing?

 

2011 CTT 103K miles
I've owned this vehicle for 6 years and about 60K miles. This was the first year it took on daily driver duties during the winter.
Pulled out of my 45 degree F garage in sport mode and about 50 miles into a 150 mile highway trip in -5F weather, I got the red chassis failure warning. The ride did not appreciably change so I continued.
The warning cleared itself then reappeared a couple times. My icarscan gave me:
220-Vent solenoid valve, ON time exceeded
284-Control position not adjustable, vehicle too high or too low
When I reached the parking lot, I was able to clear codes and get the car to High Level 1, but not High Level 2 (dash warning Level Not possible)
Also the following values:
System pressure (sensor) 1.9 bar
System air quantity (calculated) 18.39 gal
Spring strut pressure front left 7.44
Spring strut pressure front right 2.91
Spring strut pressure rear left 2.64
Spring strut pressure rear right 2.91
Heights: deviation from required level, front left (calculated) 10.01 inch
Heights: deviation from required level, front right (calculated) 9.89 inch
Heights: deviation from required level, rear left (calculated) 0.16 inch
Heights: deviation from required level, front right (calculated) 0.28 inch
Confused now because I exited the car and it looked perfectly normal for High Level 1--up a little tall, even front to back and side to side.
No more time to troubleshoot, so she stayed outside for the next two sub-0F nights. I returned to the car in balmy afternoon 20F weather and found the fronts slightly lower than the rear.
Started the car and immediately got a red chassis failure that quickly resolved itself. I was able to get the car to normal height, and desiring to get home more than troubleshoot, I left it there and made it the 150 miles back.
Parked in my 45F garage. Set the level system to jack mode and measured body heights:
All at 454mm
Rechecked heights at 2 hours and 4 hours with no change. After 24 hours, the fronts actually came up to 457mm, rear still at 454mm.
Now the car will reach all requested levels, but does seem to be a little slow about making changes.
Here's the remaining mystery:
at about 50F
System pressure (sensor) 4.6 bar
System air quantity (calculated) 21.14 gal
Spring strut pressure front left 7.44
Spring strut pressure front right 2.91
Spring strut pressure rear left 2.64
Spring strut pressure rear right 2.91
Heights: deviation from required level, front left (calculated) 0.24 inch
Heights: deviation from required level, front right (calculated) 0.16 inch
Heights: deviation from required level, rear left (calculated) 0.0 inch
Heights: deviation from required level, front right (calculated) 0.08 inch
Actual measurement of the accumulator pressure (with my HVAC gauge) = 10 psi (.7bar)

It looks like my vehicle doesn't like the extreme cold, but I really want it to like the cold!
It looks like it could use slight calibration (bring the nose down and the tail up).
I don't know if I should trust the icarscan readings (or maybe my sensors) for the following reasons:
-Heights look correct now, but were way off on the fronts in the extreme cold
-Strut pressure Left Front is much different than others
-Strut pressures in extreme cold are EXACTLY the same as three days later in 50F garage (weird or no?)
-variance from code reader pressure and actual gauge pressure

Next steps (and questions)
I will be adding nitrogen with the theory that the low pressures and quantities are requiring too much compressor duty.
I am debating on pulling vacuum first to help remove moisture as maybe frozen valves could be the issue (any hazard here, like the whole car coming down?)
Since my code reader doesn't seem to do this procedure, it will be somewhat of a guess. (The icarscan lists the procedure, but will not accomplish it)
Does anyone know if this procedure includes drawing a vacuum first before filling as you would with air conditioning?
And I'll ask this question again, because I'm hoping more answers emerge over time:
Besides PIWIS (and somebody mentioned a Launch, though not specific model), what code readers are actually able to do the component replacing, bleeding, testing and calibrating functions for the level system?

 

Regarding your height issue: you have a leak. That needs to be addressed before doing anything, unless you like wasting time.

Regarding your height settings: measurements from the wheel center to the fender are what you use for calibrations, not the electronic deviations.

 

An inconsistent leak it seems.
From my earlier post, all four corners were measuring 454mm for at least 4 hours then the fronts actually raised by 3mm by the 24 hour point. So two days ago I ruled out a leak.
However, last night in 10F weather, the vehicle seemed perfectly fine for a couple short trips, then garaged at normal level. After about a 20 hour rest in a 45F garage, the right front looked lower than the rears and left front!
I started the car and it quickly levelled itself then the compressor ran for another 30-40seconds.
So I'll check for obvious leaks next chance I get and brace myself for a new pair of bags.
Any thoughts on the Spring strut pressure front left reading?

 

I am not sure why you think you ruled out a leak - you have a leak, otherwise you could raise to the proper levels, and the ride height would not drop.
The struts are the most common leak source, so if you want to figure this out in the most effective manner, fill all of the struts so the car reaches somewhere between High Level 1 and 2, put the Leveling System in Jack Mode, then disconnect the air lines at all four corners (or just the corner you suspect), measure the fender to wheel center heights, and then see what measurements exist the next day. The strut that is the lowest is your leaker.

 

Disregard, this message sent by mistake

 

The reason I ruled out a leak was I did exactly what you just said (and maybe I should've said ruled out a strut leak),
from my earlier post:

"Parked in my 45F garage. Set the level system to jack mode and measured body heights:
All at 454mm
Rechecked heights at 2 hours and 4 hours with no change. After 24 hours, the fronts actually came up to 457mm, rear still at 454mm.
Now the car will reach all requested levels, but does seem to be a little slow about making changes."

Now I just realized: both times I have seen the front lower itself, the car was left in either level high 1 or normal--as opposed to when I put the car in jack mode and observed no leakdown.
I'll see if I can repeat these tests, but seems to indicate a valve block issue?

 

You have a strut leak. Fix that first! When cold your o ring is shrinking and letting the nitrogen out. Pretty soon, you'll not be able to lift the car at all and you'll end up with chassis failure, even when it's warm. We've all been though this. Granted, when mine first did this in freezing Washington temps, I drove it and once back to California, I think I got another year or so out of it before it fully went out. Right front went first, followed by the right rear. The left front would have probably gone after the right front but I replaced them in pairs.

Don't trust any readings when the car is in freezing temps.

 

I seem to remember reading that there really is no way to repair these struts— nothing simple like slipping a new o- ring on is there?
So then which replacement struts did you choose and what has your experience with them been?
Obviously preferred, but Is the PIWIS required to do this or can I just fill all parts with nitrogen individually as they go on, top of the accumulator, and see what happens?

[QUOTE=RAudi Driver;19233219]You have a strut leak. Fix that first! When cold your o ring is shrinking and letting the nitrogen out. Pretty soon, you'll not be able to lift the car

 

I think your problem can be fixed with the o ring. I also don't think you can get a complete set of Bilsteins right now. Maybe just the fronts are available as I recall a member not being able to procure one side of the rear.

Read this thread.

https://rennlist.com/forums/diy-caye...top-mount.html

 

You are correct, there's none in the US and none in Germany. I spoke to Bilstein a few weeks back. Arnott might have some?

My car does exactly the same, if I leave it in low 1 it's fine, and most of the time if i leave it in normal it's fine for a long while, even when freezing, but if I leave it in high 1 it will leak out in about 45 minutes.

 

I had a leak in both FR and FL struts that I finally broke down and had fixed 2 years ago.

It would only show up at 0* F:


Anything warmer than that and you'd see no sag at all, even at 10* F. When it would get to 0* F, the fronts would leak overnight and the pressure difference between the rears and the fronts would cause that weird effect you see in the pic. All the rest of the symptoms are the same.

Once I had the airbags replaced, I have not had a single issue. Prior to that, I was concerned it might've been the valve block or compressor. My indy tested it and was confident it was the struts. Experience since would suggest he was right.

FWIW, I had the struts rebuilt by my indy. He sourced refurb airbags from Porsche and reused my OEM shocks and assemblies. Rides like new. He had originally pushed me towards the Arnotts because, in his words, "you should pay more for parts than for my labor." A few weeks later, he said he had talked to his distributor again and that the Arnotts had something like a 30% failure rate.

 

I had a small leak in the right front strut and a miniscule leak in the left front. All the code reading, measuring and speculating couldn't hold a candle to a spray bottle full of Dawn.
Interesting notes:
While in jack mode, it took 48 hours for my right front strut to decrease by about 1/2 inch. In normal mode it would do the same overnight. It didn't seem like a big leak to me until I hit the top of the strut mount with the soapy water--pretty obvious.
The toughest part of this job was paying for parts.
Previous posters had suggested buying:
95834301820 Mount. (Upper)
and
N90367701 Air Suspension Spring Seal
This seal is No Longer Available, but according to the Parts guys at ByersPorsche, it has been replaced with:
97034360500 Air Suspension Spring Seal
What used to be a grossly overpriced o-ring at $5 is now a STOOPIT-ly overpriced o-ring at $15.
I assumed this thing must be made of Rearden metal or asteroid ore, so I bit the bullet and bought 2 of them--spoiler alert, it's an o-ring. It says it's a 2x11, but it seems just a bit thinner than my other 2x11 o-rings, so I used it on the right strut and it appears to be working.
I'm not convinced that the new mount was required, but I used it since I had it.
Accumulator pressure spec is 10-17 bar, so after the strut got filled and the car re-levelled itself, I charged the accumulator with 13.5 bar of Nitrogen, took the vehicle off jack mode and heard a loud outgassing from the valve block--apparently the system thought 13.5 was a little high.
Bottom line: I was assuming the worst and expecting to pay for a pair of new struts, but the information in this forum gave me confidence with a much cheaper solution.
Thanks Rennlisters!

 

I have a slow leak in my right front, too; sucks; I already replaced them once. Hopefully, it's something easy.
My more pressing issue is I can't figure out how to tell my car it HAS air suspension again. Once I figure out WTF I did with my X431 to tell my car it's Air suspension was deleted, I'll track down the leak.

 

I've not read anyone who's been able to tell the car there's no air suspension anymore after switching to coils!