Hate to beat a dead horse but....air suspension issue
 

Hello All,

I have a 2004 Audi A8. Since I got it I have noticed the ever persistent solid orange light after about 15 minutes of driving. I figured it was a small leak and I need to get it in before the compressor decides it's had enough and dies one me. As long as I kept it in dynamic there was no issues, trying to go any higher and the compressor couldn't keep up. Once the cold hit I got the flashing orange and green lights, my front end was completely flat. Parked it in the heated garage, once it thawed I was able to turn it on and it pumped up fine. I have an appt the 18th of this month to get it inspected. Was hoping it wouldn't be a strut....

Now here is the weird thing, I got my tires replaced about a week ago and on the way home the flashing green and orange lights came on again...i thought great the front end is down again. I limped her home to notice the front was perfectly fine....but the back was all the way down to the floor. Now I have never ever heard of this happening on the A8 as they are suppose to have an air reserve in the struts.

Let the car warm up turned it on and it pumped up to normal height and it hasn't happened since (been about a week).

So now i'm thinking it is probably not the struts that are bad since the front ones that normally fully deflate stayed up fine while the backs went flat. Is this starting to point at the combi valve as being the culprit?

I did have a tech tell me he had seen some problems with the valve block on 2004's.

It looks like Valve Block problem. You have to scan it first.

Thank you for the quick replies! Mishar I don't know how you get to every post on these forums but I have followed a lot of your advice since owning this car. So thank you.

I got codes

01583 - Leak in System Detected - frequency 89
01400 - suspension level control; lower limit exceeded - frequency 89
01772 - level control pressure sensor G291 - frequency 70
00776 - Level Control System Sensor; Front Left (G78) - frequency 1

I am thinking the last one is just a fluke due to the extremely cold weather here.

First thing is that leak. It is probably one of front struts. You have to find it with soapy water.

Rest of it may be OK but you will see once there is no leak.

You would still think it could be a strut leak? It just seems odd, if a strut was leaking wouldn't that one always deflate before/when another deflates? normally the front two are the ones to fully deflate, but when I had the back two fully go down and the fronts were fine....it made me rethink if there was an air leak in one of the struts since if so it would have went down before the back two did.


I could be completely wrong but it would just make sense. :/

You are right. Leak could be from Valve Block. May be difficult to detect it if it is intermittent. It could be caused by freezing if there is any amount of water in the system. Compressor has dehumidifier but I don't think it can last forever. I don't have experience with that but it may be good to check it. I should do that too. It might prevent other problems.

That would make sense, it didn't really fully deflate until it got to the negative temps, and would not inflate until i got the car in a heated garage. So there is definitely water in the lines somewhere. I read some other post where the owner took apart his compressor to find it was full of water which leaves me worried. :/

Is the dehumidifier integrated into the compressor, or completely separate component?

Dehumidifier is part of the compressor.

I'm experiencing the left front leak overnight issue now.
Sometimes also after a 12hr day at work also. I am thinking strut at this point, but will have to do some leak checking come spring time. Pumps right up when comes out of sleep mode via the reservoir.