okizas

I have a 2003 D3 A8. There is a really unusual issue with the front suspension. Every cold start, the front suspension is very soft. Car goes into every bump with its front. There are no faults in VCDS, the car level is fine – in fact, and everything works as it should be. The problem goes away after I drive a bit, leave the car for about 10 minutes and drive again – then it’s everything OK.

This issue first appeared 4 month ago with G291 fault in VCDS. I checked for leaks – could not find any. Then I have left my car in a garage for couple of weeks – the front did not lower at all, only the back of the car was lowered. Once I opened the trunk, the accumulator pumped the back struts and the car was raised in normal position (398 mm). So, it seems that there is definitely no leak in the system.

Then I decided to monitor the compressor. It showed about 8 bar pressure so I have order a new piston ring from eBay. I have replaced the ring, even replaced the dryer module with brand new absorber for heavy duty compressor.

The G297 fault was gone for two weeks BUT the main reason – too soft front – is STILL UNSOLVED! There are NO faults, the leveling of the car goes flawlessly, the height is OK (416 front, 398 rear), but i cannot understand what is the problem. The dealer suggests replacing the G291 valve yet it does not show any faults, and no warranty under this.

Any thoughts?

mannyo1221

As far as I am aware the damping and air suspension are handled separately.

There is an electronically controlled damper in each strut, in addition to the air bag. If you look under the scuttle panels in the engine bay, you'll see a wire coming out the top of each strut with an electrical connector. Check that these are connected and not suffering from water ingress.

Petahs

If you have a vcds cable check this out explains the measuring blocks of the control module for logging purposes.

krazzz

What dryer module did you use? Can you send a link to the source? I am convinced I have a water/freezing problem and want to replace the dryer.

mishar

Can you explain this a bit better? What exactly you mean with "very soft" and "goes into every bump"?

Nick Conlon

I think he was referring to the feeling of no struts. I got the same feeling when the air completely let out of mine. When you go over a bump instead of absorbing it the car moves up a down in a wide range of motion....just like it would if it were just on springs with no struts.

okizas

Yes it feels like that. I try to stop and go from comfort->dynamicnthen back again and sometimes it helps. Still, no fault registered in the vcds.

okizas

I bought the dryer from local shop which repairs air tools. They told me, that very similar dryer coms on small packages in eg. shoes to absorb water. They look like small white *****. The ones i took from mine was red color, this means they are dead. Some say, that you can heat them up with a hair dryer, but i decided to replace with brand new ones.

mishar

Not any clearer.

When there is no air in the front air springs nose is extremely low, all weight is supported by bump stoppers and there is virtually no suspension travel, making it extremely stiff, harsh ride. Most definitely not soft.

So if it is that kind of "soft" and the front end is at normal level it could be that you are loosing contact on previously mentioned wires coming into the shock absorbers.

Nick Conlon

hmmm that is strange then, when my suspension went down to the bump stops up front, with the nose super low to the ground any bump caused the car to bounce excessively like you were on a bus, or a semi that has air ride. It was never stiff, and it only acted this way when they went flat. Same went for my back two, when they fully deflated then the back end bounced like crazy going over bumps.....which is definitely not good when it is so low. :/