A6 air suspension, crying like a little girl

[toby t]

Hi everyone

Complete newb to this forum, so apologise for coming straight out and begging for help ! 

There is so much information available here (and I've ploughed through alot of it), but I was just hoping someone might be able to help out and point me the right way!

 

I have a 2007 a6 allroad, which I love. After 3 trouble free I've got my first air suspension problem .

 

The problem started a few months ago when the local garage replaced some of front suspension struts for mot as a result of worn bushes. He struggled getting it to bits and didn't recalibrate the suspension (not sure if he needed to though)

 

I've had an intermittent fault ever since where pumping up could be a problem and the mmi would grey out randomly while driving (ignition off and on again would fix this)

 

Now packed up altogether and it won't rise of the bump stops. 

There is a fault code on my old thing 02646

With the ignition on, I can here the compressor run for a short time (loudly) But nothing happens. 

After that, a constant clicking of a relay (not sure if that's connected to this problem ?!)

I've just tried it in jacking mode, still no moment. However I did notice air escaping loudly from somewhere in the, top r/h cornor of the engine bay when I switched the engine off.

 

It sounded more inside the engine bay, than the wheel arch.

 

Anybody got any ideas where to start ? 

Thanks in advance 😊

[Steve Q]

Could definitely be the relay at fault. At least the compressor is working. Or a module fault. 

[Trevor]

Worth checking under the bonnet for the exact location of the leak as maybe a small bore air pipe from the compressor to the strut or alternatively the strut itself is leaking. maybe get someone to cycle the ignition to run the compressor

[toby t]

Thank you so much for the replies chaps, it's a big help.

It failed a couple of weeks ago, inconveniently at the same time I managed to snap one of my fingers (unrelated !)
and today was the first time I've been able to get the wheels off and have a proper look !

With the ignition on the compressor will run before shutting off, the mmi greys out.
Does not lift at all.

There is a fault code, 02646
Drive motor "b" current sensor circuit range/performance.

This will clear, and the mmi comes back and the compressor runs again, but then shuts off and mmi greys out as before without lifting.

In either scenario when you turn the ignition off there is a reasonably loud hissing for about 20 seconds in one spot only. Its loudest from the top r/h cornor of the engine bay,
rather than with my head inside the corresponding wheel arch.

Not small bore, but there are two rubber pipes in that area of the engine bay, One of which seems to get very cold, very quickly and condensates very quickly.
Not sure that's related, but my knowledge of these things isn't great so I thought I'd mention it !

My gut was a leveling sensor,  it used to randomly grey out while driving and ignition off and on again would solve this.
It's also never sagged on a cornor always evenly.

Any thoughts ?
Thanks

[Steve Q]

Yea it could be a level sensor and probably the cheapest part to change. 

[toby t]

Thanks Steve, the problem started after the local village garage replaced some of the front suspension struts for the m.o.t, then just got worse and worse. 

Sorry to keep asking more questions, but do you think it would be wise to order 2 new sensors and replace both front ones ? 

I'm assuming the level sensors are the small units with a lever and rod connecting them to the lower arms ? 

Other than physically swapping in the new parts, anything else required, I.e calibration? 

I really appreciate all the help so far, thanks again

Toby

[Steve Q]

No need to apologise were here to help. They might need to be coded but I'm not 100% sure. 

[toby t]

So if I replaced both sensors myself at home, would the car lift straight away ?

so I know it worked (if that's the problem) then take it to a garage to be 'set up' ?