Air suspension sounds

mannyo · #1 17th February 2014, 08:32 PM

Quick question to all those with a D3. Had the compressor rebuilt three weeks ago.

If you drive along normally with the radio off, and the air compressor runs when it switches off mine seems to make a very audible pssch sound which you can hear from in the cabin. You don't hear it with the radio on since the audio drowns out the sound. I also dont recall ever hearing the car level out when removing a heavy object, which I can hear now (its a controlled ssshhh for 2 or 3 seconds) which stops suddenly when the valve closes.

The guy that rebuilt the compressor and refitted has had the car back and says it looks ok, but I am not so sure. I do wonder if the vent/intake pipe has come loose or detached. its all working fine functionally, but I don't want the compressor to be breathing bad air if something has come off.

I can access the area of the compressor, I was in there on Sunday trying to find the parking sensor wiring. I don't know how the compressor is orientated and thus where to find the vent pipe.

I've started to build a relationship with another specialist, so may seek a second opinion.

Delboy · #2 17th February 2014, 08:47 PM

Only time I hear any noise from suspension is when engine is off and I'm outside and lock the car, it then settles down releasing air.

Other than that I hear nothing

PsYcHe · #3 17th February 2014, 09:30 PM

Not conscious of hearing it other than when turning the car off and locking the doors. Will have a play around tomorrow if I remember.

Conquistador · #4 17th February 2014, 09:54 PM

Like others, the only time I hear it is when I exit the car and it sometimes lowers a little. Definitely shouldn't be able to hear any 'pssshhhhhhh' sound when inside the cabin.

jonk · #5 17th February 2014, 11:40 PM

Just like Manny, I had mine rebuilt too... I too can hear exactly this noise only when crawling through slow traffic and everything else is quiet or the radio is very low.

All seems to be working just fine though since the new piston ring and seal was on. Heart was in my mouth just once earlier this week as the passenger rear looked noticeably lower and I thought I had a leak, but I think it was just parked on very uneven ground as all looks well both on and off since and no warning lights.

This air ride suspension and its worries ages me about 50 years... I'm like a coiled spring just waiting for something to rupture or break...

M-A8 · #6 18th February 2014, 12:45 AM

Same like others, only when locking the car. It takes what, couple of seconds since I lock the car and I can hear compressor releasing the air for no more than 2sec.
I do feel car raising or lowering for example when I stop at the traffic lights same as everyone I believe as car constantly tries to level it self, but no pssssh, sorry.

snapdragon · #7 18th February 2014, 07:14 AM

I only hear mine a second after locking the car when it lowers to adjust for the loss of passenger weight. It is quite quiet so I doubt it would be audible in the cabin or when the engine is on.

mannyo · #8 1st March 2014, 02:45 PM

Whilst I was digging around replacing a parking sensor today, I have FIXED the sound and normal service has now resumed.

Basically a pipe had come off, the plastic pipe that comes from the compressor goes around the back towards the front of the car and then upwards. There it connects to another pipe which is on the car, this is the joint that had come apart. Its held together by a pipe clip, whilst I had the foglight out, I was able to re-attach and secure the clip properly.

Now the expelled air is vented through the noise dampers and air filter rather than straight to atmosphere. Only concern is how much water and other rubish did the system ingest whilst pressurising. Hoepfully it will all be expelled again over time.

mannyo · #9 1st March 2014, 05:26 PM

Quote:

Originally Posted by jonk

Just like Manny, I had mine rebuilt too... I too can hear exactly this noise only when crawling through slow traffic and everything else is quiet or the radio is very low.

You might want to check your compressor intake pipe, see previous post as mine was not connected to another pipe.

Remove front nearside foglight grill by releasing the outer clips by the front wing. Now grasp the grill on the edge close to the centre grill and pull whilst applying gentle upwards motion. The grill is held on by four clips (2 top and 2 bottom) and you need to release them carefully, there are no holes or anything to insert a screwdriver like on the D2.

Now remove the foglight, held in by three screws, two outer and one inner. and disconnect the wiring.

Look into the opening where the light was and there is a smallish pipe coming down from the top (not the aircon ones). Follow this pipe down and it should have a clip on the end, and it should be attached to the air compressor intake pipe. If the pipe is hanging in thin air, it should be easy to find where it goes as the air compressor intake is pretty close to the end.