D3 suspension rises after standing for week
 

Hi there,

My d3 s8 has been standing for a week. The suspension ride height looked very low. When I opened the door, it hissed and the car rose by at least 15cm before getting in and starting. Is this normal or sign of a leak in the air system?

After normal drive, no further droop and no hissing.

Thanks for any advice, experience or suggestions. I have vcds but not sure how to test compressor.

Thanks

Richardracer

When I got back to my D3 after leaving it for 3 weeks it had also dropped a little, and also rose as soon as I woke it up before starting the engine.

Any droop like that is a slow leak in maybe a strut or line

It's possible to both test the compressor Psi and individually test the front and back axles air suspension using the modified label file for VCDS that Delboy found (I've done this recently). If the car wasn't started for a week then it may well have dropped on its suspension but if it is ok in normal use then sounds like nothing to worry about. If you are at one of the upcoming meets at either castle Combe or Beaulieu then I'll bring my vagcom and show you how to do that +++

Mine always drops down when left for long periods.

I got no leak, no errors and reconditioned pump.
I think its normal.

From what I read, the car self tests it's levels every 2, 5, then 10 hours when parked. Then after a while stops checking to save power.

It is normal for it to sink when parked a little but 15mm may be a bit strong.

Mine can sit for a week and it will go up a little bit it's sports air so it doesn't climb heaps. Check with vcds.

Mike

I have to disagree, if the car sinks noticeably over a 3-4 week period then there is a leak somewhere and its most likely going to be a strut, that said if its fine after leaving it for a week then I personally wouldn't go looking to repair it quite yet.

I suppose it could also be a reservoir or a check valve leaking also, but the only way to tell is to inspect all with some soapy liquid spray and see if you can physically see any bubbles etc plus check for any codes that have popped up

Yes Neil there is a possibility of the valve block leaking internally and we would never find that out unless it was removed from service and bench tested but that's out of the realms of normal folks testing.

The reason I bring up the struts is plenty on the US forums have had similar leaks that are slow and they turn out to be struts, one test that they try is to park it in lift mode then apply jacking mode.

The theory behind it is the bag will be unrolled to a different spot and may stop the drop or make it worse depending on where a pin hole in the bag might be.

It's not unreasonable to see how they are the most likely candidate for leaks, they are the only moving part and they have a fat girl sitting on top of them with countless hot cold cycles on the rubber.

There is also the corrosion point where the brass valve fits to the aluminium canisister, worth paying particular attention to that area for soapy bubble testing.

This is something I need to investigate on mine.

Merc's also have a common problem with leaking struts. Here's a good write up.
http://www.mercedesmedic.com/air-sus...isit-workshop/

Having read various information here and there a 4mm drop per 24 hours is permissible on the VW Tourage. Couldn't find what is allowable on the D3.