NoBrakes

So whenever park and i lock my car (2007 S-350) I hear something like a vaccum noise like Swoooosh from the vent on the hood, Like the car was sucking air, our pushing air out i cant tell exactly... Im new to S-Class.. is that a normal thing?? does anyone else's car do it?? or maybe the vents are blocked or something?? what does it mean exactly ?

Shadly1

That's your airmatic system releasing pressure. It's normal.

BOTUS

my car has never released any air from its suspension - in fact pull the fuse and if ambient pressure is static the car will stay the same height for 6 months - if it dumped air in 6 months it would be on the floor...

usually, 98%+ of the time my car makes no noise at all when turning off other than the locking - however on my car if its very hot and humid and or I did a particularity long drive the AC will dump some condense as the key comes out of the ignition straight on to the right bank's red hot CAT - after reading people dispute this and ramble on about something a euro car certainly never does (dumping suspension air) I noticed last summer its much more common for the AC condense trick - and its super loud


.

Shadly1

I'm pretty sure it's only dumping the excess pressure in the reservoir tank to preserve the life of the reservoir. There's definitely an audible start and stop to the pressure release that's controlled by the valve block.

Lotus GT

I had a similar noise until I replaced the filter/hose assembly on the Airmatic pump - the hose was split at the pump end.

RichDMB

My S550 always releases air when I turn off the car and even makes sounds when I hit the unlock button on the remote.

EasyPhil

This is an item people should be checking and replacing.

Arrie

When you drive the down force pulls the car down. Airmatic has a set riding height for the car so it adds air in the springs so that the car stays at the set level.

When you stop the car it raises above the set level obviously as the down force disappears. When you exit the car and lock it the Airmatic lets air out from the springs to bring it back to set height.

My car does it from locking it and I think it will lower down also if it sits still long enough without locking and even in traffic if stop is long enough.

It will not lower immediately when you stop as it would be silly to do that each time you stop at traffic lights for a short time so when you lock the car it knows that driving is done and it lowers.

This is how my 2012 S550 works and the same goes with my 2010 E550 and on top of that my 1985 Lincoln Mark VII LSC that I had at one time also did it.

Perfectly normal to hear that air release and it tells you Airmatic is working. If you stop hearing it you might have a problem.

Senecat

Mine too. I just assumed the system was making self-leveling adjustments and purging. Nothing that ever concerned me. These cars are still doing all kinds of crap after you turn them off before they actually go to sleep.

But I will be looking into what Lotus mentioned, now that he mentioned it, while I replace my struts tomorrow.