Hissing sound from the front of the car after shut down??
Thread Starter
Super Member
Joined: May 2008
Posts: 646
Likes: 16
15' W222
Hissing sound from the front of the car after shut down??
I have done a search but haven't come up with anything conclusive so I thought I'd just ask for my specific issue.
I'm praying this is normal and not an airmatic issue.........
........when I shut down the car and exit I notice a hissing sound and the front of the vehicle lowering *** if it's releasing air and or pressure. And subsequently raises when I start the car. Is this normal, if not what should be my next step??
I'm praying this is normal and not an airmatic issue.........
........when I shut down the car and exit I notice a hissing sound and the front of the vehicle lowering *** if it's releasing air and or pressure. And subsequently raises when I start the car. Is this normal, if not what should be my next step??
MBWorld Fanatic!
Joined: Mar 2005
Posts: 3,455
Likes: 11
From: Long Island, NY
W220 S65 AMG
Remain calm. Perfectly normal. 
Watch this video of my old car and notice right about 0:40 the car releases some pressure from the Airmatic system: http://www.youtube.com/watch?v=7ftR5mEBDBU
Watch this video of my old car and notice right about 0:40 the car releases some pressure from the Airmatic system: http://www.youtube.com/watch?v=7ftR5mEBDBU
Member
Joined: Jun 2008
Posts: 78
Likes: 2
From: Alabama gulf coast, formerly Charlottesville, Virginia
2004 W220 (S430), 2001 R129 (SL500 Sport)
My '04 W220 makes all sorts of hisses, grunts, wheezes, and farts when it's going through its shut-down cycle. You won't notice it if you are in an open parking lot and/or you get out of the car immediately. I left my wife in the car to run in a store right after we bought the car, and she was white as a sheet when I got back. The AC dampers and valves all cycle to rest, the soft close vents, the suspension sometimes vents....it's a symphony. It does some of the same thing when you start up, but you have engine noise, AC fan noise, the radio may be on...so you never hear it. It's worth standing around to listen sometime.
