Underwhelmed

New GL450 (1200 miles) has been making a hissing noise after the engine is turned off and you exit the car. Today it made the noise right after the valet handed it over.

The hiss is brief and sounds like a quieter version of a semi-trailer's brakes.

Anyone know if this is normal for the airmatic suspension or if I should have it checked out at the dealerhip?

Thanks

abcdef

This is normal operation. Drive on . . . do not stop at the dealer

boxboss

The initial builds of the GL had airmatic compressor issues, but those were quickly dealt with. What is your build date?

Underwhelmed

build date was early may this year

Newbie_2_MB

I have the same sound with a January '07 build date. Kind of sounds like a big sigh coming from the vehicle.

oinick

The sound you hear is normal. It is the airmatic adjusting itself. Actually the car will adjust itself even if you come to a stoplight and get slowed or stopped. The car will raise and lower itself as it is programmed to do.

You will get used to it, just like having your wife hiss at you when you say something stupid.

Newbie_2_MB

Ah, a man who is well-trained

AsianML

Are you here to keep the GL guys in check?

Newbie_2_MB

A girl's gotta do, what a girl's gotta do

str8line

Mine makes that sound when I close the door. I wonder if it's air being released from the interior?

blittle

Actually, the vehicle will do this quite frequently if you open and close the doors or the tailgate ( engine running or off ) If you watch closely, you can see the front or rear going up or down. Perfectly normal.

AutoSaurus

I believe it was carprsn who described it as a hot frying pan with water poured on it!

It is normal and it happens not only when exiting, but also while in motion. I heard it several times just today.

Jack450

I have a Jan. '07 build date. Initially started noticing what seemed to be a front end suspension problem in that it would make a "thud" noise going over even small potholes, etc. Thought it was just me or it was the low profile tires. Just recently it showed a Malfunction Symbol Message on the Multifunction Display. The symbol is a pic of the GL with an arrow pointing up. Took to the Memphis dealer(not where I bought it). Two days later back in business. Advisor said they replaced the compressor and that they have seen this problem before. Did not want to give back the C230 Sport loaner. What a fun little car!

StevethePilot

C230 Sport! You lucky son of a gun. Phoenix Motor gives out plain C230's, the cheapest they've got. Not that I mind still driving a Merc, but PLEASE! A Sport!

AutoSaurus

I just reported to NevadaJack last night that I am hearing this very sound also! I can't pin point where it is coming from other than the front right side and it mainly happens while traveling over rough roads, etc. It doesn't happen all the time but its happening more often now. To me it sounds like a door not closed all the way. I've receive no error messages and the air suspension seems to work just fine so far.

Jack450

Sound like you may need to get it checked out. By the way, some guys who own big trucks tell me that it's not too uncommon that a turbo hose will blow off after taking delivery of a new truck. And like I had mentioned before, I have an '05 Ford diesel that done it 4 or 5 times. I think they fixed with two clamps, cleaned it with brake cleaner and some type of adhesive.

Nevada Jack

After reading Jack450 post...I thought of what you mentioned last night Jack. Seems like a similar situation...

AsianML

Does the thud sound like a dead body rolling around in the trunk?

ksdprasad

That is normal. GL programmed to adjust air suspension only when the doors are closed.

StevethePilot

Does it sound like a Youper locked in a box?

AsianML

Geez, I was wondering because E-Class Airmatic folks have experienced the same noise.

sylviap

Hello. Bought a 2013 GL450 4matic as CPO w/ 31,000 miles almost 2 weeks ago. Just noticed a brief screeching noise after the car is turned off. Some of the earlier posts from above say it's a "hissing" sound. Sometimes the screeching noise happens and sometimes it doesn't. Can anyone tell me what this problem might be? Other than that it is a really nice ride! Thanks!