I'm trying to figure out what this noise is. I dont drive the G regularly but my wife says it usually happens at a stop. It sounds like a acorn hitting the top corner of the roof but it's clearly not.

Has anyone experienced this noise? Is there any chance it's the vent-flaps behind the window closing when the car comes to a stop? What are these rear vents behind the rear window on the exterior of the G for?

The sunroof guide tube came loose. It's a simple 10 minute fix. Pull the rear inner panel off and reconnect the hose. The inner panel just pulls off by removing the pinch seal on that side of the door frame and slide the panel out. You will probably have to unplug the speaker but that's all it takes. From there, you can see the metal tube and the rubber hose hanging there also.

Nick

Looks like this is not the issue for me. I took this area apart and everything is connected. Can anyone else think of something that might be making this noise. It sounds like its coming from in the headliner area just above the drivers side rear door.

Just so you dont think you are crazy I too had the noise. I know exactly what you are talking about. It does have something to do with the sunroof. I took mine in under warranty after the sunroof failed (started making a bad sound on opening) and as an added bonus the noise never came back. I used to have a fear that is was a weld popping or something. Unclear if the sound had anything to do with the failure.

Just received my car last Friday (used 2010 only 32,000km) and today I got this sound while opening the roof! So what did MB say the problem is?

I had a noise like that I traced to a nut that came loose and rolled around freely. The nut was from the rear center of the ceiling paneling. It started vibrating at first (Most noticable during cold starts) then it just came loose and started rolling around until I stepped on the brakes real hard and went flying towards the front of the ceiling where it got stuck somewhere. Now no more noise. I didn't want to remove my whole ceiling paneling again just to find the nut so it stays there until I find a more important reason to remove my ceiling paneling. It sounds like your nut fell int the C pillar. Also, there are brackets that connect the rear plastic louvers on the interior of the C pillar to the interior paneling. It happened to mine; luckily not into the void behind the paneling but on my rear carpet. It sounds like yours is bouncing around in there.

Try this... Picked it up on another forum but haven't tried it yet...

G63, 11,000km. Had the sunroof sound last night.
Guess it's time for the service center

I can't believe how someone can make such a car, and have such a problem as this left unsolved for so long!!! I have the sound... I just open and close as if not hearing anything absolutely abhor giving away cash to dealers, and so weary of doing a DIY on it...
One other thing BlackSL, with your lineup of Mercs, how does the G compare service-wise to the rest of the family on the long run? Been Merc acquirers ourselves for decades, but just now gone down the G road...

Service wise I guess not that good. Hong Kong only has one MB importer, so they've basically monopolised the mb brand.

It takes forever to book the cars in and for it to be serviced. A normal routine service might require the day away for 2-3 days....

Strange enough that, indeed, MB dealerships worldwide aren't the best experience. I have a Volvo and do find the dealership experience much more pleasant... at least you don't feel ripped off, you feel job is done ONLY because it MUST be done, treatment is more respectable and personal, rather than from the tip of the noses of the stealership employees. We still buy MB cars