Years ago I heard the story, that CA Volkswagen dealer send a technician to Germany only to learn how to repair their sunroofs.
I've been repairing them in the past, but it takes really good hand skills. On the side of being natural mechanic, I have some jewelery experience as well, so it wasn't too hard for me.
Good idea is to put blue masking tape around work area to avoid greasy fingerprint on the upholstery.
Good luck.

 

My first Mercedes was an '89 300E...SWEET friggin ride! I totaled it on new year's day, 2003 when a carload of Messicans pulled out of a bar in front of me at 2 am and they fled the scene in their 90 ish Mustang with the driver's side front wheel leaning at a 45 degree angle...police never found them. Fortunately, my wife and I weren't hurt, just left Mercedes-less. Today I bought a '94 C280...when I test drove it I was like "oh yeah...that's what I've been missing!" One of the defects it has is that the plastic guides(?) for the sunroof sort of "exploded" into a bunch of pieces, according to the guy I bought it from. The glass just sort of lays in place, with the wind whistling through the hole in the roof, but it will prop up in the popped up position, sort of, but there's no way to seal it against the elements (temporarily) except by the ol stand by, duct tape...or I was thinking at least transparent tape.
I have NO experience with this type of repair but am very handy and mechanically inclined. (Built a number of engines, including a couple of Opels and Harleys, along with manual trannys, in addition to water pump, tensioner, idler pulley on the 300E) I bought a repair manual on DVD on Ebay today and am hoping this subject may be covered in it. Any shared experience on this subject will be greatly appreciated!

Bill w/ponytail

 

Thanks for the tape tip, Katjek 1! I would've trashed my headliner without even thinking about it....until I was finished and looked up! Turned out to not be so hard...apparently the tracks had never been lubed except from the factory and the grease had gotten sticky, making it hard to operate until the plastic parts and guides couldn't take it any more and kablooey. Got it working, with a new drip rail, but still need to replace the rollers and guides, etc.

Anybody have any tips on central locking system? I sat in a gas station for 15 minutes searching the owner's manual, then looking for the manual release for the filler cap the first time. The key in the lock will close the windows, but doesn't lock or unlock anything but the door it's in. The rear headrests go down...I think I understand that they're vacuum operated too, and I just assume they're on the same system as the locks. Found out the alarm system works good too! The fuse for the courtesy lights and locks was blown and I replaced it, but still no locks. I don't have the slightest idea where to look for the pump. I bought a manual on CD on Ebay, but it's apparently proprietary software from the factory, as it won't allow me to use it or fully install it.

 

Sounds, like it was the hard way [sm=bustedsign.gif]

The fuel door lock operates together with door locks, so sounds, like you have malfunction.
I am not sure if you have electric vacuum pump for the locks, or use the main installed on the engine.
Electric pump would be somewhere under a seat.
Good luck and enjoy.

 

Welll, I got a new (used) pump as my old one's housing was melted around the motor. Mine was a Bosch and the new one is a Mercedes and the air fittings are a little different, causing me to have to tie-wrap the connection. It works, but not with the key in the driver's door. The key will unlock the whole car from the door, but won't lock it. The central locking switch will lock the whole car, but is of no use when exiting the car. I wonder if the difference in pumps could be the cause or if the problem is elsewhere? Anybody have more of a clue than me?