W124 Sunroof Issue - Tilt okay - No Slide

[Addbhp]

This issue just started this weekend. I still have the tilt/vent function, but the ability to slide back isn't working. The sunroof drops down, but won't move back. When the tilt works, the liner panel also started to get hung up last week, but by starting the slide back function, which worked last week brought the panel down. Car is a 1990 300e. With spring finally here and no AC I really love my sunroof. Did a seach but all links to images have expired. I only have the car manual, no repair manual so as much detail would be great.

[babymog]

Might be simple binding cable. Did it work slowly before, or quickly and consistantly?

[Addbhp]

Was working perfectly before last week, when the lining wasn't dropping fully when closing from the tilt. But had been nice and smooth, greased last year, no noise.

If a cable is binding, how would I access that?

[sean33612]

lol, i have a 1991 300e and it does that sometimes, the tilt would always work perfectly, but sometimes after it closes, you could find that the sunroof on the right side dosent close down all the way, its not noticible, but when you push the padding it goes up so that you see the gap, but even with that the sunroof slides perfectly, its just at random times it wont slide. youll hear the belt running for bout 2 sec then it stops, but it dosent even move in that 2 sec, it just wouldent budge, but there are random days which it works fine.

[Addbhp]

I got a slightly better look at lunch at the passenger side lining, looks like it has come unattached, and is not rising with the tilt function, will try tonight to see if reattaching that helps, although not exactly sure how it's connected to the metal panel.

[JonL]

My W201 roof acted like that for a short while, now it does nothing. It seems that the mechanism that raises the back of the roof has broken and is jamming the roof. The FSM says that the roof must be partially opened to remove it, and I cannot open my roof at all so I am in a bit of a quandary. I've managed to slip the interior trim back and I think I can remove some of the hardware that will allow me to take the roof panel out, but I'm waiting 'till the weather is consistently warm to fool with it some more. Perhaps your roof is on its way to a similar fate?

[Jeremy5848]

My 1987 300D Turbo (W124, OM603) is currently at the local dealer for exactly that problem. They completely rebuilt the sunroof last September using all the latest upgraded parts.

I use the pop-up feature a lot but rarely slide the sunroof open. A week ago, in cleaning the car, I decided to open the sunroof and found that it would move only an inch or two and then stall. I immediately closed the sunroof (the tilt still worked, BTW) and took the car back to the dealer.

They found that some of the new parts had broken (the cast pot-metal track pieces) and are replacing them on warranty. So far, they have not been able to find a cause. The sunroof motor has never been replaced and they are not eager to do so since it would cost me over $400 plus labor. However, they can't find anything else to point to.

At the moment, I'm waiting to get the car back (they even gave me a loaner for the weekend, a 2009 C350). The service manager's advice of last Friday was "don't use the sliding part of the sunroof, since we can't figure out what is causing the parts to break."

I pass on this tale for the information of others and also to ask if anyone has had a similar problem that was eventually traced to the motor or clutch.

Jeremy

[Jeremy5848]

OK, the dealer's mechanic has figured out the problem. Turns out that the breakage of the bridge was caused by old damage in the headliner panel, which they did not catch and replace last September when they did the overhaul of the sunroof.

In the W124, the headliner panel (124 780 02 40) has two fabric "side flaps" (I'll call them) that act as wind blocks when the sunroof is popped open at the rear. In my headliner, one of the side flaps was worn and the other was actually broken loose at one end. This end jammed in the track on one of the few occasions when I actually opened the sunroof, causing one of the bridges to break.

This is a much better hypothesis than "bad motor," which neither I nor the service manager liked. The good news is that the part is still available and the dealer will install it for free and not charge me for the broken parts, which is reasonable since they should have caught the headliner problem last September.

The bad news is that the headliner has to come from Germany and even with 15% MBCA discount will cost me $500. If I were doing this job all by myself I would try to repair the existing panel but since the dealer is doing the work, I want to leave them with absolutely no excuses if there is ever another failure.

This is the first concrete reason I've ever read for why 124 sunroofs break, aside from old, dirty, lack of grease, cable broke, etc. I pass it along in case it might help someone else. There are threads here and elsewhere with good DIY instructions for taking the sunroof apart. If yours still opens, you might consider removing the headliner panel just to see what condition it's in. Might save you some later grief.

Jeremy

[remotemark]

Originally Posted by Jeremy5848

This is a much better hypothesis than "bad motor," which neither I nor the service manager liked. The good news is that the part is still available and the dealer will install it for free and not charge me for the broken parts, which is reasonable since they should have caught the headliner problem last September.

The bad news is that the headliner has to come from Germany and even with 15% MBCA discount will cost me $500.
Jeremy

You can get a brand spanking new headliner from World Upholstery or GAHH for half that. There are even less expensive quality ones, too.

[Jeremy5848]

Originally Posted by remotemark

You can get a brand spanking new headliner from World Upholstery or GAHH for half that. There are even less expensive quality ones, too.

Apples and oranges. I'm not talking about the headliner per se but a part of the sunroof. That has to come from Mercedes (or from a junkyard).

[ps2cho]

How can you get the headliner off if it does not open?

[Jeremy5848]

Originally Posted by ps2cho

How can you get the headliner off if it does not open?

There are a couple of threads here and on other forums talking about just such a situation. You have to unclip the headliner at the front and then reach back inside with a tool to unclip the back without breaking anything. It's doable but not easy. If I were to do it myself I'd want a helper who had been there before.

I apologize to whoever originally posted the attached picture as part of a DIY write-up. I like to credit my sources but I failed to note where this picture of the headliner piece came from. The filename is "18liner1.jpg." As you can see, it's not just a piece of fabric (but just like Mercedes to charge $600+ for it).

[babymog]

That's a part I've thrown away a couple of times, used should be under $20 and a good 10minute replacement job.

[babymog]

Removal of the sunroof headliner:

Open the sunroof ~4-6" .... 30seconds.

Pull carefully down along the front edge of the sunroof headliner to release the 4 clips ... 1minute

Open the sunroof fully .... 30seconds

Slide the liner panel forward, up and out of the opening ... 30seconds.

About 2.5minutes if you read this first, an hour if you're a M-B tech and attracted to the service writer.

[hd wood]

Babymog: How do you open the sunroof (slide it backward) if only the pop-up works? Mine kind of jams if you push the slide switch but doesn't go anywhere. Do you have to go thru the trunk and crank it? stormwindalpacas@comcast.net dave

Anyone else can feel free to chime in too. lol