W124 sunroof jammed by dirt? - PeachParts Mercedes-Benz Forum

Jeremy5848 · #1 06-18-2009, 03:31 PM

My 1987 300D Turbo (W124, OM603) had its sunroof completely rebuilt last year by the local dealer. It got all of the upgraded parts (over $700 in parts even with the MBCA 15% discount) and the dealer (who owed me a favor) didn't charge for the labor.

I rarely slide open the sunroof but often use the pop-up feature to vent heat out of the passenger compartment. Yesterday I tried to slide open the sunroof but it moved only an inch or two and jammed.

No expensive noises, just stopped moving. I was able to slide it closed; the pop-up feature still works. Today it will still slide open only a couple of inches so I haven't forced the issue.

I suspect that enough dust has been sucked into the mechanism (especially driving with the pop-up open) to turn the special MB grease into grinding compound and stop the sliding mechanism.

I am considering opening the sunroof as far as it will go and squirting something like WD-40 onto the rails to see if I can free it up. Once I have it open all the way I can remove the rail covers and do a thorough cleaning and re-greasing with the special MB grease, which I have.

Before I do anything I thought I'd better ask here: should I take a chance or should I go to the dealer and let them fix it, even though it will cost me $$$? I don't want to risk all of those expensive new parts.

Jeremy

NH82W123 · #2 06-18-2009, 03:45 PM

Jeremy,

No warranty on the work by the dealer?

Charlie

Jeremy5848 · #3 06-18-2009, 04:27 PM

Yes, I'm sure they would warranty the failure of a part or their work. However, the sunroof worked perfectly when they finished so I just assumed it was dirt.

But let's me use my head about this . . . the work was done last September at 141,434 miles, so only nine months and 6,000 miles have passed. AFAIK, FSM calls for clean/regrease every year or two so it isn't even due yet.

So yes, it's worth a try. I'll stop by the dealer, see what they say. Thanks for asking the question.

EDIT

Car goes to dealer Monday 22 June 2009 to have sunroof checked. With luck it will be covered under warranty.

Jeremy5848 · #4 06-22-2009, 07:07 PM

So the dealer has the car, the sunroof is apart and they actually found some broken parts that they had installed last September. Replacements are on their way up from Fontana (So Cal). Hopefully this will all be covered by warranty. The service manager wants to go through the thing thoroughly, figure out why it failed. Certainly wasn't from overuse--I rarely open the sunroof although the pop-up feature gets lots of use.

NH82W123 · #5 06-23-2009, 10:05 AM

Sounds like something really went wrong if they're finding broken parts. Hope it's all covered!

Jeremy5848 · #6 06-23-2009, 09:09 PM

Just heard from the service manager. The replacements for the parts that broke are in, they are parts that were installed last September so they are covered under warranty (whew!). They asked to keep the car another day because they want to understand why it is breaking.

Jeremy5848 · #7 06-24-2009, 01:13 PM

Service manager just called . . . one of the new parts was broken in shipping.

They immediately re-ordered but it will now be tomorrow at the earliest for a resolution of this problem.

Jeremy5848 · #8 06-26-2009, 12:22 AM

Service manager called this morning . . . the mechanic wants to replace some more parts (on their dime, at least) but of course the parts are in New Jersey and won't be here until next week.

The plan now is for them to put the sunroof sufficiently together that I can have the car for the weekend and return it to them on Monday to complete the repairs. They have a courtesy shuttle that will pick me up so I don't even have to get myself down to the dealer.

Even with the delays I'm glad I took it in rather than trying to fix it myself.

pawoSD · #9 06-26-2009, 12:41 AM

That's some A+ service there, sounds like that dealer has it on the ball. MB used to be legendary for service like that....hopefully its making a comeback. Our local dealer is pretty nice/helpful too.

Jeremy5848 · #10 06-26-2009, 01:04 AM

They are nice people:

Smothers European
Santa Rosa, California

NH82W123 · #11 06-26-2009, 08:30 AM

Nice that you won't have to be without the car for the weekend. Hope they can get things completed for you on Monday.

Jeremy5848 · #12 06-26-2009, 08:42 PM

Smothers decided they didn't want to put my 87's sunroof back together, give me the car for the weekend, and then take it apart again on Monday . . . so they gave me a loaner, a new C350. Seems to be a nice car and the 400-page owner's manual will give me something to read over the weekend. I'm having trouble finding the glowplugs, though.

The service manager says they are a little bit concerned about the sunroof motor in my '87. It was not changed when they did the overhaul last September but appears to be in good condition. They don't want to replace it on a whim because it is a $400 part that I would have to pay for, and possibly the labor too.

However, they can't yet find anything else to blame for the breakage that occurred (and I don't know exactly what broke until I finally see the paperwork, next week). Their suggestion is that I avoid using the sliding part of the sunroof, which is not a problem for me since I typically use only the pop-up feature anyway.

I can't imagine why the sunroof motor would, as it were, "strip the gears" of the sunroof, but there it is. Since the dealer is eating the entire cost, including the loaner (I have to put fuel in it), I can hardly whine about their advice. Still, I'd like to hear from anyone on the forum who has had sunroof problems, especially in a W124, that were ultimately blamed on the motor.

Jeremy

Jeremy5848 · #13 06-29-2009, 06:04 PM

OK, here's "the rest of the story." It may have learnings for all W124 owners so pay attention!

Turns out that the recent breakage of the sunroof mechanism was caused by old damage in the headliner panel, which they did not catch and replace last September when they did the overhaul. 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 sunroof motor," which neither I nor the service manager were happy with. 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.

In the meantime, I can have the car back this afternoon with a working sunroof but no headliner, returning the C550 loaner, which was fun to drive but I wouldn't want to pay for its fuel on a regular basis. Over the long weekend, I plan to remove the old, cracked dash, replace all of the climate control vacuum pods, and install a new-to-me, uncracked, freshly painted dash. Once the new headliner arrives, the car will go back in for a day and I'll have a good sunroof.

Those of you who have an original, still working W124 sunroof might want to pull the headliner panel (fairly easy to do if the sunroof will open) and inspect those side flaps for wear. It may even be possible for a clever DIY-er to repair the side flaps rather than replace the whole thing. If that prevents breaking the opening mechanism, it's worth whatever you have to do.

I'll try to get pictures of the damaged headliner.

Jeremy