Ok, some time after buying my 560 SEL I noticed a slight leak. Its been getting worse. So after putting up with it for a few months I decided to dive into it. I took the head liner front panel down to check the moonroof for leaks and found none. Previously and even during this test I poured water into the tracks with it open to see if I could make it leak. Nothing. So I set a hose on top the car, cranked the water up and sat inside. After some time I found several very small leaks around the windshield. But the locations did not add up. My leak will form between the front headliner piece (where the vanity mirrors mount) and the A pillar cover.

But I decided to take all the trim off the windshield and re-seal it. Happy that the horrible shape of the gasket was indeed the problem, I was content in mind that I had solved the issue. Until a storm yesterday.

The leak appears to be the same. It does pronounce itself when cornering like before and the flow of water seems the same. I attached a pict to show where it leaks. Some leaks out of the top and then will follow downward along the a-pillar cover. And some leaks out the bottom. I check the dor seals and they are fine. I also pulled off the cloth-rubber inner door seal and like before, not water along there.

I guess I can only assume its the moon-roof that is the cause, but from all appearances it appears not. Any ideas? I keep her garaged every night, but I still worry about any water damage/rusting that may occur as this water makes its way through the inside.

Attached Thumbnails

 

__________________
1991 560 SEL / 185k miles
1992 750il / 17k miles - project car

Mine had leaked in both of those spots at one time; turned out to be the windshield seal... Have you checked out the sunroof seal and cleaned out the drain tubes with a pipe cleaner?

__________________
_______________________________________________

1987 560SEL (210,000 miles)

Get Permatex flowable silicon windshield & glass sealer. I would start applying at roof-windshield seal area and do the leak test after waiting for over for the sealer to bond. Slowly narrow it down to specific area that is your culprit. Hope this helps.

Yup, made sure they were cleaned out. Water flows out very well front and back. I should mention that the windshield seal was bad because it was replaced at one time. At least it appears to have been. Does not have the MB star stamped on it.

As I mentioned, I already sealed it. But I will take it apart and remove more of the bad seal and put a larger amount of new sealant. But at this time, it does not appear to be the windshield.

Was thinking there is a common failure point. After reading it seems there is only one, and its the drain tube to tube connection of the moonroof. Which I also re-sealed. But I did not remove the tube, so maybe it leaking from the top if it?

Will keep working on it.

__________________
1991 560 SEL / 185k miles
1992 750il / 17k miles - project car

From my experience with these 126s its the front windshield seal. My green SD did it, we had the window replaced and after a while the seal leaked again. I applied a good amount of silicon sealant to the area and that seemed to stop it. The black SEL did the same thing. However I had the window replaced and it hasnt leaked again yet.

On these cars there is no gasket seal for the front windshield as there is on the rear. The front is a rope type seal that (according to the FSM) is heated up via 12v and melts/seals into place. Now whether or not glass places practice this I dont know. Some might just use a caulking gun and go with it.

I've never had a water leak from a sun roof drain tube, at least not in the front of the car. My gold SD leaks from the rear only when under high pressure from an automatic car wash type device.

Have you removed the A pillar covering and headliner bit where the visors/rear view mirror are? That might help you find the leak.

__________________
Cruise Control not working? Send me PM or email (jamesdean59@gmail.com). I might be able to help out.
Check here for compatibility, diagnostics, and availability!

(4/11/2020: Hi Everyone! I am still taking orders and replying to emails/PMs/etc, I appreciate your patience in these crazy times. Stay safe and healthy!)


82 300SD 145k
89 420SEL 210k
89 560SEL 118k
90 300SE 262k RIP 5/25/2010
90 560SEL 154k
91 300D 2.5 Turbo. 241k
93 190E 3.0 235k
93 300E 195k

What is weird is that I thought I did a good job sealing the windshield. Maybe I did not! And like I mentioned, I poured water down the drain tubes - lots of water - and could not create the leak.

So I did then pull the headliner panel and a-pillar cover then sat inside with a water hose pouring over the car. Thats when I found the the windshield leaking.

I only sealed one side from top center down to the lower corner. I will pull it apart again and run the hose. Just bugs me that the water amount has not changed.

By the way, that rear view mirror was a pain to get off. Damaged the mount bracket and all. I do not like that design one bit.

__________________
1991 560 SEL / 185k miles
1992 750il / 17k miles - project car

Mine was doing the same thing for a while. I brought it to a decidated glass repair shop and they put in a new windshield and a new seal. Solved the problem on the first shot for little hassle (A new windshield really isn't very expensive so dont' be afrid)

I half job probably won't do it. You have to remove the entire windshield.

__________________
1982 300GD Carmine Red (DB3535) Cabriolet Parting Out
1990 300SEL Smoke Silver (Parting out)
1991 350SDL Blackberry Metallic (481)

"The thing is Bob, its not that I'm lazy...its that I just don't care."

That may be my next step. I am guessing an install is less than $200 and could save thousands in work later on if I ignore it.

__________________
1991 560 SEL / 185k miles
1992 750il / 17k miles - project car