AMG855

Bit random this one as I cant find the source...

1. Sunroof is new and drains are clear
2. Scuttle and associated run off clear
3. Firewall grommet not leaking
4. Door seals are fine.
5. Roof rails are sealed.

Hole in LHS water pooled. c.Half a litre.

Insulation trim that covers that hole.

Inside hole, rear where majority of water is sitting. This is taken after 90% removed.


At a loss. Pictures attached of "leak hole" when I checked it post rain it was FULL and overflowing down the interior and under the carpet.

Any help would be brill.
2003 (53) S211 Wagon.

nd-photo.nl

Did you also check under the fusebox in the engine compartment?

See thread for detail shots (last 2 pictures of the first post): https://mbworld.org/forums/w211-amg/...r-install.html

AMG855

It's the opposite side on a RHD car, taken out Aux battery and nothing blocking there either.

nd-photo.nl

Aha, I didnt know that, thanks for pointing that out

kiluminati616

i had a similar issue a few years back and my sunroof drains tubes were cracked. check this post for more info:
https://mbworld.org/forums/w211-amg/...avy-rains.html

AMG855

Think this is it, just had a look under headliner... pipe is certainly not aged well. Will follow your post. Nice one.

kiluminati616

nice, glad it helped! it's held up decently over time but i will say one of the sides still leaked slightly after i drove in rain for several hours once. I've also had a garage most of the time since then so it hasnt had to experience a day of rain. maybe some plumbers tape around the end of each could help alleviate that.

good luck!

AMG855

Updated solution.

So there were ultimately two issues with the S211 causing the wet footwell and soaked insulation.

Issue 1, was indeed the sunroof drain. It was blocked resulting in water pooling at top of pipe and backing itself out of the union causing a drip that ran down the headliner, the A Pillar and ultimately the inner sill causing the litre of water to pool (I used a 100ml syringe and pipe to draw the water out and it was roughly 10 full drawers) it hasn't filled since and it's been pissing down ever since.

Issue 2. This was the tricky one. Once the carpets were out I noticed that some of the insulation was still wet, investigating further it had nothing to do with original source of leak, I ran my hand under far left insulation and found some corrosion that was wet. It appears that by the ground point in the footwell corrosion has eaten a hole through, or at least the start of one, enough to wick water from underneath the car. I've prepped and filled with fibreglass filler on both sides so hopefully its resolved. For now....

Thanks all for your help.

AMG855

So the 2 items above did something to slow the pooling, it was however 2 completely different issues that were the primary causes

1 - there is an MB star bulletin that I found in the depths of the internet (attached) that details a procedure for a leak. In short it's due to degraded panel bond causing seep into the a pillar then gravity does its thing and the only escape point is through a hole that your side carpet clips to. Drill a hole and job done.

2 - this was the sneaky one. Bottom of windscreen had come away from bond so water snuck in an started to corrode. New windscreen and a bit of sanding/inhibitor/prime job and done. No more footwell juice.