124 water leak into cabin solved - PeachParts Mercedes-Benz Forum

Chris W. · #1 09-22-2012, 07:55 PM

I know that this isn't diesel-specific, but anyway. I have described my unsuccessful efforts to find the source of a massive leak into the driver's footwell of my '95 E300D in other threads on the board, here's one... w124 water leak in cabin- please help!

Anyway, while having a look at my rear, yes rear brake disk the other day I spotted something I never noticed before. In the forward section of the rear wheel well are a couple of what appear to be body plugs which are coated over with undercoating. The lower one was flapping in the breeze, having come loose due to corrosion, I believe. It was held on by some undercoating only. So there was a nice ~2cm opening right into the interior structure of the car! Perfect for receiving water thrown forward by the rear wheel. So I folded that bad boy back down and slathered on some silicone seal and made sure it was good and coated, no water going to get in now.

And I waited for the next available rain storm, which happened a couple days ago. Voila! No more gallons of water coming in. It clearly was traveling from the area at the front of the wheel well into the the rear driver's side footwell, which also got wet, and then forward into the front footwell. By the gallon!

Here is a photo of the re-sealed plug in the rear wheel well, and you can see another one above it. I put my floor mat/foam block back in, which I've been driving without for months, and I'm loving having a dry car!

Rgds,
Chris W.
'95 E300D, 376K

vstech · #2 09-22-2012, 10:07 PM

amazing find, but I'd NEVER use silicone on a metal body part. plenty of body puddys or window putty sealers that do not cause additional corrosion.