my car has an interior water leak - PeachParts Mercedes-Benz Forum

240dddd · #1 02-28-2011, 03:58 PM

I recently bought a 1985 300D. The rear passanger floor accumulated a lot of water during a rainstorm last night, but I can't tell where the leak is, i.e. no obvious holes in floor pan or obvious places where water is dripping in.

Can anyone comment on what the most likely culprit would be?

thanks.

rhodes2010 · #2 02-28-2011, 04:04 PM

If it has a sunroof and the sunroof drain holes are clogged this might cause this.
Lot so stories on this board about leaks and drain holes needing to be cleared.

My 1980 300D would get rear water from a dried out rear window seal.
So dry that the window was loose and I could move it around.

Random Guy · #3 02-28-2011, 04:08 PM

The major area that I am aware of that cause trouble is the sunroof drains. There is a drain in each corner of the sunroof pan, and if the drain on the low corner of the car is blocked the water will overflow from the pan into the car. I have also heard that the little spouts that the drain lines attach to can rust off. A temporary solution if just one corner is clogged is to always park with another corner as the low one. My '84 has had a clogged drain ever since I got it, and that has been my workaround. It is slightly annoying having to pay attention to the topography when you park, though.

240dddd · #4 03-03-2011, 01:54 AM

Found the problem to be a hole in the fire wall below the battery tray.

There was so much muck built up under the plastic fender lining that water could not drain out from under the battery. There is a small spot of rot that is allowing water into the firewall.

I know the best way to do this would be to cut out the rot and weld in a new piece of metal, but I don't have time for that right now. Plus it seems like such an awkward spot to work in.

Does anyone know of a jb-weld like epoxy that could be used to at least temporarily fill over the hole?

Aquaticedge · #5 03-03-2011, 01:56 AM

there's this putty stuff you can get. you mix it together (comes as 2 parts in one) put it over the hole and it Dries like concrete.

Stretch · #6 03-03-2011, 02:52 AM

Quote:

Originally Posted by Aquaticedge

there's this putty stuff you can get. you mix it together (comes as 2 parts in one) put it over the hole and it Dries like concrete.

See

http://www.kbs-coatings.com/KBS-NuMetal-Epoxy-Putty_p_19.html

for example...

layback40 · #7 03-03-2011, 02:55 AM

Clean the rust off & put some fiberglass/resin there.

Aquaticedge · #8 03-03-2011, 03:15 AM

Quote:

Originally Posted by Army

See

http://www.kbs-coatings.com/KBS-NuMetal-Epoxy-Putty_p_19.html

for example...

yep, same stuff, except the stuff I'm thinking of has a green resin on the outside and a white polymer on the inside, you mix em together and it makes the same fix really

tbomachines · #9 03-03-2011, 07:54 AM

Quote:

Originally Posted by layback40

Clean the rust off & put some fiberglass/resin there.

x2, or pay a welder to do a quick patch.

NoSparkNeeded · #10 03-03-2011, 10:02 AM

Make sure to check the bottoms of the hood hinge pockets for holes as well. I lived with a leak there for months that I couldn't find CRfromTexas
opened my eyes and I ended up using POR15 soaked fiberglass cloth to patch. So far so good.

Stretch · #11 03-03-2011, 10:57 AM

Quote:

Originally Posted by NoSparkNeeded

Make sure to check the bottoms of the hood hinge pockets for holes as well. I lived with a leak there for months that I couldn't find CRfromTexas
opened my eyes and I ended up using POR15 soaked fiberglass cloth to patch. So far so good.

True true!

I've got some picture of my repairs here:-

http://www.peachparts.com/shopforum/showthread.php?t=286079

But in the end I found out it was the bloody windshield seal!