Water in Backseat Footwell on Driver's Side
Joined: Nov 2016
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From: Maryland
2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
I checked the windshield for leaks under the A-pillar trim and there were none. When I pour water in the sunroof channel, it flows out by the front wheel well. I'll have to check this other drain hose you are referring to.
Junior Member
Joined: Feb 2019
Posts: 37
Likes: 9
From: New Jersey
C207 E550
FYI even though water seems to be flowing fine from the sunroof channel to the front wheel well, some of it may be leaking on this connection hose so might be a good idea to check it out.
This is the rubber connection hose that is in between the sunroof channel and the a-pillar (main body) drainage hose.
This is the rubber connection hose that is in between the sunroof channel and the a-pillar (main body) drainage hose.
Last edited by xxdemo; Oct 3, 2023 at 04:12 PM.
Joined: Nov 2016
Posts: 7,847
Likes: 3,498
From: Maryland
2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
There could also be a leak in the small drain hose that connects the sunroof drain to the body drain hose.
Try removing the driver side A-Pillar trim, driver side Rubber Door Seal, driver side Ceiling Handle and then the Driver side Sunvisor. Removal for these is a liitle complicated but can easily be found on youtube by searching "W204 headliner removal"
Pull down the headliner a bit and the inside of the headliner should now be accessible from the driver side and you should be able to see a small rubber hose that connects the sunroof drain to the main body drain.
This hose is just secured by being pushed in and when this is loose (which is more likely) or torn (which is very unlikely) it can also drip water into the cabin through the headliner through the a-pllar down to the floor.
Test by running water into the sunroof drain and see if this hose remains dry.
I found this to be loose and leaking water too into the driver side floor combined by the window seal leak.
Try removing the driver side A-Pillar trim, driver side Rubber Door Seal, driver side Ceiling Handle and then the Driver side Sunvisor. Removal for these is a liitle complicated but can easily be found on youtube by searching "W204 headliner removal"
Pull down the headliner a bit and the inside of the headliner should now be accessible from the driver side and you should be able to see a small rubber hose that connects the sunroof drain to the main body drain.
This hose is just secured by being pushed in and when this is loose (which is more likely) or torn (which is very unlikely) it can also drip water into the cabin through the headliner through the a-pllar down to the floor.
Test by running water into the sunroof drain and see if this hose remains dry.
I found this to be loose and leaking water too into the driver side floor combined by the window seal leak.
Did everything and the hose was fully attached and intact (as if new). At first, I poured some water down the wrong (inner) channel that the sunroof rides on and got a few drops of water run down the headliner. I thought, "What the heck!" Then I realized what I did and tried again -- bone dry.
Sunroof drain hose.
At this point, I'm thinking the problem was a clogged drain tube all along. We'll see after the next big rain.
Last edited by JettaRed; Oct 3, 2023 at 06:25 PM.
Junior Member
Joined: Feb 2019
Posts: 37
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From: New Jersey
C207 E550
If all was dry you might be right.
Water might have accumulated in the headliner due to the clogged sunroof drain later bringing it down even after unclogging it.
In my case all started with a clogged sunroof drain but leaking continued and I found both the windshield seal and that little hose loose which probably happened while I was trying to unclog the sunroof drain.
Water might have accumulated in the headliner due to the clogged sunroof drain later bringing it down even after unclogging it.
In my case all started with a clogged sunroof drain but leaking continued and I found both the windshield seal and that little hose loose which probably happened while I was trying to unclog the sunroof drain.
