In my 2014 E350 Wagon I just noticed the carpet in the rear hatch area was moist after a few days of on and off rain. Specifically, the area that was wet is the corner of the carpet near the drivers side, closest to the tail light. The bottom floor in that corner was wet, all the way to the handle to live up the rear seat cushion. It only extended about 6” into the center of the rear hatch floor. The passenger side was totally dry.

i removed the spare tire and the floor beneath the tire was also a bit moist. None of the vertical surfaces were wet, except for a small piece of that black carpet fiber stuff that’s just below the center of the scuff plate. See photos where I’m pointing.

I removed the scuff plate and there’s no obvious moisture there.

there was a bit of moisture below the accessory battery, but not much. Again pointing in the photo.

one thing I did recently is replace the drivers side tail light, after the wife cracked one against a fence. I had done this before so I think I installed it correctly. I’ll attach photos of the weatherstrip all around the tailgate area as well to see if I missed something.

has anyone had any water enter their rear hatch area like this? And if so, did you find the issue?

any other ideas?

also, I looked under the bumper and I could see what appears to be the rear window washer pump. Last photo. Is there supposed to be a cover over this area so water doesn’t enter?

thanks.

Black fiber-carpet was a bit moist right where I’m pointing. But no other vertical surface of this fiber-carpet molded section.

After removal of the scuff place, found no moisture there

Also moist in the bottom of this area, including some moisture underneath the fiber carpet. Mostly on the left side.

Drivers side new taillight. Small gap between plastic flange and the door weather strip. I have since hit this with a heat gun to gently lay the tail light seal a bit better against the weatherstrip.

Passenger taillight.

Upper left hinge area

Upper right hinge area

Right side weather strip

Left side lower taillight area

Right side lower taillight area

Tiny bit of moisture below the rear batter but seemed old moisture since it was dirty.

Under the rear bumper this whole area is exposed. Is there supposed to be a cover here?

Just helping to rule some things out:
Does it smell of wiper fluid?
Could it be AC condensation drain clog?

Only asking because I've read other models having moisture issues in the floor due to these issues.

I just smelled it and there is no obvious distinctive smell, other than slightly moldy wet carpet type of smell. It’s subtle.

and I don’t know where the AC condensation drain plug is. Can you help guide me?

also, the actual lift gate is not wet at all anywhere.

I closed the hatch after removing the scuff plate and rear seat and sprayed with water all around the door and into the bumper where the hatch door closed. After opening it back up, no moisture anywhere other than the few drops of water that were coming off the newly wet lift gate.

I can't remember which model had this issue but they found the seals around the brake lights were bad. Maybe check those? Some users will put tissue paper in various areas to help them figure out where the leak might be from. You could try that method.
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Yes there should be a plastic panel under the bumper cover.

thanks! I’ll try this tissue paper idea. Thanks.

seriously?? Maybe that’s an issue there.

anyine one know the part number or name of this cover so I can find one and install it?

I've had water intrusion from clogged front sunroof drains on my 2011 S212....it would run down the A-pillar. There was a YouTube video I was able to find that helped in my situation. I would check your rear sunroof drain since the water intrusion is localized to the rear. Do a search on YouTube for procedure to clean out rear drains if that is indeed your problem.

thanks raj. I have the single sunroof not the panoramic. Are there rear drains for that as well?

my wagon sits sort of lower in the front, so it seems that any water that gets through the sunroof rubber seal would go forward not backward. But I will look for that video you mentioned.

thanks

I just did a quick search on YouTube and came up with this video which gives you a sense of where the drains are located beneath all the interior trim...

Thanks raj. What a gem of a video. Can’t believe how many helpful people load up random videos that help random people.

I’ll take a look tomorrow at the sunroof drains. It’s dark now. I found a bunch of videos about how to unclog them if they’re clogged.

your video implies that the water exits on the front side of that rear most side window. Sort of behind the second row seats. I found moisture at the rear most part of the cargo floor. But water is funny and travels all sorts of ways.

thanks again Raj.

As the video stated...it drains behind the rear wheels on either side...check that drain behind your left rear tire.

I just went out to check the drain from the inside of the rear cargo area. I removed the left side rear carpeted panel and the black cover that’s behind that cover, exposing the wiring and components. I see a rubber black hose. Picture below. It’s totally dry back there. That area’s Floor is bone dry too.

do you think this is the drain tube?

also opened the sun roof and can only see the two front drain holes. Can’t see the rear holes because the opened sunroof glass is in the way.

I also looked under the rear wheel and can only see the black wheel well panel. I can’t see the drain outlet. Perhaps it’s behind that panel.

The black hose that you're pointing out sure looks like the drain pipe to me. As I stated in my situation, I had to manipulate the front drain valve that exited between the front door between the door frame and door behind the front fender liner .I was able to wedge my hand into the slight opening and squeeze the valve which resulted in a lot of thick goop being freed and clearing the drain. I've never had to clear my rear drains so I'm unable to give you further hints. The drain holes for the rear are obstructed like you said by the sunroof glass but they are there.

Ok got it. Yes I saw a few videos that you asked me to see on YouTube showing how the drain outlet is shaped like a “+” and squeezing it makes it open up.

it’s raining right now here in Oakland. Tomorrow, I’ll open the sunroof and pour some water in the trough to see if it drains out the rear. I’ll raise the front of the wagon to make sure it’s tilted backwards.

thanks again Raj.

One tech said they snip the plus part out so no debris will clog those drains in the future

It’s been raining hard and I just went to check the car and the very corner of the carpet is soaking wet. The small 2”x2” section of carpet that remains when you pull out the 3rd row seat bottom. On the drivers side. It’s attached to the vertical carpeted section that has the release handle that you pull in order to drop the 2nd row seat backs. Only that part was wet. Everything else around there was totally dry. Except…

for the inside of the rubber weatherstrip closest to that lower left corner of the rear hatch opening.

I removed the scuff plate and pulled back the weather strip and noticed it was wet on the inside of that strip at that corner.

then I looked at the outside of that weatherstrip, just under the drivers side taillight and noticed a peculiar thing about the weather strip. It had a “wing” section that was tucked into the gap just to the left of the hatch opening. I pulled out that little bit of weatherstripping and it sat nicely against the body section that’s under the taillight.

in the photo above you can see just below the tailight, it’s just white body paint. Check out the pic below. Once I pulled that strip out, it covered part of the white body and covered the little gap. It’s got an angled section of rubber toward the bottom that angled back in to the gap. That’s just how it’s designed. Check it out:


Before. Notice below and to the right of the taillight and compare to the “after” pic below.

After: notice how there’s now a strip of rubber below and to the right of the taillight. This strip covers a small gap in the body panel. I think this rubber strip prevents water from going places it shouldn’t.

It’s going to rain all night so I’ll check to see if water continued to get in or not in the morning.

I think you might have found the source of your particular leak. I'll double check my rear taillights later today and look for the rubber strip you posted to see their positioning. Excellent sleuthing.

So it rained all night and there was no additional water in that area. See photos below.

Raj, or anyone else. Can you upload a pic of your wagon’s weather seal? Specifically the section that’s next to the tail light and below.

As you can see in the pic below, there’s a small section of weather strip that covers the little gap between the tail light body panel and the hatch opening panel. But on mine, it still leaves about a 3” long section of gap between those two panels where the weather strip doesn’t have enough of a “flange” to fill that gap. It just tucks into the gap. Perhaps that’s the design.

but I’m wondering if my weather strip was installed upside down or something.


The is the small section of carpet that would get wet. The water would then get soaked up by the seat bottom carpet making it seem like the whole area was getting dripped on. But it’s just this small section right next to the weatherstrip. I removed the scuff plate to show that it’s totally dry under there.

This is the section of weather strip that I pulled out to cover the gap between body panels. But there’s still about 3” left of body panel gap below this angled section of weather strip. Wondering if it’s supposed to seal all the way to the bumper. Mine has a slight opening there where water presumably enters and exits behind the rear bumper

I wonder if your water intrusion occurs while driving then?

Probably you’re right.

but I just did something that maybe solves it. I noticed the weatherstripping section this runs all along the bottom of the hatch opening (above the rear bumper) was tucked into that panel gap.

I pulled out the weather strip and carefully re-sat it, but this time making sure that the weather strip was NOT tucked into that gap, leaving the small “flange” to cover that panel gap.

Hopefully this fixes the issue. Maybe someone installed it incorrectly. I know the dealer did some work back there a while back.

again, can someone do me a favor and upload a photo of their wagon’s rear hatch weather stripping? Particularly the lower section below the taillights and all along the bottom of the hatch opening, above rear bumper?

thanks!


Notice the weatherstrip angles and tucks into this panel gap, leaving a gap for water to get in. This is how it was installed.

Again, weather stripping tucked into the panel gap

I pulled out the weather strip and reinstalled, leaving a small piece of stripping to cover that gap.

Also, all along the bottom of the opening, above the bumper, a small strip of weatherstripping covers this tiny gap.

Hoping you solved your mysterious leak with that simple fix, seems probable. 🤞🏽

Here are the pics you requested @hecdog ....bear in mind I own a 2011 S212....maybe MB changed the weatherstripping layout in later years. Hopefully someone with your year S212 can confirm if that's the case.



Left taillight area.

Right taillight area.

Weatherstripping is tucked in behind rear body colored plastic panel.

Different angle to show the weatherstripping .

Weatherstripping follows behind the plastic bumper panel.