Guys, I had my car parked in the rain for the first time since I bought it today, and when I drove home I noticed a pretty big puddle of water in the drivers side floor mat. After looking under the dash, the only spot I can find is right behind the gas paddle. Everything else is dry.




Is this a common issue? Any ideas on how to fix it?

Thanks, Martin

 

I would check the sunroof water drains and be sure that the drains below the windshield are not clogged with leaves and crap.

 

Any idea on how I can remove that plastic piece right below the windshield? Don't want to break it.

I also notices that the plastic piece is really tight to the windshield in the middle of the car, but then on the sides there is a little gap. But it's only leaking on the drivers side.
Could that gap be the issue, and if so, how do I fix that?

 

No that bottom black plastic piece is just cosmetic. The drain holes at the bottom of that plastic piece are what need to be clear so water can drain properly.

 

I'll have to check into that closer.
I seen the drain on the passenger side, right out of the corner of the plastic piece, and it's clean.
On the drivers side, since the wiper is mounted right there in the corner, there is no drain out of the plastic piece, just a hole. So the drain needs to be below that. I got some leaves and stuff out of that compartment, but I didn't seem to get everything.

Time to get out the flash light and air compressor.

 

I had passenger side clogged with dirt and natural junk. It has been so densely packed so I used... power wash on full setting. Omg. It blew that clogged drain with dirt guts all over the car.

 

I've cleaned out the drain closest to the driver side fender, there was a bunch of leaves and stuff down there, but it was really tough to get to, due to the design of the channel before it went down the drain tube.

Then I poured a glass of water down all four drains and it came out at the bottom of the car right away. So I'm hoping I fixed the problem.

I'm still a little concerned about the plastic piece under the windshield not being a tight fit to the glass. Any more opinions on that?

 

I used to fix drain problems on my w126 and BMW'S by fishing weed eater line down the drains, just a thought.

 

WOW, great idea!

 

Yes, great idea. I'll give that another try just to be safe.
And then it's waiting for some more rain

 

Since the large plastic cover is what runs water to the drains, it obviously is not doing its job if it has pulled up from the base of the windshield. Think how many gallons of water run down your windshield glass in a heavy rain. If a lot of that is running under the large plastic piece, then it obviously is not going in the drains. Where exactly it can go under there to get in your car, I do not know. Anyway, I can tell you exactly how that large piece works and how to get it off if you need to since I had to fix mine. If yours has popped up, I'm guessing that either your car has had a new windshield or some other repair under there like the wiper assembly. It's the sort of piece that requires some care to install, and some guy at the glass shop is not paying that much attention. Anyway:

Right at the bottom of the glass there is a little aluminum channel that runs the whole length of the windshield base. It's only 1/4" to 3/8" wide and shaped like a little "u". On the black piece, about 1/2" down from the top edge there is a "tab" that runs it's entire length. In profile, it looks sort of like an arrow - a skinny stick with a little head on it. The tab on the black piece is supposed to snap into the channel and the "head" of the arrow holds it in as it goes under little ridges at the top edge of the channel. Yours is obviously not snapped in all the way along its length. While it's possible the long tab has partially broken off the black piece, that's unlikely. So the first thing to try is just to take the side of your fist and smack it from the center out towards the edges and see if it will pop back in. If working correctly, it fits very tight to the windshield. If it won't snap in, it's because somebody was not careful and has deformed the aluminum channel. They have opened the "mouth" of the U too much and it won't hold the tab. That was my issue. So I used a rounded piece of hard wood - maple - and slowly massaged it back to a uniform opening, and now it's perfect. To remove the black piece, there are four screws at the front above the rear of the engine, the drains, a couple clips holding wires and hoses, and you need to remove the wipers. And there is one little rubber molded piece at the far edge on the passenger side that unclips. Then you just need to slowly work the tab up from the channel starting at one end. It's a fairly easy job, and takes no longer than it took me to type the description.

 

I had Trans Am so I very familiar with leaks. I would put my daughter in the hatch area with a flashlight (because she could fit) and I'd run a garden hose all over the leaky area till she pin pointed the leak. Another tip, if the issue is a rubber seal, silicone diver's grease works wonders. An $8 container from Amazon will last a lifetime. Just used it to fix the wife's Z3 top.

 

And I'll add that the black piece has a little flat piece of weather strip right at its top edge that is supposed to be tight to the windshield. If working correctly virtually no water can get under there and it all goes to the drains. The piece is by no means just cosmetic.

 

My 05 CLK doesn't have a weather strip at the top of the black plastic. Probably a design change.

Your theory that water running under the black strip would enter the cabin means that the lower edge of the windshield is not sealed, and also the cabin would be flooded driving in any kind of rain storm. Obviously that is not the case.

 

I'll bet yours does have the weatherstrip. Its' very small and rectangular - maybe 1/32" inch thick and is almost integral to the plastic. And my "theory" has nothing to do with the base of the glass being sealed. It has to do with where water can go if it's flooding that area under there. Look at it this way, if the issue is only the base of the glass being sealed, then why are people telling him to address a leak by cleaning the drains? That water is not getting under glass, it's coming in through some opening because it's not being directed out the drains. That large piece not being sealed is the same issue as plugged drains, just on a much larger scale.

EDIT: The little weatherstrip is not right on top where you can see it. It's on the back side of the plastic piece, maybe 1/8" down from the top. But if you look close at where that plastic actually touches the glass, you can sort of see it under there.

 

Thanks for the write up, Yidney. I'll give it a shot tonight!

What's interesting is, that the plastic piece is loose on both sides of the car, but I'm only getting water on the drivers side.

I'll report back with what I find.

EDIT:
I've found this pic on the web:



Just making sure, you're talking about the little ridge on the top of the part in the picture.

Here is another, it's in the bottom this time.

Oh, and I can confirm that little seal piece that presses against the windshield. Mine has that too.

 

I checked into this really quick at lunch time, and I might have bad news.
I was trying to look behind the plastic piece, and I didn't see that aluminum channel the plastic lip is supposed to go into.
Could somebody please post an exploded view that shows this part, so I could check into buying one?

But you can actually see that little seal on the plastic part.

Can anybody tell me if this is an original windshield, or if it had been replaced:


I also wanted to follow up on the drain cleaning issue.
Here is a picture that shows how the water flows down the plastic cowl piece, through the channel and then down the drain tube, in case somebody is having issues locating them. I know I sure did

 

MB glass has an MB symbol. Looks like your windshield was replaced at some point.

 

That's what I figured, no star...
So who ever installed it, might not have been too thorough, damaged the aluminum channel and maybe just thrown it away.

How big of a deal is it to get the wipers off?

 

I believe that original glass has white signature sticker in right bottom corner . Daimler AG something. At least mine has one. This is a good indication of authenticity.

 

If you ever had your windshield replaced there might have been a gap in the sealant.

 

I just bought the car 2 weeks ago, so if that happened, it would have been before my time...

 

Found this picture, but that aluminum channel is not on here:

http://www.mbpartsworld.com/showAsse...=0&modelYear=0

This is informative too:

http://www.mbpartsworld.com/showAsse...=0&modelYear=0

 

Alright, I took the plastic windshield cowl cover off and I did see what's supposed to be that channel. But whoever installed the windshield might have screwed up, as there is a step down from the windshield to the channel, and the web on the plastic piece doesn't seem to be long enough to reach the channel.

I pried the channel open some more as suggested above by Yidney. But I could only get a 10 inch section to snap into the channel. The remainder is actually worse than before.

I'll take it back off to see if I can get some more opening and try again.
Sorry I didn't get any pics today, will do that on the next try as well.

 

Martin_F this might be useful to watch. I gives you a good view of what is under the plastic beauty piece. It's for an earlier model but the attachments are most likely similar.