I have had several Mercedes and have had problems with water on the rear passenger floor and in the trunk. This is a 1985 300 TD with sunroof. Also I seem to have problems with the climate control. When the car is sitting, no problem, but when you drive, it just turns the heat off. If I switch the heat off and then back on, It works for a while, then the same thing happens.

Craig,

There have been a number of posts regarding water in rear floorboard and trunk.

The trunk is drained by simply reaching under the rear quarter panel on each side. There is a rubber drain that has four petals shaped much like a heart valve. Simply move them around with your finger and it will probably drain. If not use a piece of wire, screwdriver, etc.

The rear floorboard problem is most often cured by clearing four drains which are under the hood. Two of them are directly below the hood hinges. The other two are inboard from the hood hinges, one below the battery, the other below the fuse box. What I mean is that they are further down the firewall from the battery and fusebox. Be dilligent, find all four of these drains and clear them out thoroughly with baling wire (for city people, coat hangers seem to substitute quite well for the high tech baling wire tool).

If you will search, there have been many posts regarding the cruise control, climate control problem you mentioned. I have no personal experience about this one.

Good luck,

And since you have a sun roof, clear the drains in the corners of the sun roof while you've got the bailing wire handy.

Thanks for the reply folks, You have been a tremendous reassurance to me. By the way, I see that you are lovers of MB, I am also. Aside from this 85 300TD, I just got a 1993 S350 TD, That has all the trimmings, and I have a 1990, 260E that is quite a car as well. I also have had a 1985 200, and a 1981 230E; and a 1971 220D. So needless to say, I love these cars! So again, thanks for the help!

Craig

There is also a post like this one in the Diesel section. I think it is something like "240D Flooded"

drains
 

I have a rear winshield leak on my 83 300D and I cleaned out all the "drains" this week-end and the water just poured out ...... thanks for all the info on this forum.

Regarding the drains Larry referred to as under the rear quarter panels: If the massage method Larry describes has little or no effect, the drains may be accessed by cleaning out your trunk and removing the trunk liners to get at the drains from above. I clean the drains in my 300E this way, not the other way. I don't know why or how, perhaps its from all the grungy golf shoes and clubs that occupy my trunk from time to time, but dirt, leaves and general crud can accumulate in there and block the drains. After I purchased the 300E, I cleared out 5 sections of N Gauge track, 6 model telephone posts and an N Gauge oak tree in the left well. Baffled me.

Regarding all of the drains. The rubber drains on my old 300D were so brittle that the massage method destroyed them (which is why I clean the ones in the 300E the way I do). Cheap to replace, though.

As to these rubber "drains" located in the wheel wells, I always thought of them as vents, but I suppose they double as both.

But this doesn't address the reason why calphil is getting water in his trunk in the first place.

The reason I reply is because i'm also getting water in my 300E trunk, and always at the same location: in the wheel wells presumably through those vented rubber grommets located underneath the trunk liner in the wells.

Is this normal? I've checked the sunroof drain tubes and they're fine, as well as the tailight assembly gasket/seals, and the trunk seal itself. All are ok. The body-formed drains that the grommets attach to have deteriorated somewhat, leading me to believe that the deterioration allows water to enter (less height to enter trunk). Anyone else have this problem?

Also, the water only enters trunk after driving in rainy conditions --I can hose water on my trunk all day long and it will remain dry.

TIA

~Paul

I just finished a long-running battle with water in the trunk. Part of the problem was a leaking window gasket. The water from the lower driver's corner of the rear window ran into the speaker depression on the rear window shelf and dripped out the speaker wire hole and into the trunk. It was also intermittent and depended on the amount of water in the depression as well. I replaced the seal and used silicone sealer in the window channel of the seal as well as around the metal window opening.

The main leak was around the trunk seal. I removed the seal, cleaned and painted the seal channel and replaced the seal with a new one using 3M black weatherstripping glue. I still had the leaking. I had installed the seal just like the old one, but it did not "look" right to me. I even checked out another vehicle and it too had the seal installed the same way. On a whim (and also as a last resort) I removed the seal and cleaned out the channel again. I reinstalled it in reverse fashion and voila, the leaks ended. I also used permatex black silicone rather than weatherstripping glue.

I don't know if I can describe the installation, but I installed the seal with the "tall" side (the side which contacts the trunk lid) towards the inside of the trunk. The seal now forms a channel for the water toward the outside of the trunk. If you can visualize a cross-section of the seal, it resembles a "J". The "hook" of the "J" is facing toward the outside of the trunk. Also there is a small bump or bead on the "tall" side of the "J". This bead fits exactly at the top of the inside lip of the channel on the inside of the trunk. This leads me to believe this is the correct installation rather than the way the original seal was installed. Also, I'm not sure the seal in the car was the original seal (same with the other car I looked at as an example).

The seal will fit either way, but this way solved my leaks. It also made the trunk lid harder to shut (similar to the doors when new seals are installed.

water on the floor in the back seat
 

If you have vents behind the rear windows.....thats the problem....just bang off the vent cover(it gets pushed on the sheetmetal rail and holds with its metal biting clip edge) with a block of wood and mallet that will expose the vent slots......then clean them well with a toothbrush and soap....let it dry well and smear clear silicone caulking over the cracks in the sealant that the factory smeared in there. What is happening is the roof drains down the sides of the roof and the water passes over the vent area....when there are cracks in the sealant the water leaks into the car through the rear roof post and drains onto the floor....usually by way of under the rear seat. Pull the seat and dry it all well after you fix the sealant leaks and you should be OK.

This is a very common problem on older Mercedes as you know. My 85' had water in the passenger rear floor as well. I was told several times that it was probably the drains under the front cowl. I checked them and they were clear. I actually noticed that my water problem went away after I changed my antenna seal - which is odd, because the antenna is on the driver side and the water was on the passenger side. Strange, but it went away after that.

It was a week later, I thought I would check the drains anyway, as all of the water had not evaporated by then - but as mentioned, they were clear. Since you have a wagon and the floor setup is different, this may not be your problem. It may actually be your drains.

Good luck

Still searching for drain holes...
 

I have a "new" 1978 300D. No rust (it was an AZ and CA car for almosta all its life). Taking preventive action, I have decided to clear out the drains which might cause rust for me (as I live in the rainy Pacific NW).

I have found the drains under the hood hinges, and one under the fuse box. I have cleaned out a TON of debris. But I have NOT been able to find a drain under the battery on the firewall. In fact, I cannot reach anything under the batter. Am I supposed to take out the battery?? Could someone post a picture or diagram which would help me understand the location of the drain?

My sunroof will not open (broken!), so I cannot access the sunroof water drains. Is there another way to clean them?

And last, the channels above the doors are filled with pine needles and debris. I have tried needle-nose pliers, and jet spraying with water. I am wondering if there is a great way to clear these out from above or below or wherever the access to this drain might be.

It isn't raining these days in WA, so it's an ideal time to get prep done.

Thanks for any help!! I appreciate this forum!! :)

bb