w123 water Leak in car - PeachParts Mercedes-Benz Forum

steeleygreg · #1 09-10-2011, 07:05 PM

82 240D with a strange water leak which is isolated to the rear driver passenger side of the car. The front floor boards on either side are dry. Could this be coming from the "B" pillar area or the rear window ? Any help would be appreciated.

IVIuzzy · #2 09-10-2011, 07:32 PM

most likely rear window , check the trunk under plastics to confirm. however it is difficult because the rear footwell is the lowest part of the car. gravity explains the rest.

most common imo is the rear window seal, unless u have a window that isnt closing all the way

bd1308 · #3 09-10-2011, 08:36 PM

Rear window probably, my car has some silicone under a small gap at the rear window courtesy of the PO.

Palangi · #4 09-10-2011, 10:05 PM

Air conditioner running?

Could be that the condensation drain hose has crumbled into powder.

steeleygreg · #5 09-11-2011, 08:00 AM

Thank you. I have a tendency to agree with IVIuzzy and bd1308 and suspect the rear window also, but I don't understand how water gets into the passenger compartment from the rear window. I've found puddles of water in the trunk well's before due to a rear window seal in another car.
As for the AC unit, although the pump is there it doesn't have a belt connected to it and has not been run since I've owned the car, so I'd have to rule that out.

IVIuzzy · #6 09-11-2011, 10:40 AM

steeleygreg, it gets into the passenger compartment because the rubber seal is behind the seat on the deck lid. some water, im my expierence, goes into the trunk, and some goes behind the seat, under the bottom part, and puddles up on the floor. you can remove the bottom of the seat, um sure theres water in there too. id try to keep it dry as much as possible until you get this fixed. the carpets tend to hold moisture on the floor. air+ moisture = rust. rust on a unibody = real bad. id definately get this issue addressed. you can find on here many diy's to change your own rear window. or depending on your location it is about $75 for labor, and about 80-100 for gasket. im not sure what fastlane carries anymore its been a while since i ordered one.

good luck keep those floors dry!

steeleygreg · #7 09-11-2011, 12:39 PM

IVIuzzy, thanks for the explanation. Since I'm currently cleaning the carpets (both floor mat and the factory mat) I'll also pull the seat and see what other damage has been going on. I'll post my findings!
This is the second 240d which I bought. Purchased from a family member which has been in the family for 20 years. Had to help her out! Both run and one is a daily driver, but both are still projects.

As for the windows (both front and back) I found one willing to pull and put a new seal in. Cost is as you estimated $75.00 and I supply the gasket. Since I'm and engine person and learning body work, its money well spent. I've seen prices ranging from $32.00 to $75.00 for the gasket. Also have a source for the glass if one breaks. I'll probably wait a few weeks and purchase the rear window shield from this source, since it appears to have the window-defroster molded into the glass (not original) and is still operational.

steeleygreg · #8 09-12-2011, 06:30 AM

Water is coming in through the B-pillar on the driver side. Anybody got an idea of how it's leaking in ?

Stretch · #9 09-12-2011, 07:23 AM

Check the door seals at the top...

As for pictures of the rust in a uni-body warning posted above by IVIuzzy have a look here:-

My W123 saloon / sedan old accident repair (and a bit of rust repair) thread

When water leaks into the floor pan area it can only go down. Unfortunately MB used a rubberised undercoating that traps water and helps it to run along the length of the car. (Double) Unfortunately there's a spot welded joint between the floor pan and the outer sill / rocker / longeron which suffers...