My '89 300E leaks into the driver's floor. The AC condenser drains are not the problem. Running the AC for long periods leaves no water, and both drains under the car drip when I park it. I don't believe yet that it is a windshield leak, since it sat in a hard rain for several hours recently with no leaks. It seems to come from driving in the rain and comes from above, I believe, having put towels in the floor and up the firewall as high as the pedals. The water seems clean, but does seem so far to come from above floor level. My shop has cleared drains in the sunroof and one under the brake booster. Where are the drains in the sunroof located and what is the best way to clean them out? Do you have any other ideas on finding this leak?

You might consider looking into the possibility of leaking around some breach in the firewall. Does your car have the "sound insulation panel" (what I call the belly pan) underneath the engine/transmission? If so, it should keep out almost all environmental water intrusion from below.

You say the water appears clean - does it have a smell? Does it have any color? I was thinking that it might be something that runs in from the engine compartment along a hose or wire(s) that run into the cabin. I was thinking windshield leak (rusted out area underneath the rubber molding that holds the window in) but you said that the car was dry after a hard rainstorm...

Good luck - since I have the same year/model car I will be watching this. Once you've figured it out I'd like to see what you found out.

__________________
Jay Yambrovich
Scotts Valley, CA.

1993 300 CE Cabriolet (A124) 131K miles
1997 C-280 133K miles

2000 BMW R1100RT 69K miles
1989 300 E 216K miles (sold)

The sunroof drains run from the 2 front edges of the sunroof frame through the A-pillar to the back of the front fenders. The rear hoses run along the C-pillar, through the trunk (behind the quarter panel upholstery) and through a horizontal ledge in the quarter panels to the outside behind the rear bumper.

The best way to clean them out is to (gently) blow some pressure air through the pipes. The front drains are rather easy, the rear is difficult...

Is it possible that water comes leaking in from the door? There has to be an anti-water-plastic screen stuck behind the door panel. Maybe this screen is not good anymore (open at the bottom) and water comes leaking in from here?

greetingz,

__________________
1990 300SL-24
1993 C250D with a minor 600+k kilometer
www.MBenzNL.com(the Netherlands)

Are you using antifreeze in the radiator? If so, check the leaks to see if they match the color of the antifreeze. Mine was leaking antifreeze from the bottom of the water pump, (there is a hole in the underside of the water pump that it is not obvious from the above). I had to replace the pump but yours may be something minor such as a leaking hose or something.

I would go for the sunroof drains as well. My 300CE had the same problem. The hoses for sunroof drain had shrinked and let the water out in the driver- and passenger floor. (Possibly from heat when repainting the car)

__________________
Emil Österman, Stockholm - Sweden

MB SL500 -93 - Silver
MB 230CE -84 - Silver
MB 230E -82 - Yellow
MB 180B -59 - Green

Thanks to you who sent in helpful ideas. FWIW I have eliminated the sunroof drains; the carpet under the door sill does not get wet, but I will check the plastic door seal; there is a drain from somewhere below the brake booster, I'm told, which may be blocked. My car has no belly pan under the engine. I find no breaches in the firewall other than the grommeted holes for cables, etc.
Since I put towels on the firewall but not reaching the floor, I believe their getting soaked strongly implies water through a firewall opening or perhaps from the above- mentioned drain, which has NOT been cleaned, and I cannot find.
I'm going to try silicone seal to close any leaks through the firewall grommets and finding the elusive drain somewhere beneath the brake booster.