Mercedes-Benz Forum banner

1 - 15 of 15 Posts

·
Registered
'09 ML350 & '92 S600
Joined
·
4 Posts
Discussion Starter #1
I have an S600 with a leak that fills my rear passenger side with water, and I've lost the PSE pump because of it. The floor has gotten wet a couple times over the past two summer seasons when i drive the car, but nothing like this.

Ive removed the floor carpeting in the rear pass. seat, as well as the pass front seat in attempt to trace the root of the problem... both were quite water logged.

With the water hose i have tested:

1. sunroof drain hole (front)... its is free of debris, water drains efficiently
thru bottom of front fender.
2. sunroof channels running to C-pillar... drains well thru rear end.
3. Hood drains in both upper corners... again drains well to the floor.
4. door seals.. not leaking.
5. A/C running, piping has no cracks or leaks... tried varying fan speeds, with
no new water formation.

Im at a loss for additional ideas. I want to know it anyone has had a similar problem??? And how they resolved it.

Ideas that I might explore:
1. Chance the seal around the front windshield.
2. Clean the A/C drainage. (Not sure how to do that though... any advice??)

Any info would be appreciated!
 

·
Premium Member
1997 S600 (sold)
Joined
·
4,660 Posts
Usually this is the rear sunroof drains getting clogged with debris. It may be worth reaming out the drain tubes in case there is partial blockage that slows drain flow.

If it's getting into the rear seat well where the PSE pump is, it must be coming from up high in the rear. Front windshield and AC drains cannot be the culprit. Other possibility would be the rear window seal.

Brett
 

·
Premium Member
1999 S600 Sedan, 1999 S600 w/ 4-pl seating, 1995 S600 Coupe, 2-1992 600SEL's, 2002 ML55, 1998 SL600
Joined
·
2,425 Posts
I just had a similar condition in my ML. The FRONT passenger foot well was accumulating water. It turned out to be the a/c condenser drain was misaligned, causing it to leak in the front passenger well.

Our 600SEL's have TWO separate a/c units, one for the front, one for the back. After exhausting all other options that Brett suggests, you might want to see where the REAR a/c unit is draining its moisture.
 

·
Registered
'09 ML350 & '92 S600
Joined
·
4 Posts
Discussion Starter #4
Thanks guys. I'll try cleaning out the drains w compressed air first
Then entertain the more expensive alternatives.

Keep u guys posted. Thanks for the advice again.
 

·
Registered
'09 ML350 & '92 S600
Joined
·
4 Posts
Discussion Starter #5
Ok so here is the latest greatest!!

The weather here has been dry as a bone, and I managed to dry out the entire car, as well as make sure there is no crap built up in any of the drains. I even took it through a touchless high pressure car wash without any leaking.

Ive been driving the car with the A/C running, and everything has been ok. Yesterday, for whatever reason, there was a tiny build up of water again in the back passeger seat area. There was NO rain, or puddles on the road, and the A/C setting were sitting in the same position as the previous days drive.

So as I was actually getting excited that i might soon get to start closing things up, i find myself mulling over new possibilities.

Does the S600 have a second a/c unit in the trunk that might be leaking? Is it possible to get a 1/2 cup of water from condensation alone??
 

·
Premium Member
1997 S600 (sold)
Joined
·
4,660 Posts
Are you talking about water in the floor of the rear (wet carpet)? Or pooled under the seat where the PSE pump is located? I can see the rear AC evaporator leaking condensate into the rear footwells. The rear AC evaporator is below the center armrest.

I don't know how water could get up under the rear seat unless it was pooled on top of the headliner from the high pressure car wash and made its way down to the seat after a couple of days.

Brett
 

·
Registered
1993 Mercedes-Benz 300SE & 1998 Mercedes-Benz C230
Joined
·
257 Posts
Water test. Have someone outside with water hose & you can listen and look at any drainage issues. Sunroof could also be rusted out around the drain holes which will cause water to simply fall into the back paneling, or could be the seal on the windshield(s).
 

·
Premium Member
1997 S600 (sold)
Joined
·
4,660 Posts
I should say I'm not 100% certain where the evaporator is located for the rear system. I know there is a separate one. You can hear that the blower is right there under the armrest, but I'm not sure exactly where the evaporator is. I'm sure you can find some info online. Or try alldatadiy.com. It's not too much for a year subscription, and it's worth it if you'll be doing a lot of DIY stuff.

Brett
 

·
Registered
'09 ML350 & '92 S600
Joined
·
4 Posts
Discussion Starter #9
To this point I've kept the carpets (covering
the floor boards) folded upward, to allow the water
to dry. I have now removed that carpeting entirely
to determine where the leak is from. Brett I wish I had
an answer for u... The problem w the s600 is that
it has channels that allow communication from the front
seat, to the foot area of the back seat, and all the way
to the area where the pse pump sites.

I took out the carpeting just to be able to see where the
water enters. Up to this point it has occurred so randomly,
that I'm having trouble determining the source. I believe
it's coming from the front end. With the carpeting out, my
Plan for the weekend is to check out the front A/C drain.

I'm slowly running out of guesses, but I'll keep u posted.
How could I possibly know if my A/C is misaligned?!
 

·
Premium Member
1997 S600 (sold)
Joined
·
4,660 Posts
Again, I don't see how water could get from the floorboard up onto the shelf where the PSE pump sits. If that's where the water is, it must be coming from above.

If the water is in the rear floorboard, then maybe it is flowing from the forward footwell. I'm not sure about the AC condenser drains in front. I think you'd just have to dig for them from the interior, remove carpet, etc, which you already have a good start on. Do you get any visible drainage onto the ground under the car at all when you run the AC?

Brett
 

·
Registered
mercedes w140 s320
Joined
·
2 Posts
I have an S600 with a leak that fills my rear passenger side with water, and I've lost the PSE pump because of it. The floor has gotten wet a couple times over the past two summer seasons when i drive the car, but nothing like this.

Ive removed the floor carpeting in the rear pass. seat, as well as the pass front seat in attempt to trace the root of the problem... both were quite water logged.

With the water hose i have tested:

1. sunroof drain hole (front)... its is free of debris, water drains efficiently
thru bottom of front fender.
2. sunroof channels running to C-pillar... drains well thru rear end.
3. Hood drains in both upper corners... again drains well to the floor.
4. door seals.. not leaking.
5. A/C running, piping has no cracks or leaks... tried varying fan speeds, with
no new water formation.

Im at a loss for additional ideas. I want to know it anyone has had a similar problem??? And how they resolved it.

Ideas that I might explore:
1. Chance the seal around the front windshield.
2. Clean the A/C drainage. (Not sure how to do that though... any advice??)

Any info would be appreciated!
Probably is your heater core leaking if you missing water in the engine bay! I have a similar problem with mine s320 and also lost pse pump!:|
 

·
Premium Member
1997 S600 (sold)
Joined
·
4,660 Posts
Probably is your heater core leaking if you missing water in the engine bay! I have a similar problem with mine s320 and also lost pse pump!:|
So coolant leaking into the footwell was able to wick up the carpet and fill the recess below the rear seat enough to flood the PSE pump? I'm surprised. That must have been a lot of coolant. Could you not smell it in the cabin or notice the soaked, squishy carpet before the cabin got that full of coolant?

Brett
 

·
Registered
mercedes w140 s320
Joined
·
2 Posts
So coolant leaking into the footwelli was able to wick up the carpet and fill the recess below the rear seat enough to flood the PSE pump? I'm surprised. That must have been a lot of coolant. Could you not smell it in the cabin or notice the soaked, squishy carpet before the cabin got that full of coolant?

Brett
I just have been bought a car and for few months didn't turning heat on, and first time when I thurn it on there was a bad smell but I didn't know what the smell is, and the carpets was dry, coolant was leaking through the vent or somewhere beneith the carpets! I have been surprised as well with amount of coolant beneith rear sets,!
 

·
Registered
'91 560SEC, '91 300SE (sold), '98 Yota, '02 S-10 Hauler
Joined
·
8,934 Posts
I too have been having a water problem with my 91 300SE (W126) in the passenger side rear floor, if I back in the D/W it's in the front. So far I have sealed/glued the sunroof shut as I don't use it anyway, done the water hose test on the doors, windows, roof, etc, checked the drains in the cowl at the bottom of the windshield, re-sealed the rubber strip along the bottom of the windshield, pulled, cleaned, and re-sealed the moulding on right side "A" pillar and still it leaks. This is not a coolant leak because of no coolant smell. I had to unplug the theft alarm a while back because the plug would get damp and set the alarm off. After washing the car if I immediately went for a drive it was ok, if it sat for about an hour or more I had to wait til the next day or "alarm city". I'm running out of ideas and areas to check :surrender: any other ideas please ?
 

·
Registered
2003 S55 AMG Kompressor
Joined
·
361 Posts
How about checking the W126 section ? Maybe your heater box is rusted, a very common problem in these car (and rather expensive and pretty involved to be fixed)
 
1 - 15 of 15 Posts
Top