w124 water leak in cabin- please help! - PeachParts Mercedes-Benz Forum

unclbob · #1 08-24-2009, 01:58 PM

Hi everyone,

I just had the car 87 300d out in the rain the other day and came back and notices the carpet under both seats was wet/damp. I tried to determine where it was coming from and noticed the carpet running up the transmition tunnel between seats was also very damp which surprised me.I checked under both front mats and under the plastic so I could see down to the floor boards and it was dry on both sides.

1. I learned the sunroof vents could be clogged so I took apart the side pillar or column between front and back door just to side and rear of drivers door and checked it for any evidence of water running down where the drain lines run and it was super clean!

2. I learned the front collection channels in the front around the wiper area can get clogged with vegitation so I checked them and they were all clean

At first I thought it could be coming fron under the car and into the tranmition tunnel --could that be a leak area?? The under carriage is mostly rust free for the age of the car

I have mold allergies and water leaks obviously can cause mold so any help would be appreciated as this could be huge problem for me!!

Thanks, Bob Ny

aersloat · #2 08-24-2009, 07:18 PM

I get all kinds of water leaking into mine. I am pretty sure that my main sources are the front sunroof drains. The front drains are in both front corners. Run some nylon weed-eater line into the drain and see where it daylights. When it did it on mine it daylighted near the front door hinge and I think the drain hose essentially empties right into the a pillar and then dumps on the carpet. Dealing with that is on my short list since having a leaky car is no good in Portland.

unclbob · #3 08-24-2009, 08:02 PM

Hey Thanks! I almost bought a w123 but all of them I looked at were leaking in the cabins at one place or another so I thought this newer model would be better as far as leaks go. I will do what you suggested. . . did you find the water under your seats too? I suppose the water could have wicked up the carpet on the trans tunnel but that sounds hard to believe??

When I took apart the plastic bottom to the side pillar where it meets the side carpet I did see black plastic tubes that looked like they could be drains up from the sunrroof or vacuum type hoses?? and there was no eveidence of any water. I plan to check out the under carraiage too. I am susspiciouse of the windshield, doors and that front drain, water channel area as I guess water could go from the front of the windshiled down and end up running back into the car? Thanks again for you guidance

babymog · #4 08-24-2009, 10:16 PM

Unusual for a windshield to leak. Sunroof drains are possible, do run a weedeater string or equivalent down the front drains to ensure they are clear. Next possiblilty is the drains beside the battery and the brake booster, not sure where it'd get in the car though, unless someone has removed/replaced the climate control box around the heat and A/C evaporator, it is supposed to be sealed to the firewall.

The other thing that is down in that area is the condensation drains for the air conditioning, there is a tube on each side of the tunnel just inside of the console edges, they tend to disintegrate over time and could cause water from the A/C to leak there, ... people have replaced those foam hoses with rubber hose with good results.

Knocking in wood here, but I've had nearly a dozen 124s, never one that leaked and I live in the Michigan rain forest.

aersloat · #5 08-25-2009, 03:31 AM

My carpets can get pretty soaked. I have found that parking facing uphill helps a bunch... that of course sends most of the water to the rear sunroof drains. The hoses at the b pillar were probably vacuum lines or bundled power.

If your door weatherstripping is worn you can get some water infiltration there as well, although not as much. Both of my rear fixed side windows in the cargo area of my wagon leak around the glazing gaskets. A friend has a slight later 300TE and his rear windows leak enough that they are almost always fogged in the winter.

unclbob · #6 08-25-2009, 12:04 PM

Thanks Jeff, I will try the weed eater line but wouldnt that leak run down the pilars and they were super dry and clean when I looked? Its nice to know your 124's have been dry. . . . just my luck as I need a dry one! I do see one whole in the bottom of the battery compartrment and near the brake booster area on the other side. I will check around these areas. As far as the climate control box Im not sure whwere that is but I know the previous owner retrofited the a/c for the new freon. I will look into this too. possible mice ate something as they were around both these areas. I appreciate the leads

Bob

unclbob · #7 08-25-2009, 12:12 PM

Thanks Aersloat, I will try to open my sunroof manually as it is inoperable and check drains. Have you been able to tell where the water runs from the bad front darins? Is it down your pilars as mine are super clean and dry no water evidence at all. I suppose if it is a new leak they could still look clean I will make sure the carpet is dry then hose test the doors and windows. I am still susspicous of something running from the front firewall area down the middle of the trans tunnel but thats going to be harder to find. . . . Be well, Bob

babymog · #8 08-25-2009, 02:05 PM

If you haven't had the sunroof open ever, as in the PO disabled it and it is "broken", you might be opening the proverbial can of worms when you open the sunroof.

unclbob · #9 08-25-2009, 05:29 PM

Hi Jeff,

I think this is good advice. Anyway where would the water drain, leak or run if there were drain/line probs at the sunroof and I can look there to get my answer. . . I checked the drivers pilar as I mentioned!! Maybe I should consider selling and finding a dry car like yours were? Thanks for the ideas Bob

babymog · #10 08-25-2009, 09:46 PM

If clogged, the water will overflow into the cabin at the sunroof opening, usually as you drive and slosh it around. If not connected at the sunroof, just outside of the sunroof frame through the headliner.

I'm betting your problem is lower.

NC Benz · #11 08-26-2009, 05:55 AM

Another thing to check....

If you are running the AC a lot, and end up with wet carpets, look for a clogged AC drain (under dash, top of drive shaft "arch").

Try running without AC and see if it dries up at all.

Just a thought.....

aersloat · #12 08-26-2009, 12:34 PM

The forward sunroof drains run forward down the pillar adjacent to the windshield then down in front of where the front door hinge is and I believe are supposed to daylight under the car. There are a couple of threads documenting fixes to these drain hoses. I guess they can come apart at couplings and can end up dumping water behind the carpet in the front seats, which can end up running everywhere. If your sunroof doesn't open that makes diagnosis more difficult for sure. Trying to manually open it might not be the best idea unless you are prepared to address why it isn't working.

Bama1 · #13 08-26-2009, 11:08 PM

Try searching the postings for "Windshield seals" , "Battery trays", or "firewall corrosion"...read them then go inspect yours...and then post what you discover.

good luck

PS: try this one for starters Water Leaking onto floor mats

babymog · #14 08-27-2009, 12:29 PM

But be sure that it is applicable to the 124 body, the 123 had many more rust issues and have been on the road much longer. 126 also had rust issues around windows that are rare on the 124.

Jeremy5848 · #15 08-27-2009, 01:30 PM

For water leaks that appear to involve the transmission tunnel, the a/c drain hose is always the first place to check. It's also possible that in addition to moisture frozen out of the air by the evaporator, water (rain) coming in to the climate control system would drain at that spot. Either way, that is the first place to check.