Water Panic !

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John Peerce

Active Member
Joined
Oct 9, 2003
Messages
176
Location
London, UK
Car
C43 AMG
Driving the car today i heard the sound of water dripping inside .. and true enough there was a liquid puddle in the front passenger footwell ! i felt, smelt and looked at the colour of the liquid and all the evidence is that its water, not coolant or anything else. Note that it had rained for about 1 and half hours this morning (my car is parked outdoors) and also i washed it yesterday with hose etc.

The water did not come through the door (seals are dry) but, from underneath the glove box. I can actually see and hear water dripping coming down from the undercasing of glove box as I was turning corners/braking. The glovbox compartment itself is dry when opened, so the water seems to have accumulated in the space between the comparment and the undercasing (the one which you have to unscrew to get to the air cabin filter)

Please advice as to what could have caused this ..

Is there something i could do to fix this , or is it a trip to the dealership ?

the water on the carpet is not drying despite using a full kitchen roll ( so it seems to have gone through the carpet), is there likely to be any damage to any electrics etc from this ?

If its starts raining again tonight, what could i do to prevent more water coming in until this fixed ?
 
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John

I have the same thing in my passenger footwell, although it is underneath the carpet, and has soaked the foam behind the steel footplate, to which the alarm module is attached.

It is only at floor level though, and never seems to flood - just gradually soak the foam. Still haven't worked out where its coming from, although suspect a blocked drainage channel from the bonnet / wiper area.

Fuzzer posted some instructions on another thread today / yesterday on how to try and remedy this.

S.
 
Sounds to me like the A/C inlet box drain is blocked. Under the bonnet there is a box like a air filter box on the passenger side, this is directly above the A/C blower and pollen filter. There is a drain plug that is prone to filling up with leaves and debris causing a leak inside.
 
Thanks jimmy. Its quite a tight fit in the engine compartment, how accessible is this drain plug ? can it be reached such that its cleaned (even if with using a long stick etc)

Should i also avoid using the A/C until the whole area is dry to prevent any electrical short circutes or anything else happening ?
 
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ps anyone with close up pics of the engine bay and the area where the drainage problems could be ( especially with a W202 car) would be very much appreciated.
 
I've just opened mine up and checked . . . . no blockage.

Basically . . . bonnet up to 90 degrees. Unclip passenger side plastic trim around windscreen wiper by pushing towards the rear of the car

4 screws and a plastic nut underneath that

Lift up the rubber seal, and this will allow you partial access into the air box. The rubber plug in the bonnet which is connected to the bottom of this box, is just to the left of the bonnet support strut, in between the ECU, and the edge of the top of wheelarch.

Stick your finger inside the rubber plug, and stick something long inside the top of the airbox until it touches your finger - you will then be able to feel whether there is any debris or not! - I found none today ! so imagine that the wetness in my footwell is the result of an old leak which was never mopped up properly.

S.
 
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Use newspaper to mop up water in cars, it works a treat.

To test for water ingress use a hosepipe and start at the bottom of the car and work upwards.
Have someone on the inside looking for drips.
 
Thanks to each and every one who replied. I followed Jimmy's and Sym's instructions, and, as many of you had suspected, the rubber plug at the bottom of the air box was blocked. When i partly lifted the cover of airbox i could already see about 1 and half inchs of water (at its deepest). I used a bendy stick to clear the rubber plug. Poured water on the windscreen to test, and true enough water did not drop into the footwell, but went through the rubber plug. Note there was just a plug at the bottom of the box, no hose or anything else, so that water was simply being drained into the engine bay then the dripping into the ground/street.

I opened the panel under the glovebox and the foam inside was wet (from before) but little else. left it open to dry. I plan to re-do the above procedure later this summer and enusre its thoroghly clean. Is there anther plug at the other end of the box or is the passenger side one the only one ?

Now that the cause is known, would any damage have ocurred to the system(eg air con/heating system, pollen filter, fan etc ?) due to water leaking in ?Would it be worthwile not to use the air con system for few days waiting for things to "dry out" ? or is this pointless ?
 
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This is the biggest reason for A/c evaporator failure.

If you've caught it early then it shouldn't be a problem.

This is the subject of an MB bulletin instructing technicians to keep it clear at every workshop visit.
 
Dieselman, when you say that this can lead to failure of evaporator, do you mean sudden failure, or is it a longer term thing such as rusting etc. ? ( i ask because AFAIK my air con still works, so does that mean i escaped damage ?) Also is it better to switch on the system to allow it to dry out ?

I was actually thinking about whether clearing blocked waterways in the car is part of the A or B sevice (it should at least be part of the B service). I am not aware that it is, but your comment suggests they already do that sort of check..
 
Its a pain ...

I had to spend ages cleaning all my creme carpets when all this black water came into my car :(

Glad you got it sorted.

Maybe someone with a W202 could do a Howto as it looks like a problem. :D
 
John Peerce said:
Dieselman, when you say that this can lead to failure of evaporator, do you mean sudden failure, or is it a longer term thing such as rusting etc. ? ( i ask because AFAIK my air con still works, so does that mean i escaped damage ?) Also is it better to switch on the system to allow it to dry out ?


Rust is the issue.

I was actually thinking about whether clearing blocked waterways in the car is part of the A or B sevice (it should at least be part of the B service). I am not aware that it is, but your comment suggests they already do that sort of check..


Errr. Hmmm.! Yours was blocked wasn't it?
 
I still have a pond in the boot, at the back on the passenger side.

Im sure its somthing to do with the rear window seals.

The side insurlation 'fur' is always damp and stinks
 
KillerHERTZ said:
I still have a pond in the boot, at the back on the passenger side.

Im sure its somthing to do with the rear window seals.

The side insurlation 'fur' is always damp and stinks

Are you sure the boot seal is ok?I had too replace my seal a couple of months ago due to excessive water in the boot mainly by the battery!Everything looked ok on top visably but the water was coming in from under the lip and trickling down.Cost too fix was £30
 
Well, the rear window steams up at the bottom when theres any mosture in the air & ive placed my hand up above the leccy ariel which was wet also...
 
I am certain this should have been posted in the interior section! Moving...
 
i noticed recently that when it rains i find that on opening the doors there is quiet a bit of water on the door sills (seems to have trickeled down from the rubber seals somewhere). Not a major thing as such (as it doesnt get into the car, its just on the sills), but more of a longer term worry that this water might lead surely lead to corrosion ??.. i had the doors painted recently and for the life of me i can't remember if this used to happen before or is it becuase the rubber seals were damaged or re-fitted badly after the doors were painted !

Does anyone else get this "water on the sills" ?
 
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Hello John, yes mine does. There are two seals as you probably know and the water never gets inside. I think its just cappilary attraction along the rubber and metal then when you open the door it all lets go. I must admit i've wondered myself. I used an old gasmans trick of trapping paper in the seals and pulling on it to prove the seal is OK and water isnt getting through.The sill is quite a substantial part so paint and rustproofing will be substantial as well.
 

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