OP
OP
ItalianTuneUp
MB Enthusiast
Well I've been doing some reading on this problem and it seems to be a relatively common issue and is caused by blocked drains, of which the car appears to have several.
USA class action lawsuit for flooding issues:
Before I go on, I discovered that this is a known problem and in the USA a class action lawsuit was issued against MB and covered W220 (S-class) & W215 (CL) models from MY2001 until MY2006 inclusive. Of course, UK owners are not protected against this problem by this lawsuit. More on the lawsuit here:
Mercedes-Benz Class Action Settlement Of Class Action Lawsuit Over Mercedes-Benz S-Class W220 and Mercedes-Benz CL-Class W215 Reed Valve Water Leakage | Class Action Lawsuits In The News
TIME TO GET PAID...LAWSUIT AGAINST MERCEDES-BENZ USA, LLC. - MBWorld.org Forums
Main drain hole: ventilation plenum chamber (aka scuttle drain / cowl)
The main drain is at the bottom of the ventilation plenum chamber. It becomes blocked once enough dirt, dust, leaf / plant debris has fallen into it.
Cleaning this drain out seems relatively simple: locate plenum chamber grille, release clips/latches & lift off the grille, look down into chamber and locate the plug hole (reed valve), poke long pointy object into the plug hole to clear out all blocking material, replace grille.
See this post which describes the above process and provides pictures showing the various parts mentioned:
W220 Plenum chamber unblocking pictures - Mercedes-Benz Owners' Forums
Failure to keep this drain clear of debris is eventually likely to cause interior flooding. See the following advice from Honest John:
"It is vital to keep ventilation plenum chamber drains clear of debris or water will overflow and dampen carpets, vent blower motor and wiring loom, causing shorts and sometimes necessitating a new loom. If buying used, feel for damp front footwell carpets."
Source: Buyers' guide: Mercedes S320CDI (from 2000) - Telegraph
Other drains:
It seems that there are other drains to allow the car to drain water after rain / car wash. I will try to cover these once I've read up more on where they are and how to clear them out. Think I saw that these other drains are located within the wheel arches. Also there appear to be two drain holes at the front of the sunroof recess (open sunroof to see them?).
Also, within the bonnet area, just in front of the windscreen, on the driver's side in the corner, appears to be another area where dried leaf debris etc can collect. Due to the cramped space, this area seems tricky to reach into. I suspect that a torch and compressed air line might be essential to help clear this area out.
This is described here - look for post #37 by KevinJ:
MBWorld.org Forums - View Single Post - 2nd S Flooded This week! S Owners Keep your Drains Clean!!!
which is taken from this thread:
2nd S Flooded This week! S Owners Keep your Drains Clean!!! - MBWorld.org Forums
USA class action lawsuit for flooding issues:
Before I go on, I discovered that this is a known problem and in the USA a class action lawsuit was issued against MB and covered W220 (S-class) & W215 (CL) models from MY2001 until MY2006 inclusive. Of course, UK owners are not protected against this problem by this lawsuit. More on the lawsuit here:
Mercedes-Benz Class Action Settlement Of Class Action Lawsuit Over Mercedes-Benz S-Class W220 and Mercedes-Benz CL-Class W215 Reed Valve Water Leakage | Class Action Lawsuits In The News
TIME TO GET PAID...LAWSUIT AGAINST MERCEDES-BENZ USA, LLC. - MBWorld.org Forums
Main drain hole: ventilation plenum chamber (aka scuttle drain / cowl)
The main drain is at the bottom of the ventilation plenum chamber. It becomes blocked once enough dirt, dust, leaf / plant debris has fallen into it.
Cleaning this drain out seems relatively simple: locate plenum chamber grille, release clips/latches & lift off the grille, look down into chamber and locate the plug hole (reed valve), poke long pointy object into the plug hole to clear out all blocking material, replace grille.
See this post which describes the above process and provides pictures showing the various parts mentioned:
W220 Plenum chamber unblocking pictures - Mercedes-Benz Owners' Forums
Failure to keep this drain clear of debris is eventually likely to cause interior flooding. See the following advice from Honest John:
"It is vital to keep ventilation plenum chamber drains clear of debris or water will overflow and dampen carpets, vent blower motor and wiring loom, causing shorts and sometimes necessitating a new loom. If buying used, feel for damp front footwell carpets."
Source: Buyers' guide: Mercedes S320CDI (from 2000) - Telegraph
Other drains:
It seems that there are other drains to allow the car to drain water after rain / car wash. I will try to cover these once I've read up more on where they are and how to clear them out. Think I saw that these other drains are located within the wheel arches. Also there appear to be two drain holes at the front of the sunroof recess (open sunroof to see them?).
Also, within the bonnet area, just in front of the windscreen, on the driver's side in the corner, appears to be another area where dried leaf debris etc can collect. Due to the cramped space, this area seems tricky to reach into. I suspect that a torch and compressed air line might be essential to help clear this area out.
This is described here - look for post #37 by KevinJ:
MBWorld.org Forums - View Single Post - 2nd S Flooded This week! S Owners Keep your Drains Clean!!!
which is taken from this thread:
2nd S Flooded This week! S Owners Keep your Drains Clean!!! - MBWorld.org Forums
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