W220 reed valve
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W220 S320, W126 380SEC, W111 220SE
W220 reed valve
Having replaced a damaged rear SAM module, and dried out wet carpets I went to check the reed valve in the front cowl for debris blocking any water drainage. There was a few leaves and twigs covering it, but not enough to cause the flooding to the rear SAM. A previous mechanic must have broken the valve in order to fix a water problem. I've checked MB forums over this known issue, and some suggest removing the valve completely, as well as adding a valve in the side of the cowl assembly to allow water drainage. My question is, is a reed valve over the air intake necessary, if so, are these valves available as a spare part seperately, or do I need to buy the whole cowl assembly? I notice there are two outlets the valve covers, presumably one for air intake to the filters and climate control, the other for water drainage? Advice would be much appreciated!
#2
The reed valve is completely unnecessary , it just is supposed to block debris while letting water pass
Jaguar had a similar problem with a rubber piece called a duckbill
In both cases they get clogged with debris then water accumulated rather than passing through , and overflows into the AC blowers then into the interior carpeting . Very stupid design and very simple to fix
You don't need to add any Valve anywhere - simply drill a hole in the lower side of the plastic reservoir where the water accumulates, so it can never pool again
Jaguar had a similar problem with a rubber piece called a duckbill
In both cases they get clogged with debris then water accumulated rather than passing through , and overflows into the AC blowers then into the interior carpeting . Very stupid design and very simple to fix
You don't need to add any Valve anywhere - simply drill a hole in the lower side of the plastic reservoir where the water accumulates, so it can never pool again
Last edited by tusabes; 07-16-2016 at 06:42 PM.
#3
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In both cases (Benz and Jaguar) the valve is there to stop leaking exhaust from entering the interior of the vehicle. Auto manufacturers are super-sensitive to that possibility ever since GM killed a family with CO back in the 1960's. The engineers consider it totally unacceptable to have an open pathway from the engine compartment to the interior.
I was amazed when posts appeared in the Forum saying that Benz suggested drilling a hole into the HVAC intake plenum from next to the exhaust manifold.
I was amazed when posts appeared in the Forum saying that Benz suggested drilling a hole into the HVAC intake plenum from next to the exhaust manifold.
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Thanks or the input guys. Wally's point about blocking off CO from the air feed to the cabin is a valid one, and I have a solution to drain water from the cowl, routing it away from the exhaust. I'll keep you informed.
#5
In both cases (Benz and Jaguar) the valve is there to stop leaking exhaust from entering the interior of the vehicle. Auto manufacturers are super-sensitive to that possibility ever since GM killed a family with CO back in the 1960's. The engineers consider it totally unacceptable to have an open pathway from the engine compartment to the interior.
I was amazed when posts appeared in the Forum saying that Benz suggested drilling a hole into the HVAC intake plenum from next to the exhaust manifold.
I was amazed when posts appeared in the Forum saying that Benz suggested drilling a hole into the HVAC intake plenum from next to the exhaust manifold.
In actuality , in both cases of the Mercedes reed valve and the jaguar duckbill , the only purpose is to block debris while letting water to pass. They do not stop air /exhaust from passing anywhere , that is not their purpose . They are not airtight and exhaust can still pass through them even when unclogged
The reservoir with the reed valve is behind the first false firewall , so there is no issue with drilling a hole in the reservoir . You just need to make sure the location where you drill the hole doesn't dump water on the fuse box
Last edited by tusabes; 07-19-2016 at 04:49 AM.