CDI Water separator
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Joined: Apr 2007
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From: USA
2006 E320 CDI
CDI Water separator
2006 E320 CDI, so there is a water sensor in the fuel filter, but once water is detected what happens? What displays? There is Nothing in the owners manual (that I could find) about this.
Is there a fuel drain somewhere? I saw where an older Mercedes had a fuel drain.
TIA
Is there a fuel drain somewhere? I saw where an older Mercedes had a fuel drain.
TIA
Super Member
Joined: Jan 2010
Posts: 563
Likes: 31
From: The Villages, Florida
2006 E320 CDI
I thought I read somewhere a light would show in the instrument panel , but after looking at the owners manual, I did not see any mention of it. As to bleed out water, that is the small round knob on top of the filter. This will bleed air and water out of the filter. I may have read only one post where someone had water in their system. Unless you got some bad diesel, you should be ok. Most fueling stations have a filter on the pump to stop water from entering your tank. If you notice the fuel pump running slow, it filter is partially plugged.
Mike T.
Mike T.
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Super Member
Joined: Apr 2007
Posts: 633
Likes: 48
From: USA
2006 E320 CDI
I thought I read somewhere a light would show in the instrument panel , but after looking at the owners manual, I did not see any mention of it. As to bleed out water, that is the small round knob on top of the filter. This will bleed air and water out of the filter. I may have read only one post where someone had water in their system. Unless you got some bad diesel, you should be ok. Most fueling stations have a filter on the pump to stop water from entering your tank. If you notice the fuel pump running slow, it filter is partially plugged.
Mike T.
Mike T.
Anyway any water would be below the fuel I suppose (water drains are on the bottoms of aircraft tanks) so I don't see how that knob on top of the filter could be used to bleed anything other than air. And when I replaced my filter I did not need to open that knob and I didn't pre-fill the filter with fuel (as some on forums reported that it was necessary, its not) And what about the water sensor? And attempting to bleed water out of that top knob would make an awful mess and lay on the pan below, stinking up the place. As I said older Mercedes had a drain hose and valve according to what I saw. And yes gas stations have filters on the pumps but lots of gas stations are run by idiots, who don't have the sense to maintain a pump properly, they have no idea what B10 means for example. And I have had water in my fuel (truck) many times from crap gas stations or condensation. So a water drain has to be/should be easy to use, with easy access and not make a mess.
Thread Starter
Super Member
Joined: Apr 2007
Posts: 633
Likes: 48
From: USA
2006 E320 CDI
I don't have water in my fuel now but I just want to know about the water sensor and how it reports water in the fuel to the driver.
Anyway any water would be below the fuel I suppose (water drains are on the bottoms of aircraft tanks) so I don't see how that knob on top of the filter could be used to bleed anything other than air. And when I replaced my filter I did not need to open that knob and I didn't pre-fill the filter with fuel (as some on forums reported that it was necessary, its not) And what about the water sensor? And attempting to bleed water out of that top knob would make an awful mess and lay on the pan below, stinking up the place. As I said older Mercedes had a drain hose and valve according to what I saw. And yes gas stations have filters on the pumps but lots of gas stations are run by idiots, who don't have the sense to maintain a pump properly, they have no idea what B10 means for example. And I have had water in my fuel (truck) many times from crap gas stations or condensation. So a water drain has to be/should be easy to use, with easy access and not make a mess.
Anyway any water would be below the fuel I suppose (water drains are on the bottoms of aircraft tanks) so I don't see how that knob on top of the filter could be used to bleed anything other than air. And when I replaced my filter I did not need to open that knob and I didn't pre-fill the filter with fuel (as some on forums reported that it was necessary, its not) And what about the water sensor? And attempting to bleed water out of that top knob would make an awful mess and lay on the pan below, stinking up the place. As I said older Mercedes had a drain hose and valve according to what I saw. And yes gas stations have filters on the pumps but lots of gas stations are run by idiots, who don't have the sense to maintain a pump properly, they have no idea what B10 means for example. And I have had water in my fuel (truck) many times from crap gas stations or condensation. So a water drain has to be/should be easy to use, with easy access and not make a mess.
Thread Starter
Super Member
Joined: Apr 2007
Posts: 633
Likes: 48
From: USA
2006 E320 CDI
the sensors have a date stamp on them week / year. First i tested the new one as described previously. And the center does display a warning (attached). My old sensor still works as well, I couldn’t think of any other means of testing it without purchasing a new one ($100). So the good news is that the driver is notified of water in the fuel (info missing from the owners manual and also not in WIS) unfortunately there is no supervisory circuit so if somebody forgets to replug the sensor cable when changing the fuel filter you would never get the warning.
For some reason It wont let me attach a photo.
For some reason It wont let me attach a photo.
Last edited by ot1; Nov 12, 2018 at 01:09 PM.
