car wash leak under dash
#1
12-07-2010, 10:45 AM
car wash leak under dash
When I drive my 1996 C Class through a car wash, water pours into the passenger area from under the dashboard. I would estimate about a pint or so each time. I am at a loss as to where to look for the cause. I figure it's either deteriorated weather stripping or a plugged drain but haven't a clue where to start looking. I don't use a brushless carwash so it isn't a matter of pressure.
I would appreciate any suggestions here as I don't fancy the idea of spending hundreds on what could be a simple fix but I have a feeling I could get hosed on this if I take it to a dealer.
Thanks
UPDATE: I have read in other areas of this site that this is a problem with other models too and it relates to the drain for the air intake. I learned how to remove the grates over the air intake trough and find no clog on the drain hole but I am assuming that is also where the air is taken in as I can find no other inlet. So, I now am not sure how to figure out if there is a clog further down or how to clear it. If it's also an air intake, pressuring the drain with air won't work.. Still looking for guidance.
UPDATE: The water is coming in through the air duct system for the heater/air conditioner. I removed the cabin air filter and it was wet. I looked up inside the filter box and it all looked in tact so I have to figure the water is entering where the air intake is under the hood. Only problem is, I don't have a clue where that might be. Anyone help with this one aspect?
I would appreciate any suggestions here as I don't fancy the idea of spending hundreds on what could be a simple fix but I have a feeling I could get hosed on this if I take it to a dealer.
Thanks
UPDATE: I have read in other areas of this site that this is a problem with other models too and it relates to the drain for the air intake. I learned how to remove the grates over the air intake trough and find no clog on the drain hole but I am assuming that is also where the air is taken in as I can find no other inlet. So, I now am not sure how to figure out if there is a clog further down or how to clear it. If it's also an air intake, pressuring the drain with air won't work.. Still looking for guidance.
UPDATE: The water is coming in through the air duct system for the heater/air conditioner. I removed the cabin air filter and it was wet. I looked up inside the filter box and it all looked in tact so I have to figure the water is entering where the air intake is under the hood. Only problem is, I don't have a clue where that might be. Anyone help with this one aspect?
Last edited by revdarkwing; 12-08-2010 at 04:58 PM.
#2
12-10-2010, 09:55 AM
Problem discovered and solved
Well, thank goodness for persistence. With no help from this forum or Mercedes customer service line, I have finally gotten to the bottom of the problem and fixed it for nothing.
I am most disappointed in the folks at the Mercedes hot line. I phoned them twice and got no help. The first time I was told to remove the cabin air filter and to find the fresh air inlet myself.. something not possible unless you are a contortionist.. and then only maybe. Why he wouldn't tell me.. is beyond me.
The second time, a different guy told me where the air comes into the car but didn't help at all to resolve the problem.
The problem was a clog that could not be seen in the water trough drain on the passenger side of the car. Neither guy at Mercedes could tell me where the water outlet was. Finally, I filled a gallon jug with water and kept looking till I found it. The drain is about an inch to 1.5 inches in diameter and extends from the front of the plastic catch trough under the hood at the bottom of the drain on the side facing the frontof the car. You can locate the drain hole it by removing the plastic screens extending forward from the bottom of the windshield and looking in the trough.
It doesn't look like a drain really but has a flexible rubber flap over the drain. When you pour water into the trough, you should be able to see water flowing out then down to the ground. It should flow freely. In my case, it was trickling out. (I was told by the Mercedes CS guy that it is supposed to trickle out.. another misstatement)
I reached down with a long screwdriver and carefully pulled the flap open and a sizable chunk of wet organic debris came out and the water started flowing freely. It was as simple as that. I put the car back together and ran it through the car wash with my fingers crossed and not a drop came into the car.
I simply can't believe that the folks at MBZ didn't tell me about the nozzle and the flap and that from time to time it can get clogged... even if it doesn't show at the top of the drain. It seemed to me that they were more interested in getting me into a dealership to have it looked at as if I wanted to spend a few hundred dollars doing some unnecessary repairs when it was a 10 minute fix.
In total the repair took me two days to find (working a little each day since it was in the single digits outside and not that much warmer in the garage) and but a moment to fix once discovered.
Props to me and shame on Mercedes. Hope this helps save someone else from an equally frustrating time.
I am most disappointed in the folks at the Mercedes hot line. I phoned them twice and got no help. The first time I was told to remove the cabin air filter and to find the fresh air inlet myself.. something not possible unless you are a contortionist.. and then only maybe. Why he wouldn't tell me.. is beyond me.
The second time, a different guy told me where the air comes into the car but didn't help at all to resolve the problem.
The problem was a clog that could not be seen in the water trough drain on the passenger side of the car. Neither guy at Mercedes could tell me where the water outlet was. Finally, I filled a gallon jug with water and kept looking till I found it. The drain is about an inch to 1.5 inches in diameter and extends from the front of the plastic catch trough under the hood at the bottom of the drain on the side facing the frontof the car. You can locate the drain hole it by removing the plastic screens extending forward from the bottom of the windshield and looking in the trough.
It doesn't look like a drain really but has a flexible rubber flap over the drain. When you pour water into the trough, you should be able to see water flowing out then down to the ground. It should flow freely. In my case, it was trickling out. (I was told by the Mercedes CS guy that it is supposed to trickle out.. another misstatement)
I reached down with a long screwdriver and carefully pulled the flap open and a sizable chunk of wet organic debris came out and the water started flowing freely. It was as simple as that. I put the car back together and ran it through the car wash with my fingers crossed and not a drop came into the car.
I simply can't believe that the folks at MBZ didn't tell me about the nozzle and the flap and that from time to time it can get clogged... even if it doesn't show at the top of the drain. It seemed to me that they were more interested in getting me into a dealership to have it looked at as if I wanted to spend a few hundred dollars doing some unnecessary repairs when it was a 10 minute fix.
In total the repair took me two days to find (working a little each day since it was in the single digits outside and not that much warmer in the garage) and but a moment to fix once discovered.
Props to me and shame on Mercedes. Hope this helps save someone else from an equally frustrating time.
Last edited by revdarkwing; 12-10-2010 at 10:05 AM.
#3
04-27-2022, 01:08 PM
Well, thank goodness for persistence. With no help from this forum or Mercedes customer service line, I have finally gotten to the bottom of the problem and fixed it for nothing.
I am most disappointed in the folks at the Mercedes hot line. I phoned them twice and got no help. The first time I was told to remove the cabin air filter and to find the fresh air inlet myself.. something not possible unless you are a contortionist.. and then only maybe. Why he wouldn't tell me.. is beyond me.
The second time, a different guy told me where the air comes into the car but didn't help at all to resolve the problem.
The problem was a clog that could not be seen in the water trough drain on the passenger side of the car. Neither guy at Mercedes could tell me where the water outlet was. Finally, I filled a gallon jug with water and kept looking till I found it. The drain is about an inch to 1.5 inches in diameter and extends from the front of the plastic catch trough under the hood at the bottom of the drain on the side facing the frontof the car. You can locate the drain hole it by removing the plastic screens extending forward from the bottom of the windshield and looking in the trough.
It doesn't look like a drain really but has a flexible rubber flap over the drain. When you pour water into the trough, you should be able to see water flowing out then down to the ground. It should flow freely. In my case, it was trickling out. (I was told by the Mercedes CS guy that it is supposed to trickle out.. another misstatement)
I reached down with a long screwdriver and carefully pulled the flap open and a sizable chunk of wet organic debris came out and the water started flowing freely. It was as simple as that. I put the car back together and ran it through the car wash with my fingers crossed and not a drop came into the car.
I simply can't believe that the folks at MBZ didn't tell me about the nozzle and the flap and that from time to time it can get clogged... even if it doesn't show at the top of the drain. It seemed to me that they were more interested in getting me into a dealership to have it looked at as if I wanted to spend a few hundred dollars doing some unnecessary repairs when it was a 10 minute fix.
In total the repair took me two days to find (working a little each day since it was in the single digits outside and not that much warmer in the garage) and but a moment to fix once discovered.
Props to me and shame on Mercedes. Hope this helps save someone else from an equally frustrating time.
I am most disappointed in the folks at the Mercedes hot line. I phoned them twice and got no help. The first time I was told to remove the cabin air filter and to find the fresh air inlet myself.. something not possible unless you are a contortionist.. and then only maybe. Why he wouldn't tell me.. is beyond me.
The second time, a different guy told me where the air comes into the car but didn't help at all to resolve the problem.
The problem was a clog that could not be seen in the water trough drain on the passenger side of the car. Neither guy at Mercedes could tell me where the water outlet was. Finally, I filled a gallon jug with water and kept looking till I found it. The drain is about an inch to 1.5 inches in diameter and extends from the front of the plastic catch trough under the hood at the bottom of the drain on the side facing the frontof the car. You can locate the drain hole it by removing the plastic screens extending forward from the bottom of the windshield and looking in the trough.
It doesn't look like a drain really but has a flexible rubber flap over the drain. When you pour water into the trough, you should be able to see water flowing out then down to the ground. It should flow freely. In my case, it was trickling out. (I was told by the Mercedes CS guy that it is supposed to trickle out.. another misstatement)
I reached down with a long screwdriver and carefully pulled the flap open and a sizable chunk of wet organic debris came out and the water started flowing freely. It was as simple as that. I put the car back together and ran it through the car wash with my fingers crossed and not a drop came into the car.
I simply can't believe that the folks at MBZ didn't tell me about the nozzle and the flap and that from time to time it can get clogged... even if it doesn't show at the top of the drain. It seemed to me that they were more interested in getting me into a dealership to have it looked at as if I wanted to spend a few hundred dollars doing some unnecessary repairs when it was a 10 minute fix.
In total the repair took me two days to find (working a little each day since it was in the single digits outside and not that much warmer in the garage) and but a moment to fix once discovered.
Props to me and shame on Mercedes. Hope this helps save someone else from an equally frustrating time.
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