Pano water leak, 2012 coupe
06-04-2022, 02:51 PM
#1
MBWorld Fanatic!
Thread Starter
Pano water leak, 2012 coupe
My car is normally parked facing uphill in the driveway and I’ve never had any water leaks. Last week it was parked facing downhill during a heavy rain, and the next morning the passenger side carpet, seat and headliner up near the A pillar were all wet. I assumed that the pano roof drain on that corner was plugged. I looked for video about unplugging and found nothing that looked like my pano. Mine has a channel, along the front edge near each corner, that appears to drain towards the windshield. I can’t see any rear drains.
I tested the drains using a turkey baster full of water. With the car parked facing uphill, I squirted water gradually into the drain channel so that it all runs into the channel and none of it runs back along the sides of the pano. I get water pooling briefly in the gap along the top of the windshield glass (unexpected), and then I get a little water dripping out behind the front wheel (as expected). To my surprise, I also got an equal amount of water running out just ahead of the rear wheel. I don’t understand the drain layout so didn’t think water in the front could drain out the back or could show up along the top of the windshield glass.
I repeated the test with the car facing downhill. Water again briefly filled the gap along the top of the windshield glass, and then began dripping out behind the front wheel. The back was dry. Both sides seemed to flow about the same speed.
I tried running the plastic string from a weed-eater down into the front drains to clear them but couldn’t get it in very far (1 to 2 feet?). I then repeated the water testing, and nothing had changed.
Is it normal for water draining from the pano to pool in the gap along the top of the windshield glass?
Can anyone explain how the drain system runs and maybe point me to a schematic or parts diagram?
Is there an easy way to be sure my drain system is fully clear and not plugged?
I tested the drains using a turkey baster full of water. With the car parked facing uphill, I squirted water gradually into the drain channel so that it all runs into the channel and none of it runs back along the sides of the pano. I get water pooling briefly in the gap along the top of the windshield glass (unexpected), and then I get a little water dripping out behind the front wheel (as expected). To my surprise, I also got an equal amount of water running out just ahead of the rear wheel. I don’t understand the drain layout so didn’t think water in the front could drain out the back or could show up along the top of the windshield glass.
I repeated the test with the car facing downhill. Water again briefly filled the gap along the top of the windshield glass, and then began dripping out behind the front wheel. The back was dry. Both sides seemed to flow about the same speed.
I tried running the plastic string from a weed-eater down into the front drains to clear them but couldn’t get it in very far (1 to 2 feet?). I then repeated the water testing, and nothing had changed.
Is it normal for water draining from the pano to pool in the gap along the top of the windshield glass?
Can anyone explain how the drain system runs and maybe point me to a schematic or parts diagram?
Is there an easy way to be sure my drain system is fully clear and not plugged?
06-24-2022, 12:53 PM
#2
MBWorld Fanatic!
Thread Starter
Bumped - almost 250 views but no feedback yet.
Surely there's someone in this group of experts who could help a soggy friend!
Thanks
Surely there's someone in this group of experts who could help a soggy friend!
Thanks
06-27-2022, 10:28 AM
#3
Member
I don't have the pano roof but I clear my sunroof drains with an air compressor. I just use a cone tip to seal in tip of drain and purge. Will be surprised what comes out probably. Might give it a try.
07-27-2023, 05:18 PM
#4
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amg gt
Same problem
hi I’m having the exact same problem, could you tell me where the drains are on the pan roof as I couldn’t see any, also were the bottom for the front drains behind the wheel arch liner?
My car is normally parked facing uphill in the driveway and I’ve never had any water leaks. Last week it was parked facing downhill during a heavy rain, and the next morning the passenger side carpet, seat and headliner up near the A pillar were all wet. I assumed that the pano roof drain on that corner was plugged. I looked for video about unplugging and found nothing that looked like my pano. Mine has a channel, along the front edge near each corner, that appears to drain towards the windshield. I can’t see any rear drains.
I tested the drains using a turkey baster full of water. With the car parked facing uphill, I squirted water gradually into the drain channel so that it all runs into the channel and none of it runs back along the sides of the pano. I get water pooling briefly in the gap along the top of the windshield glass (unexpected), and then I get a little water dripping out behind the front wheel (as expected). To my surprise, I also got an equal amount of water running out just ahead of the rear wheel. I don’t understand the drain layout so didn’t think water in the front could drain out the back or could show up along the top of the windshield glass.
I repeated the test with the car facing downhill. Water again briefly filled the gap along the top of the windshield glass, and then began dripping out behind the front wheel. The back was dry. Both sides seemed to flow about the same speed.
I tried running the plastic string from a weed-eater down into the front drains to clear them but couldn’t get it in very far (1 to 2 feet?). I then repeated the water testing, and nothing had changed.
Is it normal for water draining from the pano to pool in the gap along the top of the windshield glass?
Can anyone explain how the drain system runs and maybe point me to a schematic or parts diagram?
Is there an easy way to be sure my drain system is fully clear and not plugged?
I tested the drains using a turkey baster full of water. With the car parked facing uphill, I squirted water gradually into the drain channel so that it all runs into the channel and none of it runs back along the sides of the pano. I get water pooling briefly in the gap along the top of the windshield glass (unexpected), and then I get a little water dripping out behind the front wheel (as expected). To my surprise, I also got an equal amount of water running out just ahead of the rear wheel. I don’t understand the drain layout so didn’t think water in the front could drain out the back or could show up along the top of the windshield glass.
I repeated the test with the car facing downhill. Water again briefly filled the gap along the top of the windshield glass, and then began dripping out behind the front wheel. The back was dry. Both sides seemed to flow about the same speed.
I tried running the plastic string from a weed-eater down into the front drains to clear them but couldn’t get it in very far (1 to 2 feet?). I then repeated the water testing, and nothing had changed.
Is it normal for water draining from the pano to pool in the gap along the top of the windshield glass?
Can anyone explain how the drain system runs and maybe point me to a schematic or parts diagram?
Is there an easy way to be sure my drain system is fully clear and not plugged?
07-27-2023, 06:41 PM
#5
Junior Member
MB Tech here. Open the sunroof and there will be 2 drains in either corner of the front of the sunroof, behind the wind deflector. Remove front wheels and fender liners and you will find the drains run to there on the side closest to the doors. There will be "rubber like fingers" on the end of the drains. Cut those off...They cause debris to accumulate in bottom of drains and prohibit drainage. After cutting just flush water through the top sunroof drains and you will clear all the debris out. Should never be an issue again.
Last edited by Spanky63; 07-27-2023 at 06:47 PM.
07-28-2023, 12:31 AM
#6
MBWorld Fanatic!
Thread Starter
OP here. Problem solved. Turns out that the Texas sun had done a number on my windshield adhesive. A light push on the top corner of the windshield from inside would visibly move the glass away from the frame. The local glass shop agreed to try removing the glass and regluing, but warned me that the glass frequently breaks. Unhappily, they were right. Happily, new glass and new glue cured my leak.
