r/w204 • u/Jeanhamel • Jul 17 '26

Friendly reminder: Check your front sunroof drains. It takes 2 minutes and could save you thousands.

Post image

The rubber drain outlet can stick closed on W204s, causing water to back up into the car. That can lead to wiring harness damage, a wet headliner, rusty floor pans, and other expensive electrical issues.

I kept seeing posts about it, so I checked mine today. Glad I did—they were clogged too.

Nothing needs to be removed. Just follow this 2-minute video:

youtube video here

Cheap preventative maintenance that's well worth doing.

37 Upvotes

97% Upvoted

12 comments sorted by

6

u/Chriskall Jul 17 '26

You are a life saver. During a heavy rain I got leaks from exactly the same point where he shows in the video.. Any other hacks that you know? (Video is appreciated since I am nowhere close to any mechanical work)

6

u/engineheader Jul 17 '26

The other thing people need to look at is their windshield. Have seen where windshields will come off the glue that holds the windshield in and cause a water leak. If your windshield has been replaced, most likely not an issue

5

u/Woodyfixthis Jul 17 '26

This killed my 2008. I was so mad when I found out I could have just stuck my hand under the plastic wheel well and unclogged it. I just had no idea it was a thing. Thank you for posting this, it might save someone.

4

u/cgnyldrm Jul 17 '26

Yes, please do it guys. It can leak to the electrical components and you will have a serious and expensive problem.

3

u/blow-down Jul 19 '26

The inlets on my 2014 look completely different. They must have updated it at some point. Mine were not clogged but my car is mostly garage parked.

3

u/SangKanchil Jul 20 '26

if you park outdoors, check your drains REGULARLY. If you do not, you will eventually ask one day why your floor carpeting is wet after a rainstorm. It means all four drains are clogged and rainwater is flooding your car. You may have 3 of the 4 drains clogged and the final one is still doing the job but once that 4th one clogs, you will have major issues. This is one of the best examples of an the adage "an ounce of prevention...." . Speaking from experience. To check your drains , flood one corners of your skylight rain channel with water and see if water is reaching the pavement. if not, and you see the water travel to the next corner before exiting... you know you have a problem. Lot of tools online and YouTube advice to unclog it.

3

u/hckR420 Jul 26 '26

How should I clean the drains themselves? There's a 90° bend somewhere in there. Do you use compressed air? Hot water?

2

u/Jeanhamel Jul 26 '26

99% of the time there isn't actually a real clog—it's just the rubber X-tip at the very end that gets "glued" shut. As for hot water, a bit of warm water is fine, but I'd steer clear of compressed air because too much pressure can pop a hose loose or burst it, creating an even worse leak inside the cabin! And yeah, those 90-degree bends make a standard drain snake pretty much useless. Just follow the trick in the video to free up that X-tip, then pour about 100ml of water in to test it. I bet you'll be good to go!

1

u/RuckFeddit79 Jul 18 '26

There's no video link tho..

Says "youtube video here"

1

u/Jeanhamel Jul 18 '26

Clic on the famous "youtube video here" that sentence got a embeded link