Davidlorrain

I just got this car a couple months ago. Twice I heard what sounds like water sloshing from my face vent! First time was a 4 hr ride with AC on, second time just after a going threw a car wash with AC on but not for long! Any ideas what's up?!

haggisuk

Yeah the drains are blocked most likely the ones under the pollen filter but possibly the ones for the AC which are accessed by peeling back the carpet on the transmission tunnel.

There is loads of posts about it and a quick Google will throw up plenty of info.

Btw if you don't address this you will end up one day with a car that's fit for the breakers yard because it can and will flood the inside of the car and there is lots of electronic modules under the carpets.




This is the drain, that's under the pollen filter with my hose thing inserted to flush the leaf litter out of it. My car is RHD and this is looking in from passenger side. On my S8 I can't see the other drain for the brake servo




Going in past various hoses




This is my weapon of choice for cleaning the sunroof drains and plenum area drains

Davidlorrain

Thanks!! I brought it in to the dealer the first time it happened, they did not find anything clogged. Spent an hour looking so they say, but I'm sure they didn't check it all!

MP4.2+6.0

Yep, basic clogged drains, more so if you took it to car wash and then had it. I would suspect under plenum ones first. Pull off entire plastic cover behind motor. Just take off the rubber weather strip across firewall then get the cover pieces off. Expect find lots of leaves and debris in there. Clean it all out; way better if you have a basic air hose, or exhaust side of a shop vac. Can try vacuum, but a lot of stuff is stuck under components and you need to blow it back and forth to get it all out. Also look over HVAC filter assembly carefully with those same covers off--right there in the center. Look at the little drain fittings molded into that assembly that are supposed to direct water down and to the sides. Probably the more basic plenum drains though.

Davidlorrain

A drain for the outside of the car can back into the vent system??

the_duke

Yes. Water level will get high enough to enter the car.

MP4.2+6.0

Yes, if drain is clogged and it is plenum area, it can fill up like a tub and enter car, ultimately likely through HVAC filter area if it gets that high. If HVAC filter cover/drains can go straight in and down. If drain is clogged and are the ones at the bottom of HVAC unit that deal with condensation from AC function, can fill and eventually pee out the vents, especially rear floor ones first. The first couple are often also tied to weak draining in the HVAC unit, so it can be multiple clog points. If sunroof drains clogged, you can get a sudden shower on your head entirely separate from the others. Any can literally total the car at their now depreciated value if it is serious and gets a bunch of electronics modules soaked and contaminated. Commonly clogging is debris that gets into drains. Sometimes it is at the end of the drain tube where they use a molded pinch approach to hose to minimize air noises flowing into it. But sometimes those pinch areas get sealed closed over time with rubber just sticking to itself, and then water backs up.

Davidlorrain

Thanks it cleared up on its own! Must be a slow drain!!

Giovanni Giovino 6.0+6.0TT

David,
Be sure to clean the drains as all have stated, otherwise next time you may not be so lucky, there is a reason the drain is slow, it is most likely clogged, if you choose to ignore it then next time you may fry some electronics !!


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richard-tx

A slow drain is bad. Pull the carpet back, remove the drain hoses and clean them and reinstall. Don't worry about the hose clamp. It really isn't needed.