bentwookie

2010 Q5 3.2L

The other day after a bunch of rain, my wife and son casually mentioned that there was a literal puddle of water in the footwell in the rear on the passenger side. Yikes! I dried it all out, but it returned the next day.

What I've tried and observed:

• There was no noticeable dampness in the headliner
• There was a huge amount of water in the rear passenger footwell. It was an actual puddle the first night.
• There was a small amount of dampness in the front passenger footwell
• There was a small amount of dampness in the foam behind the glove box
• After driving to Tahoe in dry weather (after drying it out completely), we were rewarded with a frozen puddle the next morning in the rear-passenger wheel well
• Back home, I ran the AC for a good half hour and didn't see any drips on the ground.
• I removed a garbage bag of leaves from the cavernous area between the engine and the firewall, but didn't see any standing water
• I cleaned up the drain in the bottom of said cavernous area.
• I didn't see any obvious problems with the door or sunroof seals.
• After drying it out a third time, running the AC and washing the car, a bit of dampness returned in a very localized spot in the passenger rear footwell. No dampness in the front footwells
• The sentinel paper towels I placed in the vent under the front passenger seat remained dry

My initial (and current) guess was that it's something to do with the AC condensation drain. Every VAG car I've own has dumped water on my feet, why should this one be any different? That I didn't see the usual drips on the ground after running the AC for half an hour is suspicious. But if it's the AC, why isn't the front footwell consistently wet? That the headliner is totally dry would seem to rule out the sunroof? True?

As I can't think of anything better to do, I'd like to actually clean the AC drain lines. Can someone point me to a guide on how to do that? I'll happily take pictures and document the process if someone can point me in the right direction

Thanks in advance for any guidance you may have.

KevinGary

choppstixxx

Also check to make sure your plenum area (the space between the firewall and the engine bay, under the plastic tray below your wipers) is cleaned out. That gets filled with leaves and debris, if the drain gets clogged it will start seeping into the passenger side area.

Bob Petruska

bentwookie

Not yet. It wasn't obvious to me on how to do that. What should I be looking for, some kinda hole up front, at the corners? I gather from other posts that weedwacker string is good at poking at it.

Does anyone have a guide on how to clean out the AC drain?

Thanks!

Redd

The moonroof does have drains that come down the "B" pillar. (Subject to a recall for leaking and corroding the air big in the B pillar.) If there was something wrong there, water coming down the B pillar could pool in the rear floor that way, I think. Getting access to confirm that, requires removing the door sill trim and the B pillar trim, a lot of parts. I'd hate to say it, but maybe trying to hose down the car, once with the roof seams taped over, then again with them exposed, might tell you if that's where the water is coming from.

I don't know if there's any AC "drain" with rear AC options, the normal drains are on either side of the console, way up front, and shouldn't be able to flood the rear.

bentwookie

Thanks for the reply. Should I expect dampness in the headliner if the sunroof is the culprit? It does seem the most likely cause at this point though. Do the doors have drains?

Thanks.

Redd

The drain tube goes down into the B pillar, so it is possible the headliner would be bone dry and the water just running in the side of the roof panel, and then down the B pillar. I'm not intimately familiar with how they've plumbed that.
Doors have drains, yes, but that's only to let water drain out the bottom of the doors, from anything getting past the window weatherseal.

In a well-equipped shop, someone might have a smoke machine. (Somewhat like theatrical fog machines.) Or sometimes they use "canned smoke" or a "smoke flare". Any of these can fill a car with non-toxic white smoke, and in theory if there's a leak, it will come wafting out from the place that water has been getting in. Very effective--but I have no idea if that's normal Audi equipment.

MurrayA4

Redd I had a smoke machine in my garage, OTC, and it was a daily use machine.Most common leaks were in hatch/trunk areas.Worked much better than having one of my sons crawl in there with a bright light while I hosed the outside of the vehicle.Smoke machines are also a basic necessity for finding exhaust leaks and Evap problems.Costs some bucks to buy but cheap to operate and very quick payback + happy customers.

Redd

Murray, that's all well and good, but the important thing is did you have genuine Jamaica Blue Mountain coffee to serve? Or just that Starmucks stuff?

One really needs to have priorities, you know.