Razman

Up until now I've not had any issues with the drains, but we had a brief monsoon this morning and after making it in to work and drying out I went down to get something out of my car, only to find the driver side passenger footwell flooded.

I pulled out the center console AC vents (for the passengers) and noticed that the ducts were full to the brim with H2O! At least it's water-tight for the most part, but I'm off to find a wet/dry vac on my lunch to suck everything out.

That said, I've yet to perform the obligatory search on what caused this (I've seen threads on addressing drain issues) but if anyone has any insight as to what could have done that or where the source might be I'm all ears.

Thanks,

Raz

Tony Barbz

Raz, have not got to look at my rear blind yet but having owned my A8 D2 for about 7 years now I was not aware of a repair manual available By Bentley.
Silverd2 replied to my problem about front fog lights and if you check
www.partsgeek.com you can order a manual. I have bumbled along these past years and did not realise there was such a repair manual available to the layman until siverd2 posted.

I do not know the answer to your leaks - I am a builder and not really mechanical - but with the manual it might make life easier to sort these type of things out - I hope!!

Silverd2 seems to be on the ball about this model so maybe he might have a solution - batting for you.

Tony

Razman

Thanks Tony, I'll definitely need to get one. Case in point, found an old post about the vacuum lines for the secondary air pump air injection system relays/solenoids. One of mine was dangling; I replaced them, but one line goes behind the engine compartment wall between it and the fender - back to the leak detection pump. There is a diagram underneath the hood, but I have no clue where that pump is. I think I solved those codes, but I want to replace all the tubing.

Ugh, I need some Rhino ramps or something so it's easier for me to get up underneath the car (I miss my '89 Suburban for this reason). Then I can access the drains and ensure they're clear.

Mine is real clean, just needs a few things resolved and then it will be practically perfect. You'll kick yourself when you realize how easy it is to get to the window shade - it's a simple system, not sure why the dealer wants over $1K for the part!!

While where on the subject of small annoyances, is there any connection between the speed sensor and the radio volume/winshield wiper speed? I know the radio is supposed to adjust the volume, and I read that the wiper intermittent speed is also supposed to adjust to how fast you are going. Any experience with those? I don't detect any changes at all, regardless of speed.

Raz

S8ilver

http://www.audidiy.com/a8.html

http://www.audipages.com/Tech_Articl...tordrains.html.

http://www.audipages.com/Tech_Articl...sereplace.html

Razman

Thanks S8ilver, I have the DIY page already bookmarked just hadn't dug into it again yet for this issue. Much appreciative for the links.

Raz

Razman

This past Saturday I ran into the same issue - water in the A/C duct due to some rains that morning. It started raining again today so I made time to check things out.

I took half a gallon of hot water and poured it in the void that collects the water; I could see it seep out of the driver side drain but couldn't see the passenger side spout. I then took one of those long, flexible grabbers (with the thumb push-button) and snaked it under the air intake (according to one of the links that shows copper tubing) and WHOOSH out ran all the water!

Not sure what was covering the drain but I ran another two gallons of hot water through it just to be sure (first one had a little Dawn in it to clean it up a bit). Apparently it just needed to be agitated. Yay, no more wet passenger compartment!!

Raz

BrianC72gt

There are 4 drains in the cowl area to control outside water. Ther are also 2 two drains inside the passenger compartment from the bottom of the A/C condensor pan to drain off water vapor that condenses back to water droplets as the A/C does its thing.

IF you get water in your vents, then water is filling the cowl area under the hood, cresting over the center cabin air inlet and flooding the air ducts. The other really big problem to watch out for when this happpens is a wet ECU/TCU. These critical components are located in the underhood electronics box on the passenger side of the car. There is a tiny drain underneath this box that drains into the wheelwell (search "pinch your nipples"). The little rubber drain nipples easily get clogged up with debris, then this area fills up with water and you get all kinds of crazy error codes and random performance issues.

Many years ago, this problem cost me a TCU. ECU, Fuel Pump, Coils and a lot of clean up and troubleshooting. Ignore it at your peril.

Razman

Hi Brian,

Thanks for the response - I've been watching the "upper" cowl drains by checking them regularly and keeping those areas clear of debris. The ECU compartment is fine; I popped it open to see what was in there and caught a whiff of 13-year old electronics (not a bad smell IMO) so I think it's been pretty well sealed up all this time. Gotta get back in there over the weekend and do the cruise control fix by re-soldering the cap's.

Anyway, got some other questions about drainage - if you can offer insight great, if not maybe someone else can. No Bentley manual yet but that's on the "to-get" list.

Is there a difference between where the water was entering and the A/C condenser tray? I've seen water drip out when it was warmer (and had AC running) so I think those drains are clear (didn't exhibit any other signs/symptoms as listed on the forum). Why would water collect only in the center duct, lowest point w/o drainage I suppose?

Also, where do the sunroof drains exit the body? I haven't had any issues there either, but I expected to see something similar to what the drains looked like for the front upper cowl areas somewhere underneath. Knowing would give some peace of mind.

All else is well, have other minor projects but thankfully nothing major.

Raz

BrianC72gt

Don't forget, that electronics box is wide open on the bottom. They sealed the top pretty well, but the water gets in from underneath.

twentysevenlitres

When the plenum fills up (area in front of windscreen) the next large drainage hole is the air intake for the HVAC system. A/C doesn't create a lot of water quickly, so partially blocked drains still drain ok, but not when there's a large water influx!

The rear drain is the only one with that same nipple design, it drains on either side of the boot (trunk) behind the rear wheel wells. Pull the battery cover out from the RHS and you can see the right hand drain pipe behind the battery. You can remove the (blue) hose from the nipple housing which you can then pull from the where it mounts in the fender.
The LHS is in the same place, just harder to get to and some of the entertainment gear may be in the way.
These need to stay clear as water influx in the boot (trunk) can drown the central locking pump, the parking sensor ECU and the Bose Amp (where fitted), plus any gear you have stored in with the spare tyre.

The front drains can be seen near the front door hinges when the door is open.
They don't have nipples, but it may pay to ocassionally clear them using compressed air or something like a bicycle brake cable.