Barry1394 Posted August 12, 2009 Report Share Posted August 12, 2009 Hi, Keep getting water coming into my air-con system. Definitely not coolant as can pump out via vent clean water. Heard about this 'Botangs Hole' that is under the bonnet on the passenger side and can be accessed without removing the ECU, but I can't get near it. The floor is all wet on that side also but I don't see how this would let it into the air-con. Have just had a lot of rain here and it now sounds like I must have about a gallon of water in the air-con system! Movement of the car sends it all sloshing over the inside of the vents. When the fan is on full I can see water splashing out the front and rear vents. I just don't know how it is getting in, or how to remove it as pumping it out the vents with a tube isn't removing it all. Can anyone advise? Regards, Barry. Link to comment Share on other sites More sharing options...
sloss Posted August 14, 2009 Report Share Posted August 14, 2009 There is a drain hole that exits under each front wheel arch. It's terminated in a cross section shaped bit of rubber that bungs up and stops the water draining away. Just pull the rubber bit off and clear the tube of leaves etc. Throw the rubber bit away. If this tube is blocked then water fills up under the ECU and drains into the car, if it doesn't do that then it will knacker the ECUs instead. I inspect the drain holes for blockages from time to time to avoid such things. I'm not sure if these are also the heater plenum drains too but I don't get water in if I keep them clear. Stew, Link to comment Share on other sites More sharing options...
PsYcHe Posted August 14, 2009 Report Share Posted August 14, 2009 Probably not Botang's hole. Check the drains above the wings, but more importantly, under the fan cover in the engine bay, most likely culprit. Audipages.com has a procedure. Link to comment Share on other sites More sharing options...
Barry1394 Posted August 18, 2009 Author Report Share Posted August 18, 2009 Thanks for the help chaps, I think we are homing in on it. I went into my local Audi dealer to check what the story is. They did mention those drain pipes under the wheel arches but I've already seen those and given them a clean. It seems there is another drain right under the plenum chamber so any water dropping into the engine compartment through the vent against the windscreen can build up and drop through into the car, mainly on the passenger side. After it has rained it can really build up around the rear of the engine. The guy reckoned it was a fairly big strip-down job as you have to take out the heater fan to get to it. Also, to drain out the existing water I need to open up the plastic vents. They said in some cases they drill holes in the bottom of the vents (presumably at the lowest point). I don't know if there are any other drain points nearby, but I guess it makes sense to connect a tube from the drill hole to a route out underneath. Barry. Link to comment Share on other sites More sharing options...
wsurfa Posted August 18, 2009 Report Share Posted August 18, 2009 There are also drains on either side of the transmission tunnel at the front (under the dash) , if water has built up and not drained from these, then they may also be blocked. I think they were meant to drain condensation from the ac system Link to comment Share on other sites More sharing options...
sutherland Posted August 18, 2009 Report Share Posted August 18, 2009 There are also drains on either side of the transmission tunnel at the front (under the dash), if water has built up and not drained from these, then they may also be blocked. I think they were meant to drain condensation from the ac system Yes, if there is no water trickling out under the car when the a/c is running it is probably those drains that are blocked. You'll need an air hose to clear them out. Link to comment Share on other sites More sharing options...
Barry1394 Posted August 20, 2009 Author Report Share Posted August 20, 2009 I took it through the car wash yesterday and the water pours out in volume from underneath over a very wide area from the engine compartment. Presumably, it should come out mainly from distinct points if the drains are working OK; this isn't the case. I've seen pictures of these drains points on the gearbox tunnel so I'm going to try and get at these and clear them out. I don't have an air-line so I'm going to use a Foghorn compressed air cannister via a tube to try and blow them out. There are also drains in the sunroof channels and I can't see where these come out either so I'll blow those out too. Link to comment Share on other sites More sharing options...
A8-dobbo Posted August 21, 2009 Report Share Posted August 21, 2009 Yes, if there is no water trickling out under the car when the a/c is running it is probably those drains that are blocked. You'll need an air hose to clear them out. That was my problem as well. Freezing cold water dripping onto the wife's feet every time we went round a roundabout, along with worrying water sloshing around inside the dash noises ! Sounded like it would be rather expensive if I didn't sort it. Carpets out, unclipped the flexibles, got about a litre of water out of each side (keep a jug ready when unclipping the orange piece that joins the drain pipe (90deg bend that probably the place that blocks). I also pushed a flexible plastic tube down the drains to make sure they were clear and now the a/c drains outside the car, not onto the carpets ! Link to comment Share on other sites More sharing options...
sutherland Posted August 21, 2009 Report Share Posted August 21, 2009 The guy reckoned it was a fairly big strip-down job as you have to take out the heater fan to get to it. Barry, it would be a fairly big strip down job to get it, but you don't need to. Just get an old wire coathanger or some fence wire and poke it around (non-violently) under the fan for a while. You will hear it scratching around on the metal underneath and then after a while you should see the water start to pour out under the car. It should come out on both sides of the gearbox if you've cleared both sides. It does work, just requires a bit of patience. Link to comment Share on other sites More sharing options...
Barry1394 Posted August 24, 2009 Author Report Share Posted August 24, 2009 Hi Sutherland, Ok, this sounds like the way to go. When you say get to "under the fan", do you mean from the engine compartment or inside the car through the front vent? Seems to me the tunnel drains are nearest the vent on the inside - much further to go from within the inlet housing in the engine compartment. Either way, I've given it a go and its fairly restricted through either route. I can get a coat-hanger down about a foot either route before it hits something fairly hard and won't go any further. Is it the tunnel drains I'm trying to get at here? BTW: It doesn't seem to be caused only by rain - I think this maybe just condensation. Barry. Link to comment Share on other sites More sharing options...
sutherland Posted August 24, 2009 Report Share Posted August 24, 2009 If I understood your report of the Audi technicians comments correctly, he was talking about the fan under the bonnet immediately in front of the windscreen. There is a plastic cover over the wiper motor that you would need to remove and then poke a wire in under the big square black box in the centre. If this is what's causing the problem it will probably be full of water down there or will not drain away when you pour water down into that area. If there is a pool of water in there and you clear the blockage you will see water start to pour out under the car. Link to comment Share on other sites More sharing options...
PsYcHe Posted August 24, 2009 Report Share Posted August 24, 2009 That's the fella. Sometimes it blocks at the top with leaves, sometimes further down. if you can get under the car, you'll see some pipes either side of the gearbox, and some orange ones not too far away too if I remember rightly which let out the water from the air con. Link to comment Share on other sites More sharing options...
Barry1394 Posted September 9, 2009 Author Report Share Posted September 9, 2009 Ok, so I found these drain points on the tunnel, pulled them out, and sure enough they were well and truly blocked! Full of dirt and leaves. Also, about a pint of water came out of the air-con unit on the passenger side, less on the driver's. I slapped myself on the back and drove off into the sunset. 2 days later, I can still hear water moving about in the air-con unit! Re-checked those drains again but all looks good. Help! Link to comment Share on other sites More sharing options...
sutherland Posted September 9, 2009 Report Share Posted September 9, 2009 I'd say you need to tackle both sets of drains. I assume you got to the one's under the fan when you mention leaves and muck, but did you also blast air down the drains with the orange rubber connections? You'd need to remove the carpet panels on the sides of the transmission tunnel and (assuming you don't have compressed air) make a trip to your local filling station, then use the air hose to fire some air down these pipes. That's the way I've always done it in the past and clearing both sets of drains has always cured the problem. I guess the other possibility is that there is a pile of muck under your fan box and that these drains have already blocked up again. Link to comment Share on other sites More sharing options...
Barry1394 Posted September 9, 2009 Author Report Share Posted September 9, 2009 The drains I am referring to ARE the orange ones under the carpet and trim on the gearbox tunnel. These can be pulled right off to get at them. They just seem to drain the water down the inside of the tunnel (ie. underneath the car) - there's nothing else behind there, no tubes or anything. When I take them off again they are clear with no blockages. The only other ones I am aware of are under the wheel arches, and these seemed OK. If there are more under the fan (ie. access via the bonnet), then I haven't ventured here yet - I was warned this was a big stripdown. However, the sound of the water does seem to indicate near the top and front. Looks like I might have to get the socket set out! Link to comment Share on other sites More sharing options...
PsYcHe Posted September 9, 2009 Report Share Posted September 9, 2009 There are two under the main fan unit.. A bit of a bugger to get to from the top.. Audipages.com has a writeup for all the drains. Link to comment Share on other sites More sharing options...
sutherland Posted September 9, 2009 Report Share Posted September 9, 2009 If there are more under the fan (ie. access via the bonnet), then I haven't ventured here yet - I was warned this was a big stripdown. That'll be where the problem is and if you take the plastic covers off above the wiper motor you will probably see standing water. This was what I was talking about when I suggest you poke around with a coat hanger or something under the fan box. Don't waste time stripping it down, just get a wire or something and poke around under the big black box in the centre for as long as it takes for the debris to be moved and the water will start pouring out under the car. Link to comment Share on other sites More sharing options...
Barry1394 Posted September 10, 2009 Author Report Share Posted September 10, 2009 Ok, I've checked out the article (audipages Unclogging the A8 Evaporator Drains). Seems this last part, the one with the copper tube, is where I need to check. This seems to be outside/underneath the fan assembley. If I need to go inside the fan with a coat hanger, is there another drain inside too? My engine bay is not the same as that and there is no way I can get a tube under there without taking out the ECU and/or stripping down the fan. Link to comment Share on other sites More sharing options...
r8dream Posted September 10, 2009 Report Share Posted September 10, 2009 here is the hole your looking to clean with the wire,it is the oval slot in the sheet metal which is under the heater fan assembly.a rubber tube like funnell thing drops the water out on both sides of the gearbox, john Link to comment Share on other sites More sharing options...
Barry1394 Posted September 10, 2009 Author Report Share Posted September 10, 2009 Thanks for the picture John. That makes sense now. Looks like a fan unit removal job. Not sure I'm going to strip things back as far as you have! Must be doing some serious work there! Cheers. Link to comment Share on other sites More sharing options...
r8dream Posted September 10, 2009 Report Share Posted September 10, 2009 (edited) photo was thanks to ian and david at a8parts, as they brought an a8 bodyshell to the annual a8oc meet in leicester in june. i took loads of pics for future reference, glad they went to all the effort. you really don't have to remove the fan unit, just get underneath the car and grab the rubber drains and squeeze like your milking a cow, and stuff should come out, or cut the bottom 1" off the rubber so all the leaves go right out in the first place, i did all my drains like this and never clog anymore now. Edited September 10, 2009 by r8dream Link to comment Share on other sites More sharing options...
sutherland Posted September 10, 2009 Report Share Posted September 10, 2009 Looks like a fan unit removal job. Why are you so determined to remove the fan? You really don't need to. Just try the coathanger method or the cow-milking as someone else suggested. Link to comment Share on other sites More sharing options...
Barry1394 Posted October 22, 2009 Author Report Share Posted October 22, 2009 It was just an omen that it needed to happen http://www.tyresmoke.net/forum/audi-a8-s8/122000-fan-noise-all-time.html Link to comment Share on other sites More sharing options...
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