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View Full Version : Please Help Location of Air Con drain tube ('96 Passat)?



notts_dave
24-09-2008, 01:00 AM
Hi Guys,

I've been having a problem with the windows misting up on my 1996 1.9Tdi Passat.

The bulk head drainage holes around the pollen filter are clear so I don't think it's water getting into the ventilation system from there.

Although I'm not getting water on my carpets I'm wondering if the problem might be a blocked drain tube from the Air Conditioning evaporator but can't see where it exits under the car to check. Can someone describe where it is and can it be seen and cleared easily without having to use ramps or an inspection pit?

Hope someone can help because it's driving me mad!

Dave

HorseOffaGypsy
24-09-2008, 11:34 PM
Dave,

Can't help you on the location of the air conditioner drain, but I've had similar troubles before with the drain from the sun roof blocking (leading to water leaking down the inside of the A pillar, down the back of the soundproofing - the front of which is water proof so the carpet doesn't get wet - but leaves damp in the inside of the car). It's worth checking these if you've got a sun roof.

Good Luck!

HoG

notts_dave
25-09-2008, 12:56 AM
Hi HoG,

thanks for the suggestion but unfortunately I don't have a sunroof

I found the Aircon drain tube eventually, it opens into the engine bay but it was clear

I'm going down the 'blocked pollen filter' route as suggested to me by a mechanic, fitting a new one tomorrow, I'll post a follow up if it works

Dave

HorseOffaGypsy
25-09-2008, 11:32 PM
A couple of other suggestions if the pollen filter dosen't do anything....

1) Check the grommets around the cable entries as they pass through the bulkheads - especially any "after market" fitment - aerials, alarm wiring and the like. If they been put in badly its amazing what you can get running down these. (This can lead to water going behind the soundproofing so your carpets stay dry..)

2) A badly bonded windscreen can allow small amounts of water in behind.

3) Check the bottom of the doors for damp. If the membrane/foam sheet behind the door panels are torn water can get in from the outside and "seep" through.

Good Luck!

HoG

mike67ld
23-10-2008, 11:22 AM
I think it's the one accessible under the bonnet. On the silver heatshield behind the engine, there are 2 U-shaped flaps. Lift up the RH one and there is a black rubber hose outlet which I assume to be the evaporator drain hole. Can anyone else confirm? My Passat is a '96 2.0 petrol, 166k miles, heading to 186k (speed of light! Ha, ha!).

Mike

notts_dave
24-10-2008, 02:11 AM
I think it's the one accessible under the bonnet. On the silver heatshield behind the engine, there are 2 U-shaped flaps. Lift up the RH one and there is a black rubber hose outlet which I assume to be the evaporator drain hole. Can anyone else confirm? My Passat is a '96 2.0 petrol, 166k miles, heading to 186k (speed of light! Ha, ha!).

Mike

Thanks for the info Mike, you're quite right about the aircon drain hose location.

Unfortunately when I checked it wasn't blocked so I'm still on the trail of the souce of the humidity.

Stragely, the windows mist up not only when the weather is wet but also when it's cold???

I do have a very small radiator leak (half a pint a year loss), but I can't see this being the source?

Dave

mike67ld
24-10-2008, 11:15 AM
Hi Dave

How coincidental! I get exactly the same misting up as well in the same conditions! Air con, when working, clears it though. And I lose the coolant at the same rate; but it's not serious enough to warrant investigation

I did discover the other day, an extremely soggy front passenger footwell and it turned out the water was getting in through the inside of the door, oozing past the bottom front corner of the 'watertight'(!) seal, dripping onto the plastic sill moulding and under the carpet, thoroughly saturating the the foam padding. Having ripped it all out, and gradually drying it, I'm hoping the misting problem will go away or be much less when I get it all back together.
To fix the door leak I carefully peeled off the black door seal I gaffer taped some sheets of heavy polythene to the door frame such that the bottom edge was INSIDE the door to the deflect the water inwards and hopefully solve the wet footwell problem.

I hope this helps.

Mike

notts_dave
02-11-2008, 03:54 PM
Thanks for that Mike,

sounds like you've discovered the source of your misting up, I've not noticed any damp carpets but I'll have a good look just in case.

I've been driving with my aircon on permanantley, not very fuel efficient but better than driving with the windows down!

Dave

mike67ld
02-11-2008, 06:46 PM
I did an experiment with aircon on our other VW, a Bora. It has cruise control and a multi-function computer with instantaneous mpg readout. On a nice flat traffic-free road I set the cruise to 50 mph and noted fuel consumption without aircon, then switched it on and checked again. There was only 0.1mpg difference on a 130bhp diesel.

So it hardly makes any difference as far as I can tell! The REAL culprit is our roof mounted bike carrier filled with 4 bikes.......!

Mike

andy e
04-11-2008, 10:31 PM
cause of condensation is possibly the aircon, do you use it in winter? if you do try this, switch it of for at least a week,the condenser collects water on it but as the weather is damp the condenser does not dry out, so when you turn car on, instant fog on all windows turning aircon on drys it out but dosn't get rid of problem, only when the condenser is dry will the problem go away. only use air con once a week to lube seals and compressor