A/C leak from dash

Post Thu Feb 24, 2005 2:54 am

Hi all. I have a air conditioning water leak coming from the box in the center of the dash. I have cleared the pipes manually and with compressed air but the water leaks out the corner of the box still. Anyone know whats in there? and is there any good articles on how to get that box out. I love my car

Post Thu Feb 24, 2005 5:53 am

whats in there is a heat exchange matrix which is basically a radiator around which compressed freon gas is pumped under pressure and therefore cold, this in turn cools the air that is forced through the matrix by your fan. What happens is the air then becomes denser and the moisture in the air condensates and this is left usually on the outside of the matrix this is the leaking water you are getting. It should collect in a drip tray and flow through a pipe which exits around the propshaft (hence the sizzling noise as is drips also onto the exhaust) the matrix is accessable from the passenger footwell and the drain pipe is blocked probably at the bottom of the matrix at the water collection tray. clean it and your leak should stop.

mr lee

Post Thu Feb 24, 2005 6:06 am

My car is right hand drive. There is a drainage pipe that comes out the side of the box on the drivers side. I have had the rubber connection pipe out and tried to poke around in there carefully but to no avail. Are you saying i can take the side of the box off to access that area? Sounds like my weekend is going to be spent playing with my car. Yaaay!

Post Thu Feb 24, 2005 6:19 am

both mine are left hand drives and m A/C matrix is on the right so i am presuming yours is opposite but unsure!! be very careful if you start to open that area as the freon pipes from the compressor are brazed pipes and if you bend em theyll break! that is a pain in the arse to fix! try running the A/C with all the panels under the footwell off and check exactly where the water comes from. Sounds obvious but the only way. dont forget that some (but only a little) condensation will appear on the Freon pipes too but if you have a considerable amount of leaking water i doubt that is the problem. A tip when trying to find the leak is run the A/C in the evening when the relative humidity is higher so you should in theory get more condensation.

i will have a look at mine today and see if there is anything else i can suggest.

mr lee

Post Thu Feb 24, 2005 6:50 am

I aready have the panels off. I can see the water leaking from the corner of the box near the side outlet pipe. A very small amount seems to drip down the pipe itself but a nice steady drip comes from the corner of the box near it. I don't want to have to take the whole dash out just to get that box out to have a look. Hopefully you or someone will have a sneaky way of getting in there

Post Thu Feb 24, 2005 7:58 am

On a RHD E30, the heater matrix still comes out on the left (passengers) side of the heater box. The A/C evaporator comes out on the other side.

To get at the drain pipes inside the box, you should only need to remove the heater matrix though. Once the heater valve and water connections have been removed, it can be unscrewed, and will just slide out of the box. You should then be able to get in the bottom of the box to check for blockages.

I recently fitted an A/C heater box to my car, and there were three drain tubes. One is just behind the centre console, and drains through the top of the tunnel onto the gearbox, and the other two are at the front corners (one each side) of the heater box.

Ian.

Post Sat Feb 26, 2005 6:14 am

ok got the side off the box (right hand side of car). I can get a thin wire to go into the drainage pipe from where i have opened up the box. I still get water coming out of the bottom of the box in the corner nearest the drainage pipe. I don't understand why. I could post a pic but I don't know how. Any help would be appreciated.

Post Sat Feb 26, 2005 6:56 am

sounds like its cracked? if you take a picture then save on computer then goto www.photobucket.com and set up a free account. put your pictures on this site and it will give you a http address for the picture. then when posting just click img then insert the http address for the picture and alt p and it will show your picture on the preview.

mr lee

Post Sat Feb 26, 2005 7:24 am

ok I'll give this a go. here is the pic (hopefully). If I were to screw the side back on the box then the leak drips out of the bottom corner (to the right of the drainage pipe in pic. What to you think guys? can't see any cracks or damage to plastic casing.

Post Sun Feb 27, 2005 11:07 am

If the drain tube is not blocked, then it may simply be that the seal on the removable cover is leaking. Try cleaning all the surfaces, or even use a bit of silicone sealant to seal it up.

Cheers,

Ian.

Post Mon Feb 28, 2005 5:50 am

Alrighty I got some silicon sealer. We'll see how we go. I had another feel around and it seems that there is a small lip on the bottom of the box and just above that is a small hole for the condensation to go through. looks like the water gathers there and then overflows to the main part of the bottom of the box (where the drains are) hopefully the sealant will stop the water escaping from the box the wrong way. Maybe over time my box is out of alignment or has warped to cause the water to flow the wrong way. Enough of my ramblings. i'll let you know if it works