I took the beast on a nice drive today. It was pretty hot outside, so I had the AC on all the time. After about an hour, I drove through a right bend on the freeway, and had water drip on my right foot.

I vaguely remember this has been discussed before, but I could not find the thread tonight. I simply don't remember the remedy for this.

My suspicion is that condensed water forms in the heater box and exits through the foot vents when it should drain (where?) instead.

Can you guys refresh my memory on this issue?

 

Sometimes the drain on the bottom of the box can get clogged and cause the system to fill up.

I had it happen to me and when it let go it dumped at least 1 gallon of water onto the exhaust and made me think the heater core went out.

The drain is just on top of the y of the catalytic converter, or in the S4s' case, the H

You can stick some metal wire into the drain pipe to dislodge the clog or remove the carpeted covers on the side of the center console to gain access to the rubber tube that is the drain .

Then squeeze it a few times to see if the clog can be dislodged.

The drain pipe has two openings going into one that dumps onto the cat, one pipe drains from under the evaporator and the other drains from the floor vents to catch any water that could blow by.

Otherwise it's the heater core, but I doubt that since the water wasn't hot I'm assuming and it didn't smell like antifreeze while you were driving.

 

Nicole,

All a/c systems knock moisture out of the air as it is cooled and thus a/c systems have a catch pan underneath the evaporator with an outlet nozzle at the low point that is usually drained to the underside of the car. Assuming my memory serves me correctly this nozzle sits at the front drivers side of the air handling unit [near the firewall]. If the hose rots and/or falls off you get your tootsies washed.

If you live in an area of low relative humidity [desert type conditions- Silly Valley?] very little water will emerge. However in such conditions there will be dust in the air and this can gets into the air handling unit - sooner or later the dust also gets into the drain pipe and could possibly form a weak cement with the condensed water and thus blocks the drain pipe.

If you can find the tail pipe a bit of wire can be used to try and disturb any blockage that may be present as stated in the earlier post.

Rgds

Fred .

 

Thanks, guys! Now that you explained it again, I realize there hasn't been any condensed water dripping from the car after yesterday's drive. I will look into it as soon as I get a chance.

 

My 84 does the same thing

 

Nicole, you've been into the 928 scene for longer than I have. This is a helluva time to get cold feet!

 

Hola Mädel, alles klar?

The drain is located at the bottom of the HVAC unit and drains the AC water onto the cat heat shield. The bad news is: to clean the little rubber hose, you'll have to remove the cat and the heat shield on top.
Below a picture of the location on my GTS...

 

Oh no - that's not what I was hoping to hear! I may have to defer this until there is another reason to drop the cat... ugh!

 

Off topic but reminds me of a write up on the AC Cobra back in the day. The writers says "the sole purpose of the heater in the AC Cobra is to keep your right foot wet".

 

Having just recently got my AC to work again, I too had a bit of water dripping on my right foot during cornering the other day. However, given that it's not soaking the carpet routinely, I don't think the drain is clogged. Maybe just SLIGHTLY clogged, or maybe condensation somewhere else? It hasn't reoccurred, so maybe actually making use of the drain with some regularity now is cleaning it out.

Nicole, if your car has been sitting a while, and it's not a lot of water, maybe running it some more might clear it up?

 

What Jeff said, plus...

That drain tube is likel a favorite place for insects to raise their young. It may be that some water from the top will flush the remains out the tube at the bottom. I've never tried accessing the drain tube from the top, since the bottom of the air handler sits pretty close to the tunnel. In my experience, you can drop the front of the exhaust more easily than disassembling the console anyway. The front comes loose on mine at least once a year for thrust bearing check. Lower the front just enough to get to the heat shield bolts, and slide the shield out of the way I think. I've not removed that shield myself (yet), so some speculation. Looking at GPW's undercar cleansing for the Carmel street show, that may change this coming winter. (!)

 

Check your heater hose where it passes through into the cabin Nicole when the clamp is loose it drips on the go foot. It would be warm water though..

 

it was cold water, non-sticky.

 

golden s..., nevermind. sorry.