964 water leak hot air intake

Stian911 · 05:07 PM

My 964 is leaking water.

I first discovered it because all my floor mats were soaking wet.

When I drove off there was a lot of water dripping from below the dash, hitting my foot.

After some investigation I found that the water is coming from the hot air vent underneath the driver side of the dashboard.

Can anyone tell me what kind of problem I'm up against here?

Best regards!
S

RedCoupe · 03-05-2014, 08:12 PM

I think it may be coming from the plenum chamber in the front trunk just in front of the windshield. Normally, hot air comes forward from the engine through the sill and the up through a paper/foil hose to a fitting that ultimately connects to the heating/cooling assembly high in the rear of the trunk. Because the plenum takes in fresh air, there has to be a drain for driving in the rain and car washing, etc. And of course when you are using A/C, the evaporator is condensing water out of the air. If the drain is clogged, the whole assembly may be filling up with water and then the water is draining down the hoses that normally bring hot air in. If you take the plastic cover off at the rear of the trunk you may be able to verify that it is indeed full of water. Somebody may know exactly where the drain hose is.

Stian911 · 03-06-2014, 06:07 AM

@RedCoupe: thank you for your reply. I have removed the "grit gurad" and the plastic cover around the air inlet in front of the windshield. The system doesn't seem to be filled with water. I have also cleaned the drain outlets underneeth the car.

I fear that my next step will be to remove the tank + blower assembly in the trunk to get to the drain hoses.

bazar01 · bazar01's Garage

You need to go to the Porsche online parts catalog. Look up in the ventilation section and you will see thewater drain tube diagram. If you can find the drain outlet under the car, part # 16, you can blow compressed air and see if you can make the condensate to drain.

Here is the link. Select the model and year of your car.
Porsche Original Parts Catalogue - Parts and Diagnostic Information - Porsche Service - Dr. Ing. h.c. F. Porsche AG
Good luck.

Stian911 · 03-06-2014, 09:42 AM

Quote:

Originally Posted by bazar01

You need to go to the Porsche online parts catalog. Look up in the ventilation section and you will see thewater drain tube diagram. If you can find the drain outlet under the car, part # 16, you can blow compressed air and see if you can make the condensate to drain.

Here is the link. Select the model and year of your car.
Porsche Original Parts Catalogue - Parts and Diagnostic Information - Porsche Service - Dr. Ing. h.c. F. Porsche AG
Good luck.

Thank you, Sir. The catalog is of great help. Both for the disambling and asembling part of the job.

Any ideas of what is actually causing the water to flow into the cabin air instead of trough the drain? Can it be that the drain line has come disconnected?

Stian911 · 03-11-2014, 05:06 PM

Do you think I have to remove gas tank and fan housing unit to solve my problem? Anyone?

Stian911 · 03-23-2014, 10:19 AM

I have checked all drains. They apear NOT to be clogged. I have also tried to blow compressed air from the drain near the fuelpump.

This afternoon I poured water into the air inlet just below the windshield. Seems like 80% of the water runs through the drains and ends up under the car. In som strange way 20% of the water comes into the cabin trough the air inlet under the dash. Both right and left side of the centre pedestal.

So my next step is to remove tank, fusebox etc and remove the fan house in order to check whats going on? NOT a job I want to start now since the spring is here.

Thanks for all your replies above, guys!