Windshield, side windows and rear window fogging up !

[Pozuelo]

This week we are having a very damp days in Madrid. I had noticed once before that the windows and windshield were fogging somewhat. I used the front and rear defrosters/demisters but found the front one loud and ineffective, especially in the passenger side. Today, during my drive through the rain alone, I noticed very little fogging, but as soon as my wife entered the car, it started fogging up quickly and the front demister took over five minutes to clear up ! I put the A/C in the normal mode as air conditionings’ most important function is to reduce humidity ! Since 1988, when I bought my first Mercedes wagon, I had not had any windows fog up on me even with 7 passengers and the vast expanse of glass ! This was using the A/C compressor all year round. Not the greatest for mileage efficiency, but I never had trouble with any of my AC systems even when I had the cars for well over 250,000 kms. So I don’t know whether my AC on the Taycan is not working properly or is designed in such a way where the humidity is not reduced. Anyone can help me ? I am thinking of buying a temperature and humidity sensor to check the actual values.

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[Christian J]

Sorry you're having problems. I would have your dealer check to see if your drainage hose is working properly. It's a recall item and your car may have the problem which could be leading to increased humidity inside the car.

 

[wemct]

Also have the dealer check the refrigerant levels. Some on the forum have reported low levels which caused issues with the AC.

 

[Pozuelo]

Thanks for your suggestions. Will ask for an appointment at the dealer. It is wholly owned by Porsche Spain, in turn owned by Porsche AG. Will be my first service visit since delivery on July 1. I will ask them to update all outstanding issues which may affect my vehicle. Will report results.

 

[NC_Taycan]

Sorry you're having problems. I would have your dealer check to see if your drainage hose is working properly. It's a recall item and your car may have the problem which could be leading to increased humidity inside the car.

+1 for this. Had this symptom and root cause on other vehicles (including a Cayenne).

 

[Mad Pat 66]

Has anyone noticed how poor the demister (Max) is at clearing the windscreen, or is it just me?
Drove the car for 15 minutes today and returned two hours later to find all the windows seriously steamed up inside, still hadn’t cleared properly nearly 30 minutes later.
Also, there seems to be a fundamental flaw in the design, as the vents are broken up by a 6 inch area of solid plastic right in the centre which prevents the centre part of the screen from clearing.

 

[NC_Taycan]

As @Christian J mentioned, have your dealer check if your car needs the air conditioner condensate drain hose campaign applied (or if yours might be clogged). Any condition preventing condensate from being evacuated from the interior will lead to this.

 

[Mad Pat 66]

As @Christian J mentioned, have your dealer check if your car needs the air conditioner condensate drain hose campaign applied (or if yours might be clogged). Any condition preventing condensate from being evacuated from the interior will lead to this.

Will do, as it’s booked in to get the PCM system looked at as well, as it’s suddenly locked up, just as other owners have experienced.

 

[WalterG]

Will do, as it’s booked in to get the PCM system looked at as well, as it’s suddenly locked up, just as other owners have experienced.

Have you tried turning the air recycle off? That seemed to help me. Also try turning the fan speed higher and the airco eco mode off if you haven’t already.

 

[Mad Pat 66]

I’ve tried everything and found all settings to be poor but extremely disappointed with the demister, which seems weak and not up to the job.

 

[WalterG]

I’ve tried everything and found all settings to be poor but extremely disappointed with the demister, which seems weak and not up to the job.

Here’s a good post from REIL (about halfway down the page) about using the individual adjustment option to select more ventilation for the front windshield (and footwell).
https://www.taycanforum.com/forum/threads/car-misting-up.3161/page-2

 

[MaKin]

Any updates on the outcome of your dealers checking the situation?

 

[MaKin]

For all of you who did not yet experience this dangerous problem.

 

[Mtljckt]

Same here, my car gets misty if I turn the air recirculation on. After the weather turned cold screen gets foggy suddenly, which was very dangerous several times (passing a truck at night). I have the ionization feature add-on, if that matters.
Anyone else seeing this often? Never had a car where recirculating air will produce so much humidity.

 

[_Brian_]

Same here, my car gets misty if I turn the air recirculation on. After the weather turned cold screen gets foggy suddenly, which was very dangerous several times (passing a truck at night). I have the ionization feature add-on, if that matters.
Anyone else seeing this often? Never had a car where recirculating air will produce so much humidity.

I have experienced this effect in the past with other vehicles when I switched the HVAC setting to recirculation. I did a little research and concluded that the amount of moisture from exhaling (particularly if there are multiple occupants) exceeded that capacity of the A/C to dehumidify the cabin. The condensation temperature (dew point) at the surface of a cold windshield is pretty high resulting in fogging. Others may have different experiences, but my fix has been to not use recirculation in any of my vehicles.

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