New 2012 JSW Windows fog up when raining

motorhead2

Well-known member
Joined
Oct 21, 2012
Location
California
TDI
2012 Jetta TDI Sportwagen
First off I searched both this forum and the TDI 101.
Our 2012 JSW will really fog up inside in the rain. I have owned many VW's and this seems unusual. I mean it is immediate. No leaks in the car. Only 2000 miles on the car. No sunroof. Yes I turn on the A/C but it seems to me that water is building up somewhere in the HVAC. I am obviously under warranty but it is damn near a waste of time to take it to them and just get told "It's normal" or "We couldn't get it to do it"
Yes....at 60yrs old I am a bit cynical about DEALERS. It is tough being a long time mechanic and letting some idiot work on my car. But as these cars get more and more complex, we are at the mercy of the dealer.
SO....Any ideas out there??
 

IMAAaron

Veteran Member
Joined
Jan 19, 2010
Location
PA
TDI
2013 JSW - Third time's a charm
Check for moisture in your spare tire well please. Water has a tendency to pool there if your rear wiper leaks.
 

SomeJ

Veteran Member
Joined
Aug 30, 2011
Location
central New Mexico
TDI
2011 JSW TDI 6m
Do you use the defroster? And do you have it set to recirculate air or use outside air? I found my car will fog up really quick when there is lots of moisture in the air and set to recirculate.

J
 

NRU73

Veteran Member
Joined
Mar 8, 2004
Location
N.E.
TDI
02 GOLF TDI Silver, 5 Speed
It sounds like a Recirc issue.

Turn it off and it will probably clear up.
 

Cogen Man

Veteran Member
Joined
Jun 4, 2011
Location
Kingston, Ontario, Canada
TDI
2011 Golf TDI DSG.
Mine did this for a while when new.(2011 Golf) I think it was more what was on the dash than moisture. But there was some moisture also. A couple of really good cleanings of the glass on the inside helped. I'm talking about 4 times. If recir is on that will fog her up also.
 

Vidgamer

Veteran Member
Joined
May 8, 2011
Location
Atlanta, Ga
TDI
2011 Golf TDI (turned in)
I have some anti-fog wipes, and that just seems to make things worse! Doh! The problem I'm having lately is when it's cold and right from the start it streaks on the outside. The wipers are crap. I don't know why I expect the dealer to replace them at the normal service intervals, or to at least ask me if they should...

But yeah, try wiping down the inside more if it keeps fogging, and use the A/C to defog when necessary.
 

Cooper

Veteran Member
Joined
Jul 21, 2010
Location
MA
TDI
2011 JSW (traded in 5/2015)
Mine would fog up, too. Just pulled out the owner's manual and read how to use the defrost mode correctly.
 

lou95gts

Veteran Member
Joined
Sep 24, 2010
Location
Caledon
TDI
2010 Jetta
Air conditioning needs to be on to defog. It dries the air.

Sent from my SGH-I747M using Tapatalk 2
 

Conrad -JSW

Veteran Member
Joined
Dec 9, 2011
Location
Northern Illinois
TDI
2012 JSW DSG
Mine did this for a while when new.(2011 Golf) I think it was more what was on the dash than moisture. But there was some moisture also. A couple of really good cleanings of the glass on the inside helped. I'm talking about 4 times. If recir is on that will fog her up also.
+1. Mine did the same thing till I gave the inside of the windshield a good cleaning. I think that there was something on the inside that caused it to fog up more than it should have.
 

motorhead2

Well-known member
Joined
Oct 21, 2012
Location
California
TDI
2012 Jetta TDI Sportwagen
Thanks guys... I thought I was going to have to take it to the dealer. That in itself is a bad dream! We'll clean it real good and someone suggested Rainx has a product for inside windows if needed.
 

c17chief

Veteran Member
Joined
Sep 9, 2010
Location
NJ
TDI
2011 Golf 2dr
+1. Mine did the same thing till I gave the inside of the windshield a good cleaning. I think that there was something on the inside that caused it to fog up more than it should have.
Yup. And it's not really one of those once you give it a good cleaning you can forget about it forever either. Even with my truck that only sees about 5k or less a year these days, I still need to give the inside glass a good cleaning every few months even if it has hardly been driven, to prevent excessive fogging inside when it's that time of year. Makes me wonder if some of it is a result of outgassing of the plastics and other materials besides just plain ole moisture or maybe some circulated road grime and stuff.


And the antifog/rainX type stuff....that sort of stuff actually works very well on the interior side of glass. The only problem is that stuff also has to be applied correctly and is somewhat difficult/takes some effort to do. It really has to be applied evenly but very lightly at the same time and buffed on very well or else you end up worse off then you were to begin with. Just a quick wipe the windows with that stuff gives you all those nice streaks and such while still fogging up nearly just as much as before.
 

gmcjetpilot

Veteran Member
Joined
Aug 18, 2008
Location
Memphis TN
TDI
2010 JSW TDI DSG Matalic Grey
Thanks, I'll check that. My main problem though is the windshield
I am just going to assume you don't have a leak and it is just the ambient weather conditions (temp and dew point).

This may sound stupid but make sure your defrost controls are set correctly (don't ask how I know :rolleyes:). When driving the icons on the controls are kind of small to read while driving.

The reasons for foggy windows are: 1) The window or surface is below DEW POINT of the air, moisture collects. Dehumidifying the air (with AC), drys air and lowers DEW POINT temp. 2) However you have to evaporate existing moisture off window even if you dry the air. HOT AIR heats the collecting surface to above DEW POINT temperature, and this is what melts the frost or evaporates the foggy window. So 1) lower dew point temp or 2) raise the temperature of collecting surface. You need both moisture and (lower) temperature below dew point to make dew, fog... and if the dew point is below freezing, dew becomes frost.

Air direction control either straight up or 10-11 O'clock. In the straight-up, 12 O'clock setting the AC comes on automatically. This puts all or most of air to window. I some times go to the right one clock and turn AC off use just heat... not sure what is better, experiment.

Temperature control in straight up, however this may turn AC off? I don't know if initially it is better to go full hot or cold? READ MANUAL. With the engine cold I would initially set temp control to full cold (CCW) "blue side" until the engine starts to warm up. However after engine starts to show temp, I would go full hot on the temp control. HEAT is what melts frost off or evaporates the fog. Yes AC is a "air dryer", lowers dew point, but heat is what "melts" the condensation or fog or frost off of window.

Fan set to full, but it makes WAY too much noise. That's one picky complaint I have of the car, with the fan in high or max it's just loud.

Things you can do:
Use some "hygroscopic" dryer pellets (chemicals) in a container, to absorb humidity. I don't know the brand or form, but I have used these dyer pots in the past in a personal aircraft. They do absorb water and fill with water they absorb. I also ran an extension into the plane and ran a 100W light bulb at night.

Get a frost-heater, install, plug in for 3 hours before you drive, making sure your engine is warm before you drive. I have one on a timer and it helps. When I start at home after warm up the engine is near operating temp, but drops to 160 F but comes up fast. The car starts easy and engine sounds normal. At work when I can't plug in, the engine takes a few revs before it starts and makes more noise for a bit.

Clean and treat outside of your windshield with Rain-X. Clean the inside of the window as well of course, but I never tried rain-X on the inside. It can't hurt. Rain-X fills all the micro pours in the glass and makes it hard for the water to stick to and fill.

Last if you live in a high humidity area this may be (????) normal if the humidity and temperatures are just right (wrong). The weather is fairly mild here and my car is garaged... Right after I got my car and did not know the controls. I had dew or fog on my window. Not knowing the car well I inadvertently put the temperature control to full cold (blue). I was in heavy traffic and the controls were not like the Acura's I drove the last 20 years. The window would not defrost. Once I realized I had it on blue, I set full hot (red) and window defrosted. The engine was also just warming up and I may have also had direction control not set correctly. Read the manual and try different settings.
 
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