A Lot Of Windshield Condensation At Night.

[LandoCommando]

An Excessive Amount Of Windshield Condensation At Night.

I have never run into such an issue with any other vehicle I have owned so I'm wondering if there is an underlying special TDI or VW issue here that I'm not aware of.

I have come out of the office at night on several occasions to find the inside of my windshield covered with an exuberant amount of condensation. Last night I wiped a little hole to see out of and then drove home. It took 15 minutes of driving for the windshield to clear up and even when I got home there was still some left in the corners.

I only have to drive about 6 or 7 miles in the morning to work and the times this has happened I believe it was 32°ish in the morning then worked its way up to 40° during the day. On my drive to and from work the car only warms up within the last mile of the drive so the cabin usually doesn't get the chance to get very warm.

Now, I know about condensation and why/how it forms but what I don't know is why it happens to this car and not any other I've ever driven.

I'd also like to add that I believe I have an exhaust leak somewhere because the cabin smells like diesel exhaust if the car sits and idles in the same place for more than 30 - 40 seconds. Could this be exacerbating the situation?

 

[Ski in NC]

Check your floorboards for damp carpet. If rainwater gets in the car somehow, it raises humidity in car when all closed up and parked. Humidity then condenses on the coldest thing which is the windshields at night.

Car got a sunroof??

If you know it is not going to rain, leave windows cracked open an inch.

 

[jettawreck]

And never use the "recirculate" setting. That won't vent moist air.
If you suspect excessive moisture inside the car, drive with full heat on and rear window or sunroof open a crack (if you can stand it) to vent as much as possible.

 

[showdown 42]

These guys have the right idea,you are getting moisture in from some area in the car. Start looking at floor ,then if you have a sunroof,the drains might be clogged. Water is an insideous pain. JP

 

[IndigoBlueWagon]

Sunroof drains may be filling the footwells. Or the A/C evaporator drain may be plugged and soaked the carpet during the summer, now you're noticing it. Or your heater core may be leaking and the smell is actually coolant, not diesel. This will make the windows especially slow to clear, and leave an oily film on the glass.

 

[rpl3000]

I had the same problem. The sunroof drains were blocked and that made the carpet damp.

 

[whyfish]

RE; Condensation

Here in Oregon, its been a pretty wet fall/early winter. Even with no leaks in my cabin, I bring enough moisture into the car from wet shoes to wet rain shell.

I sometimes have the same experience with window fogging. I crank the fan up to 4, set the dial to defrost and run the AC and in just one or two minutes, the condensation is gone.

The AC air is dry, cold air and will suck up any moisture in your cabin. But still, you may want to check the drain plugs on your sunroof. They do clog up. I clean mine out every fall, before the rain sets in. You'll be astonished with all of the junk that can accumulate in those drain lines.

 

[JB05]

Running the A/C is a good idea, but it won't activate below 40F.

 

[LandoCommando]

Carpets feel dry, unless the coolant smells a lot like diesel I'm pretty sure its diesel exhaust, the condensation isn't leaving any residue after it dries, and I don't have a sun roof. I will check for a clogged a/c evap drain tomorrow.

Thanks

Also, I'm not sure if this is related but I notice that on cold days my windows tend to fog up extremely easy and quickly. Even if the car is warm and I've been driving it for awhile, if I turn the blower down to 0 or 1 my windows start to fog. So to keep the fog off I usually never take the blower off 3 and my chest level vents are always pointed at the windows.

 

[Thirstyturtle328]

I had this problem in February when I first bought my car. My carpets were dry BUT i pulled the little plastic cover off from the drivers footwell (above your feet, under the steering wheel) and there is some insulation type stuff attached to that which was soaking wet. The leak turned out to be coming from my windshield cowl where a big wiring harness comes into the car. I had lots of debris (stick/leaves/pine needles) stuck in there and it had rotted a seal. I just cleaned it and caulked it, been running dry since. I would do further investigation into any possible dampness/leaks.

Also, try cleaning the inside of all your windows really well with a good window cleaner (windex will work fine if you don't have tinted windows). If i don't clean mine for a few months then they fog up much easier.

 

[vwdieseling]

Is it an aftermarket replacement windshield. I had mine replaced do to being broken. In some cases they are not sealed properly by the installing technician. It doesn't leak, but I get a lot of frozen haze on the inside it seems. My gasser Beetle never does this. I have the same problem it takes me an extra five or ten minutes to get on the road after work in the mornings. All of the other posts pertain to this matter, and I have explored them for solutions. I was just throwing this possibility out since I experiance it, and have checked all other avenues. Mine is a 2000 Beetle and you can imagine what the already visual bubble that sits across the great picnic table of a dash can be like.

 

[vwdieseling]

I had this problem in February when I first bought my car. My carpets were dry BUT i pulled the little plastic cover off from the drivers footwell (above your feet, under the steering wheel) and there is some insulation type stuff attached to that which was soaking wet. The leak turned out to be coming from my windshield cowl where a big wiring harness comes into the car. I had lots of debris (stick/leaves/pine needles) stuck in there and it had rotted a seal. I just cleaned it and caulked it, been running dry since. I would do further investigation into any possible dampness/leaks.

Also, try cleaning the inside of all your windows really well with a good window cleaner (windex will work fine if you don't have tinted windows). If i don't clean mine for a few months then they fog up much easier.

I am going to check mine in my Beetle. it is on the passenger side where the ECM is located under the dash plate by the cabin filter.

 

[LandoCommando]

I'm not sure if the windshield was replaced. I've only had the car for 2 months.

I will check under that plastic cover. Thanks for the tip.

 

[vwdieseling]

I'm not sure if the windshield was replaced. I've only had the car for 2 months.

I will check under that plastic cover. Thanks for the tip.

Just an idea, the windshield should the VW marking on the corner just an easy way to tell. I think my problem is something else that is causing it, but I know what your going through.

 

[Lug_Nut]

I leave the sun roof tipped up during the day in the sunny parking lot at work. The windows are up and locked so no chance of a reach-in. The sun warms the interior to vaporize the moisture that then can waft out the sunroof.
My drains are clear, but wet jackets and hats or snowy shoes can add more moisture in an instant.
And this A4 Jetta is worse than any other car I've had.
(positive spin): It may just be sealed tighter and without the sunroof to vent the moisture, what is inside stays inside to perpetually vaporize and condense over and over.

 

[Hyde7278]

Pull the sill plate trim off and lift the carpet alittle and see if there's water if not putt your hand under the carpet and feel the padding. If it wet remove the front seat and rear seat bottom and lift the carpet as high as you can and wedge a pipe or something to hold the carpet up as high as possible. Then use a shop vacuum to vacuum the water up and then vacuum the padding out. Then place a fan blowing on the underside of the carpet until its dry then you have to find out where is leaking.