Moisture on inside of windshield

Got a question about my new 15 Golf TDI. I’ve noticed sort of a bad smell when the defroster is first turned on when the car starts. Also, there seemed to be a bit of moisture on the inside of the windshield in the morning. It goes away as soon as the defroster starts drying it out. I imagine the car sat for quite some time. Any ideas?

Check the cabin filter, easy to do and cheap enough to replace. Mine was full of crap on my car that was a buy back car. On previous vehicle I had moisture from defroster was from a bad heater core

dobeonguard said:

Got a question about my new 15 Golf TDI. I’ve noticed sort of a bad smell when the defroster is first turned on when the car starts. Also, there seemed to be a bit of moisture on the inside of the windshield in the morning. It goes away as soon as the defroster starts drying it out. I imagine the car sat for quite some time. Any ideas?

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I get this occasionally aswell. Not a coolant smell but more of a hot garbage smell.

GreenLantern_TDI said:

I get this occasionally aswell. Not a coolant smell but more of a hot garbage smell.

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I get that the day after Taco Tuesday.

OP: BG makes a product called FrigiFresh. It works wonders for HVAC system funk. Take the cabin filter out, I'd get a new one if you haven't already, and while it is out, turn the blower on LOW and spray the can into the cabin filter cavity while moving the mode selection to all its positions... then shut the blower OFF, continue to spray to saturate the entire HVAC case, spray a little on the new filter, and put it back together and let it sit for an hour or so.

dobeonguard said:

Got a question about my new 15 Golf TDI. I’ve noticed sort of a bad smell when the defroster is first turned on when the car starts. Also, there seemed to be a bit of moisture on the inside of the windshield in the morning. It goes away as soon as the defroster starts drying it out. I imagine the car sat for quite some time. Any ideas?

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also check spare tire well for water

Had the same moisture problem on my passat. It was same problem as the b5.5's had which was plenum drains clogged with debris. Had the VW dealer snip off all the duck bill drainhose ends on not only the plenum drains but the sunroof drains as well. Moisture problem solved and fixed for good. Got it done when the car was almost new two years ago so no funky smell developed. They did it under warranty.

thundershorts said:

Had the same moisture problem on my passat. It was same problem as the b5.5's had which was plenum drains clogged with debris. Had the VW dealer snip off all the duck bill drainhose ends on not only the plenum drains but the sunroof drains as well. Moisture problem solved and fixed for good. Got it done when the car was almost new two years ago so no funky smell developed. They did it under warranty.

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Where are the plenum drains located?

GreenLantern_TDI said:

Where are the plenum drains located?

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http://forums.tdiclub.com/showthread.php?t=496736&highlight=drain+plug

AGOODHI said:

http://forums.tdiclub.com/showthread.php?t=496736&highlight=drain+plug

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Yes this explains the sun roof drains but not the plenum drains that Thundershorts had referenced.

So I installed a new MANN cabin air filter from IDParts, the better one than OEM it looks like. That seemed to cure the smell that comes out. I have checked the spare tire well, no moisture. We haven't had rain here for the past week or so, but this weekend it poured. We drove in the rain on Saturday and I didn't notice any leaks, but moisture did start to develop on the inside. The defroster clearly is functioning well. Car sat Sunday and Monday, and this morning there was a good bit of frost on the inside of the windshield. My Golf doesn't have a sunroof. I guess I will make an appointment to have the plenum drains checked. Any other ideas?

the horizontal window seals by the side view mirror are known to weep and cause moisture inside the cabin,

So we figured out where the moisture is coming from. I had it in to the dealer and the plenum drains are fine. However... Both rear doors are leaking water in down near the speakers. They said it's common on the cars that were sitting for an extended period of time on the buybacks. There are seals inside near the speakers that rot out. VW has a fix for it and they are going to fix it. They left the car in their car wash under high pressure water to find where the intrusion was coming from. There was a little puddle on both sides, something I didn't notice because I never left the car in a car wash for 10 minutes.