All Windows Fogged?? - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Man, I don't understand this. Lately, last 3 or so days, everytime I get into the car all the windows are fogged from the inside. Not sure why... 99 Boxster. I live down in Mobile, AL and we have been getting alot of rain. I don't feel any wet carpet so I'm thinking there isn't water in the car but heck if I know... Any ideas guys? I'm waiting for a warm day to drop the top without rain and make sure everything is dried out. edit: has been fairly humid out and I am going out to check drains now.

Well, I went and checked both drains in the back, one on each side behind the seats...Not clogged or any standing water. I also checked both drains in front next to the battery...No standing water or clogged. I did notice a little residue around the top of the back hatch where the seal is for the oil and coolant so I might order a new coolant cap in hopes that fixes that issue. I had to add about a quart of coolant over the last 2 months or driving 2 weeks ago. It still looks 99% full in comparison to what it was 2 weeks ago.

If its the original top, it maybe porus. Spray a couple of coats of scotch guard or raggtop sealant. Don't get any on the plastic window or body. Top should be dry and clean before applying spray.

Hey man, I live in Florida and get the same problem. It's basically humidity and a temperature change from inside and outside of the car. During the summer mine hardly ever fogs, but this time of year, expect it. The scotch guard is a good idea or any convertible top repellent works. Need to do mine soon too. JB

Quit trying to have sex in your car, take a blanket!! Fog is usually a moisture/temp differential. take a paper towel and see if there is water gathering anywhere else, under seats,under floor matsback window area..... Check under your convertible top where it goes down into the boot thingy also. Do you keep your car stored outside? Moisture might be in your air ducts also. It might be climate also. I second the scotch guard on the top idea!!

Set your HVAC controls to bring in fresh air. Don't recycle your cabin air.

If it smells sweet... heater core.

I do keep my car stored outside. Didn't find any water where the top is stored. Nothing was wet inside the car either. I am going to get some ScotchGuard tonight and give that a shot. I have a feeling that is a major part of the issue. The 'roof' had water drops on it this morning when I shut the door it rained on me. Thanks guys. I'll let you know if it fixes the problem.

And I just found the carpet is wet behind both seats. How easy is a heater core to replace? Ofcourse I'm doing the alternator right now too...

No Scotchguard please! Raggtop! It is made for your top.

I think the heater core is in the front of the vehicle, not behind the seats. I know you already checked your drains, but you might try pouring some water and double checking it exits the vehicle where it should... Also, 303 makes a fabric protectant designed for canvas convertible tops. I read somewhere it's easier to apply. Some advice, I used the 303 product recently, and used a mix of painters plastic and paper to mask off the windows. It soaked through the paper pretty quickly, so stick with plastic. -james

Any luck yet? I just bought my 99 Boxster three weeks ago. Just this week the cabin has started to gather a lot of condensation overnight. The windows are getting covered in condensation. I also got "rained on" earlier this week- looked up and there were water droplets all over the roof. Nice way to start out the day in my nice work clothes... lol I haven't found any water on the dash or floorboards either. No problems other than this so far.

Yoadrian: You probably need to re-waterproof your canvas. This kit is a good place to start: http://www.amazon.com/303-Fabric-Convertible-Cleaner-Protector/dp/B000A8JNF0/ref=sr_1_14?ie=UTF8&s=automotive&qid=1267138438&sr=8-14

+1 on leaky heater core, since you have had to add a quart of coolant. See if you have any drops of liquid near the gas pedal and/or on the equivalent spot on the passenger side. Much easier DIY on the Boxster than just about any other car. You can access it and change it from outside the car, at the base of the windshield. Regards, Maurice.

Thanks for the advice. I'll try this soon and we'll see how it works out.

I used that kit recently and it worked quite well. One piece of advice, I don't think they wrote it on the bottle but in a pamphlet that I didn't read until I had finished applying: Do not saturate the fabric with the protectant. They recommend two light coats over going heavy. -james

I bought a new radiator cap and all problems went away. I don't quite understand it but I'm okay with that. No more condensation inside or on back in the little compartment in the trunk