Help with fogging windows

I have a n 81 mercedes 240d and every morning its the same problem. I have dew on all the outside windows and fog on the inside. The windows have a frosted light green cover every morning.

The windshield is the worse and doesnt really clear up til I hit 45 on the road where I live. I try the wipers, ac and physically wiping it. The other windows work pretty well with wiping them. I do not seem to need any water, as a heater core leak would make the windows fog on the inside, but it goes away after I get rolling.

Ive tried rain x, fog x and they seem to do nothing for fog. Rain x works wonder in rain.

Thanks.

I had a tiny heater core leak in my car (around the hose clamp) and it didn't lose enough water to notice but it sure caused the windows to fog. You could also smell the anti-freeze smell.

Greg

Try glycerin soap. Get a bar, make a bunch of streaks on the window surfaces (about one every 6-9") and then rub it in with a soft rag. They used to sell a stick for that purpose at car shows and it was nothing but glycerin soap; but it did work.

It may be moisture inside the car. If it leaks when it rains inside, then it will fog up. Usualy though thats once you get rolling and it heats up and steams up the windsield though.

Make sure the windows are up and the inside is dry, and that will help. Also clean the windshield with something that will remove residue from exhaust (desiel, etc) as that can make a milky film that looks like the windows are fogging up, and it will appear when there is humidity in the car. Get rid of the film, and it won't fog up so bad, or if it does, it will go away fast and not be so milky.

Make sure the evaporater tray is draining (like when you seel water under the car when you stop).

Rain-X indoor window treatment,,,works great!

I've tried the treatments and they really only make the problem worse after a few days. Just use windex or something else with ammonia and scrub the inside spotless. The cleaner it is, the less fog will gather. Also if you wipe it with anything when driving, clean it spotless when you're done. I have a Cabriolet that leaks pretty bad, so it's horrible to defrost in the winter.

BTW, if you think Rain-X is good on the windshield (outside) Try a product called Aquapel made by PPG. It works like fresh RainX for 3+ months and doesn't clog the wipers or wear off on contact spots of the wipers path.

one rule of thumb my dad, grand-dad, and great-grand-dad all used the right hand rule: put the heater to the right(warm), put the air-intake to the right(from outside), and the air flow intensity to the right(max). it always worked for all the old cars we ever had.

Try leaving two windows open just a crack on each side of the car. This will allow cross-winds overnight to draw moisture out of the vehicle. If you're in a high crime area, this might be a poor idea. YMMV.

For the windshield exterior, I always put a good squirt of dish washing detergent in the washer reservoir when refilling it. When you spray the windshield, it acts as a wetting agent and eliminates streaks and annoying blobs on the windshield. This works both in the summer and winter. Cheap and effective. Again, YMMV.

In my experience, if you do not have the windows extremely clean (definitely not just a Windex job) and you use Rain-X or the Anti-Fog, the windows will streak and will be very annoying at night. Plus, it's a royal PITA to clean the windows enough once the stuff is applied. I dearly love Rain-X on the windsheild, but the antifog wipes can be a real drag to use unless you do a very, very thorough prep job. Also, any sort of antifreeze leak will make things bad and even worse with an antifog treatment.

If you don't have a coolant leak and the windows are super clean, then the stuff works pretty well, though.

Thanks, will try some of this stuff.

It does or did have an interior leak on both sides. I sprayed the areas outside with some do it your self undercoating. It seems to not leak, but am sure there is moisture that I will never get rid of in it.

You are supposed to clean the inside before use of the fog x cloths? I thought they did both clean and applied the protectant chemicals to reduce fog? That maybe my problem. That was one reason I bought the pretreated cloths as they at least from the brief reading of the directions didnt require the pre work of the liquid product.

Yeah, I tried the windows open, defroster on, seems the ac clears them best on the inside, but causes more moisture on the outside.

If you absolutely have to fix the problem as a last resort drive to southern AZ for a 2 week vacation, ideally around Yuma. Any moisture trapped in the car will be long gone by the time you leave. We would get moisture problems with our planes on the east coast but after a week of TAD in Yuma they would be cured.

Seriously, I had the same issue with a Nissan something or other back in the late eighties. I never could fix it so I just carried a dry towell with me all the time.

nevermind

As a last resort, turn your defroster on, blower high, a/c on... and the windshield should clear quite quickly. If you don't have a/c then I would have to go with everyone else that suggests checking for moisture inside the car and equalizing the inside/outside temps.

You may consider one of those little vent fans that you roll up into the window frame. It's just a low-volume "muffin" fan, but this will certainly prevent window fogging. There are the solar powered type, which you probably won't want, but there are cigarette lighter types too (intended for car storage or something).

I've read that the ammonia in Windex and other cleaners will attack the adhesive of window tint, which then causes the tint to start bubbling.

The ArmourAll window cleaner is tint safe, and does a pretty good job cleaning up bug guts, etc.

db said:

I've read that the ammonia in Windex and other cleaners will attack the adhesive of window tint, which then causes the tint to start bubbling.

The ArmourAll window cleaner is tint safe, and does a pretty good job cleaning up bug guts, etc.

Click to expand...

That's true. If you have tinted windows you need to look for ammonia free glass cleaner. My friend who owns a tint shop uses these aresol cans of glass cleaner, they seem to work the best.

Find a piece of scrap carpet the size of your windshield, and cover it (outside) with the carpet - use the wiper blades to hold it down. That will eliminate the frost/dew on the outside. My dad has been doing that for about 15 years in Alaska, and even parking his car outside on the coldest nights, when he removes the carpet, there's not a spot of frost on his window.

The inside is due to moisture buildup in your car - you need to get it dried out and keep it dry.

Yeah, the interioir leaks, seems the drivers seat has sunk throughthe floor. Windows are tinted, but they have that factory green tint to them when they made em.

Ive been using the ac and the dried up fog x cloth and so far its doing. I saw a pretty good deal at sams club the other day 4 cans of window clean for 11 bucks. I saw the same one can product for sale at an auto store 4 bucks for one can.

Going to try and clean the front inside of the window and try installing fog x again properly after a good cleaning.

If you interior leaks, try using DAMPRID and leave it in your car. The dessicant will absorb the moisture and you will be surprised how much moisture Damprid.

My car had some rubber seal issues in the trunk that caused some leak when it rained hard. The result is similar to yours, fogging interior windows. I used damprid and it slowly went away. It may take time to get all the moisture out but it works. I think you can get damprid at lowes, homedepot and grocery stores. Good luck!

All the cars I've had for the last 35 years would turn on the AC automatically when you turned the heater to the defrost position. The AC dries the air and it removes the thin film of moisture from the inside of the windshield in a few seconds, even when the engine is cold.

If that's not happening in your car, I'd guess there is water getting into the ducts that carries the air to the windshield, or the AC isn't turning on.

Many years ago I had a 1968 Pontiac that handled things better than any other car. It would always direct a small amount of air against the windshield no matter how the heater and vent controls were set. Sometimes in the morning or evening of cool damp days, a little film of moisture will form on the inside of the windshield. Just a tiny amount of air from the heater would keep it clear.

All the cars I've had since shut off all the air to the windshield unless I specifically turn on the defroster. This is just plain stupid. I'm now forced to turn on the defroster which means a loud fan and AC and loss of control of the heating and venting. Really really stupid.

If I knew how to get at the flapper valve that shuts off air to the windshield, I could just stick a pencil or other object in there to keep it from fully closing.