How can I get this strange fog off the inside of my windshield?

October 17, 2007 9:09 AM

My old Toyota Camry gets a strange oily build up on the inside of the windshield every month and a half--traditional cleaning methods don't work. How do I clean it? Help me not crash and die.

My '87 Toyota Camry has seen better days, but it has no leaks. Nevertheless, every month+ or so, a build-up accumulates on the inside of the windshield, making rain/nighttime driving scary as hell.

I've tried traditional glass cleaners--they simply move the fog around, creating even more annoying swirls. Someone suggested using alcohol, which works slightly better (but it still means I have to scrub the whole windshield several times in order to make my car driveable again).

What is this stuff and how can I get rid of it more easily? My month is up and I've got to clean again this weekend.

posted by eralclare to Travel & Transportation (26 answers total)

The uber-mind has much to say:
http://www.google.com/search?hl=en&q=auto+glass+cleaner
posted by jeffamaphone at 9:11 AM on October 17, 2007

I was going to ask if you were a smoker, but this Yahoo question sounds remarkably similar.
posted by prostyle at 9:16 AM on October 17, 2007

This could be antifreeze, which would be coming from your cracked heater core. Does this buildup correspond to turning on the heat? Is there an associated antifreezy odor?
posted by pullayup at 9:16 AM on October 17, 2007

I've had this happen in a Tercel from a pinhole leak in the heater core. I just bypassed the heater core with new hose and a couple pipe clamps, as it's an expensive repair.
posted by M.C. Lo-Carb! at 9:17 AM on October 17, 2007

Best answer: My mom's old Camry used to get this, too.

Try cleaning with terrycloth and Invisiglass or vinegar (this mixture may be better than plain vinegar).

If you use Armor-all on the dash, don't - i always suspected it might be buildup getting heated and evaporating upwards.
posted by odi.et.amo at 9:17 AM on October 17, 2007

Here's a better description of what might be happening.
posted by pullayup at 9:20 AM on October 17, 2007

I always carry a microfiber cloth in the car. When it gets bad, especially driving into the sun, I just wipe it clean. I've noticed that sometimes it takes a bit of pressure to get it off. The microfiber seems to lift it off easier and without streaking, than a typical cloth or paper towel.
posted by enobeet at 9:24 AM on October 17, 2007

This could very well be a result of the vinyl in the interior deteriorating as a result of UV exposure. A number of companies sell products that are claimed to slow this process down. I have no experience with any of them so I can't recommend one. If you can park indoors or under a cover of some sort, it should also help.

I had the same issue with my '78 Monza and I recall using Bug & Tar Remover (basically alcohol) to clean it.
posted by tommasz at 9:25 AM on October 17, 2007

Response by poster: Wow! Thanks for the cleaning recipes. No smells accompany the gunk, but even auto glass cleaner seems to tremble before it. I'll take a look at the heater core and try the vinegar. I'm wary of adding the Fog-ex stuff, as I've seen it add to the fog problem instead of prevent it--anyone have opinions on this?
posted by eralclare at 9:25 AM on October 17, 2007

A friend's car once had a complete heater core failure and this is exactly what happened, except it happened really fast, not over days. It's almost certainly antifreeze.
posted by GuyZero at 9:30 AM on October 17, 2007

I think it might be sap from a tree (at least something like that) I used to park slightly under a pine-like tree and would see this type of thing start to build up. Maybe you are parking near something similar?
posted by ForeverDcember at 9:44 AM on October 17, 2007

Response by poster: Not parking underneath anything but the sky. And there really is NO anti-freeze smell--is the heater core issue still possible?
posted by eralclare at 9:49 AM on October 17, 2007

I've heard this one on Car Talk a number of times. Have a reliable mechanic check your heater core. It may be cracked or otherwise leaking, and when it does the contents deposit on the inside of your windshield. If you don't have a reliable mechanic, check out the site's "Mechan-X Files", which contains user recommendations. ObDisclaimer: I am not affiliated with NPR, WBUR in Boston, or Dewey, Cheetem and Howe.
posted by Fferret at 10:25 AM on October 17, 2007 [1 favorite]

It's almost certainly anti-freeze, as GuyZero says-- and it is very dangerous to your health.

The major toxic ingredient is ethylene glycol, and Wikipedia has this, among many other things, to say about it:

[It is] widely used as an automotive antifreeze. In its pure form, it is an odorless, colorless, syrupy liquid with a sweet taste. Ethylene glycol is toxic, and its accidental ingestion should be considered a medical emergency....

Ethylene glycol poisoning is a medical emergency and in all cases a poison control center should be contacted or medical attention should be sought. It is highly toxic with an estimated LD100 in humans of approximately 1.4 ml/kg.[5] However, as little as 30 milliliters (2 tablespoons) can be lethal to adults.[6]....

Symptoms of ethylene glycol poisoning usually follow a three-step progression, although poisoned individuals will not always develop each stage or follow a specific time frame.[5] Stage 1 consists of neurological symptoms including victims appearing to be intoxicated, exhibiting symptoms such as dizziness, headaches, slurred speech, and confusion. Over time, the body metabolizes ethylene glycol into other toxins, first to glycolaldehyde, which is then oxidized to glycolic acid, glyoxylic acid, and finally oxalic acid. Stage 2 is a result of accumulation of these metabolites and consists of tachycardia, hypertension, hyperventilation, and metabolic acidosis. Stage 3 of ethylene glycol poisoning is the result of kidney injury, leading to acute kidney failure.[7] Oxalic acid reacts with calcium and forms calcium oxalate crystals in the kidney.

Please note that it is described as odorless. These are signs and symptoms of acute poisoning from ingestion, not chronic exposure to vapor such as you have had. However, since it is completely miscible with water, it is readily absorbed by the lungs.

I'm sorry to do this to you, but I feel that I must: does your 'n. c. syncope' predate your acquisition of this car?
posted by jamjam at 10:50 AM on October 17, 2007

Just to add to the discussion- I have an 07 Honda Civic and it gets the same kind of deposit on the inside of the windshield. I find it highly unlikely that anything like that is broken on a car with less than 10k miles. There must be other explanations beyond the heater core.
posted by zennoshinjou at 11:02 AM on October 17, 2007

Also- Mine isn't oily, its more milky/hazy, but swirls/streaks when I clean it unless I clean with pressure in perfectly straight lines in one direction.
posted by zennoshinjou at 11:03 AM on October 17, 2007

Listen to Jamjam. Go see a mechanic right away.
posted by LarryC at 11:08 AM on October 17, 2007

Nthing heater core. Check your carpets for any discoloration or pools of anti-freeze. However, it sounds like you may just have a small crack, so even if you don't see any pools, that doesn't mean there's not a problem. It just means that you can get it fixed now and you don't have to clean anti-freeze out of the carpets.

The ethylene glycol in your anti-freeze is a desiccant, so when it gets muggy out (such as when it's raining), it likes to soak up the vapor--hence the fog.

Go to a radiator repair shop instead of a normal mechanic. They should be able to do a simple test to find leaks (potentially saving you a good bit of money).

zennoshinjou: That's exactly what anti-freeze does. I hope your car is still under warranty.
posted by dsword at 11:09 AM on October 17, 2007

Best answer: I doubt it's antifreeze from a leaking heater core. You'd smell that right quick. It's probably just plasticizers evaporating out of the plastic used in the upholstery, common issue in a 20 year old car.

Unless you smoke, in which case it's probably tar residue.
posted by ikkyu2 at 12:36 PM on October 17, 2007

It's a film built-up from your breath and, generally, your oily, warm presence in the car. Honsest. You see this a lot these days. And, yeah, it's a bitch to clean off.
posted by Thorzdad at 12:44 PM on October 17, 2007

Best answer: I use ammonia and water to clean it up, and yes, it's a combination of outgassing from the polymers in the plastic when the sun hits it and your stinky breath and any other outgassing solvents in the car such as soda pop left to dry up, etc.
posted by SpecialK at 1:00 PM on October 17, 2007

Response by poster: Quite a split of public opinion! No, I don't smoke. The syncope greatly predates the car (and I no longer "have" it, actually). And the fog occurs even in the height of summer, when there is very little humidity. I've also heard from mechanics I've been to for other car issues that it is "just a Toyota thing," so I'm inclined to think that this isn't a heater core issue that I've had for several years, and has no evidence beyond this gunk.

My oily, warm presence and stinky breath thank you for your suggestions and info!
posted by eralclare at 1:10 PM on October 17, 2007

If you want a quick and dirty test of whether it's ethylene glycol, wait until it builds up again, get as much as possible on a couple of clean fingers, and taste it. Ethylene glycol would taste sweet.
posted by jamjam at 1:23 PM on October 17, 2007

This happens in my 1995 SAAB (143k miles). It had a very slight coolant leak, which I've pretty much stopped using an additive. Given that history, I suspected the fogging was antifreeze related, although I don't smell anything. Still, it's worth investigating that possibility.

The idea that it's caused by off gassing from old vinyl and leather is one I hadn't considered.
posted by schoolgirl report at 1:33 PM on October 17, 2007

Seconding microfiber. Use windex and microfiber to loosen it, then just keep polishing, with a lot of pressure, as the windex dries. Or just change to a dry microfiber cloth. Elbow grease is the secret ingredient.

When you park, leave the rear windows cracked half an inch.
posted by Myself at 1:41 PM on October 17, 2007

Heh. I used to have an '87 Camry, and I traded it in in Hillsboro. It would be funny if you bought my old car. Anyway, no heater core issues with mine, no smell, but it did have that terrible window fogging issue. I just kept Windex and newspaper in my car all the time.
posted by peep at 2:24 PM on October 17, 2007