[SF] Fogging issues

Fly

Fly

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Joined
Jul 24, 2011
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325
Location
Canada
As soon as temps drop below -5C I have a LOT of fogging issues. Even if the car is running with the fans to the max, it still fogs and even in driver's side windows. I can deal with it in the windshield by using the appropriate fan setting, however nothing seems to help for the side windows.

And as my rear defroster is damaged and will only work in the lower half of the window, it's also an issue with rear visibility.

A lot more than buddies with other cars in the same weather.

Do other SF owners have the same issue? Is it a design flaw or is it there something I can do to reduce that problem?
 
Gidday Fly

Are you using the air-con?

I run my air-con on with the heater. It tends to be a very effective defogger.

You can buy a repair kit to fix the rear window defogger element.

Another issue that can cause this to happen excessively is if you have any kind of body grease or sweat on the inside of the windows (from you, or from the upholstery). It doesn't need to be much - one molecule thick is sufficient! Body sweat and grease are polarised molecules that sit with one end stuck to the glass and the other end is hydrophilic (loves water molecules - filthy things ... :iconwink: :biggrin:), so attracts water fog to stick to them.

Clean the inside of all your windows with methylated spirits (denatured alcohol) using a very clean cotton cloth. Old undies are ideal (washed ... :poke: :iconwink:). Then clean them all with a freshly washed chamois or artificial chamois that has been washed in a very dilute solution of dish detergent, and wrung out well.

I never touch the inside surfaces of the windows with my bare hands. If I do get a patch of gunk, I wipe it with a hand towel I have in my side pocket for the purpose. When I wash the cars, I clean the inside of all the windows with a fake chamois.

Same principles apply to the outside of the windows. "Road grime" also consists of many different polarised molecules ... Some stick to your windscreen, others to your wiper blades. The result a smeary mess because the wiper blade and the windscreen can't actually come into contact with each other ...
 
Try air on recycle heater on full and a/c. Always worked for me at when up skiing (–5 C most of the time not any colder though). As for the rear demister check the contacts are clean either side of the window, might just need replacing. The a/c takes the moisture out of the air, make sure the carpet and upholstery is as dry as possible which is hard in winter and snow. Less moisture in the cabin the less there is to create condense in the air and cool on the windows fogging them up.
 
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The owners manual advises that fogging can be an issue on recycle, try on fresh with heater on full plus a/c. As idw said, also check for water in the cabin, foresters seem to have a prob with leaks in the rear filling up the spare wheel well.

+1 for the rear demister repair kit
 
Don't think there's much water. Haven't done any significant crossings (nothing over 6in ever) and I keep all mats (except the driver's) in the shed when I don't expect other people for the very purpose of ensuring a minimal airflow to release moisture out of the carpet. A/C is worth a try though considering it's almost useless in the summer (barely make the air any colder) I would assume it wouldn't work in the winter either. But I''ll try and see how it goes!

I tried a rear remister and it didn't work for some reason... I'll have to give it another try I guess.
 
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Gidday Fly

Your air-con should get the air at the vents down to around 5-9°C in summer after idling for a few minutes.

If it isn't, then perhaps you need either a re-gas or other maintenance.

I had to have the a/c in my '93 Impreza re-built after it lost all its gas (R12). Unfortunately it was re-filled with R134a.
Now I know better, and would specify HyChill refrigerant, which works far better with systems that were originally designed for R12 refrigerant than does R134a. It also happens to work better than R134a in systems that are designed for R134a ... Like about 30% better!! Lookie here:

https://www.hychill.com.au/
 
I definitely do need a re-gas... It barely lowers the temp by 3-4C. On a good day. And that might just be a placebo effect :lol:

Duly noted. Added to the Foz's todolist!
 
Fly said:
Don't think there's much water. Haven't done any significant crossings (nothing over 6in ever)
Click to expand...

I meant rain leaks lol. Places to check are seals around windows (make sure doors are properly adjusted), the tailgate rubber & esp the seals around where the wires go through for the tailgate. Theres lots of other little ones as well like where the rear bumper screws on.

I havent tried the RainX anti-fog but the windscreen treatment is excellent :biggrin:
 
NachaLuva said:
I havent tried the RainX anti-fog but the windscreen treatment is excellent :biggrin:
Click to expand...
I have & was a little disappointed actually :(

It does help a bit though, but it's nowhere as good as their windscreen treatment. It's absolutely fantastic :quitar:

Regards
Mr Turbo
 
Fly, we had the fogging up problem with SWMBO's Camry after she had to drive through moderately deep water on Geelong Road during a flood episode.

The next morning it was as fogged up as anything. Running the air-con (and heater) for some weeks eventually dried the carpet out, as did leaving the windows open on warm sunny days. Not very much got in. Not enough to warrant removing all the carpets etc. But it was enough to cause the sort of problems that you are having.

I agree with NL that you should check around doors and windows to ensure that water is not getting in around them; and also check all the points where the body shell is penetrated by the wiring loom, etc.

One that is often overlooked is cleaning out the drain pipes for the air intake vents just below the windscreen. If these are blocked, water can be sucked into the car via the air vents. They can easily become blocked ...

Don't use wire to clean them!! Bloody obvious, but worth mentioning ...
Use something like a soft flexible plastic tube, or other similar makeshift tool.

Also ensure that the drain pipe from the cabin air-con radiator is clean and clear using the same method.

I am not sure where any of these drain tubes are on my Forester/s. They will be there somewhere. They were pretty obvious on our Impreza and Camry.
 
Really good tips! Now to convince a friend to let me use his heated garage so I don't freeze my donkey off doing it in the driveway at -10 (assuming I'm lucky and it's a warm day), LOL

I did about 1000km this weekend and keeping the AC on really did help so that's a start!
 
NachaLuva said:
The owners manual advises that fogging can be an issue on recycle, try on fresh with heater on full plus a/c.
Click to expand...

In reality the warning about fogging on recycle in the manual really only applies with AC off. If you have the AC on, it will strip out so much moisture from the air that whether the source was recycled or fresh air won't matter - the resulting air from the vents will be very dry either way, assuming the AC is working well. This is why AC is so effective for defogging.

idw said:
Try air on recycle heater on full and a/c. Always worked for me at when up skiing (–5 C most of the time not any colder though).
Click to expand...

When using AC to defog in cold climates recycle on might actually be the better option as you say. In fresh mode, I suspect that such cold outside air as the source risks freezing the evaporator, compared to using recycle in which case the warmer interior air will be the source. (The only caveat here is that, regardless of recycle or fresh mode, in very cold conditions the AC may automatically disable (even if the button is on) to protect itself, leaving you with no dehumidifying effect in which case recycle mode is going to make things worse.)
 
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