Ridin Dirty

Kinda over the top neurotic as i mentioned but anyone drive their 993tt in winter? The one year i did i learned my viscous coupler was kaput; so i only had 2wd for the longest time and i would have never known.

but that's not my question........everything about the 993tt should love the cold and she does but that leaves us with the only real worry and that's.....road salt. The northeastern US is in a deep freeze today with some cities cancelling new years festivities due to the cold. Everything is frozen. There is tons of salt on the roads but roads are cleared and dry. Since so frozen the roads are just "dusty" with rock salt.... lots of it tho of course.

My question is: if the car gets rock salt "dusty" is that necessarily bad? My laymen interpretation is as long as its not the wet slurry of rock salt its not detrimental; would need the water to complete the reaction for corrosion factor....right?
Ha probably wrong but....any opinions why? Any chemists out there?

thanks
joe

Basal Skull

Well, salt dust is probably better than the slurry you talk about, but I don't think it's really safe. Rust occurs as you know from iron, oxygen, and water. Water can be moisture from the air too. Salt acts as an electrolyte to speed the process. Galvanized parts help but eventually the zinc is oxidized then the iron underneath will start to rust. (don't remember much more than that from my high school chem and biochem degree about rust, although I can probably write some equations if I really had to).
But getting back to your question, I wait til there's a good downpour and I don't see anymore of that dust before I take my cars out. Was able to take the cars out yesterday as I thought it would be okay after some good rain, but found some roads were freshly salted... The liquid brine solution that they also use now I heard is worse as it tends to get sprayed up and gets into nooks and crannies. I usually spend some time washing the undersides (especially of the cayenne which is my daily) when the weather gets a little better.

FrenchToast

I think no one would argue with your bravery to drive the car in the 'salt,' I think most can agree that it is not good for the car.

The dust on the exterior of the car isn't really an issue. The exterior paint itself is pretty strong and won't easily rust just from salt exposure. It's the dust that accumulates on the underside or in cavities.

This dust and other dirt rarely if ever gets washed away. It holds water, which slowly eats at the outer protective layers until the metal is bare, at which point the moisture can corrode the area even quicker. A salty moisture is even worse.

But, yes, if the car must be driven in the winter it is best to keep the car as dry as possible. Make sure the garage (assuming it is garaged) is as dry as possible. In the spring I would pull all the fenderliners out and wash off the gunk inside the wheel wells and under the car.

And yes, the spray (magnesium chloride, and other chemicals IIRC) is indeed worse for just about everything. It is a greater cause for corrosion, causes more detriment to the ecosystem, and is more expensive.

Government highway departments even acknowledge its detriment to a car's condition, albeit in very small print.

In most cases, yes, which is why it is important to keep the entire car dry. Seeing as how your region probably has something called snow, this is difficult. Winter is a drier part of the year, however, moisture can still accumulate all over the car. Moisture condenses from the air at points all over the car whenever the weather changes. Concrete always absorbs moisture. The walls, ground, etc. absorb moisture.

JasonAndreas

Cosmoline will protect most of everything on the bottom of the car. You will have issues with corroded fasteners but that is only a problem when it comes time to loosen them. I never had a problem finding a self service car wash that included an under carriage spray when I drove my 964RSA every winter in New England for 20 years... Having an unheated garage may have helped too. The real issue during a New England winter is that you will sand blast the front end. And the DPW (even on the Mass Pike...) allow a certain amount of gravel to be mixed with sand. Which you will become acutely aware of for the first time. Throw on a set of Nokian Hakkapeliitta R2 and you'll find yourself wanting to go out driving at night before the plows hit the roads!

FrenchToast

Respectfully, I disagree. Cosmoline is a sacrifical coating designed to last until customer delivery. It is primarily for ocean-liner shipping.

There may be additional cosmoline inside the body cavities, but this does not protect exposed components.

The body shell itself probably won't have much damage, aside from the well known issues such as windshield area and rear frame rails which could rust-through. Everything that is not part of the bodyshell (brake lines, fenders, swaybars, suspension components, etc.) are going to corrode heavily.

O.B.1

JasonAndreas

But here we are 20+ years later and it is still there and covering everything. Meanwhile trying to remove it with anything other than xylene is an exercise in futility. If you are in the USA, crawl under your 993TT and look behind the plastic undertray pieces.

Because they are really fun to drive in the winter. And the easily preventable long term effects are not what people think they are.

PiB993

Why don't we use sacrificial anodes like in ships and pipelines? I have a little rust under the battery plate that you just can't get to to clean it up.

Also from another thread (can't find it this second). A European with a 993 iirc had major rust all along the inside car floor. He was pretty handy. Stripped it all out, cleaned up the rust and properly coated it. But it was also mentioned that the chassis has crimp areas where exterior water can sometimes wick straight inside.

FrenchToast

In my experience anything that is left over after a few years is pretty dried up. Its water displacing (and rust preventing) abilities are pretty questionable.

IMO, if you intend to keep the car, drive it often in winter, and don't want to deal with large amounts of rust, the car ideally should be fully cleaned, touched up as needed, and all surfaces and cavities coated in purpose oil.

You can of course skip this, however, after ten years of winter driving you'll be doing a lot of rust-related repairs. Not just on the shell, but on brackets, suspension components, brake lines, fuel lines, etc.

If you happen to live in an area where they use little or no road salt, that is a different story.

993 could be different, but on most cars any crimp areas are either sealed pretty well or have drains in them. In the case of the latter, these drains do clog quite easily.

ronnie993tt

I'd find a Krown shop that has 993 experience and redo it annually. A fellow r-lister with a 26 year old, daily Ontario winter driven, Krown treated 4 Runner shows no rust. We've had great results on our Ford SUV's. Good luck.

Leeroy89

Oops… please delete mods

Essexmetal

Yup salt SUCKS but I like to think it is better to write off a car over several years instead of instantly.

Happy winter everyone.