Technical why the underside is already rusty?

[andy1]

ok one is my panda 1.3 multijet from 2006 and 75.000kms.
it has known several years parked outside but never any very long inactivity,
it was always used at least once a week

the other (with evident rust) is a fiat 500 pop, plate registered 24/05/2019, that was outside a fiat car dealer with just 16130kms, (he said it was a car used by some company)
why on earth would it be this rusty already?

I am going paranoid, people is out there trying to get me ha ha ha

 

[chris3234]

It's just how quickly lightly treated steel rusts
The parts have only a thin coat of paint most of the time to protect them and that's soon warn away by water spray from the roads then this quickly starts rusting when it gets wet


This is especially true in the UK with our wet weather and few warm days to try it out

 

[portland_bill]

Can't see anyting of any concern there, all just normal.

 

[jrkitching]

Yes, this is just what cars do. Better corrosion proofing of the parts would indeed be nice to see, but it would add to the cost of the car. Since most owners don't keep new cars beyond the point where corrosion becomes an issue, there isn't much incentive for the manufacturers to spend more on something the initial buyer won't perceive as a benefit.

Modern mass market cars have a design life of about 10-12 years; if used in normal conditions, they shouldn't develop a corrosion related issue sufficient to make the car an economic write off within that timeframe. That isn't to say you won't have to carry out corrosion related repairs before then (Fiat steel sumps are a good example of parts which often don't go the distance).

If you think that's bad, try going back to the 60's; cars from that era would often be rusted out after as little as 5-6 years.

If you're a DIY owner planning to keep the car a long time, it pays to do some additional rustproofing; this is by far and away best done when the car is new, before it's driven on wet roads. These days, though, 99.9% of new car buyers won't bother.

 

[Pugglt Auld Jock]

Looking closely at the 500, there's some surface rust on the exhaust which is to be expected. flex joint looks in very good nick though, wish mine looked so good. A couple of bolt heads - front mount of suspension wishbone? again with surface rust. The only bit I would find a bit disappointing is the driveshaft which you might hope would be better protected. Mind you it's relatively massive and will need to become an awful lot more deeply corroded than that to be a problem and that's going to take years. All the bits that cause problems, like underbodywork and subframe looks really good. So I think my comment would be "unsightly but of no consequence" I'd buy it if the price was right.

PS someone needs to slap a "dod" of thick anti seize on the track rod end threads and locking bolt! I wish most of the one's I'm usually faced with had as little rust on them!

 

[jrkitching]

The only bit I would find a bit disappointing is the driveshaft which you might hope would be better protected.

I've seen new cars in showrooms with driveshafts that looked that bad.

Some ferrous components are given no protection whatsoever; take a look at the rear drums on many Fiats.

someone needs to slap a "dod" of thick anti seize on the track rod end threads and locking bolt!

Well worth doing on any car.

One of the worst is probably the '90's Vauxhall Astra; the track rods are high up in the wheelarch, right in line of all the spray.

Most tyre fitting places will refuse point blank even to attempt to track them.

 

[Baglady1990]

Personally I’ve taken great care to help protect my exposed bits n bobs under my 500! It’s a late summer job get under your car “safely” & get that waxoyl painted on! I still shudder when I see rear drums rusting to oblivion ?

 

[Ralf S.]

Agreed. The driveshaft is solid steel. You could dump it into the ocean and it'd still be there in 50 years time.. (albeit covered in barnacles...) so they don't actually need to be painted or protected at all.

The factory finish is some kind of black Japan flash coat, so that it looks nice when you buy a new one... but the finish is fairly thin and porous and it doesn't last long.

Some other manufacturers could presumably use a more rust resistant steel in their driveshafts.. so they might look better for longer.. but apart from the impression that the car is higher quality (not to be under-estimated, probably) it doesn't actually last longer than an unpainted one, since it's usually a seized on but knackered CV joint that goes, before the driveshaft gets terminally rusted.


Ralf S.