[LetsrollM550]

Has anyone spotted rust on any of their doors, I have a 2018 M550 and every door is rusting on the bottom edges, it looks like it is along the welding bead. I'm a little distraught as the car has 3,400 miles on it and I always wipe out the door jambs and it gets waxed monthly. It just got dropped off at the dealership this AM so waiting to hear what's going to happen. Just wondering if this a isolated problem or common. Thanks!

[AP]

Well I thought the doors were made totally from aluminium so there can't rust as such.
Sure it is rust? What colour is it?
Any pics?

[Zap-xpilot]

You are sure you’re not confusing a brown residue for the glue? On the bottom of both my f80 and g30 doors I have visible yellow/brown glue residue. Not pretty but quite far from rust.
I’d be shocked if a g30 is rusting already..

Pictures would help

[LetsrollM550]

Originally Posted by Zap-xpilot

You are sure you're not confusing a brown residue for the glue? On the bottom of both my f80 and g30 doors I have visible yellow/brown glue residue. Not pretty but quite far from rust.
I'd be shocked if a g30 is rusting already..

Pictures would help

I will post pics (dealer has car) when I can, definitely rust, it's on the outside and it has pitted areas on both back doors.

[Zap-xpilot]

Originally Posted by LetsrollM550

I will post pics (dealer has car) when I can, definitely rust, it's on the outside and it has pitted areas on both back doors.

Wow!
I await pics with great interest. If a g30 is rusting in Texas already, then this doesn’t bode well for Swedish salty and icy winters...

[LetsrollM550]

Originally Posted by AP

Well I thought the doors were made totally from aluminium so there can't rust as such.
Sure it is rust? What colour is it?
Any pics?

That's what I thought, but it has crept up to the size of a dime on one door you can see it standing outside the car directly above rocker panel, and pitted the rear doors on the edge as it curves up near the wheel well. Will post photos asap

[clee1982]

Originally Posted by LetsrollM550

That's what I thought, but it has crept up to the size of a dime on one door you can see it standing outside the car directly above rocker panel, and pitted the rear doors on the edge as it curves up near the wheel well. Will post photos asap

Isn't there 10 year or something rust protection? I'll go straight to the dealer

[Zap-xpilot]

Originally Posted by LetsrollM550

That's what I thought, but it has crept up to the size of a dime on one door you can see it standing outside the car directly above rocker panel, and pitted the rear doors on the edge as it curves up near the wheel well. Will post photos asap

Just checking: the car was/is brand new? There have not been any botched bodywork repairs?

[jwong77]

Originally Posted by clee1982

Isn't there 10 year or something rust protection? I'll go straight to the dealer

He did even before posting here, thats why he says in his post that he just dropped off his car with the dealer.

[Zap-xpilot]

Originally Posted by clee1982

Isn't there 10 year or something rust protection? I'll go straight to the dealer

That warranty is pretty useless. If you actually read the legal text it is only applicable if there is structural rust on the panel, as if in poke-a-finger-through rust. Rust never really shows that way. Also, there are plenty of caveats, the car should only ever be serviced at authorized dealers and the like..
At least this is what the warranty looks like in Sweden. This may of course be different in other countries.

When I spoke to my dealer he agreed that in practice it was worthless.

But I’d presume that rust on a new high end BMW produced in 2018 is something that both the dealer and BMW would consider shocking and highly out of the ordinary and try to remedy ASAP and without any hassle or publicity.

Worries me though, cause I had plans to keep the car at least five years or so.,
Still, too early on to draw conclusions.

I guess we await pictures

[AP]

Yes will be interesting.
I'm no expert but thought aluminium could not rust although I thought it could oxidise which I thought was a whiteish colour?
Any experts here confirm!

It's not wax used to protect it whilst being delivered that wasn't removed as part of the pdi possibly?

[LetsrollM550]

Still waiting to hear what the dealership says, haven't heard anything back yet, I will keep a good update on this situation.

[Johnny Grabble]

Originally Posted by AP

I'm no expert but thought aluminium could not rust although I thought it could oxidise which I thought was a whiteish colour?

You are correct. Aluminium corrodes but does not rust. It forms the oxide rapidly on the exposed surface which appears white/colourless. The formation of the oxide actually completely prevents the aluminium from further corrosion.

The red/brown colour of rust is caused by the oxidation of iron. Steel is an alloy of iron. (Stainless steel contains chromium which forms an oxide a bit like aluminium and it is this oxide which makes stainless steel so rust-resistant).

So if the OP genuinely does have rust on his car's doors, the doors are made of steel, not aluminium.

[Zap-xpilot]

Do we know for certain that the doors on the g30 are from aluminium? Does the same apply for the g31 as well? Are we talking about all doors or just the fronts?

[LetsrollM550]

Originally Posted by Zap-xpilot

Do we know for certain that the doors on the g30 are from aluminium? Does the same apply for the g31 as well? Are we talking about all doors or just the fronts?

All doors

[LetsrollM550]

I am traveling this week, I hope to have answers on Friday, the service advisor called me yesterday saying some of the discoloring is from a sealant BMW uses to prevent rust and corrosion, and has been cleaned, but he said they also have found some abnormalities on the edges of the rear doors. I will update this on Friday (hopefully).

[lemetier]

Originally Posted by LetsrollM550

All doors

All the doors are aluminum so it can't be rust.

Is it basically like this on the outside and oozing out from the weep holes on the bottom corners of the door panels?

[LetsrollM550]

Originally Posted by lemetier

All the doors are aluminum so it can't be rust.

Is it basically like this on the outside and oozing out from the weep holes on the bottom corners of the door panels?

Not like that, as soon as I get the car back I'll post pics. Besides the discoloring the texture feels different from the normal surfaces and feels rough.

[lemetier]

Originally Posted by LetsrollM550

Not like that, as soon as I get the car back I'll post pics. Besides the discoloring the texture feels different from the normal surfaces and feels rough.

Probably should have taken the pics before dropping it off. As many of us have said, the doors are aluminum so they cannot rust.

Who washes the car, how often, and is the water source exceptionally hard? Have you driven it on winter treated roads? Both can leave heavy mineral deposits in a short amount of time. Mix in some brown cosmoline, brake dust, and good old dirt, and it can get funky.

[Warp Ten]

Originally Posted by lemetier

All the doors are aluminum so it can't be rust.

Is it basically like this on the outside and oozing out from the weep holes on the bottom corners of the door panels?

I have seen that sort of discoloration on many BMWs over the years and I think it comes from lubrication used on the door hinges. Don't think it is rust for a couple reasons posted here, but I could be wrong. Have you had your car in for service since you bought it? The techs may be lubricating the hinges each time. --Bob

[lemetier]

Originally Posted by Warp Ten

I have seen that sort of discoloration on many BMWs over the years and I think it comes from lubrication used on the door hinges. Don't think it is rust for a couple reasons posted here, but I could be wrong. Have you had your car in for service since you bought it? The techs may be lubricating the hinges each time. --Bob

The "weeping sills" is from cosmoline and mineralized water coming out of the drain holes and mixing with road dust.

The cars are covered in it prior to the ocean voyage and it gets everywhere.

[High Flier]

You can try the magnet test. The magnet will be attracted to iron and steel, but not aluminum. Just be careful, place something soft between your magnet the the paint.

If there is any steel inside the door and if it is rusting, you probably wouldn't see any signs on the outside for a car this new.