Underbody clean or nah?

[James31]

What do you guys think about this underbody?
what do you think the “white” residue is

Car is low mileage and is located in no snow state but does see a fair bit of rain.

[oceansize]

You are overthinking this as the only thing that matters is rust or better yet, the lack thereof.

[Jickel180]

Or driven on a caliche/gravel road. That stuff is hard to clean off but just cosmetic.

[timmo]

You are overthinking this as the only thing that matters is rust or better yet, the lack thereof.

I wish mine looked like that!

[Slideways]

That appears to be light surface corrosion. Nothing to worry about and pretty normal for a car that was parked outside for a few weeks/months.

[bigjae46]

White residue is corrosion on the aluminum diff cover. It has probably seen road salt at some point.

[Casa de Mesa]

White residue is corrosion on the aluminum diff cover. It has probably seen road salt at some point.

Probably is a safe assumption. That said it doesn't look bad at all and aluminum will do that without salt. My car has never seen salt roads but spent a couple of days outside one winter where a warm and humid air mass moved through quickly. EVERYTHING had condensation on it from cold parts in warm air. Happened twice and my undercarriage went from fairly pristine to having that white residue on all raw/uncoated aluminum bits, including the ones I installed new (FCAs, lollipops, etc.). So I'm 100% certain it wasn't due to salt.

[bigjae46]

Probably is a safe assumption. That said it doesn't look bad at all and aluminum will do that without salt. My car has never seen salt roads but spent a couple of days outside one winter where a warm and humid air mass moved through quickly. EVERYTHING had condensation on it from cold parts in warm air. Happened twice and my undercarriage went from fairly pristine to having that white residue on all raw/uncoated aluminum bits, including the ones I installed new (FCAs, lollipops, etc.). So I'm 100% certain it wasn't due to salt.

The aluminum turns white because it reacts with something, might be something other than road salt. I wouldn't worry about it. Its not like rust where the aluminum will continue to corrode.

FYI...the trick with road salt is to keep the car in sub-freezing temps. Once you park in...let's say a heated garage...that's when the corrosion starts.

[FBloggs]

White residue on steel/iron and plastic is likely to be weathered/aged cosmoline.
Cosmoline is also the whitish crust on the underbody plastics.
It is a protectant from sea salt and other corrosive agents during ocean transport.
It is casually sprayed on by machine, I believe.
when the car is being prepped for sale, the cosmoline is casually sprayed with a removing agent, by a disinterested employee. Ergo the spotty appearance of the underbody.
white residue on on the aluminum diff cover has been explained.
Cosmoline on the diff would be adarker crust in the diff cover.

I remember as a child, my father's anger at receiving his brand new Opel, totally covered in cosmoline.
I thought it looked cool... matte before matte paint, lol.

[Lee_Enfield]

I wish this level of corrosion was alarming around here. My poor old pickup...

Gravel combined with salt is great for traction, but the paint? Not so much.

But i agree, aluminum alloys will naturally corrode with a white powder being the aftermath. Even just moisture will do it. There is also all the random chemicals that are just on the roads that get kicked up.